b Ivacaftor decreases monocyte sensitivity to interferon-{gamma} in people with cystic fibrosis By openres.ersjournals.com Published On :: 2020-04-19T07:30:12-07:00 Management of cystic fibrosis has been revolutionised by the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulators. These compounds treat the underlying molecular basis of the disease by increasing activity of defective CFTR channels, which improves many clinical parameters and enhances patient quality of life [1]. Next-generation modulators, also known as triple combination therapy, promise to be highly efficacious in up to 90% of patients [2] and will likely dramatically change the landscape of cystic fibrosis disease. Studies examining individuals before and after initiation of CFTR modulators have revealed novel functions of CFTR and shown that CFTR modulators do not reverse all disease manifestations [3–5]. Thus, knowledge of the post-modulator cystic fibrosis disease state is crucial for understanding what continued therapies will be needed for people with cystic fibrosis and what new challenges may arise. Full Article
b Management of acute COPD exacerbations in Australia: do we follow the guidelines? By openres.ersjournals.com Published On :: 2020-04-19T07:30:12-07:00 Objective We aimed to assess adherence to the Australian national guideline (COPD-X) against audited practice, and to document the outcomes of patients hospitalised with an acute exacerbation of chronic obstructive pulmonary disease (COPD) at discharge and 28 days after. Methods A prospective clinical audit of COPD hospital admission from five tertiary care hospitals in five states of Australia was conducted. Post-discharge follow-up was conducted via telephone to assess for readmission and health status. Results There were 207 admissions for acute exacerbation (171 patients; mean 70.2 years old; 50.3% males). Readmission rates at 28 days were 25.4%, with one (0.6%) death during admission and eight (6.1%) post-discharge within 28 days. Concordance to the COPD-X guidance was variable; 22.7% performed spirometry, 81.1% had blood gases collected when forced expiratory volume in 1 s was <1 L, 99.5% had chest radiography performed, 95.1% were prescribed systemic corticosteroids and 95% were prescribed antibiotic therapy. There were 89.1% given oxygen therapy and 92.6% when arterial oxygen tension was <80 mmHg; 65.6% were given ventilatory assistance when pH was <7.35. Only 32.4% were referred to pulmonary rehabilitation but 76.8% had general practitioner follow-up arranged. Conclusion When compared against clinical practice guidelines, we found important gaps in management of patients admitted with COPD throughout tertiary care centres in Australia. Strategies to improve guideline uptake are needed to optimise care. Full Article
b Efficacy and safety of two doses of budesonide/formoterol fumarate metered dose inhaler in COPD By openres.ersjournals.com Published On :: 2020-04-27T00:30:10-07:00 Inhaled corticosteroid/long-acting β2-agonist combination therapy is a recommended treatment option for patients with chronic obstructive pulmonary disease (COPD) and increased exacerbation risk, particularly those with elevated blood eosinophil levels. SOPHOS (NCT02727660) evaluated the efficacy and safety of two doses of budesonide/formoterol fumarate dihydrate metered dose inhaler (BFF MDI) versus formoterol fumarate dihydrate (FF) MDI, each delivered using co-suspension delivery technology, in patients with moderate-to-very severe COPD and a history of exacerbations. In this phase 3, randomised, double-blind, parallel-group, 12–52-week, variable length study, patients received twice-daily BFF MDI 320/10 µg or 160/10 µg, or FF MDI 10 µg. The primary endpoint was change from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV1) at week 12. Secondary and other endpoints included assessments of moderate/severe COPD exacerbations and safety. The primary analysis (modified intent-to-treat) population included 1843 patients (BFF MDI 320/10 µg, n=619; BFF MDI 160/10 µg, n=617; and FF MDI, n=607). BFF MDI 320/10 µg and 160/10 µg improved morning pre-dose trough FEV1 at week 12 versus FF MDI (least squares mean differences 34 mL [p=0.0081] and 32 mL [p=0.0134], respectively), increased time to first exacerbation (hazard ratios 0.827 [p=0.0441] and 0.803 [p=0.0198], respectively) and reduced exacerbation rate (rate ratios 0.67 [p=0.0001] and 0.71 [p=0.0010], respectively). Lung function and exacerbation benefits were driven by patients with blood eosinophil counts ≥150 cells·mm–3. The incidence of adverse events was similar, and pneumonia rates were low (≤2.4%) across treatments. SOPHOS demonstrated the efficacy and tolerability of BFF MDI 320/10 µg and 160/10 µg in patients with moderate-to-very severe COPD at increased risk of exacerbations. Full Article
b Survival benefit of lung transplantation compared with medical management and pulmonary rehabilitation for patients with end-stage COPD By openres.ersjournals.com Published On :: 2020-04-27T00:30:10-07:00 Background COPD patients account for a large proportion of lung transplants; lung transplantation survival benefit for COPD patients is not well established. Methods We identified 4521 COPD patients in the United Network for Organ Sharing (UNOS) dataset transplanted from May 2005 to August 2016, and 604 patients assigned to receive pulmonary rehabilitation and medical management in the National Emphysema Treatment Trial (NETT). After trimming the populations for NETT eligibility criteria and data completeness, 1337 UNOS and 596 NETT patients remained. Kaplan–Meier estimates of transplant-free survival from transplantation for UNOS, and NETT randomisation, were compared between propensity score-matched UNOS (n=401) and NETT (n=262) patients. Results In propensity-matched analyses, transplanted patients had better survival compared to medically managed patients in NETT (p=0.003). Stratifying on 6 min walk distance (6 MWD) and FEV1, UNOS patients with 6 MWD <1000 ft (~300 m) or FEV1 <20% of predicted had better survival than NETT counterparts (median survival 5.0 years UNOS versus 3.4 years NETT; log-rank p<0.0001), while UNOS patients with 6 MWD ≥1000 ft (~300 m) and FEV1 ≥20% had similar survival to NETT counterparts (median survival, 5.4 years UNOS versus 4.9 years NETT; log-rank p=0.73), interaction p=0.01. Conclusions Overall survival is better for matched lung transplant patients compared with medical management alone. Patients who derive maximum benefit are those with 6 MWD <1000 ft (~300 m) or FEV1 <20% of predicted, compared with pulmonary rehabilitation and medical management. Full Article
b High cytomegalovirus serology and subsequent COPD-related mortality: a longitudinal study By openres.ersjournals.com Published On :: 2020-04-27T00:30:10-07:00 Background Positive serology for cytomegalovirus (CMV) has been associated with all-cause mortality risk but its role in COPD mortality is unknown. The objective of the present study was to assess the relationship between CMV serology and COPD mortality. Methods We analysed data from 806 participants in the Tucson Epidemiological Study of Airway Obstructive Disease who, at enrolment, were aged 28–70 years and had completed lung function tests. We tested CMV serology in sera from enrolment and defined "high CMV serology" as being in the highest tertile. Vital status, date and cause of death were assessed through death certificates and/or linkage with the National Death Index up to January 2017. The association of CMV serology with all-cause and cause-specific mortality risk was tested in Cox models adjusted for age, sex, level of education, body mass index, smoking status and pack-years. Results High CMV serology was marginally associated with all-cause mortality (p=0.071) but the effect was inversely dependent on age, with the association being much stronger among participants <55 years than among participants ≥55 years at enrolment (p-value for CMV-by-age interaction <0.001). Compared with low CMV serology, high CMV serology was associated with mortality from COPD among all subjects (adjusted hazard ratio (HR) 2.38, 95% CI 1.11–5.08; p=0.025) and particularly in subjects <55 years old at enrolment (HR 5.40, 95% CI 1.73–16.9; p=0.004). Consistent with these results, high CMV serology also predicted mortality risk among subjects who already had airflow limitation at enrolment (HR 2.10, 95% CI 1.20–3.68; p=0.009). Conclusions We report a strong relationship between CMV serology and the risk of dying from COPD, and thus identify a novel risk factor for COPD mortality. Full Article
b Low adherence to inhaled corticosteroids/long-acting {beta}2-agonists and biologic treatment in severe asthmatics By openres.ersjournals.com Published On :: 2020-04-27T00:30:10-07:00 Eligibility criteria for a biologic treatment for severe asthma include poor disease control despite a full medication plan according to Global Initiative for Asthma steps 4–5 [1]. Adherence to inhaled therapy should be verified as part of that prescription requirement [2]. In fact, it has been demonstrated that poor adherence is a major cause of uncontrolled asthma, regardless of its severity [3]. Furthermore, biologics do not exert a disease-modifying effect [4]; in contrast to allergen immunotherapy, which is able to permanently modulate the way the immune system reacts to allergens beyond the immunotherapy treatment course [5], biologic therapy withdrawal usually leads to asthma relapse [4]. Thus, a low adherence rate to inhaled treatment in patients undergoing biologic therapy raises some issues related to sustainability. Full Article
b The Transcriptional Aftermath in Two Independently Formed Hybrids of the Opportunistic Pathogen Candida orthopsilosis By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT Interspecific hybridization can drive evolutionary adaptation to novel environments. The Saccharomycotina clade of budding yeasts includes many hybrid lineages, and hybridization has been proposed as a source for new pathogenic species. Candida orthopsilosis is an emerging opportunistic pathogen for which most clinical isolates are hybrids, each derived from one of at least four independent crosses between the same two parental lineages. To gain insight into the transcriptomic aftermath of hybridization in these pathogens, we analyzed allele-specific gene expression in two independently formed hybrid strains and in a homozygous strain representative of one parental lineage. Our results show that the effect of hybridization on overall gene expression is rather limited, affecting ~4% of the genes studied. However, we identified a larger effect in terms of imbalanced allelic expression, affecting ~9.5% of the heterozygous genes in the hybrids. This effect was larger in the hybrid with more extensive loss of heterozygosity, which may indicate a tendency to avoid loss of heterozygosity in these genes. Consistently, the number of shared genes with allele-specific expression in the two independently formed hybrids was higher than random expectation, suggesting selective retention. Some of the imbalanced genes have functions related to pathogenicity, including zinc transport and superoxide dismutase activities. While it remains unclear whether the observed imbalanced genes play a role in virulence, our results suggest that differences in allele-specific expression may add an additional layer of phenotypic plasticity to traits related to virulence in C. orthopsilosis hybrids. IMPORTANCE How new pathogens emerge is an important question that remains largely unanswered. Some emerging yeast pathogens are hybrids originated through the crossing of two different species, but how hybridization contributes to higher virulence is unclear. Here, we show that hybrids selectively retain gene regulation plasticity inherited from the two parents and that this plasticity affects genes involved in virulence. Full Article
b Tetanus Toxin cis-Loop Contributes to Light-Chain Translocation By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT The clostridial neurotoxins (CNTs) comprise tetanus toxin (TT) and botulinum neurotoxin (BoNT [BT]) serotypes (A to G and X) and several recently identified CNT-like proteins, including BT/En and the mosquito BoNT-like toxin Pmp1. CNTs are produced as single proteins cleaved to a light chain (LC) and a heavy chain (HC) connected by an interchain disulfide bond. LC is a zinc metalloprotease (cleaving soluble N-ethylmaleimide-sensitive factor attachment protein receptors [SNAREs]), while HC contains an N-terminal translocation domain (HCN) and a C-terminal receptor binding domain (HCC). HCN-mediated LC translocation is the least understood function of CNT action. Here, β-lactamase (βlac) was used as a reporter in discovery-based live-cell assays to characterize TT-mediated LC translocation. Directed mutagenesis identified a role for a charged loop (767DKE769) connecting α15 and α16 (cis-loop) within HCN in LC translocation; aliphatic substitution inhibited LC translocation but not other toxin functions such as cell binding, intracellular trafficking, or HCN-mediated pore formation. K768 was conserved among the CNTs. In molecular simulations of the HCN with a membrane, the cis-loop did not bind with the cell membrane. Taken together, the results of these studies implicate the cis-loop in LC translocation, independently of pore formation. IMPORTANCE How protein toxins translocate their catalytic domain across a cell membrane is the least understood step in toxin action. This study utilized a reporter, β-lactamase, that was genetically fused to full-length, nontoxic tetanus toxin (βlac-TT) in discovery-based live-cell assays to study LC translocation. Directed mutagenesis identified a role for K768 in LC translocation. K768 was located between α15 and α16 (termed the cis-loop). Cellular assays showed that K768 did not interfere with other toxin functions, including cell binding, intracellular trafficking, and pore formation. The equivalent K768 is conserved among the clostridial neurotoxin family of proteins as a conserved structural motif. The cis-loop appears to contribute to LC translocation. Full Article
b Genetic Association Reveals Protection against Recurrence of Clostridium difficile Infection with Bezlotoxumab Treatment By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT Bezlotoxumab is a human monoclonal antibody against Clostridium difficile toxin B, indicated to prevent recurrence of C. difficile infection (rCDI) in high-risk adults receiving antibacterial treatment for CDI. An exploratory genome-wide association study investigated whether human genetic variation influences bezlotoxumab response. DNA from 704 participants who achieved initial clinical cure in the phase 3 MODIFY I/II trials was genotyped. Single nucleotide polymorphisms (SNPs) and human leukocyte antigen (HLA) imputation were performed using IMPUTE2 and HIBAG, respectively. A joint test of genotype and genotype-by-treatment interaction in a logistic regression model was used to screen genetic variants associated with response to bezlotoxumab. The SNP rs2516513 and the HLA alleles HLA-DRB1*07:01 and HLA-DQA1*02:01, located in the extended major histocompatibility complex on chromosome 6, were associated with the reduction of rCDI in bezlotoxumab-treated participants. Carriage of a minor allele (homozygous or heterozygous) at any of the identified loci was related to a larger difference in the proportion of participants experiencing rCDI versus placebo; the effect was most prominent in the subgroup at high baseline risk for rCDI. Genotypes associated with an improved bezlotoxumab response showed no association with rCDI in the placebo cohort. These data suggest that a host-driven, immunological mechanism may impact bezlotoxumab response. Trial registration numbers are as follows: NCT01241552 (MODIFY I) and NCT01513239 (MODIFY II). IMPORTANCE Clostridium difficile infection is associated with significant clinical morbidity and mortality; antibacterial treatments are effective, but recurrence of C. difficile infection is common. In this genome-wide association study, we explored whether host genetic variability affected treatment responses to bezlotoxumab, a human monoclonal antibody that binds C. difficile toxin B and is indicated for the prevention of recurrent C. difficile infection. Using data from the MODIFY I/II phase 3 clinical trials, we identified three genetic variants associated with reduced rates of C. difficile infection recurrence in bezlotoxumab-treated participants. The effects were most pronounced in participants at high risk of C. difficile infection recurrence. All three variants are located in the extended major histocompatibility complex on chromosome 6, suggesting the involvement of a host-driven immunological mechanism in the prevention of C. difficile infection recurrence. Full Article
b Lack of Evidence for Microbiota in the Placental and Fetal Tissues of Rhesus Macaques By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT The prevailing paradigm in obstetrics has been the sterile womb hypothesis. However, some are asserting that the placenta, intra-amniotic environment, and fetus harbor microbial communities. The objective of this study was to determine whether the fetal and placental tissues of rhesus macaques harbor bacterial communities. Fetal, placental, and uterine wall samples were obtained from cesarean deliveries without labor (~130/166 days gestation). The presence of bacteria in the fetal intestine and placenta was investigated through culture. The bacterial burden and profiles of the placenta, umbilical cord, and fetal brain, heart, liver, and colon were determined through quantitative real-time PCR and DNA sequencing. These data were compared with those of the uterine wall as well as to negative and positive technical controls. Bacterial cultures of fetal and placental tissues yielded only a single colony of Cutibacterium acnes. This bacterium was detected at a low relative abundance (0.02%) in the 16S rRNA gene profile of the villous tree sample from which it was cultured, yet it was also identified in 12/29 background technical controls. The bacterial burden and profiles of fetal and placental tissues did not exceed or differ from those of background technical controls. By contrast, the bacterial burden and profiles of positive controls exceeded and differed from those of background controls. Among the macaque samples, distinct microbial signals were limited to the uterine wall. Therefore, using multiple modes of microbiologic inquiry, there was not consistent evidence of bacterial communities in the fetal and placental tissues of rhesus macaques. IMPORTANCE Microbial invasion of the amniotic cavity (i.e., intra-amniotic infection) has been causally linked to pregnancy complications, especially preterm birth. Therefore, if the placenta and the fetus are typically populated by low-biomass microbial communities, current understanding of the role of microbes in reproduction and pregnancy outcomes will need to be fundamentally reconsidered. Could these communities be of benefit by competitively excluding potential pathogens or priming the fetal immune system for the microbial bombardment it will experience upon delivery? If so, what properties (e.g., microbial load and community membership) of these microbial communities preclude versus promote intra-amniotic infection? Given the ramifications of the in utero colonization hypothesis, critical evaluation is required. In this study, using multiple modes of microbiologic inquiry (i.e., culture, quantitative real-time PCR [qPCR], and DNA sequencing) and controlling for potential background DNA contamination, we did not find consistent evidence for microbial communities in the placental and fetal tissues of rhesus macaques. Full Article
b Detecting and Monitoring Porcine Hemagglutinating Encephalomyelitis Virus, an Underresearched Betacoronavirus By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT Members of family Coronaviridae cause a variety of diseases in birds and mammals. Porcine hemagglutinating encephalomyelitis virus (PHEV), a lesser-researched coronavirus, can infect naive pigs of any age, but clinical disease is observed in pigs ≤4 weeks of age. No commercial PHEV vaccines are available, and neonatal protection from PHEV-associated disease is presumably dependent on lactogenic immunity. Although subclinical PHEV infections are thought to be common, PHEV ecology in commercial swine herds is unknown. To begin to address this gap in knowledge, a serum IgG antibody enzyme-linked immunosorbent assay (ELISA) based on the S1 protein was developed and evaluated on known-status samples and then used to estimate PHEV seroprevalence in U.S. sow herds. Assessment of the diagnostic performance of the PHEV S1 ELISA using serum samples (n = 924) collected from 7-week-old pigs (n = 84; 12 pigs per group) inoculated with PHEV, porcine epidemic diarrhea virus, transmissible gastroenteritis virus, porcine respiratory coronavirus, or porcine deltacoronavirus showed that a sample-to-positive cutoff value of ≥0.6 was both sensitive and specific, i.e., all PHEV-inoculated pigs were seropositive from days postinoculation 10 to 42, and no cross-reactivity was observed in samples from other groups. The PHEV S1 ELISA was then used to estimate PHEV seroprevalence in U.S. sow herds (19 states) using 2,756 serum samples from breeding females (>28 weeks old) on commercial farms (n = 104) with no history of PHEV-associated disease. The overall seroprevalence was 53.35% (confidence interval [CI], ±1.86%) and herd seroprevalence was 96.15% (CI, ±3.70%). IMPORTANCE There is a paucity of information concerning the ecology of porcine hemagglutinating encephalomyelitis virus (PHEV) in commercial swine herds. This study provided evidence that PHEV infection is endemic and highly prevalent in U.S. swine herds. These results raised questions for future studies regarding the impact of endemic PHEV on swine health and the mechanisms by which this virus circulates in endemically infected populations. Regardless, the availability of the validated PHEV S1 enzyme-linked immunosorbent assay (ELISA) provides the means for swine producers to detect and monitor PHEV infections, confirm prior exposure to the virus, and to evaluate the immune status of breeding herds. Full Article
b Subtle Variations in Dietary-Fiber Fine Structure Differentially Influence the Composition and Metabolic Function of Gut Microbiota By msphere.asm.org Published On :: 2020-05-06T07:29:31-07:00 ABSTRACT The chemical structures of soluble fiber carbohydrates vary from source to source due to numerous possible linkage configurations among monomers. However, it has not been elucidated whether subtle structural variations might impact soluble fiber fermentation by colonic microbiota. In this study, we tested the hypothesis that subtle structural variations in a soluble polysaccharide govern the community structure and metabolic output of fermenting microbiota. We performed in vitro fecal fermentation studies using arabinoxylans (AXs) from different classes of wheat (hard red spring [AXHRS], hard red winter [AXHRW], and spring red winter [AXSRW]) with identical initial microbiota. Carbohydrate analyses revealed that AXSRW was characterized by a significantly shorter backbone and increased branching compared with those of the hard varieties. Amplicon sequencing demonstrated that fermentation of AXSRW resulted in a distinct community structure of significantly higher richness and evenness than those of hard-AX-fermenting cultures. AXSRW favored OTUs within Bacteroides, whereas AXHRW and AXHRS favored Prevotella. Accordingly, metabolic output varied between hard and soft varieties; higher propionate production was observed with AXSRW and higher butyrate and acetate with AXHRW and AXHRS. This study showed that subtle changes in the structure of a dietary fiber may strongly influence the composition and function of colonic microbiota, further suggesting that physiological functions of dietary fibers are highly structure dependent. Thus, studies focusing on interactions among dietary fiber, gut microbiota, and health outcomes should better characterize the structures of the carbohydrates employed. IMPORTANCE Diet, especially with respect to consumption of dietary fibers, is well recognized as one of the most important factors shaping the colonic microbiota composition. Accordingly, many studies have been conducted to explore dietary fiber types that could predictably manipulate the colonic microbiota for improved health. However, the majority of these studies underappreciate the vastness of fiber structures in terms of their microbial utilization and omit detailed carbohydrate structural analysis. In some cases, this causes conflicting results to arise between studies using (theoretically) the same fibers. In this investigation, by performing in vitro fecal fermentation studies using bran arabinoxylans obtained from different classes of wheat, we showed that even subtle changes in the structure of a dietary fiber result in divergent microbial communities and metabolic outputs. This underscores the need for much higher structural resolution in studies investigating interactions of dietary fibers with gut microbiota, both in vitro and in vivo. Full Article
b Molar element ratio analysis of lithogeochemical data: a toolbox for use in mineral exploration and mining By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 Molar element ratio analysis of element concentrations consists of four basic tools that provide substantial insight into the lithogeochemistry (and mineralogy) of rocks under examination. These tools consist of: (1) conserved element ratio analysis; (2) Pearce element ratio analysis; (3) general element ratio analysis; and (4) lithogeochemical mineral mode analysis. Conserved element ratio analysis is useful in creating a chemostratigraphic model for the host rocks to mineral deposits, whereas Pearce element ratio analysis and general element ratio analysis are primarily used to identify mineralogical and metasomatic controls on rock compositions and to investigate and quantify the extent of the material transfers that formed the host rocks and mineralization. Lithogeochemical mineral mode analysis converts element concentrations into mineral concentrations using a matrix-based change-of-basis operation, allowing lithogeochemical data to be interpreted in terms of mineral modes. It can be used to provide proper names to rocks, an important activity for an exploration geologist because of the implications that rock names have on genetic processes and mineral deposit models. This paper provides a review of the theoretical foundations of each of these four tools and then illustrates how these techniques have been used in a variety of exploration applications to assist in the search for, evaluation and planning of, and the mining of mineral deposits. Examples include the evaluation of total digestion lithogeochemical datasets from mineral deposits hosted by igneous and sedimentary rocks and formed by hydrothermal and igneous processes. In addition, this paper illustrates a more recent geometallurgical application of these methods, whereby the mineral proportions determined by lithogeochemical mineral mode analysis are used to predict rock properties and obtain the ore body knowledge critical for resource evaluation, mine planning, mining and mine remediation. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b New developments in field-portable geochemical techniques and on-site technologies and their place in mineral exploration By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 This paper focuses on handheld and top-of-hole techniques which have appeared since 2007 or have undergone major improvements, and discusses their benefits, challenges and pitfalls, why we use them and what to expect from them. There is an ongoing need to be innovative with the way we undertake mineral exploration. Recent technological advances that have been applied to successful mineral exploration include on-site or portable instruments, on-site laboratory technologies, various core scanners, and technologies for fluid analysis. Portable or field technologies such as pXRF, pXRD, pNIR-SWIR, µRaman and LIBS aid in obtaining chemical and mineralogical information. Spectral gamma tools, a well-known technology, recently took advantage of improved ground and airborne (drone) instruments, to complement hyperspectral imagery. At mine and exploration sites, top-of-hole sensing technologies, such as Lab-at-Rig® and various core scanners (both spectral- and XRF-based) have become useful tools to analyse metres of core as it is being drilled. Fluid analyses are not as common as analyses of solid materials, but there are advances in such technologies as anodic stripping voltammetry, polarography and ion-exchange electrodes aiming for analysis of commodity or environmentally important elements. Field-portable geochemical techniques and on-site technologies now offer instant response and flexibility for most exploration tasks. By providing relevant data within minutes, they allow safer field decisions and focus on the most promising finds, while saving valuable resources in sampling grids or drilling. More efficient laboratory analysis programs are supported by sample screening and homogeneity checking on-site. Field analyses are not always as accurate as laboratory ones, but most of the time can be correlated with them, enabling reliable decisions. The level of confidence in field-made decisions needs to be compared between later and less numerous laboratory analyses, and less precise but more abundant and immediate field analyses. It may be demonstrated that, in many cases, the fit–for-purpose nature of the latter allows a better confidence level. Quality compromises associated with field analyses can be reduced by the application of better sample preparation and quality assurance/quality control (QA/QC) procedures. Most of the further development of on-site chemical analysis is expected to be based on its integration with lab methods and on sound QA/QC practice, allowing a precise evaluation of its confidence level and uncertainties. Mineralogical analyses are constrained by our ability to interpret the data in near-real time but offer promising approaches in both surface and drilling exploration campaigns. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b Parts per trillion (ppt) gold in groundwater: can we believe it, what is anomalous and how do we use it? By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 There is a pressing need for new exploration tools to target and vector towards mineralization in covered terrains. Groundwater provides a valuable and under-utilized geochemical sampling medium, and represents an important and cost-effective tool to expose covered terrains to systematic exploration. For Au exploration, researchers agree the best hydrogeochemistry pathfinder is dissolved Au itself, with additional potential from other pathfinders (albeit non-unique) such as As, Ag, W and Mo. Despite Au's relatively low solubility, with rigorous field protocols and appropriate analytical methods, explorers can respond to dissolved Au directly with robust parts per trillion (ppt)-level analyses. Even with ppt-level analyses, a practical implication of Au's low solubility is that a deposit's dissolved Au signature is generally weaker than seen in other more mobile pathfinders, producing a smaller detectable footprint, which must be considered when designing exploration programmes. Using purpose-drilled groundwater sampling bores, explorers can collect groundwater samples at the density required to respond to dissolved Au where existing borehole coverage is otherwise insufficient. In addition to its use at the regional scale, with even tighter sample density, hydrogeochemistry also shows promise at the project scale, allowing the 3D modelling of pathfinder dispersion. For hydrogeochemistry to be widely adopted for Au exploration, explorers need confidence in ppt-level dissolved Au analyses, and the context to understand their significance. This paper aims to address these topics and provide a straightforward starting point for Au explorers interested in applying hydrogeochemistry by: (i) summarizing examples of regional sampling programmes and more focused case studies to illustrate how covered Au deposits create measurable dissolved Au footprints distinguishable from background; and (ii) sharing examples of dissolved Au analyses that are being integrated into exploration at the regional and project scales. As seen in the results, the distributions of dissolved Au in the regional- and project-scale programmes show remarkably similar and easy to interpret high-contrast, low-frequency anomalies against relatively low backgrounds. These are desirable attributes of any geochemical pathfinder. When combined with the benefits of hydrogeochemistry v. other geochemical exploration tools (e.g. groundwater can create larger footprints requiring fewer samples to detect, and groundwater can recharge from depth to reflect deeper mineralization), dissolved Au is a powerful pathfinder ideally suited for Au exploration in covered terrains. While this paper focuses on the use of dissolved Au, additional pathfinders can provide valuable information, including indications of lithological changes, hydrothermal alteration and different styles of mineralization, as well as opportunities to use secondary pathfinders when sample density or local conditions may not result in detectable dissolved Au signatures. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b Recent advances in the application of mineral chemistry to exploration for porphyry copper-gold-molybdenum deposits: detecting the geochemical fingerprints and footprints of hypogene mineralization and alteration By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 In the past decade, significant research efforts have been devoted to mineral chemistry studies to assist porphyry exploration. These activities can be divided into two major fields of research: (1) porphyry indicator minerals (PIMs), which are used to identify the presence of, or potential for, porphyry-style mineralization based on the chemistry of magmatic minerals such as zircon, plagioclase and apatite, or resistate hydrothermal minerals such as magnetite; and (2) porphyry vectoring and fertility tools (PVFTs), which use the chemical compositions of hydrothermal minerals such as epidote, chlorite and alunite to predict the likely direction and distance to mineralized centres, and the potential metal endowment of a mineral district. This new generation of exploration tools has been enabled by advances in and increased access to laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), short-wave length infrared (SWIR), visible near-infrared (VNIR) and hyperspectral technologies. PIMs and PVFTs show considerable promise for exploration and are starting to be applied to the diversity of environments that host porphyry and epithermal deposits globally. Industry has consistently supported development of these tools, and in the case of PVFTs encouraged by several successful blind tests where deposit centres have successfully been predicted from distal propylitic settings. Industry adoption is steadily increasing but is restrained by a lack of the necessary analytical equipment and expertise in commercial laboratories, and also by the ongoing reliance on well-established geochemical exploration techniques (e.g. sediment, soil and rock chip sampling) that have aided the discovery of near-surface resources over many decades, but are now proving less effective in the search for deeply buried mineral resources and for those concealed under cover. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b Advances in exploration geochemistry, 2007 to 2017 and beyond By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 Mineral exploration under relatively young, exotic cover still presents a major challenge to discovery. Advances and future developments can be categorized in four key areas, (1) understanding metal mobility and mechanisms, (2) rapid geochemical analyses, (3) data access, integration and interoperability and (4) innovation in laboratory-based methods. Application of ‘regolith-style' surface mapping in covered terrains outside of conventional lateritic terrains is achieving success in terms of reducing background noise and improving geochemical contrasts. However, process models for anomaly generation are still uncertain and require further research. The interaction between the surface environment, microbes, hydrocarbons and chemistry is receiving greater attention. While significant progress has been achieved in understanding the role of vegetation, interaction with the water table and cycling of metals in the near surface environment in Australia, other regions of the world, for example, the till-covered terrains in the northern hemisphere and arid colluvium-covered areas of South America, have seen less progress. In addition to vegetation, the influence of bacteria, fungi and invertebrates is not as well studied with respect to metal mobilization in cover. Field portable XRF has become a standard field technique, though more often used in a camp setting. Apart from a tweaking of analytical quality, instruments have probably reached their peak of analytical development with add-ons, such as cameras, beam-limiters, wireless transmission and GPS as the main differences between instrument suppliers. Their future rests in automated application in unconventional configurations, for example, core scanning and better integration of analytical data with other information such as spectral analyses. Pattern drilling that persists in industry, however, has benefited from innovative application of field-portable tools along with rock and mineral chemistry to provide near real-time results and assist in a shift toward more flexible and targeted drilling in greenfields settings. Innovation in the laboratory continues to progress. More selective geochemical analysis, imaging of fine particle size fractions and resistate mineral phases and isotope analysis are faster and more accessible than ever before. The application of genomics (and data analysis) as mineral exploration tools is on the horizon. A continuing problem in geoscience, the supply to industry of suitably trained geochemists, persists although some needs, particularly at junior level, will be met by recent initiatives at various universities at graduate level. Unfortunately, the current economic climate has had a significant impact on R&D and retention of geochemistry skills by the industry. Whilst the future is positive, significant investment is required to develop the next generation of geochemical exploration tools and concepts. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b Introduction to the thematic collection: Exploration Geochemistry at Exploration 17 October 21-25, 2017, Toronto By geea.lyellcollection.org Published On :: 2020-05-01T00:30:32-07:00 Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17 Full Article
b Medical Cannabinoid Products in Children and Adolescents By pedsinreview.aappublications.org Published On :: 2020-05-01T01:00:19-07:00 Full Article
b Blood Components for Pediatric Transfusions By pedsinreview.aappublications.org Published On :: 2020-05-01T01:00:19-07:00 Full Article
b Case 3: Polyuria and Polydipsia in an 11-year-old Boy By pedsinreview.aappublications.org Published On :: 2020-05-01T01:00:19-07:00 Full Article
b Visual Diagnosis: A Case of Stretchy Skin and Vascular Abnormalities By pedsinreview.aappublications.org Published On :: 2020-05-01T01:00:19-07:00 Full Article
b Identification and Quantitation Classifications for Extractables and Leachables By journal.pda.org Published On :: 2020-04-09T09:40:03-07:00 Extractables and leachables (E&L) are identified and quantified so that their impact on patient safety can be established and assessed. The uncertainty in the impact assessment is affected by the uncertainty in the substance's experimentally determined identity and concentration. Thus, these experimentally determined quantities must be reported not only in terms of their absolute result but also in terms of the uncertainty in the result, which is based on the amount and rigor of the information on which the result is based. In this way, the impact assessment can be tempered to account for the uncertainty in its input data. To facilitate the assignment and reporting of uncertainty, classification hierarchies are proposed and discussed for both identification and quantitation. Both hierarchies establish levels or degrees of identification and quantitation based on the uncertainty of the result and contain descriptions of the quality and quantity of information required to achieve a certain level within the hierarchy. The minimal levels that must be achieved to support impact assessment are also established. Full Article
b Advancing Biologics Development Programs with Legacy Cell Lines: Advantages and Limitations of Genetic Testing for Addressing Clonality Concerns Prior to Availability of Late Stage Process and Product Consistency Data By journal.pda.org Published On :: 2020-04-09T09:40:03-07:00 The bioprocessing industry uses recombinant mammalian cell lines to generate therapeutic biologic drugs. To ensure consistent product quality of the therapeutic proteins, it is imperative to have a controlled production process. Regulatory agencies and the biotechnology industry consider cell line "clonal origin" an important aspect of maintaining process control. Demonstration of clonal origin of the cell substrate, or production cell line, has received considerable attention in the past few years, and the industry has improved methods and devised standards to increase the probability and/or assurance of clonal derivation. However, older production cell lines developed before the implementation of these methods, herein referred to as "legacy cell lines," may not meet current regulatory expectations for demonstration of clonal derivation. In this article, the members of the IQ Consortium Working Group on Clonality present our position that the demonstration of process consistency and product comparability of critical quality attributes throughout the development life cycle should be sufficient to approve a license application without additional genetic analysis to support clonal origin, even for legacy cell lines that may not meet current day clonal derivation standards. With this commentary, we discuss advantages and limitations of genetic testing methods to support clonal derivation of legacy cell lines and wish to promote a mutual understanding with the regulatory authorities regarding their optional use during early drug development, subsequent to Investigational New Drug (IND) application and before demonstration of product and process consistency at Biologics License Applications (BLA) submission. Full Article
b Risk Assessment Approach to Microbiological Controls of Cell Therapies By journal.pda.org Published On :: 2020-04-09T09:40:03-07:00 This technology review, written by a small group of pharmaceutical microbiologists experienced in cell therapies, discussed a risk-based approach to microbiological contamination detection and control during gene and cell therapy production. Topics discussed include a brief overview of cell therapies, a risk analysis related to donor selection, cell collection and infectious agent testing, cell transformation and expansion, packaging, storage, and administration, and cell therapy microbial contamination testing and release. Full Article
b Bioprocess: Robustness with Respect to Mycoplasma Species By journal.pda.org Published On :: 2020-04-09T09:40:03-07:00 Capture bioprocessing unit operations were previously shown to clear or kill several log10 of a model mycoplasma Acholeplasma laidlawii in lab-scale spike/removal studies. Here, we confirm this observation with two additional mollicute species relevant to biotechnology products for human use: Mycoplasma orale and Mycoplasma arginini. Clearance of M. orale and M. arginini from protein A column purification was similar to that seen with A. laidlawii, though some between cycle carryover was evident, especially for M. orale. However, on-resin growth studies for all three species revealed that residual mycoplasma in a column slowly die off over time rather than expanding further. Solvent/detergent exposure completely inactivated M. arginini though detectable levels of M. orale remained. A small-scale model of a commercial low-pH hold step did inactivate live M. orale, but this inactivation required a lower pH set point and occurred with slower kinetics than previously seen with A. laidlawii. Additionally, ultraviolet-C irradiation was shown to be effective for A. laidlawii and M. orale inactivation whereas virus-retentive filters for upstream and downstream processes, as expected, cleared A. laidlawii. These data argue that M. orale and M. arginini overall would be largely cleared by early bioprocessing steps as shown previously for A. laidlawii, and that barrier technologies can effectively reduce the risk from media components. For some unit operations, M. orale and M. arginini may be hardier, and require more stringent processing or equipment cleaning conditions to assure effective mycoplasma reduction. By exploring how some of the failure modes in commercial antibody manufacturing processes can still eliminate mycoplasma burden, we demonstrate that required best practices assure biotechnology products will be safe for patients. Full Article
b The Bewildering Antitubercular Action of Pyrazinamide [Review] By mmbr.asm.org Published On :: 2020-03-04T05:30:12-08:00 Pyrazinamide (PZA) is a cornerstone antimicrobial drug used exclusively for the treatment of tuberculosis (TB). Due to its ability to shorten drug therapy by 3 months and reduce disease relapse rates, PZA is considered an irreplaceable component of standard first-line short-course therapy for drug-susceptible TB and second-line treatment regimens for multidrug-resistant TB. Despite over 60 years of research on PZA and its crucial role in current and future TB treatment regimens, the mode of action of this unique drug remains unclear. Defining the mode of action for PZA will open new avenues for rational design of novel therapeutic approaches for the treatment of TB. In this review, we discuss the four prevailing models for PZA action, recent developments in modulation of PZA susceptibility and resistance, and outlooks for future research and drug development. Full Article
b Microbiota-Propelled T Helper 17 Cells in Inflammatory Diseases and Cancer [Review] By mmbr.asm.org Published On :: 2020-03-04T05:30:12-08:00 Technologies allowing genetic sequencing of the human microbiome are opening new realms to discovery. The host microbiota substantially impacts immune responses both in immune-mediated inflammatory diseases (IMIDs) and in tumors affecting tissues beyond skin and mucosae. However, a mechanistic link between host microbiota and cancer or IMIDs has not been well established. Here, we propose T helper 17 (TH17) lymphocytes as the connecting factor between host microbiota and rheumatoid or psoriatic arthritides, multiple sclerosis, breast or ovarian cancer, and multiple myeloma. We theorize that similar mechanisms favor the expansion of gut-borne TH17 cells and their deployment at the site of inflammation in extraborder IMIDs and tumors, where TH17 cells are driving forces. Thus, from a pathogenic standpoint, tumors may share mechanistic routes with IMIDs. A review of similarities and divergences in microbiota-TH17 cell interactions in IMIDs and cancer sheds light on previously ignored pathways in either one of the two groups of pathologies and identifies novel therapeutic avenues. Full Article
b Global Organization and Proposed Megataxonomy of the Virus World [Review] By mmbr.asm.org Published On :: 2020-03-04T05:30:12-08:00 Viruses and mobile genetic elements are molecular parasites or symbionts that coevolve with nearly all forms of cellular life. The route of virus replication and protein expression is determined by the viral genome type. Comparison of these routes led to the classification of viruses into seven "Baltimore classes" (BCs) that define the major features of virus reproduction. However, recent phylogenomic studies identified multiple evolutionary connections among viruses within each of the BCs as well as between different classes. Due to the modular organization of virus genomes, these relationships defy simple representation as lines of descent but rather form complex networks. Phylogenetic analyses of virus hallmark genes combined with analyses of gene-sharing networks show that replication modules of five BCs (three classes of RNA viruses and two classes of reverse-transcribing viruses) evolved from a common ancestor that encoded an RNA-directed RNA polymerase or a reverse transcriptase. Bona fide viruses evolved from this ancestor on multiple, independent occasions via the recruitment of distinct cellular proteins as capsid subunits and other structural components of virions. The single-stranded DNA (ssDNA) viruses are a polyphyletic class, with different groups evolving by recombination between rolling-circle-replicating plasmids, which contributed the replication protein, and positive-sense RNA viruses, which contributed the capsid protein. The double-stranded DNA (dsDNA) viruses are distributed among several large monophyletic groups and arose via the combination of distinct structural modules with equally diverse replication modules. Phylogenomic analyses reveal the finer structure of evolutionary connections among RNA viruses and reverse-transcribing viruses, ssDNA viruses, and large subsets of dsDNA viruses. Taken together, these analyses allow us to outline the global organization of the virus world. Here, we describe the key aspects of this organization and propose a comprehensive hierarchical taxonomy of viruses. Full Article
b Structural Biology of the Enterovirus Replication-Linked 5'-Cloverleaf RNA and Associated Virus Proteins [Review] By mmbr.asm.org Published On :: 2020-03-18T05:29:37-07:00 Although enteroviruses are associated with a wide variety of diseases and conditions, their mode of replication is well conserved. Their genome is carried as a single, positive-sense RNA strand. At the 5' end of the strand is an approximately 90-nucleotide self-complementary region called the 5' cloverleaf, or the oriL. This noncoding region serves as a platform upon which host and virus proteins, including the 3B, 3C, and 3D virus proteins, assemble in order to initiate replication of a negative-sense RNA strand. The negative strand in turn serves as a template for synthesis of multiple positive-sense RNA strands. Building on structural studies of individual RNA stem-loops, the structure of the intact 5' cloverleaf from rhinovirus has recently been determined via nuclear magnetic resonance/small-angle X-ray scattering (NMR/SAXS)-based methods, while structures have also been determined for enterovirus 3A, 3B, 3C, and 3D proteins. Analysis of these structures, together with structural and modeling studies of interactions between host and virus proteins and RNA, has begun to provide insight into the enterovirus replication mechanism and the potential to inhibit replication by blocking these interactions. Full Article
b Touching the Surface: Diverse Roles for the Flagellar Membrane in Kinetoplastid Parasites [Review] By mmbr.asm.org Published On :: 2020-04-01T05:29:40-07:00 While flagella have been studied extensively as motility organelles, with a focus on internal structures such as the axoneme, more recent research has illuminated the roles of the flagellar surface in a variety of biological processes. Parasitic protists of the order Kinetoplastida, which include trypanosomes and Leishmania species, provide a paradigm for probing the role of flagella in host-microbe interactions and illustrate that this interface between the flagellar surface and the host is of paramount importance. An increasing body of knowledge indicates that the flagellar membrane serves a multitude of functions at this interface: attachment of parasites to tissues within insect vectors, close interactions with intracellular organelles of vertebrate cells, transactions between flagella from different parasites, junctions between the flagella and the parasite cell body, emergence of nanotubes and exosomes from the parasite directed to either host or microbial targets, immune evasion, and sensing of the extracellular milieu. Recent whole-organelle or genome-wide studies have begun to identify protein components of the flagellar surface that must mediate these diverse host-parasite interactions. The increasing corpus of knowledge on kinetoplastid flagella will likely prove illuminating for other flagellated or ciliated pathogens as well. Full Article
b CRISPR Tools To Control Gene Expression in Bacteria [Review] By mmbr.asm.org Published On :: 2020-04-01T05:29:40-07:00 CRISPR-Cas systems have been engineered as powerful tools to control gene expression in bacteria. The most common strategy relies on the use of Cas effectors modified to bind target DNA without introducing DNA breaks. These effectors can either block the RNA polymerase or recruit it through activation domains. Here, we discuss the mechanistic details of how Cas effectors can modulate gene expression by blocking transcription initiation or acting as transcription roadblocks. CRISPR-Cas tools can be further engineered to obtain fine-tuned control of gene expression or target multiple genes simultaneously. Several caveats in using these tools have also been revealed, including off-target effects and toxicity, making it important to understand the design rules of engineered CRISPR-Cas effectors in bacteria. Alternatively, some types of CRISPR-Cas systems target RNA and could be used to block gene expression at the posttranscriptional level. Finally, we review applications of these tools in high-throughput screens and the progress and challenges in introducing CRISPR knockdown to other species, including nonmodel bacteria with industrial or clinical relevance. A deep understanding of how CRISPR-Cas systems can be harnessed to control gene expression in bacteria and build powerful tools will certainly open novel research directions. Full Article
b Small-Molecule Acetylation by GCN5-Related N-Acetyltransferases in Bacteria [Review] By mmbr.asm.org Published On :: 2020-04-15T05:30:11-07:00 Acetylation is a conserved modification used to regulate a variety of cellular pathways, such as gene expression, protein synthesis, detoxification, and virulence. Acetyltransferase enzymes transfer an acetyl moiety, usually from acetyl coenzyme A (AcCoA), onto a target substrate, thereby modulating activity or stability. Members of the GCN5-N-acetyltransferase (GNAT) protein superfamily are found in all domains of life and are characterized by a core structural domain architecture. These enzymes can modify primary amines of small molecules or of lysyl residues of proteins. From the initial discovery of antibiotic acetylation, GNATs have been shown to modify a myriad of small-molecule substrates, including tRNAs, polyamines, cell wall components, and other toxins. This review focuses on the literature on small-molecule substrates of GNATs in bacteria, including structural examples, to understand ligand binding and catalysis. Understanding the plethora and versatility of substrates helps frame the role of acetylation within the larger context of bacterial cellular physiology. Full Article
b Bioavailability Based on the Gut Microbiota: a New Perspective [Review] By mmbr.asm.org Published On :: 2020-04-29T05:30:12-07:00 The substantial discrepancy between the strong effects of functional foods and various drugs, especially traditional Chinese medicines (TCMs), and the poor bioavailability of these substances remains a perplexing problem. Understanding the gut microbiota, which acts as an effective bioreactor in the human intestinal tract, provides an opportunity for the redefinition of bioavailability. Here, we discuss four different pathways associated with the role of the gut microbiota in the transformation of parent compounds to beneficial or detrimental small molecules, which can enter the body’s circulatory system and be available to target cells, tissues, and organs. We further describe and propose effective strategies for improving bioavailability and alleviating side effects with the help of the gut microbiota. This review also broadens our perspectives for the discovery of new medicinal components. Full Article
b Posttranscriptional Regulation of tnaA by Protein-RNA Interaction Mediated by Ribosomal Protein L4 in Escherichia coli [Article] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 Escherichia coli ribosomal protein (r-protein) L4 has extraribosomal biological functions. Previously, we described L4 as inhibiting RNase E activity through protein-protein interactions. Here, we report that from stabilized transcripts regulated by L4-RNase E, mRNA levels of tnaA (encoding tryptophanase from the tnaCAB operon) increased upon ectopic L4 expression, whereas TnaA protein levels decreased. However, at nonpermissive temperatures (to inactivate RNase E), tnaA mRNA and protein levels both increased in an rne temperature-sensitive [rne(Ts)] mutant strain. Thus, L4 protein fine-tunes TnaA protein levels independently of its inhibition of RNase E. We demonstrate that ectopically expressed L4 binds with transcribed spacer RNA between tnaC and tnaA and downregulates TnaA translation. We found that deletion of the 5' or 3' half of the spacer compared to the wild type resulted in a similar reduction in TnaA translation in the presence of L4. In vitro binding of L4 to the tnaC-tnaA transcribed spacer RNA results in changes to its secondary structure. We reveal that during early stationary-phase bacterial growth, steady-state levels of tnaA mRNA increased but TnaA protein levels decreased. We further confirm that endogenous L4 binds to tnaC-tnaA transcribed spacer RNA in cells at early stationary phase. Our results reveal the novel function of L4 in fine-tuning TnaA protein levels during cell growth and demonstrate that r-protein L4 acts as a translation regulator outside the ribosome and its own operon. IMPORTANCE Some ribosomal proteins have extraribosomal functions in addition to ribosome translation function. The extraribosomal functions of several r-proteins control operon expression by binding to own-operon transcripts. Previously, we discovered a posttranscriptional, RNase E-dependent regulatory role for r-protein L4 in the stabilization of stress-responsive transcripts. Here, we found an additional extraribosomal function for L4 in regulating the tna operon by L4-intergenic spacer mRNA interactions. L4 binds to the transcribed spacer RNA between tnaC and tnaA and alters the structural conformation of the spacer RNA, thereby reducing the translation of TnaA. Our study establishes a previously unknown L4-mediated mechanism for regulating gene expression, suggesting that bacterial cells have multiple strategies for controlling levels of tryptophanase in response to varied cell growth conditions. Full Article
b Multiple and Overlapping Functions of Quorum Sensing Proteins for Cell Specialization in Bacillus Species [Minireviews] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 In bacterial populations, quorum sensing (QS) systems participate in the regulation of specialization processes and regulate collective behaviors that mediate interactions and allow survival of the species. In Gram-positive bacteria, QS systems of the RRNPP family (Rgg, Rap, NprR, PlcR, and PrgX) consist of intracellular receptors and their cognate signaling peptides. Two of these receptors, Rap and NprR, have regained attention in Bacillus subtilis and the Bacillus cereus group. Some Rap proteins, such as RapH and Rap60, are multifunctional and/or redundant in function, linking the specialization processes of sporulation and competence, as well as global expression changes in the transition phase in B. subtilis. NprR, an evolutionary intermediate between Rap and RRNPP transcriptional activators, is a bifunctional regulator that modulates sporulation initiation and activates nutrient scavenging genes. In this review, we discuss how these receptors switch between functions and connect distinct signaling pathways. Based on structural evidence, we propose that RapH and Rap60 should be considered moonlighting proteins. Additionally, we analyze an evolutionary and ecological perspective to understand the multifunctionality and functional redundancy of these regulators in both Bacillus spp. and non-Bacillus Firmicutes. Understanding the mechanistic, structural, ecological, and evolutionary basis for the multifunctionality and redundancy of these QS systems is a key step for achieving the development of innovative technologies for health and agriculture. Full Article
b The M Protein of Streptococcus pyogenes Strain AP53 Retains Cell Surface Functional Plasminogen Binding after Inactivation of the Sortase A Gene [Article] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 Streptococcus pyogenes (Lancefield group A Streptococcus [GAS]) is a β-hemolytic human-selective pathogen that is responsible for a large number of morbid and mortal infections in humans. For efficient infection, GAS requires different types of surface proteins that provide various mechanisms for evading human innate immune responses, thus enhancing pathogenicity of the bacteria. Many such virulence-promoting proteins, including the major surface signature M protein, are translocated after biosynthesis through the cytoplasmic membrane and temporarily tethered to this membrane via a type 1 transmembrane domain (TMD) positioned near the COOH terminus. In these proteins, a sorting signal, LPXTG, is positioned immediately upstream of the TMD, which is cleaved by the membrane-associated transpeptidase, sortase A (SrtA), leading to the covalent anchoring of these proteins to newly emerging l-Ala–l-Ala cross-bridges of the growing peptidoglycan cell wall. Herein, we show that inactivation of the srtA gene in a skin-tropic pattern D GAS strain (AP53) results in retention of the M protein in the cell membrane. However, while the isogenic AP53 srtA strain is attenuated in overall pathogenic properties due to effects on the integrity of the cell membrane, our data show that the M protein nonetheless can extend from the cytoplasmic membrane through the cell wall and then to the surface of the bacteria and thereby retain its important properties of productively binding and activating fluid-phase host plasminogen (hPg). The studies presented herein demonstrate an underappreciated additional mechanism of cell surface display of bacterial virulence proteins via their retention in the cell membrane and extension to the GAS surface. IMPORTANCE Group A Streptococcus pyogenes (GAS) is a human-specific pathogen that produces many surface factors, including its signature M protein, that contribute to its pathogenicity. M proteins undergo specific membrane localization and anchoring to the cell wall via the transpeptidase sortase A. Herein, we explored the role of sortase A function on M protein localization, architecture, and function, employing, a skin-tropic GAS isolate, AP53, which expresses a human plasminogen (hPg)-binding M (PAM) Protein. We showed that PAM anchored in the cell membrane, due to the targeted inactivation of sortase A, was nonetheless exposed on the cell surface and functionally interacted with host hPg. We demonstrate that M proteins, and possibly other sortase A-processed proteins that are retained in the cell membrane, can still function to initiate pathogenic processes by this underappreciated mechanism. Full Article
b Contributions of a LysR Transcriptional Regulator to Listeria monocytogenes Virulence and Identification of Its Regulons [Article] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 The capacity of Listeria monocytogenes to adapt to environmental changes is facilitated by a large number of regulatory proteins encoded by its genome. Among these proteins are the uncharacterized LysR-type transcriptional regulators (LTTRs). LTTRs can work as positive and/or negative transcription regulators at both local and global genetic levels. Previously, our group determined by comparative genome analysis that one member of the LTTRs (NCBI accession no. WP_003734782) was present in pathogenic strains but absent from nonpathogenic strains. The goal of the present study was to assess the importance of this transcription factor in the virulence of L. monocytogenes strain F2365 and to identify its regulons. An L. monocytogenes strain lacking lysR (the F2365lysR strain) displayed significant reductions in cell invasion of and adhesion to Caco-2 cells. In plaque assays, the deletion of lysR resulted in a 42.86% decrease in plaque number and a 13.48% decrease in average plaque size. Furthermore, the deletion of lysR also attenuated the virulence of L. monocytogenes in mice following oral and intraperitoneal inoculation. The analysis of transcriptomics revealed that the transcript levels of 139 genes were upregulated, while 113 genes were downregulated in the F2365lysR strain compared to levels in the wild-type bacteria. lysR-repressed genes included ABC transporters, important for starch and sucrose metabolism as well as glycerolipid metabolism, flagellar assembly, quorum sensing, and glycolysis/gluconeogenesis. Conversely, lysR activated the expression of genes related to fructose and mannose metabolism, cationic antimicrobial peptide (CAMP) resistance, and beta-lactam resistance. These data suggested that lysR contributed to L. monocytogenes virulence by broad impact on multiple pathways of gene expression. IMPORTANCE Listeria monocytogenes is the causative agent of listeriosis, an infectious and fatal disease of animals and humans. In this study, we have shown that lysR contributes to Listeria pathogenesis and replication in cell lines. We also highlight the importance of lysR in regulating the transcription of genes involved in different pathways that might be essential for the growth and persistence of L. monocytogenes in the host or under nutrient limitation. Better understanding L. monocytogenes pathogenesis and the role of various virulence factors is necessary for further development of prevention and control strategies. Full Article
b The Antiactivator of Type III Secretion, OspD1, Is Transcriptionally Regulated by VirB and H-NS from Remote Sequences in Shigella flexneri [Article] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 Shigella species, the causal agents of bacillary dysentery, use a type III secretion system (T3SS) to inject two waves of virulence proteins, known as effectors, into the colonic epithelium to subvert host cell machinery. Prior to host cell contact and secretion of the first wave of T3SS effectors, OspD1, an effector and antiactivator protein, prevents premature production of the second wave of effectors. Despite this important role, regulation of the ospD1 gene is not well understood. While ospD1 belongs to the large regulon of VirB, a transcriptional antisilencing protein that counters silencing mediated by the histone-like nucleoid structuring protein H-NS, it remains unclear if VirB directly or indirectly regulates ospD1. Additionally, it is not known if ospD1 is regulated by H-NS. Here, we identify the primary ospD1 transcription start site (+1) and show that the ospD1 promoter is remotely regulated by both VirB and H-NS. Our findings demonstrate that VirB regulation of ospD1 requires at least one of the two newly identified VirB regulatory sites, centered at –978 and –1270 relative to the ospD1 +1. Intriguingly, one of these sites lies on a 193-bp sequence found in three conserved locations on the large virulence plasmids of Shigella. The region required for H-NS-dependent silencing of ospD1 lies between –1120 and –820 relative to the ospD1 +1. Thus, our study provides further evidence that cis-acting regulatory sequences for transcriptional antisilencers and silencers, such as VirB and H-NS, can lie far upstream of the canonical bacterial promoter region (i.e., –250 to +1). IMPORTANCE Transcriptional silencing and antisilencing mechanisms regulate virulence gene expression in many important bacterial pathogens. In Shigella species, plasmid-borne virulence genes, such as those encoding the type III secretion system (T3SS), are silenced by the histone-like nucleoid structuring protein H-NS and antisilenced by VirB. Previous work at the plasmid-borne icsP locus revealed that VirB binds to a remotely located cis-acting regulatory site to relieve transcriptional silencing mediated by H-NS. Here, we characterize a second example of remote VirB antisilencing at ospD1, which encodes a T3SS antiactivator and effector. Our study highlights that remote transcriptional silencing and antisilencing occur more frequently in Shigella than previously thought, and it raises the possibility that long-range transcriptional regulation in bacteria is commonplace. Full Article
b Ribosome Dimerization Protects the Small Subunit [Article] By jb.asm.org Published On :: 2020-04-27T08:00:23-07:00 When nutrients become scarce, bacteria can enter an extended state of quiescence. A major challenge of this state is how to preserve ribosomes for the return to favorable conditions. Here, we show that the ribosome dimerization protein hibernation-promoting factor (HPF) functions to protect essential ribosomal proteins. Ribosomes isolated from strains lacking HPF (hpf) or encoding a mutant allele of HPF that binds the ribosome but does not mediate dimerization were substantially depleted of the small subunit proteins S2 and S3. Strikingly, these proteins are located directly at the ribosome dimer interface. We used single-particle cryo-electron microscopy (cryo-EM) to further characterize these ribosomes and observed that a high percentage of ribosomes were missing S2, S3, or both. These data support a model in which the ribosome dimerization activity of HPF evolved to protect labile proteins that are essential for ribosome function. HPF is almost universally conserved in bacteria, and HPF deletions in diverse species exhibit decreased viability during starvation. Our data provide mechanistic insight into this phenotype and establish a mechanism for how HPF protects ribosomes during quiescence. IMPORTANCE The formation of ribosome dimers during periods of dormancy is widespread among bacteria. Dimerization is typically mediated by a single protein, hibernation-promoting factor (HPF). Bacteria lacking HPF exhibit strong defects in viability and pathogenesis and, in some species, extreme loss of rRNA. The mechanistic basis of these phenotypes has not been determined. Here, we report that HPF from the Gram-positive bacterium Bacillus subtilis preserves ribosomes by preventing the loss of essential ribosomal proteins at the dimer interface. This protection may explain phenotypes associated with the loss of HPF, since ribosome protection would aid survival during nutrient limitation and impart a strong selective advantage when the bacterial cell rapidly reinitiates growth in the presence of sufficient nutrients. Full Article
b Measuring airway clearance outcomes in bronchiectasis: a review By err.ersjournals.com Published On :: 2020-04-29T01:39:43-07:00 While airway clearance techniques (ACTs) are recommended for individuals with bronchiectasis, many trials have demonstrated inconsistent benefits or failed to reach their primary outcome. This review determined the most common clinical and patient-reported outcome measures used to evaluate the efficacy of ACTs in bronchiectasis. A literature search of five databases using relevant keywords and filtering for studies published in English, up until the end of August 2019, was completed. Studies included randomised controlled trials, using crossover or any other trial design, and abstracts. Studies were included where the control was placebo, no intervention, standard care, usual care or an active comparator. Adults with bronchiectasis not related to cystic fibrosis were included. Extracted data comprised study authors, design, duration, intervention, outcome measures and results. The search identified 27 published studies and one abstract. The most common clinical outcome measures were sputum volume (n=23), lung function (n=17) and pulse oximetry (n=9). The most common patient-reported outcomes were health-related quality of life (measured with St George's Respiratory Questionnaire, n=4), cough-related quality of life (measured with Leicester Cough Questionnaire, n=4) and dyspnoea (measured with Borg/modified Borg scale, n=8). Sputum volume, lung function, dyspnoea and health- and cough-related quality of life appear to be the most common clinical and patient-reported measures of airway clearance treatment efficacy. Full Article
b The supportive care needs of people living with pulmonary fibrosis and their caregivers: a systematic review By err.ersjournals.com Published On :: 2020-04-29T01:39:43-07:00 Background People with pulmonary fibrosis often experience a protracted time to diagnosis, high symptom burden and limited disease information. This review aimed to identify the supportive care needs reported by people with pulmonary fibrosis and their caregivers. Methods A systematic review was conducted according to PRISMA guidelines. Studies that investigated the supportive care needs of people with pulmonary fibrosis or their caregivers were included. Supportive care needs were extracted and mapped to eight pre-specified domains using a framework synthesis method. Results A total of 35 studies were included. The most frequently reported needs were in the domain of information/education, including information on supplemental oxygen, disease progression and prognosis, pharmacological treatments and end-of-life planning. Psychosocial/emotional needs were also frequently reported, including management of anxiety, anger, sadness and fear. An additional domain of "access to care" was identified that had not been specified a priori; this included access to peer support, psychological support, specialist centres and support for families of people with pulmonary fibrosis. Conclusion People with pulmonary fibrosis report many unmet needs for supportive care, particularly related to insufficient information and lack of psychosocial support. These data can inform the development of comprehensive care models for people with pulmonary fibrosis and their loved ones. Full Article
b An aberrant bi-apical Follicucullus (Albaillellaria) from the late Guadalupian (Middle Permian), with the possible oldest evidence of double malformation in radiolarians By jm.lyellcollection.org Published On :: 2017-08-10T08:29:36-07:00 An aberrant bi-apical Follicucullus specimen (Albaillellaria, Radiolaria) has been discovered from an upper Guadalupian (Middle Permian) chert block of the Kamiaso Unit of the Mino terrane, central Japan. If this specimen was formed with double malformation, it would be the oldest record of this phenomenon in radiolarians and the first record of its kind in Albaillellaria. Full Article
b Modern deep-water agglutinated foraminifera from IODP Expedition 323, Bering Sea: ecological and taxonomic implications By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 Despite the importance of the Bering Sea for subarctic oceanography and climate, relatively little is known of the foraminifera from the extensive Aleutian Basin. We report the occurrence of modern deep-water agglutinated foraminifera collected at seven sites cored during Integrated Ocean Drilling Program (IODP) Expedition 323 in the Bering Sea. Assemblages collected from core-top samples contained 32 genera and 50 species and are described and illustrated here for the first time. Commonly occurring species include typical deep-water Rhizammina, Reophax, Rhabdammina, Recurvoides and Nodulina. Assemblages from the northern sites also consist of accessory Cyclammina, Eggerelloides and Glaphyrammina, whilst those of the Bowers Ridge sites consist of other tubular genera and Martinottiella. Of the studied stations with the lowest dissolved oxygen concentrations, the potentially Bering Sea endemic Eggerelloides sp. 1 inhabits the northern slope, which has the highest primary productivity, and the potentially endemic Martinottiella sp. 3 inhabits Bowers Ridge, which has the lowest oxygen concentrations but relatively low annual productivity. Martinottiella sp. 3, with open pores on its test surface, has previously been reported in Pliocene to Recent material from Bowers Ridge. Despite relatively small sample sizes, ecological constraints may imply that the Bering Sea experienced high productivity and reduced oxygen at times since at least the Pliocene. We note the partially endemic nature of the agglutinated foraminiferal assemblages, which may at least in part be due to basin restriction, the geologically long time period of reduced oxygen, and high organic carbon flux. Our results indicate the importance of gathering further surface sample data from the Aleutian Basin. Full Article
b The unknown planktonic foraminiferal pioneer Henry A. Buckley and his collection at The Natural History Museum, London By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 The Henry Buckley Collection of Planktonic Foraminifera at the Natural History Museum in London (NHMUK) consists of 1665 single-taxon slides housing 23 897 individuals from 203 sites in all the major ocean basins, as well as a vast research library of Scanning Electron Microscope (SEM) photomicrographs. Buckley picked the material from the NHMUK Ocean-Bottom Deposit Collection and also from fresh tow samples. However, his collection remains largely unused as he was discouraged by his managers in the Mineralogy Department from working on or publicizing the collection. Nevertheless, Buckley published pioneering papers on isotopic interpretation of oceanographic and climatic change and was one of the first workers to investigate foraminiferal wall structure using the SEM technique. Details of the collection and images of each slide are available via the NHMUK Data Portal (http://dx.doi.org/10.5519/0035055). The Buckley Collection and its associated Ocean-Bottom Deposit Collection have great potential for taxon-specific studies as well as geochemical work, and both collections are available on request. Full Article
b Tarburina zagrosiana n. gen., n. sp., a new larger benthic porcelaneous foraminifer from the late Maastrichtian of Iran By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 A new larger benthic porcelaneous foraminifer of soritid affinity is described as Tarburina zagrosiana n. gen., n. sp. from the late Maastrichtian of the Tarbur Formation, Zagros Zone, SW Iran. It occurs in foraminiferal–dasycladalean wackestones and packstones, in association with Loftusia ssp., dicyclinids/cuneolinids, Neobalkhania bignoti Cherchi & Schroeder, Gyroconulina columellifera Schroeder & Darmoian, Spirolina? farsiana Schlagintweit & Rashidi, Broeckina cf. dufrenoyi (d'Archiac), other benthic foraminifers, and dasycladalean algae. Due to its elongate test and marginal chamber subdivision by aligned vertical partitions, Tarburina n. gen. can be compared with representatives of the Praerhapydionininae. The interio-marginal slit-like foramina/aperture of Tarburina represents an outstanding feature in complex porcelaneous taxa. The monospecific genus Tarburina is considered a Maastrichtian newcomer within the Late Cretaceous Global Community Maturation cycle of larger benthic foraminifera. A biostratigraphic and palaeobiogeographical restriction seems possible, as reported for many other Late Cretaceous larger benthic foraminifera. Full Article
b Exceptionally well-preserved Permocalculus cf. tenellus (Pia) (Gymnocodiaceae) from Upper Permian Khuff Formation limestones, Saudi Arabia By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 An exceptionally well-preserved specimen of the articulated rhodophyte Permocalculus, compared with P. tenellus sensu Elliott, 1955, is described from fine-grained Upper Permian limestones of the Khuff Formation of Saudi Arabia. Longitudinal medullary and sheaf-like cortical filaments extend through the uniserial series of elongate-globular, concave- and convex-terminating, interlocking segments for which they are interpreted to have functioned in articulation. The filaments tend to splay and branch laterally into the cortex where they terminate at the pores. At the terminal aperture, the filaments extend as bifurcating and possibly trifurcating branches and may serve as the origin of a new segment. Numerous elongate-globular chambers, up to five in each row and intimately involved with the filaments, are developed in the outer medulla and are considered to represent reproductive sporangia. The specimen is considered to have occupied predominantly low-energy, normal to slightly elevated salinity, shallow conditions within the subtidal regime of a lagoon. Full Article
b Biostratigraphy and evolution of Miocene Discoaster spp. from IODP Site U1338 in the equatorial Pacific Ocean By jm.lyellcollection.org Published On :: 2017-08-10T08:29:35-07:00 Assemblages of upper lower through upper Miocene Discoaster spp. have been quantified from Integrated Ocean Drilling Program (IODP) Site U1338 in the eastern equatorial Pacific Ocean. These assemblages can be grouped into five broad morphological categories: six-rayed with bifurcated ray tips, six-rayed with large central areas, six-rayed with pointed ray tips, five-rayed with bifurcated ray tips and five-rayed with pointed ray tips. Discoaster deflandrei dominates the assemblages prior to 15.8 Ma. The decline in abundance of D. deflandrei close to the early–middle Miocene boundary occurs together with the evolution of the D. variabilis group, including D. signus and D. exilis. Six-rayed discoasters having large central areas become a prominent member of the assemblages for a 400 ka interval in the late middle Miocene. Five- and six-rayed forms having pointed tips become prominent in the early late Miocene and show a strong antiphasing relationship with the D. variabilis group. Discoaster bellus completely dominates the Discoaster assemblages for a 400 ka interval in the middle late Miocene. Abundances of all discoasters, or discoasters at the species level, show only (surprisingly) weak correlations to carbonate contents or oxygen and carbon isotopes of bulk sediment when calculated over the entire sample interval. Full Article
b A Rapid Review of Available Evidence to Inform Indicators for Routine Monitoring and Evaluation of Respectful Maternity Care By ghspjournal.org Published On :: 2020-03-31T15:28:55-07:00 ABSTRACTBackground:Some opportunities to routinely capture and improve respectful maternity care (RMC) during facility-based childbirth include quality improvement (QI) initiatives, community-based monitoring efforts through community score cards (CSC), and performance-based financing (PBF) initiatives. But there is limited guidance on which types of RMC indicators are best suited for inclusion in these initiatives. We sought to provide practical evidence-based recommendations on indicators that may be used for routine measurement of RMC in programs.Methods:We used a rapid review approach, which included (1) reviewing existing documents and publications to extract RMC indicators and identify which have or can be used in facility-based QI, CSCs, and PBF schemes; (2) surveying RMC and maternal health experts to rank indicators, and (3) analyzing survey data to select the most recommended indicators.Results:We identified 49 indicators spanning several domains of RMC and mistreatment including dignified/nondignified care, verbal and physical abuse, privacy/confidentiality, autonomy/loss of autonomy, supportive care/lack thereof, communication, stigma, discrimination, trust, facility environment/culture, responsiveness, and nonevidence-based care. Based on the analysis of the survey data, we recommend 33 indicators (between 2 and 6 indicators for each RMC domain) that may be suited for incorporation in both facility-based QI and CSC-related monitoring efforts.Conclusion:Integrating RMC indicators into QI and CSC initiatives, as well as in other maternal and neonatal health programs, could help improve RMC at the facility and community level. More research is needed into whether RMC can be integrated into PBF initiatives. Integration of RMC indicators into programs to improve quality of care and other health system outcomes will facilitate routine monitoring and accountability around experience of care. Measurement and improvement of women's experiences will increase maternal health service utilization and improve quality of care as a means of reducing maternal and neonatal morbidity and mortality. Full Article