No abstract

BackgroundDiagnosis of urogenital schistosomiasis in chronically infected adults is challenging but important, especially because long term infection of the bladder and urinary tract can have dire consequences. We evaluated three tests for viable infection: detection of parasite specific DNA Dra1 fragments, haematuria and presence of parasite eggs for sensitivity (Se) and specificity (Sp).MethodsOver 400 urine specimens collected from adult volunteers in an endemic area in Western Nigeria were assessed for haematuria then filtered in the field, the filter papers dried and later examined for eggs and DNA. The results were stratified according to sex and age and subjected to Latent Class analysis.ConclusionsPresence of Dra1 in males (Se = 100%; Sp = 100%) exceeded haematuria (Se = 87.6%: Sp = 34.7%) and detection of eggs (Se = 70.1%; Sp = 100%). In females presence of Dra1 was Se = 100%: Sp = 100%, exceeding haematuria (Se = 86.7%: Sp = 77.0%) and eggs (Se = 70.1%; Sp = 100%). Dra1 became undetectable 2 weeks after praziquantel treatment. We conclude detection of Dra1 fragment is a definitive test for the presence of Schistosoma haematobium infection.

Tuberculosis (TB) and air pollution both contribute significantly to the global burden of disease. Epidemiological studies show that exposure to household and urban air pollution increase the risk of new infections with Mycobacterium tuberculosis (M.tb) and the development of TB in persons infected with M.tb and alter treatment outcomes. There is increasing evidence that particulate matter (PM) exposure weakens protective antimycobacterial host immunity. Mechanisms by which exposure to urban PM may adversely affect M.tb-specific human T cell functions have not been studied. We, therefore, explored the effects of urban air pollution PM2.5 (aerodynamic diameters ≤2.5µm) on M.tb-specific T cell functions in human peripheral blood mononuclear cells (PBMC). PM2.5 exposure decreased the capacity of PBMC to control the growth of M.tb and the M.tb-induced expression of CD69, an early surface activation marker expressed on CD3+ T cells. PM2.5 exposure also decreased the production of IFN-γ in CD3+, TNF-α in CD3+ and CD14+ M.tb-infected PBMC, and the M.tb-induced expression of T-box transcription factor TBX21 (T-bet). In contrast, PM2.5 exposure increased the expression of anti-inflammatory cytokine IL-10 in CD3+ and CD14+ PBMC. Taken together, PM2.5 exposure of PBMC prior to infection with M.tb impairs critical antimycobacterial T cell immune functions.

Exposure to air pollution particulate matter (PM) and tuberculosis (TB) are two of the leading global public health challenges affecting low and middle income countries. An estimated 4.26 million premature deaths are attributable to household air pollution and an additional 4.1 million to outdoor air pollution annually. Mycobacterium tuberculosis ( M . tb ) infects a large proportion of the world’s population with the risk for TB development increasing during immunosuppressing conditions. There is strong evidence that such immunosuppressive conditions develop during household air pollution exposure, which increases rates of TB development. Exposure to urban air pollution has been shown to alter the outcome of TB therapy. Here we examined whether in vitro exposure to urban air pollution PM alters human immune responses to M . tb . PM 2.5 and PM 10 (aerodynamic diameters <2.5μm, <10μm) were collected monthly from rainy, cold-dry and warm-dry seasons in Iztapalapa, a highly populated TB-endemic municipality of Mexico City with elevated outdoor air pollution levels. We evaluated the effects of seasonality and size of PM on cytotoxicity and antimycobacterial host immunity in human peripheral blood mononuclear cells (PBMC) from interferon gamma (IFN-γ) release assay (IGRA)+ and IGRA- healthy study subjects. PM 10 from cold-dry and warm-dry seasons induced the highest cytotoxicity in PBMC. With the exception of PM 2.5 from the cold-dry season, pre-exposure to all seasonal PM reduced M . tb phagocytosis by PBMC. Furthermore, M . tb -induced IFN-γ production was suppressed in PM 2.5 and PM 10 -pre-exposed PBMC from IGRA+ subjects. This observation coincides with the reduced expression of M . tb -induced T-bet, a transcription factor regulating IFN-γ expression in T cells. Pre-exposure to PM 10 compared to PM 2.5 led to greater loss of M . tb growth control. Exposure to PM 2.5 and PM 10 collected in different seasons differentially impairs M . tb -induced human host immunity, suggesting biological mechanisms underlying altered M . tb infection and TB treatment outcomes during air pollution exposures.

Background Changes to human respiratory tract microbiome may contribute significantly to the progression of respiratory diseases. However, there are few studies examining the relative abundance of microbial communities at the species level along the human respiratory tract. Findings Bronchoalveolar lavage, throat swab, mouth rinse, and nasal swab samples were collected from 5 participants. Bacterial ribosomal operons were sequenced using the Oxford Nanopore MinION to determine the relative abundance of bacterial species in 4 compartments along the respiratory tract. More than 1.8 million raw operon reads were obtained from the participants with ∼600,000 rRNA reads passing quality assurance/quality control (70–95% identify; &gt;1,200 bp alignment) by Discontiguous MegaBLAST against the EZ BioCloud 16S rRNA gene database. Nearly 3,600 bacterial species were detected overall (&gt;750 bacterial species within the 5 dominant phyla: Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteria. The relative abundance of bacterial species along the respiratory tract indicated that most microbes (95%) were being passively transported from outside into the lung. However, a small percentage (&lt;5%) of bacterial species were at higher abundance within the lavage samples. The most abundant lung-enriched bacterial species were Veillonella dispar and Veillonella atypica while the most abundant mouth-associated bacterial species were Streptococcus infantis and Streptococcus mitis. Conclusions Most bacteria detected in lower respiratory samples do not seem to colonize the lung. However, &gt;100 bacterial species were found to be enriched in bronchoalveolar lavage samples (compared to mouth/nose) and may play a substantial role in lung health.

Current methods to characterize microbial communities generally employ sequencing of the 16S rRNA gene (&lt; 500 bp) with high accuracy (∼ 99%) but, limited phylogenetic resolution. However, long-read sequencing now allows for the profiling of near-full length ribosomal operons [16S-ITS-23S rRNA genes] on platforms such as the Oxford Nanopore MinION. Here, we describe an rRNA operon database with &gt;300,000 entries, representing &gt;10,000 prokaryotic species and ∼150,000 strains. Additionally, BLAST parameters were identified for strain-level resolution using in silico mutated, mock rRNA operon sequences (70–95% identity) from four bacterial phyla and two members of the Euryarchaeota, mimicking MinION reads. MegaBLAST settings were determined that required &lt; 3 s per read on a Mac Mini with strain-level resolution for sequences with &gt;84% identity. These settings were tested on rRNA operon libraries generated with samples from diverse habitats: the human respiratory tract, farm/forest soils, and marine sponges (n = 1,322,818 reads for all sample sets). Most rRNA operon reads in this data set yielded best BLAST hits (95 ± 8%). However, only 38–82% of library reads were compatible with strain-level resolution, reflecting the dominance of human/biomedical associated prokaryotic entries in the database. Since the MinION and the Mac Mini are both portable, this study demonstrates the possibility of rapid strain-level microbiome analysis in the field.

The Regulator of G Protein Signaling 14 knockout (RGS14 KO) mouse strain has a unique brown adipose tissue (BAT) mechanism mediating its phenotype of healthful longevity and improved exercise performance. RGS14 KO mice demonstrated a 51 ± 8% increase in treadmill running distance before exhaustion and a 44 ± 7% increase in work to exhaustion compared to their wild type littermates (WTLs). Three days after BAT transplantation from RGS14 KO mice to WTL mice, the RGS14 KO BAT donor mice lost their enhanced exercise capacity, whereas it was gained in the WTL BAT recipients: their running distance and work to exhaustion rose by 46 ± 5% and 52 ± 7%, respectively. In contrast, when BAT was transplanted to WTL mice from other WTL mice, exercise capacity did not increase at 3 days after transplantation, but was only seen after 2 months post-transplantation. Based on these observations, our hypothesis was that the unique characteristics of RGS14 KO BAT, in inducing enhanced exercise capacity upon transplantation, are mediated by novel gene upregulation within the BAT, as well as potential interactions between the BAT and the microbiome. We found that RGS14 KO mice harbor two unique, health-beneficial strains of Akkermansia muciniphilia ( A. muciniphilia BIOML-A22 and A. muciniphilia AN78) in their gut and their BAT has a number of novel genes upregulated, including Lnpep (leucyl/cystinyl aminopeptidase), TFAM (transcription factor A, mitochondrial), and Lncbate10, the latter being a critical regulator of BAT differentiation. To address directly the role of the microbiome, the mice were treated with antibiotics for 1 week. Although WTL exercise capacity was not significantly different before and after antibiotic-induced microbiota clearance, the RGS14 KO mice lost their enhanced exercise capacity after antibiotic treatment: RGS14 KO running distance fell by 35 ± 7%, and work to exhaustion fell by 41 ± 7%. Thus, RGS14 KO BAT engages changes to resident commensal microbiota that are beneficial to exercise capacity and therefore represents a potential (and novel) therapeutic modality for improving exercise performance and for creating healthful longevity.

Metabolic and biosynthetic pathways drive cell growth and proliferation in response to nutrients and growth factors. Highly proliferating cells utilize glucose and glutamine to fuel biosynthetic processes. These two nutrients serve as substrates for the glutamine:fructose-6-phosphate amidotransferase (GFAT1), the rate-limiting enzyme in the hexosamine biosynthetic pathway (HBP), which ultimately produces UDP-GlcNAc that is necessary for protein glycosylation. Despite a role for the HBP in insulin resistance and lifespan extension, the mechanisms underlying GFAT1 regulation in vivo has remained elusive. We found mTOR complex 2 (mTORC2) controls flux through the HBP via regulation of GFAT1 expression levels in response to glucose. In the absence of mTORC2, GFAT1 expression is reduced and highly sensitive to glucose starvation. Furthermore, UDP-GlcNAc is highly diminished and glycosylation of specific transmembrane proteins such as CD147 is defective upon mTORC2 disruption. However, mTORC2 is also required for glycolysis and other biosynthetic pathways whose metabolites feed into the HBP. Thus, although exogenous UDP-GlcNAc can partially rescue glycosylation defects, it does not rescue the metabolic deficiencies in the absence of mTORC2. Like GFAT1, key enzymes of biosynthetic pathways have decreased expression in mTORC2-disrupted cells. Thus, by regulating levels of metabolic enzymes, mTORC2 coordinates flux through biosynthetic pathways in response to glucose availability. Our findings have implications for therapeutic targeting of mTORC2 in insulin resistance and cancer metabolism. Citation Format: Estela Jacinto, Joseph Moloughney, Thomas Lynch, Chang-Chih Wu, Olufunmilola Ibironke, Aixa Navia, Po-Chien Chou, Sisi Zhang, Joshua Rabinowitz, Guy Werlen. mTORC2 enhances flux through the hexosamine biosynthetic pathway by regulation of GFAT1 expression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1150. doi:10.1158/1538-7445.AM2015-1150