Our work shows that the pathogen
Clostridium difficile
chemotaxes, aggregates and forms resilient biofilms with another pathogen
Fusobacterium nucleatum
in the intestinal mucus layer.
The emergence of a novel pandemic human strain of influenza A (H1N1/09) virus in April 2009 has demonstrated the need for well-validated diagnostic tests that are broadly applicable, rapid, ...sensitive, and specific. The analytical performance and clinical validity of results generated with the novel Roche RealTime Ready Influenza A/H1N1 Detection Set using the LightCycler 2.0 instrument were characterized. Analytical performance was assessed by processing respiratory samples spiked with H1N1/09 and seasonal influenza A virus, a set of seasonal influenza A virus subtypes, and samples containing common viral and bacterial respiratory pathogens. The clinical validity of results was assessed in comparison to other assays by analyzing 359 specimens at three clinical sites and one reference laboratory. Direct sequencing was used to resolve samples with discrepant results. The assay detected virus concentrations down to <50 RNA copies per reverse transcription (RT)-quantitative PCR (qPCR). Various influenza A virus subtypes were covered. The analytical specificity was 100%. High clinical validity was demonstrated by the 99% positive agreement between seasonal influenza A viruses, 98% positive agreement between H1N1/09 viruses, and 88% agreement between negative results. The analytical sensitivity was compared to those of three other RT-qPCR assays and was found to be equivalent. The novel Roche RealTime Ready Influenza A/H1N1 Detection Set can be utilized on the widely used LightCycler platform. We demonstrate its usefulness for the rapid detection and surveillance of pandemic H1N1/09 influenza A virus infections.
We hypothesized that early-life gut microbiota support the functional organization of neural circuitry in the brain via regulation of synaptic gene expression and modulation of microglial ...functionality. Germ-free mice were colonized as neonates with either a simplified human infant microbiota consortium consisting of four Bifidobacterium species, or with a complex, conventional murine microbiota. We examined the cerebellum, cortex, and hippocampus of both groups of colonized mice in addition to germ-free control mice. At postnatal day 4 (P4), conventionalized mice and Bifidobacterium-colonized mice exhibited decreased expression of synapse-promoting genes and increased markers indicative of reactive microglia in the cerebellum, cortex and hippocampus relative to germ-free mice. By P20, both conventional and Bifidobacterium-treated mice exhibited normal synaptic density and neuronal activity as measured by density of VGLUT2
puncta and Purkinje cell firing rate respectively, in contrast to the increased synaptic density and decreased firing rate observed in germ-free mice. The conclusions from this study further reveal how bifidobacteria participate in establishing functional neural circuits. Collectively, these data indicate that neonatal microbial colonization of the gut elicits concomitant effects on the host CNS, which promote the homeostatic developmental balance of neural connections during the postnatal time period.
Background
Hispanic people with cystic fibrosis (CF) have decreased life expectancy and earlier acquisition of Pseudomonas aeruginosa compared to non‐Hispanic white individuals with CF. Racial and ...ethnic differences in the airway microbiome of CF may contribute to known health disparity, but have not been studied. The objective was to describe differences in the upper airway microbial community in Hispanic and non‐Hispanic white children with CF.
Methods
This prospective, observational cohort study of 59 Hispanic and non‐Hispanic white children with CF, ages 2−10 years old, was performed at Texas Children's Hospital (TCH) from February 2019 to January 2020. Oropharyngeal swabs were collected from the cohort during clinic visit. Swab samples underwent sequencing (16S V4 rRNA), diversity analysis, and taxonomic profiling. Key demographic and clinical data were collected from the electronic medical record and the CF Foundation Patient Registry (CFFPR). Statistical analysis compared sequencing, demographic, and clinical data.
Results
We found no significant difference in Shannon diversity or relative abundance of bacterial phyla between Hispanic and non‐Hispanic children with CF. However, a low abundant taxa‐ “uncultured bacterium” belonging to the order Saccharimonadales was significantly higher in Hispanic children (mean relative abundance = 0.13%) compared to the non‐Hispanic children (0.03%). Hispanic children had increased incidence of P. aeruginosa (p = 0.045) compared to non‐Hispanic children.
Conclusion
We did not find a significant difference in the airway microbial diversity between Hispanic and non‐Hispanic white children with CF. However, we found a greater relative abundance of Saccharimonadales and higher incidence of P. aeruginosa in Hispanic children with CF.
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