Project description:Neonatal bacterial meningitis is a leading cause of infant morbidity and mortality, yet the molecular and cellular basis of the leptomeningeal response to infection remains poorly defined. Here, we study a mouse model of neonatal E. coli meningitis, combining conditional gene knockouts, leptomeningeal single-nucleus RNA sequencing, and endothelial cell culture to explore the role of Toll-like receptor 4 (TLR4) signaling in the host response to infection. Deletion of Tlr4 in non-myeloid cells dramatically reduced the inflammatory response in all leptomeningeal cell types and abrogated the infection-associated increase in vascular permeability. In a brain endothelial cell line (bEnd.3 cells), exposure to E. coli triggered NF-κB activation, selective internalization of Claudin-5, and increased monolayer permeability, responses that were eliminated by Tlr4 knockout. RNA-seq showed that TLR4 controls an NF-κB–driven transcriptional program that orchestrates the endothelial response to E. coli. These findings reveal multiple TLR4-dependent host responses to neonatal Gram-negative bacterial meningitis.
Project description:Identification of bacterial taxa present in multiple body sites of human cadavers at different stages of decomposition Targeted Locus (Loci)
Project description:Cronobacter (C.) is an important emerging opportunistic foodborne pathogen representing significant cause of mortality in neonatal patients with bacteremia and meningitis. Knowledge on the pathobiology of Cronobacter mediated meningitis has to a large extend been explored using in vitro models. To explore the innate immune response against the neonatal sepsis/meningitis causing isolate C. turicensis z3032 in vivo, zebrafish larvae (Danio rerio) were used as infection model. Following establishment of infection in zebrafish larvae with z3032, dual RNA-sequencing of host-pathogen was undertaken to profile RNA expression simultaneously in the pathogen and the head region of the zebrafish host.
Project description:Cronobacter (C.) is an important emerging opportunistic foodborne pathogen representing significant cause of mortality in neonatal patients with bacteremia and meningitis. Knowledge on the pathobiology of Cronobacter mediated meningitis has to a large extend been explored using in vitro models. To explore the innate immune response against the neonatal sepsis/meningitis causing isolate C. turicensis z3032 in vivo, zebrafish larvae (Danio rerio) were used as infection model. Following establishment of infection in zebrafish larvae with z3032, dual RNA-sequencing of host-pathogen was undertaken to profile RNA expression simultaneously in the pathogen and the head region of the zebrafish host.
Project description:An increasing body of evidence suggests an important role of the human microbiome in health and disease. We propose a ‘lost and found’ pipeline, which examines high quality unmapped sequence reads for microbial taxonomic classification. Using this pipeline, we are able to detect bacterial and archaeal phyla in blood using RNA sequencing (RNA-Seq) data. Careful analyses, including the use of positive and negative control datasets, suggest that these detected phyla represent true microbial communities in whole blood and are not due to contaminants. We applied our pipeline to study the composition of microbial communities present in blood across 192 individuals from four subject groups: schizophrenia (n=48), amyotrophic lateral sclerosis (n=47), bipolar disorder (n=48) and healthy controls (n=49). We observe a significantly increased microbial diversity in schizophrenia compared to the three other groups and replicate this finding in an independent schizophrenia case-control study. Our results demonstrate the potential use of total RNA to study microbes that inhabit the human body.