Project description:By unbiased deep sequencing, we identified a novel, highly divergent polyomavirus, provisionally named MX polyomavirus (MXPyV), in stool samples from children. From Mexico, 12 samples (out of 96) were positive for MxPyV by MXPyV-specific PCR. We used the ViroChip microarray and PCR to screen these 12 samples for co-infection with common diarrheal viruses. Six of 12 MxPyV-positive diarrheal samples tested negative by the ViroChip and PCR, and the other 6 samples were positive for at least one known diarrheal virus. The ViroChip microarray (version 5.0, Viro5AG-60K platform, GPL15905) was used to screen RNA extracts from MX polyomavirus (MXPyV)-positive pediatric diarrheal samples from Mexico for common diarrheal viruses.
Project description:Streptococcus pyogenes (Group A Streptococcus: GAS) is a major human pathogen that causes streptococcal pharyngitis, skin and soft-tissue infections, and life-threatening conditions such as streptococcal toxic shock syndrome (STSS). A large number of virulence-related genes are encoded on GAS genomes, which are involved in host-pathogen interaction, colonization, immune invasion, and long-term survival within hosts, causing the diverse symptoms. Here, we investigated the interaction between GAS-derived extracellular vesicles and host cells in order to reveal pathogenicity mechanisms induced by GAS infection.
Project description:By unbiased deep sequencing, we identified a novel, highly divergent polyomavirus, provisionally named MX polyomavirus (MXPyV), in stool samples from children. From Mexico, 12 samples (out of 96) were positive for MxPyV by MXPyV-specific PCR. We used the ViroChip microarray and PCR to screen these 12 samples for co-infection with common diarrheal viruses. Six of 12 MxPyV-positive diarrheal samples tested negative by the ViroChip and PCR, and the other 6 samples were positive for at least one known diarrheal virus.
Project description:Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. In this study,we evaluated the genetic difference of 40 Streptococcus suis strains belonging to various sequence types by comparative genomic hybridization to identify genes associated with the variation in pathogenicity using NimbleGen’s tilling microarray platform. Application of Comparative Phylogenomics to Identify Genetic Differences Relating to Pathogenicity of Streptococcus suis
Project description:Clostridium difficile is a major nosocomial pathogen that causes severe diarrheal disease. Though C. difficile is known to inhabit the human gastrointestinal tract, the mechanisms that allow this pathogen to adapt to the intestine and survive host defenses are not known. In this work, we investigated the response of C. difficile to the host defense peptide, LL-37, to determine the mechanisms underlying host adaptation and survival. Expression analyses revealed a previously unknown locus, which we named clnRAB, that is highly induced by LL-37 and acts as a global regulator of gene expression in C. difficile. Mutant analyses indicate that ClnRAB is a novel regulatory system that senses LL-37 as a host signal to regulate adaptation to the intestinal environment.
Project description:The opportunistic pathogen Streptococcus gallolyticus is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify S. gallolyticus-induced pathways that could on the long-term add to CRC progression. Transcription profiling of S. gallolyticus-exposed CRC-cells revealed the persistent induction of enzymes involved in biotransformation pathways. Specifically, a diffusible factor of S. gallolyticus (SGF-X) interacts with the aryl hydrocarbon receptor thereby inducing CYP1 enzymes that catalyze the bioactivation of polycyclic aromatic hydrocarbons (PAHs) into toxic intermediates. Importantly, priming CRC-cells with SGF-X containing medium increased the DNA damaging effect of the PAH 3-methylcholanthrene, which was not observed for other intestinal bacteria. In conclusion, this study shows for the first time that bacteria can modulate the biotransformation capacity of CRC-cells that offers a novel theory for a contributing role of S. gallolyticus in the etiology of sporadic CRC. Key words : Colorectal cancer cells, Streptococcus bovis, streptococcus gallolyticus, host-pathogen interactions, Cytochrome P4501A1, DNA-damage, polycyclic aromatic hydrocarbons
