Project description:Compare the secreted proteins of a wild-type Vibrio parahaemolyticus strain with those of a mutant in hcp2, rendering the T6SS2 inactive
Project description:Comparative proteomics to identify proteins found in the media of Vibrio parahaemolyticus RIMD 2210633 bacteria with an active T6SS2 compared to bacteria with inactive T6SS2. Bacteria with an active T6SS2 are Vibrio parahaemolyticus RIMD 2210633 inwhich hcp1 was deleted to inactivate T6SS1. T6SS2 inactive bacteria are the former strain with an additional deletion in hcp2. Both strains express TfoX from an arabinose-inducible plasmid to induce T6SS2 activity.
Project description:Vibrio parahaemolyticus is a Gram-negative marine bacterium. Strain RIMD 2210633, the wild type strain of the organism, causes acute gastroenteritis in humans. Human intestinal factor bile often affects the global gene regulation in some species of enteropathogenic bacteria. To determine the genes in V. parahaemolyticus that respond to bile, we investigated the differences in the transcriptomes of the wild type strain and the vtrA-null strain grown in Luria-Bertani medium cultivated with or without 0.04% crude bile. The vtrA gene encodes the previously identified T3SS2 regulator. Our goal is to demonstrate bile regulon controlled by VtrA in V. parahaemolyticus.
Project description:Vibrio parahaemolyticus an emerging pathogen that is a causative agent of foodborne gastroenteritis when raw or undercooked seafood is consumed. Previous microarray data using a Vibrio parahaemolyticus RIMD2210633 chip has shown the master quorum-sensing regulator OpaR controls virulence, type III and type VI secretion systems, and flagellar and capsule production genes. In a parallel study, RNA-Seq was used to comparatively study the transcriptome changes of wild type Vibrio parahaemolyticus BB22 and a ΔopaR strain directly. Differences in mRNA expression were analyzed using next generation Illumina sequencing and bioinformatics techniques to align and count reads. A comparison with the previous microarray data showed good correlation between the shared genes. The RNA-Seq offered an insight into control of genes specific to the Vibrio parahaemolyticus BB22 strain as well as a new look at the sRNAs that are expressed. Eleven transcriptional regulators with greater than 4 fold regulation in the previous microarray study and 2 fold regulation in the RNA-Seq analysis, were chosen to validate the data using qRT-PCR and further characterized with electrophoretic mobility shift assays (EMSAs) to determine if they are direct targets of OpaR. The transcription factors chosen play key roles in virulence, surface motility, cell to cell interactions, and cell surface characteristics. One small RNA was identified in the RNA-Seq data to be quorum-sensing controlled and unidentified by other programs. The RNA-Seq data has aided in understanding and elucidating the hierarchy of quorum-sensing control of OpaR in Vibrio parahaemolyticus. The wild type Vibrio parahaemolyticus BB22 strain LM5312 and an opaR deletion strain LM5674 were analyzed for mRNA expression using RNA-Seq.