Regulatory Small RNA Qrr2 Is Expressed Independently of Sigma Factor-54 and Can Function as the Sole Qrr Small RNA To Control Quorum Sensing in Vibrio parahaemolyticus.

Bacterial cells alter gene expression in response to changes in population density in a process called quorum sensing (QS). In Vibrio harveyi, LuxO, a low-cell-density activator of sigma factor-54 (RpoN), is required for transcription of five noncoding regulatory small RNAs (sRNAs), Qrr1 to Qrr5, which each repress translation of the master QS regulator, LuxR. Vibrio parahaemolyticus, the leading cause of bacterial seafoodborne gastroenteritis, also contains five Qrr sRNAs that control OpaR (the LuxR homolog), controlling capsule polysaccharide (CPS), motility, and metabolism.

Quorum Sensing Regulators AphA and OpaR Control Expression of the Operon Responsible for Biosynthesis of the Compatible Solute Ectoine.

To maintain the turgor pressure of the cell under high osmolarity, bacteria accumulate small organic compounds called compatible solutes, either through uptake or biosynthesis. , a marine halophile and an important human and shellfish pathogen, has to adapt to abiotic stresses such as changing salinity. contains multiple compatible solute biosynthesis and transporter systems, including the operon required for ectoine biosynthesis.

CRISPR-Cas and Contact-Dependent Secretion Systems Present on Excisable Pathogenicity Islands with Conserved Recombination Modules.

Pathogenicity islands (PAIs) are mobile integrated genetic elements that contain a diverse range of virulence factors. PAIs integrate into the host chromosome at a tRNA locus that contains their specific bacterial attachment site, , via integrase-mediated site-specific recombination generating and sites. We identified conserved recombination modules (integrases and sites) previously described in choleragenic PAIs but with novel cargo genes.

Quorum Sensing Regulators Are Required for Metabolic Fitness in Vibrio parahaemolyticus.

Quorum sensing (QS) is a process by which bacteria alter gene expression in response to cell density changes. In species, at low cell density, the sigma 54-dependent response regulator LuxO is active and regulates the two QS master regulators AphA, which is induced, and OpaR, which is repressed. At high cell density the opposite occurs: LuxO is inactive, and therefore OpaR is induced while AphA is repressed.

Post-Genomic Analysis of Members of the Family Vibrionaceae.

Similar to other genera and species of bacteria, whole genomic sequencing has revolutionized how we think about and address questions of basic Vibrio biology. In this review we examined 36 completely sequenced and annotated members of the Vibrionaceae family, encompassing 12 different species of the genera Vibrio, Aliivibrio, and Photobacterium. We reconstructed the phylogenetic relationships among representatives of this group of bacteria by using three housekeeping genes and 16S rRNA sequences.

Complete Genome Sequence of Vibrio parahaemolyticus Environmental Strain UCM-V493.

Vibrio parahaemolyticus is the leading bacterial cause of seafood-related gastroenteritis in the world. Here, we report the complete genome sequence and annotation of an environmental strain of V. parahaemolyticus, UCM-V493, with the aim of understanding the differences between the clinical and environmental isolates of the bacteria.

High-salt preadaptation of Vibrio parahaemolyticus enhances survival in response to lethal environmental stresses.

Adaptation to changing environmental conditions is an important strategy for survival of foodborne bacterial pathogens. Vibrio parahaemolyticus is a gram-negative seafoodborne enteric pathogen found in the marine environment both free living and associated with oysters. This pathogen is a moderate halophile, with optimal growth at 3% NaCl.