Title: Loss of sigma factor RpoN increases intestinal colonization of Vibrio parahaemolyticus in an adult mouse model
Authors: Whitaker W, Richards GP, Boyd E
Journal: Infect Immun
Accepted date: 2013 Nov 8
Interpretive summary: Vibrio parahaemolyticus is a naturally occurring marine bacterium which causes widespread illness among fish and shellfish consumers. In spite of this fact, the mechanisms by which V. parahaemolyticus colonize the human gut to induce illness are largely unknown. Vibrios move by means of whip-like flagella which propel the organism through the water or on surfaces. Under normal conditions, motility is by two types of flagella, a single polar flagellum projecting from the end of the bacterium, and/or lateral flagella projecting from the sides of the bacterium. In this paper we describe the growth and colonization of V. parahaemolyticus in a recently developed mouse model. We also evaluate the effects of several genes known to be involved in V. parahaemolyticus motility. In the mouse model, three mutant V. parahaemolyticus that were lacking genes for flagella production out-competed the native species within the mouse intestine. Mutant strains grew faster than the parent strain in media containing various nutritional sources, including a variety of sugars commonly found in intestinal mucus. Together, these data demonstrate that V. parahaemolyticus strains, which are unable to produce polar flagella, are better suited for intestinal colonization and they reproduce more rapidly. Energy may be saved by the bacterium by eliminating the need to produce or utilize polar flagella. Thus, V. parahaemolyticus that are missing the gene for polar flagella appear to utilize that energy to stimulate the colonization of V. parahaemolyticus in the intestinal tract. This study begins to address the functions of various V. parahaemolyticus genes in vibrio colonization in the human gut. This research has implications for how various gene mutations in V. parahaemolyticus may enhance or reduce the infectivity of seafood-associated vibrios in humans.
Publication date: 2014 Feb
Related projects: Pathogen Detection and Intervention Methods for Shellfish