Journal of Microbiology

Review

REVIEW] The Role of Type III Secretion System 2 in Vibrio parahaemolyticus Pathogenicity: Hyeilin Ham , Kim Orth; J. Microbiol. 2012;50(5):719-725. Published online November 4, 2012; DOI: https://doi.org/10.1007/s12275-012-2550-2

Abstract: Vibrio parahaemolyticus, a Gram-negative marine bacterial pathogen, is emerging as a major cause of food-borne illnesses worldwide due to the consumption of raw seafood leading to diseases including gastroenteritis, wound infection, and septicemia. The bacteria utilize toxins and type III secretion system (T3SS) to trigger virulence. T3SS is a multi-subunit needle-like apparatus used to deliver bacterial proteins, termed effectors, into the host cytoplasm which then target various eukaryotic signaling pathways. V. parahaemolyticus carries two T3SSs in each of its two chromosomes, named T3SS1 and T3SS2, both of which play crucial yet distinct roles during infection: T3SS1 causes cytotoxicity whereas T3SS2 is mainly associated with enterotoxicity. Each T3SS secretes a unique set of effectors that contribute to virulence by acting on different host targets and serving different functions. Emerging studies on T3SS2 of V. parahaemolyticus, reveal its regulation, translocation, discovery, characterization of its effectors, and development of animal models to understand the enterotoxicity. This review on recent findings for T3SS2 of V. parahaemolyticus highlights a novel mechanism of invasion that appears to be conserved by other marine bacteria.

Research Support, Non-U.S. Gov't

Effect of Acidic pH on the Invasion Efficiency and the Type III Secretion System of Burkholderia thailandensis: Siroj Jitprasutwit , Wisansanee Thaewpia , Veerachat Muangsombut , Aroonlug Lulitanond , Chanvit Leelayuwat , Ganjana Lertmemongkolchai , Sunee Korbsrisate; J. Microbiol. 2010;48(4):526-532. Published online August 20, 2010; DOI: https://doi.org/10.1007/s12275-010-0078-x

Abstract: Burkholderia thailandensis is a close relative of Burkholderia pseudomallei. These organisms are very similar, but B. thailandensis is far less virulent than B. pseudomallei. Nucleotide sequencing and analysis of 14 B. thailandensis isolates revealed variation in the regions coding for the type III secreted BipD protein. The degree of B. thailandensis BipD sequence variation was greater than that found in B. pseudomallei. Western blot analysis indicated that, unlike B. pseudomallei, B. thailandensis type III secreted proteins including BipD and BopE could not be detected in the supernatant of culture medium unless induced by acidic conditions. In addition, culturing B. thailandensis under acidic growth conditions (pH 4.5) can induce the ability of this bacterium to invade human respiratory epithelial cells A549. The identification of an environmental stimulus that increases the invasion capability of B. thailandensis invasion is of value for those who would like to use this bacterium as a model to study B. pseudomallei virulence.

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