The pandemic clone of V. parahaemolyticus, consisting of O3:K6 strains and its serovariants, selleck shares the same genetic properties (trh -, tdh +, GS-PCR+) and forms the distinct cluster of clonal complex 3 (CC3) founded
by Sequence Type 3 (ST3). On the contrary the converse argument is not true as CC3 is also selleck chemical formed by non-pathogenic strains . Since ST and serotype are not linked, a diverse set of serotypes constitutes ST3 (largely caused by serotype switching via recombination) [9, 13, 17–20]. The overall genotypic diversities differ depending on the pathogenicity of strains: Pandemic strains show a high uniformity, whereas non-pandemic strains are highly diverse, leading to the observation that an analyzed geographically restricted subpopulation was genetically as diverse as the entire worldwide pubMLST database [21–24]. In contrast,
environmental tdh +/trh + V. parahaemolyticus are as diverse as the non-pathogenic populations . Diversity also depends on water temperature, with a less diverse cold water adapted population replaced by more diverse strains when temperature rises . The environmental populations are characterized by a fast evolution observable in the rapid turnover of predominant strains [25, 26]. But some clones and strain groups can persist for years in a specific habitat, creating an endemic population . With the application of MLST a high degree of genetic similarity between Dorsomorphin manufacturer environmental and pandemic or non-pandemic infectious isolates as well as the mentioned environmental clade of CC3 isolates was shown, emphasizing the potential threat even of environmental strains to human health . A clustering of strains in regard to specific Phosphatidylinositol diacylglycerol-lyase properties, like sampling time, habitat or origin is desired to establish a relationship between these properties and the genotype (in the case of MLST the ST) of a strain. However, in the case of V.
parahaemolyticus this was not possible in general [13, 19, 25]. Theethakaew et al. were able to identify distinct clusters of strains sampled either from farmed prawns or clinical cases . Due to the high genetic diversity especially of environmental strains, the identification of related strains can lack reliability; therefore clustering of strains on the basis of their amino acid sequence was applied to V. parahaemolyticus[24, 28]. Even though some studies already used MLST analysis to characterize V. parahaemolyticus strain sets, they were restricted to specific geographical areas (e.g. U.S. coast, Thailand and Peru) [23, 24, 27, 29], focused exclusively on pandemic or non-pandemic pathogenic isolates [17, 21, 22, 25, 26, 29] or were based on a limited strain number.