ABSTRACT
Objective To find out more about the population structure and clonal complex of clinical Vibrio parahaemolyticus strains in Asia.Methods Clinical Vibrio parahaemolyticus strains data were screened in Asia with complete ST and pST types from PubMLST public database,their subgroup and complex were analyzed,and the minimum spanning tree based on ST and pST types respectively was completed.Results From the database,341 items of ST and pST types of Asian clinical Vibrio parahaemolyticus strains were screened,including 157 ST,most of which were of ST3 type.Totally 214 items of data came from China (including Hong Kong and Taiwan),and covered 133 ST,most of which were of ST3 type.eBURST software was used and 17 groups and 94 singletons were found.Software STRUCTURE analysis showed that the appropriate subset number of clinical V.parahaemolyticus strains in Asia was 7,and that the average distance between samples in each subgroup was 0.9113.Conclusion Clinical V.parahaemolyticus strains in Asia show high diversity and can be subdivided into seven subgroups.ST3 type is dominating when multilocus sequence typing(MLST)is used and pST2 type is the majority by AA-MLST typing.
ABSTRACT
Objective To learn more about virulence genes and clonal complex group structure of Vibrio parahaemolyticus (VPH)strains separated from aquatic products in East China coastal areas between 2007 and 2012.Methods Seventy-nine strains separated from aquatic products in eastern coastal areas(Guandong,Fujian,Shanghai,Shandong,Jiangsu and Beijing)of China between 2007 and 2012 were identified as VPH by real-time-PCR with gene tlh.Gene tdh,trh and orf8 were also detected.Subgroup analysis and complex analysis were conducted of the VPH strains to build the minimum spanning tree respectively based on ST and pST types.Results In 79 VPH strains,gene tlh was positive while 8.86%(7 /79)of the isolates of gene tdh were positive.The carrying rate of gene orf8 was 8.86%.These 79 strains were of 69 ST types,involving 3 clonal complex and 62 singleton.By amino acid(AA)-multilocus sequence typing(MLST),79 strains covered the 23 pST types,2 clonal complexes and 1 singleton.The 363 single nucleotide polymorphisms(SNPs)were divided into 68 patterns.Conclusion VPH strains from aquatic products in eastern coastal areas of China are characterized by high polymorphisms and a low carrying rate of virulence genes.ST3 type is dominating when MLST typing is used while pST1 type is the majority by AA-MLST typing.
