Date Published: October 4, 2018
Publisher: Public Library of Science
Author(s): Xiao Chen, Qiaoyun Zhu, Fei Yu, Wen Zhang, Ruonan Wang, Xianfei Ye, Linfeng Jin, Yanchao Liu, Shufei Li, Yu Chen, Daniela Flavia Hozbor.
Vibrio parahaemolyticus is a leading foodborne pathogen in southeastern China. In this study, 105 strains of V. parahaemolyticus were isolated from fresh seafood in 2013 and 2014. The serotypes, virulence-associated genes and sequence types (STs) of these strains were analyzed. 26 defined serotypes were identified and 69 strains (65.7%) had untypeable O or K antigen. 8 strains (7.6%) had the virulence-associated gene tdh and no strain carried the trh gene. 45.7% (48/105) of isolates contained all four T3SS1 genes and 50% (4/8) tdh+trh-V. parahaemolyticus isolates lacked at least one of the four tested T3SS2α genes. 105 strains could be categorized into 84 STs and only 3 STs (ST3, ST8, ST675) had appeared in clinical strains. V. parahaemolyticus strains from seafood have more diverse and untypeable serotypes, less virulence-associated genes and more STs than strains from clinical sources.
Vibrio parahaemolyticus is a halophilic bacterium that is naturally present in marine and estuarine environments and has been isolated from the coastal regions of most continents [1–3]. Since it was first identified as a causative agent of gastroenteritis in Japan in 1950, V. parahaemolyticus had been recognized as a common contaminant of seafood and was responsible for acute diarrheal illness in human . In many Asian countries, such as China, Japan and Taiwan, approximately half of foodborne illnesses are caused by V. parahaemolyticus . In addition, V. parahaemolyticus outbreaks are frequently reported in the United States [6–7]. Even in Europe, sporadic outbreaks are consistently reported in coastal countries such as Spain, Italy and Norway [8–9].
V. parahaemolyticus is naturally present in coastal waters. There is an increase in the number of V. parahaemolyticus infections during the summer and autumn [12–13]. Therefore, we chose the period from June to October to undertake sample collection and analyzed the characteristics (serotypes, virulence-associated genes and STs) of 105 strains from seafood in Zhejiang province.