Pathogenic characteristics of Vibrio parahaemolyticus isolated from foodborne diseases in Guangzhou, 2010-2013

HUANG Jia-ying; LI Bai-sheng; TAN Hai-ling; KE Bi-xia; HE Dong-mei; KE Chang-wen; ZHANG Qiu-li

Abstract：Objective To study the serotypes, antimicrobial resistance, virulence genes and molecular character-istics of Vibrio parahaemolyticus isolated from foodborne diseases during 2010—2013 in Guangzhou.Methods A total of 108 Vibrio parahaemolyticus strains isolated from foodborne diseases were collected to serotype and antimicrobial resistance tests.PCR was used for the detection of tdh ( thermostable direct hemolysin gene ) and trh ( tdh- related hemolysin gene) .All the samples were analyzed by pulsed-field gel electrophoresis ( PFGE) .Results A total of 108 strains of Vibrio parahaemolyticus obtained from diarrhea patients with foodborne diseases were collected, among which O3:K6 (51, 47.2%) and O1:KUT (32, 29.6%) were the dominant serotypes.Vibrio parahaemolyticus isolated showed high resist-ance to ampicillin (90.7%) and cefepime (28.8%), but were 100.0%sensitive to cotrimoxazole and chloramphenicol. Multi-drug resistance was revealed in 53.6%(15/28), 20.6%(7/34), 18.8%(3/16) and 33.3%(10/30) of iso-lated strains in 2010, 2011, 2012 and 2013, respectively.Results from virulence gene detection suggested that 95.4%(103/108) isolates belonged to tdh+trh-, while 4.6% (5/108) isolates belonged to tdh-trh+.Results from PFGE a-nalysis suggested that 108 isolates were discriminated into 3 clusters and 55 different PFGE patterns with the similarity val-ue between 60.2%and 100.0%.The dominant serotype O3:K6 and O1:KUT seemed to gather in the cluster II, while serotype O4:K8 in cluster Ⅲ.Conclusion O3:K6 and O1:KUT are the dominant serotypes in Vibrio parahaemolyticus strains isolated from foodborne diseases during 2010—2013 in Guangzhou.These strains show high sensitivity to most anti-biotics, but with multi-drug resistance.Positive rate of tdh gene is high.PFGE analysis reveals genetic diversity is with-in the Vibrio parahaemolyticus strains of foodborne diseases in Guangzhou.