Investigation and pathogenic characteristics of food-borne disease outbreak caused by Vibrio parahaemolyticus
Objective To investigate and analyze the pathogenic characteristics of Vibrio parahemolyticus in a food-borne disease outbreak in Yangquan City,Shanxi province,and improve the ability to deal with food poisoning emergencies.Methods Totally 11 isolated strains from 25 patients with gastrointestinal symptoms such as diarrhea,abdominal pain,nausea and vomiting were analyzed using pulsed field gel electrophoresis(PFGE),serotyping,virulence gene detection,drug sensitivity assay and whole genome sequencing.Results All the 11 isolates were Vibrio parahaemolyticus,of which,eight carried a virulence gene tdh,one carried both virulence genes trh and tdh,one carried only a virulence gene trh,and one carried only a virulence gene tlh.The isolates were classified into three serotypes,O10:K4,O4:K63 and O5:unknown.According to the PFGE profile,11 strains were divided into five different groups.The results of the whole genome sequence showed that eight strains were the same ST type and were classified to the same clonal group.The virulence gene distribution,the drug resistance gene existence and the drug susceptibility profiles were the same,which was consistent with the epidemiological characteristics of the outbreak.All 11 strains only contained blaCARB resistance gene,and no drug-resistant plasmid was detected.They were sensitive to chloramphenicol,nalidixic acid,tetracycline,meropenem,ampicillin,ertapenem,tigacycline,ceftazidime and ciprofloxacin,and moderately sensitive to polymyxine E.None of the isolates were resistant to antibiotic drugs.Conclusion This is a food-borne disease outbreak caused by contamination of food with multiple serotypes of Vibrio parahaemolyticus.The cooked and uncooked food is stored together in the canteen to induce the opportunistic reproduction of Vibrio parahaemolyticus in suitable salty food,which leads to the occurrence of the incident.
Vibrio parahaemolyticusfoodborne diseasesepidemiological investigationpulsed field gel electrophoresiswhole genome sequencing technology