Whole genome sequencing and antibiotic resistance analysis of Vibrio parahaemolyticus isolated from a food poisoning incidents

Abstract

ObjectiveWhole genome sequencing and antibiotic resistance analysis were conducted for Vibrio parahaemolyticus strains isolated from a food poisoning incident in Huai’an City in 2023， so as to provide reference for the prevention and clinical treatment of foodborne diseases caused by Vibrio parahaemolyticus.MethodsWhole genome sequencing was performed by Illumina sequencing platform， traceability was carried out by whole genome single nucleotide polymorphism （wg-SNPs） and multi-site sequence typing （MLST） analysis， the virulence and resistance genes carried by the strains were identified in the online database， and the antibiotic resistance was performed by microbroth dilution.ResultsAmong the 12 strains of Vibrio parahaemolyticus， 3 strains were isolated from patients and 9 strains were isolated from food samples. The difference of wg-SNPs of 3 strains from patients and 2 strains from food samples were 0~2 bp， both of which belonged to ST3 type and were judged to be the same clone. The difference of wg-SNPs between the remaining 7 strains from the food samples and the isolates from patients were 11 341~37 173 bp， which was judged to be different clones. Both the patients and the food-isolated Vibrio parahaemolyticus belonged to type ST3 carried the exotoxin genes tdh and tlh， while the remaining strains carried only tlh. All Vibrio parahaemolyticus strains isolated in this event carried durg resistance gene blaCARB and had a high rate of resistance to cefazoline.ConclusionThrough whole genome sequencing analysis， the incident was caused by ST3 Vibrio parahaemolyticus carrying the tdh virulence gene and resistant to cefazoline， which showed promising application prospects of whole genome sequencing technology in rapid source tracing of poisoning events， and provided a basis for the selection of antibiotics in clinical treatment.

Keywords

• vibrio parahaemolyticus
• food poisoning
• whole genome sequencing
• antibiotic resistance
• foodborne pathogens
• virulence genes