To study the biological characteristics of, antibiotic resistance in and germicidal efficacy at different temperatures against Vibrio parahaemolyticus (V.parahaemolyticus) strains isolated from different sources in order to provide reference for clinical treatment and prevention.

Stool samples from patients with diarrhea and small seafood product specimens from markets were collected and analyzed with biochemical identification method, serotyping analysis, drug susceptibility test and germicidal efficacy test at different temperatures.

There were 107 V. parahaemolyticus strains isolated from 1 166 stool samples of patients with foodborne diarrhea with a positive rate of 9.18% and 42 from 72 seafood product samples with a positive rate of 58.30%. V. parahaemolyticus strains isolated from the foodborne diarrhea cases were divided into eight serogroups and among them, O3 and O4 were the predominant serogroups, accounting for 49.53% and 34.58%, respectively. Most of the O antigens in small seafood products belonged to serogroups of O4, O1 and O3, and four strains of O3∶K6 were isolated. Results of the drug susceptibility test showed that both of the clinical isolates and marine product isolates were highly resistant to ampicillin and the drug resistance rates were 94.39% and 88.10%, respectively. Antibiotic-sensitive strains to monocyclic β-lactams, aminoglycosides, quinolones, carbapenems, tetracyclines and sulfonamides accounted for over 90.00% or even nearly 100.00%. There were 17 (15.89%) clinical strains and three (7.14%) marine product isolates resistant to three or more kinds of antibiotics. At 80℃, the bactericidal rate for marine product isolates was 85.71% in 60 s and reached 100.00% in 90 s. At 90℃ and 100℃, these isolates could be completely killed in 40 s and 30 s. It took 120 s, 90 s and 50 s to kill clinical isolates at 80℃, 90℃ and 100℃, respectively.

This study systematically analyzed and compared the drug-resistant phenotypes of and the bactericidal efficacy at different temperatures on V. parahaemolyticus strains isolated from clinical samples and marine products. It would provide reference for preventing and controlling the spread of V. parahaemolyticus and hospital infection and for studying treatment strategies.

Vibrio parahaemolyticus; Antibiotic susceptibility; Germicidal efficacy; Temperature