Characteristics of and germicidal efficacy at different temperatures against Vibrio parahaemolyticus / 中华微生物学和免疫学杂志

ABSTRACT

Objective To study the biological characteristics of, antibiotic resistance in and ger-micidal efficacy at different temperatures against Vibrio parahaemolyticus ( V. parahaemolyticus) strains isola-ted from different sources in order to provide reference for clinical treatment and prevention. Methods Stool samples from patients with diarrhea and small seafood product specimens from markets were collected and an-alyzed with biochemical identification method, serotyping analysis, drug susceptibility test and germicidal ef-ficacy test at different temperatures. Results There were 107 V. parahaemolyticus strains isolated from 1166 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 diar-rhea 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 be-longed to serogroups of O4, O1 and O3, and four strains of O3 K6 were isolated. Results of the drug sus-ceptibility 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 monocyclicβ-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. Conclusions 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 con-trolling the spread of V. parahaemolyticus and hospital infection and for studying treatment strategies.