湖州地区食源性腹泻患者副溶血性弧菌病原学特征分析

Etiological analysis of characteristics of Vibrio parahaemolyticus in food borne diarrhea patients in Huzhou,Zhejiang

目的了解湖州地区急性腹泻患者副溶血性弧菌感染发生的季节分布、可疑中毒食品范围、耐药状况、优势血清型及毒力基因等特征,揭示其流行与发展趋势的规律。方法对2014年-2016年肠道门诊急性腹泻患者粪便分离的125株副溶血性弧菌进行药敏试验、血清分型以及PCR方法检测耐热直接溶血素基因tdh、耐热直接溶血素相关基因trh。结果副溶血性弧菌感染发生呈现时间季节聚集趋势,以6月-10月为高峰期。药敏结果显示对氨苄西林及头孢一代耐药率达100.0%,头孢二代敏感率达25.0%,其他常用抗菌药物敏感率为100.0%。17个血清型中O3∶K6最多,占59.2%(74/125),其次是O4∶K8,占10.4%(13/125)。毒力基因PCR检测显示88.0%(110/125)的分离株为tdh^+/trh^-,6.40%(8/125)的分离株为tdh^-/trh^-,2株携带tdh^+/trh^+。结论湖州地区副溶血性弧菌感染发生呈明显的时间季节特征,可疑中毒食品涉及范围广,优势血清型为O3∶K6,其次是O4∶K8。菌株对多数抗菌药物高度敏感,多数菌株携带tdh^+/trh^-。

Objective To investigate the seasonal distribution, suspected toxic food, antimicrobial resistance, superior serotype and virulence genes of Vibrio parahaemolyticus （ V. p） infection in Huzhou area, so as to reveal the epidemic and development trend. Methods 125 Vibrio parahaemolyticus strains isolated from acute diarrhea patients＇ fecal during 2014 - 2016 were con- ducted for the serotyping and antibiotic resistance test, while the virulence genes tdh and trh were detected with PCR. Results The epidemiological evidence of Vibrio parahaemolyticus infection showed seasonal aggregation trend, with the peak in June - October. The antimicrobial susceptibility test indicated that the antibiotic resistanee rate of ampicillin and the first gener- ation cephalosporins was 100.0% , the second generation cephalosporins was not sensitive to 25.0% , and the sensitivity of other commonly used antimicrobial agents was 100.0%. Among the 17 serotypes, 03 ： K6 accounted for 59.2% （74/125） , followed by 04 ： K8, 10.4% （13/125）. 88.0% （110/125） of strains from patients were tdh^＋/trh^-, 6.40% （ 8/125 ） were tdh /trh^- , and 2 were tdh ＋/trh ＋. Conclusion Vibrio parahaemolyticus infection in Huzhou area showed obviously seasonal characteristics. The suspicious poisonous food covered a wide range of products. The dominant serotype was 03 ： K6, followed by 04 ： KS. Vibrio parahaemolyticus strains are highly sensitive to most antimicrobial agents, and most virulence gene was tdh^＋/trh^-.