2014-2015年烟台市副溶血性弧菌临床分离菌株的生物学特征及分子分型研究

目的 了解烟台市副溶血性弧菌临床分离株的耐药特性、毒力基因分布情况以及分子分型特征。方法 对2014-2015年的副溶血性弧菌临床分离菌株按照美国临床实验室标准化协会(CLSI)推荐的微量肉汤稀释法进行14种抗生素的药敏试验;通过实时荧光PCR检测tlh、trh、tdh、orf8 4种毒力基因;采用脉冲场凝胶电泳对菌株基因组DNA进行分子分型。结果 (1)20株副溶血性弧菌仅对头孢唑啉耐药或处于耐受敏感之间,耐药率为5.0%,对其他13种抗生素100.0%敏感。(2)20株副溶血性弧菌均携带特异性基因tlh,其他3种毒力基因trh、tdh、orf8的阳性率分别为30.0%(6/20)、100.0%(20/20)、65.0%(13/20),毒力基因组成以orf8-tdh型为主,占60.0%(12/20)。(3)20株菌被限制性内切酶NotⅠ切出6个PFGE types(PT),带型相似度60.7%～100.0%,根据PT相似系数大于80.0%的菌株,可以分成A群和B群2个聚类群。结论 烟台市副溶血性弧菌临床分离菌株耐药较轻,毒力基因tdh、orf8的携带率较高,PFGE带型聚类群内相似度较高且存在优势明显的分子型别。

Biological characteristics and molecular typing of clinical isolates of Vibrio parahaemolyticus in Yantai,2014-2015

Objective To investigate the drug resistance,virulence gene distribution and molecular typing of Vibrio parahaemolyticus isolates in Yantai. Methods Strains of Vibrio parahaemolyticus isolated by the broth microdilution method recommended by the Clinical and Laboratory Standards Institute (CLSI) from 2014 to 2015 were tested for antibiotic susceptibility with 14 antibiotics.Four virulence genes of tlh,trh,tdh and orf8 were detected by real-time fluorescence PCR.Pulsed field gel electrophoresis was used for the genomic DNA typing. Results 20 strains of Vibrio parahaemolyticus were only resistant to cefazolin or sensitive to tolerance with a drug resistance rate of 5.0% but were totally sensitive to the other 13 antibiotics.20 strains of Vibrio parahaemolyticus carried the specific gene that,and the positive rates of the other three kinds of virulence genes were 30.0% (6/20),100.0% (20/20),65.0% (13/20),respectively.The main virulence gene was orf8-tdh type,accounting for 60.0% (12/20).20 strains were cut out 6 PFGE types (PT) by restriction enzyme Not I,and the band type similarity was 60.7%-100.0%.The strains with PT similarity coefficient greater than 80.0% could be divided into A group and B group. Conclusion The clinical isolates of Vibrio parahaemolyticus in Yantai were light resistant,and the carrying rates of virulence genes tdh and orf8 were high.The similarity in PFGE band cluster group was high and there were obvious molecular types with obvious advantages.