江苏地区空肠弯曲菌多位点序列分型和毒力基因分析

Virulence genes analysis and MLST typing of Campylobacter jejuni in Jiangsu

目的了解江苏地区空肠弯曲菌分离株的病原学特征。方法用PCR方法扩增6个毒力基因(cadF、virB11、cdtB、csrA、ggt和cst-Ⅱ)和MLST的7个管家基因并测序,通过PubMLST数据库比对获得菌株ST型,用E-test法测定细菌的耐药表型。结果在31株空肠弯曲菌分离株中,cdtB、cadF和csrA基因的携带率均为100.0%;cst-Ⅱ为48.4%;ggt为3.2%;未检出virB11基因。31株菌可分为21个ST型,其中10个为首次发现。31株菌对环丙沙星、四环素和红霉素的耐药率分别为64.5%、51.6%和6.5%,未发现对庆大霉素耐药的菌株。结论江苏地区分离的空肠弯曲菌菌株的ST型呈多样性,人和鸡分离株中的优势毒力基因谱分布相似,对红霉素较敏感,而对喹诺酮类药物具有较高的耐药性。

Objective To understand the etiological characteristic of Carnpylobacterjejuni（ C. jejuni） in Jiangsu. Methods PCR is used to amplify and sequence 6 virulence genes （cadF, vlrB11, cdtB, csrA, ggt, cst - II ） and 7 housekeeping genes. STs strains are compared with the obtained sequences with pubmlst database. Antibiotic susceptibility profile was investigated using E - test method. Results The cdtB, cadF and csrA genes were detected in 100.0% of 31 C. jejuni isolates. The cst - II and ggt genes were found in 48.4% and 3.2% of the isolates, respectively. All isolates were negative for virBll gene. A total of 21 sequence types （STs） were observed in the 31 isolates, and 10 of these STs were first described in this study. Resistance rates to ciprofloxacin, tetracycline and erythromycin were 64.5 % , 51.6% and 6.5 % of the isolates, whereas gentamicin resistance was not found in any isolate. Conclusion Our results suggest that C. jejuni population in Jiangsu showed diverse genetic nature, higher resistance to fluoroquinolones, more sensitive to erythromycin. The distribution of advantage virulence genes from human and chicken are similar.