苏州市空肠弯曲菌耐药与分子特征分析

Analysis of drug resistance and molecular characteristics of Campylobacter jejuni in Suzhou City

目的了解苏州市空肠弯曲菌的耐药情况和分子特征。方法对2018年-2022年苏州市分离的空肠弯曲菌进行全基因组测序分析了解毒力基因、耐药基因、多位点序列分型(Multi-locus sequence typing,MLST)等分子特征,通过琼脂稀释法了解其耐药表型。结果61株空肠弯曲菌被分为42个ST型别,以ST464占比最高(9.8%),包含12个CC群,以CC21占比最高(19.7%)。61株菌共检出18种耐药基因,97种毒力基因。药敏试验耐药率排前3位的抗生素分别是萘啶酸,四环素和环丙沙星,耐药率分别为90.2%,88.5%和73.8%,对红霉素100.0%敏感,多重耐药率达到41.0%。结论苏州市空肠弯曲菌多重耐药率高,携带耐药基因和毒力基因较多,克隆群以CC21为主,但ST型别较为分散,呈现较高的遗传多样性。

The purpose of this study was to understand the drug resistance and molecular characteristics of Campylobacter jejuni in Suzhou City.We conducted whole genome sequencing to investigate molecular characteristics,such as virulence genes,drug resistance genes and multi-locus sequence typing(MLST)of Campylobacter jejuni strains isolated from Suzhou from 2018 to 2022.Antibiotic susceptibility testing was performed with the agar dilution method.A total of 61 Campylobacter jejuni strains were divided into 42 ST types,among which ST464 accounted for the highest proportion(9.8%).Of the 12 clonal complexes(CCs),CC21 accounted for the highest proportion(19.7%).A total of 18 drug resistance genes and 97 virulence genes were detected in the 61 strains.The top three antibiotics in drug susceptibility testing were nalidixic acid,tetracycline and ciprofloxacin,with resistance rates of 90.2%,88.5%and 73.8%,respectively.The resistance rate to erythromycin was lowest,with 100.0%sensitivity.The multi-drug resistance rates of these bacteria reached 41.0%.The most common multi-drug resistance patterns were tetracyclines+quinolones and fluoroquinolones+chloramphenicol,accounting for 44.0%of multi-drug resistance.The multi-drug resistance rate of Campylobacter jejuni in Suzhou is high,and the strains carry many drug resistance genes and virulence genes.CC21 was the dominant clonal complex,but the ST types varied and showed high genetic diversity.