温州市食源性弯曲菌耐药特征与分子分型研究

目的了解温州市弯曲菌引起腹泻的流行病学特点,掌握弯曲菌的耐药状况、分子型别特征。方法在2017至2019年间对2家温州市区哨点医院的腹泻病例进行流行病学调查,并采集粪便标本进行弯曲菌的分离培养和常规生化鉴定,采用聚合酶链反应(Polymerase Chain Reaction,PCR)进一步鉴定,同时进行药敏试验、多位点序列分型(Multilocus-sequence typing,MLST)研究。结果909例腹泻病例弯曲菌检出率为10.2%(93/909),空肠弯曲菌和结肠弯曲菌阳性率分别为8.9%(81/909)和1.3%(12/909)。6个年龄组间及不同季节的弯曲菌阳性率差异无统计学意义(χ^2年龄=2.09,P>0.05;χ^2季节=0.468,P>0.05)。93株弯曲菌对11种抗菌药物共产生了22种耐药谱,耐萘啶酸(Nalidixic acid,NAL)-环丙沙星(Ciprofloxacin,CIP)-四环素(Tetracycline,TET)谱型最多,占38.7%(36/93)。空肠弯曲菌和结肠弯曲菌多重耐药率(耐3种以上抗生素)分别为42.0%(34/81)、50.0%(6/12)。MLST分型结果显示本地分离株中,空肠弯曲菌被分成54种ST型,含15个克隆群,最多的克隆群为ST45CC,占11.1%(9/81),结肠弯曲菌分为8种ST型,主要的克隆群为ST828CC,占83.3%(10/12)。本研究共发现16个新的ST型。结论温州市食源性腹泻病例中弯曲菌已成为主要病原,且呈现很高的多重耐药性,在遗传特征上表现为遗传多样性。

Research on distribution,drug resistance and molecular typing of foodborne Campylobacter in Wenzhou

To clarify epidemiological characteristics of diarrhea caused by Campylobacter drug-resistant condition, and molecular typing characteristics of Campylobacter in Wenzhou. Epidemiological survey was conducted in two sentinel hospitals in Wenzhou from 2017 to 2019. Stool specimens from these two hospitals were collected to isolate and culture Campylobacter. Then, conventional biochemical identification and Polymerase Chain Reaction(PCR) were used to identify the strains. At the same time, susceptibility testing and Multilocus-sequence typing(MLST) were used to investigate the strains.The detection rate of Campylobacter in 909 cases of diarrhea was 10.2%(93/909), while the positive rates of Campylobacter jejuni was 8.9%(81/909), and the positive rates of C. colon was 1.3%(12/909). There was no significant difference in Campylobacter positive rate among six age groups or different seasons (χage2=2.09,P>0.05;χsesson2=0.468,P>0.05). 22 kinds of drug resistance spectra were generated by 93 strains of Campylobacter against 11 antibacterial types, among which the majority type of spectra was Naproxinic acid (NAL)-Ciprofloxacin (CIP)-Tetracycline (TET),accounting for 38.7%(36/93). In additional, the Multiple drug resistance(MDR) rates(more than 3 kinds of antibiotics) of C. jejuni was 42.0%(34/81), and which of C. colon was 50.0% (6/12). Of all the local isolates, C. jejuni was divided into 54 sequence types(STs), containing 15 clonal complexes(CCs), and the main CC was ST45(11.1%,9/81). Meanwhile, Campylobacter colon was divided into 8 STs, and the main CC was ST828(83.3%,10/12). Totally 16 new STs were found in this study. In conclusion, Campylobacter has been the main pathogen in cases of foodborne diarrhea in Wenzhou,and showed high MDR and genetic diversity.