2017-2019年北京市人源性副溶血性弧菌病原学特征分析

Pathogenic characteristics of Vibrio parahaemolyticus isolated from diarrhea patients in Beijing,2017-2019

目的分析2017-2019年北京市引起腹泻的副溶血性弧菌血清分型、毒力基因携带情况以及抗菌药物敏感性。方法对北京市2017-2019年肠道门诊监测中分离到的295株副溶血性弧菌进行血清学分型试验,应用实时荧光PCR方法检测不耐热溶血毒素基因(tlh)、耐热直接溶血毒素基因(tdh)和耐热相关溶血毒素基因(trh),用微量肉汤稀释法进行26种抗菌药物最低抑菌浓度(MIC)测定。结果295株副溶血性弧菌有8个O群和19个K型,共28种血清型,以O3∶K6血清型为主,占63.4%(187/295),其次为O4∶KUT,占11.2%(33/295)。295株副溶血性弧菌tlh、tdh和trh基因阳性率分别为100.0%(295/295),91.9%(271/295)和2.4%(7/295)。3种毒力基因检测结果可以分成4种类型,tlh^(+)tdh^(+)trh^(-)为优势基因型,占90.5%(267/295)。药敏试验结果显示,295株分离菌株对阿奇霉素、环丙沙星、左氧氟沙星、氯霉素、阿莫西林-克拉维酸、米诺环素、亚胺培南、美罗培南和头孢噻肟100%敏感,对头孢唑林、链霉素和氨苄西林耐药率较高,分别为61.4%(181/295)、14.2%(42/295)和7.1%(21/295)。有12株菌出现多重耐药现象,占4.1%(12/295)。结论2017-2019年北京市引起腹泻的副溶血性弧菌有多种血清型,其中以O3∶K6为优势血清型。多数菌株为携带tlh和tdh基因的产毒株。菌株对多数抗菌药物比较敏感,但仍存在多重耐药现象。

Objective To analyze the serotypes,virulence genes and antimicrobial resistance of Vibrio parahaemolyticus causing diarrhea in Beijing during 2017-2019.Methods 295 Vibrio parahaemolyticus strains isolated from diarrhea patients were collected to serotype and antimicrobial resistance test by minimal inhibit concentration(MIC)method.Real-time PCR was used to detect the existence of three virulence genes tlh(thermolabile hemolysin gene),tdh(thermostable direct hemolysin gene)and trh(TDH-related hemolysin gene).Results 295 Vibrio parahaemolyticus strains were classified by 8 O serogroups and 19 K types,a total of 28 serotypes,among which O3∶K6(63.4%,187/295)and O4∶KUT(11.2%,33/295)were the dominant serotypes.The positive rate of tlh,tdh and trh was 100.0%(295/295),91.9%(271/295)and 2.4%(7/295),respectively.Results from virulence genes detection suggested that they could be divided into four genotypes,and the dominant one is tlh^(+)tdh^(+)trh^(-),accounting for 90.5%(267/295).Antimicrobial resistance test showed that all of Vibrio parahaemolyticus strains were 100%sensitive to azithromycin,ciprofloxacin,levofloxacin,chloramphenicol,amoxicillin-clavulanic acid,minocycline,imiperem,meropenem and cefotaxime,but high resistance to cefazolin(61.4%,181/295),streptomycin(14.2%,42/295)and ampicillin(7.1%,21/295).12 strains(4.1%,12/295)showed multi-drug resistance.Conclusions There are many different serotypes of Vibrio parahaemolyticus strains causing diarrhea in Beijing during 2017-2019,with the dominant serotype of O3∶K6.Most strains are toxigenic strains carrying tlh and tdh.These strains show high sensitivity to most antibiotics,but multi-drug resistance still exists.