7株伦敦沙门菌药敏检测和分子分型分析

Drug resistance and molecular typing of 7 strains of Salmonella London

目的对7株疑似伦敦沙门菌进行病原学诊断、药物敏感性和PFGE分子分型检测,为贵州省伦敦沙门菌的病原学诊断和防控提供科学依据。方法对来自贵州省的7株疑似伦敦沙门菌进行分离培养和传统生化鉴定,对明确为沙门菌的菌株进行诊断血清分型,微量肉汤稀释法测定16种药物最小抑菌浓度,脉冲场凝胶电泳(Pulsed Field Gel Electrophoresis,PFGE)进行分子分型检测。结果 7株疑似伦敦沙门菌经系统生化鉴定为沙门菌,进一步诊断血清凝集明确为伦敦沙门菌;全部菌株对链霉素(Streptomycin,STR)耐药,对阿莫西林/克拉维酸(Amoxicillin/clavulanic acid,AMC)、头孢曲松(Ceftriaxone,CRO)、头孢吡肟(Cefepime,FEP)、萘啶酸(Nalidixic acid,NAL)、亚胺培南(Imipenem,IPM)敏感,对氨苄西林(Ampicillin,AMP)、庆大霉素(Gentamicin,GEN)、磺胺异噁唑(Sulfamethoxazole,SOX)、复方新诺明(Trimethoprim/sulfamethoxazole,SXT)、阿奇霉素(Azithromycin,AZM)和多西环素(Doxycycline,DOX)的耐药率均为85. 7%,多种药物MIC50和MIC90均为所测量范围的上限,85. 7%的菌株存在耐多药的情况,57. 1%的菌株耐药谱AMP+STR+SOX+TCY+CIP+SXT+DOX+GEN+AZM; 7株伦敦沙门菌经XbalⅠ酶切后分成3种PFGE型,5株菌株PFGE带型相似性为100%,其中4株菌株的PFGE带型和耐药谱一致。结论贵州省伦敦沙门菌多重耐药情况严重,耐药表型与PFGE分型具有相关性,应加强对沙门菌的耐药和分子分型监测。

Objective To diagnose the etiology of the suspected Salmonella London strains and detect the drug resistance and PFGE types of Salmonella London in order to provide scentific basis for the etiological diagnoses,prevention and control of Salmonella London in Guizhou Province.Methods Seven suspected Salmonella London from Guizhou Province were isolated and identified by conventional techniques.Serotypes of strains confirmed to be Salmonella were diagnosed.Micro-dilution method was used to detect the minimum inhibitory concentration of 16 drugs.PFGE method was used to detect the molecular type.Results Seven strains of suspected Salmonella London typhimurium were biochemically identified as Salmonella.All strains were resistant to STR but sensitive to AMC,CRO,FEP,IPM and NAL.The sensitive rates of AMP,GEN,SOX,SXT,AZM and DOX were 85.7%.The MIC50 and MIC90 of many drugs were up to the upper limit.A total of 85.7%of the strains were muti-drug resistant.The most prevalent spectrum of drug resistant was AMP+STR+SOX+TCY+CIP+SXT+DOX+GEN+AZM,accouting for 57.1%.Seven strains of Salmonella London were divided into 3 PFGE types.The similarity of PFGE type of five strains of Samonella London was 100%,and the PFGE types of 4 strains were relevant with the resistant spectrumn.Conclusion The muti-drug resistant of Salmonella London was serious in Guizhou Province,and the resistant spectrumn was in accord with PFGE types.The resistance and molecular typing of Salmonella should be strengthened.