胸膜肺炎放线杆菌对四环素类抗生素的耐药分析及相关基因检测

四环素类药物是在兽医临床中常用的一类抗生素,为了解胸膜肺炎放线杆菌(Actinobacillus pleuropneumoniae,APP)对四环素类抗生素的耐药情况,本研究对从临床分离鉴定的85株APP进行了四环素类抗生素临床耐药情况和相关基因的分析和检测。应用药敏纸片法进行药敏试验,结果:APP对四环素的耐药率较高为76.5%,其次为金霉素54.1%、美他环素48.2%、多西环素45.9%、土霉素28.2%、米诺霉素25.9%、替加环素22.3%。采用PCR方法对四环素类10种耐药基因tetA、tetB、tetC、tetD、tetE、tetG、tetH、tet1、tetL1和tetL2进行检测,结果:tetA、tetB、tetC、tetD、tetE、tetG、tetH、tet1、tetL2、tetL1耐药基因的扩增阳性率分别为78.8%、41.2%、15.3%、8.2%、21.2%、15.3%、43.5%、24.7%和30.6%,而tetL1扩增则全部阴性,未检出其耐药基因。本研究结果为四环素类抗生素在猪传染性胸膜肺炎临床上的应用和新药研发提供了一定的理论依据。

Analyses of tetracycline resistance and associated genes in Actinobacillus pleuropneumoniae

Tetracycline antibiotics are commonly used in veterinary clinic.In order to understand the drug-resistant status of Actinobacillus pleuropneumoniae(APP)to tetracycline antibiotics,85 APP strains isolated and identified from clinical cases were analyzed and tested in this study.First,drug resistance phenotype identification was conducted using the drug sensitive paper method,the drug resistance rate of APP to tetracycline was 76.5%,followed by 54.1%aureomycin,48.2%methacycline,45.9%doxycycline,28.2%oxytetracycline,25.9%minoramycin and 22.3%tetracycline.PCR was used to detect ten antibiotic resistance genes of tetracycline,including tetA,tetB,tetC,tetD,tetE,tetG,tetH,tet1,tetL1 and tetL2.The results were that tetA,tetB,tetC,tetD,tetE,tetG,tetH,tet1,tetL2 and tetL1 showed positive amplification rates of resistance genes which were 78.8%,41.2%,15.3%,8.2%,21.2%,15.3%,43.5%,24.7%and 30.6%,respectively,while tetL1 amplification was all negative and no resistance genes were detected.The results of this study provided a theoretical basis for clinical application of tetracycline antibiotics to Actinobacillus pleuropneumoniae and for development of new drugs.