副溶血弧菌养殖对虾分离株耐药性及耐药基因分析

文章采用琼脂稀释法检测从养殖患病对虾中分离的36株副溶血弧菌(Vibrio parahaemolyticus)对16种药物的耐药性,并用PCR法检测喹诺酮类耐药基因qnrA、qnrB、qnrS和qnrVC,酰胺醇类耐药基因cat、optrA、floR和cfr,四环霉素类耐药基因tetA、tetB和tetM,磺胺类耐药基因sul1、sul2和sul3,氨基糖苷类耐药基因strA、strB、aadA和aacA,利福霉素类耐药基因arr,β-内酰胺类耐药基因bla CARB和大环内酯类耐药基因erm的携带状况,分析其耐药表型和基因型之间的相关性。结果显示,36株副溶血弧菌对β-内酰胺类药物氨苄西林耐药率最高(88.9%),其次为磺胺类药物磺胺甲噁唑(66.7%),硫酸新霉素、庆大霉素、头孢曲松和美罗培南呈现100%敏感。多重耐药副溶血弧菌比例高达61.1%(22/36),其中1株对6类抗菌药耐药。喹诺酮类耐药基因qnrVC检出率最高达72.2%(26/36);其次为氨基糖苷类耐药基因srtB,检出率58.3%(21/36);大环内酯类、利福霉素类耐药基因均未检测到。耐药基因检出率与耐药表型没有表现出一一对应的关系,提示副溶血弧菌耐药的复杂性。

Detection of antibiotics resistance and distribution of resistance genes in Vibrio parahaemolyticus from cultured shrimp

We used agar dilution method to detect the resistance of 36 strains of Vibrio parahaemolyticus to 16 drugs. And used PCR amplication and DNA sequencing to detect the antimicrobial resistance to quinolones(qnrA, qnrB, qnrS, qnrVC), phenicols(cat, optrA, floR, cfr), tetracyclines(tetA, tetB, tetM), sulfonamides(sul1, sul2, sul3), aminoglycosides(strA, strB, aadA, aacA), rifampicin(arr), β-lactams(carB) and macrolides(erm). The results indicate that the isolates exhibited high resistance to ampicillin(88.9%) and sulfamethoxazole(SMZ, 66.7%), all susceptible to neomycin sulfate, gentamicin, ceftriaxone and meropenem. In general, multi-drug resistance(MDR) was highly prevalent(61.1%), and one isolate was resistant to six antimicrobials. Furthermore,72.2% and 58.3% of the isolates were primarily mediated by qnrVC and strB, respectively;and the macrolides and rifamycin resistant genes were not detected in all the isolates. Obvious mismatch was found between the antimicrobial resistance phenotypes and genotypes, revealing the complexity of resistance to V. parahaemolyticus.