广东水禽源大肠埃希菌耐药性及氨基糖苷类耐药基因研究

Investigation on Aminoglycosides Antibiotics Resistance and Resistance Genes of Escherichia coli Isolated from Waterfowl in Guangdong Province

为了调查广东地区水禽源大肠埃希菌对氨基糖苷类药物耐药现状和耐药基因的流行情况,探索大肠埃希菌的氨基糖苷类耐药基因型与耐药表型之间的关系,本研究采用琼脂梯度稀释法测定251株广东地区水禽源大肠埃希菌对氨基糖苷类药物的耐药性和采用PCR方法检测耐药基因。药敏试验结果显示,大肠埃希菌对链霉素耐药较严重,鸭源和鹅源的耐药率分别为81.58%和75.43%,对庆大霉素和卡那霉素较敏感,耐药率分别为25%和54.86%,对阿米卡星最为敏感,其中鸭源的菌株耐药率仅为1.32%。PCR方法检测显示,aadA1和aph(3′)-1检出率较高,为84.6%和91.9%,表明携带aadA1和aph(3′)-1耐药基因的水禽源大肠埃希菌在广东地区呈流行趋势。耐药基因型与耐药表型相关性分析结果显示,耐药基因rmtB的携带与4种药物(庆大霉素、阿米卡星、卡那霉素和壮观霉素)耐药株的产生具有显著相关性,表明耐药基因rmtB对大肠埃希菌耐药株的产生起重要的作用。本试验结果可为指导广东地区水禽大肠埃希菌病的临床用药提供理论基础和研究大肠埃希菌的耐药基因提供相关的数据。

In order to understand the resistance to aminoglycosides antibiotics and the prevalence of aminoglycosides resistance genes from waterfowl in Guangdong province,explore the relationship between antibiotic resistance genes and phenotypes of antimicrobial resistance,antimicrobial susceptibilities of total 251 E. coli isolates to aminoglycosides antimicrobial agents were determined by agar dilution methods and the aminoglycosides resistance genes were detected by PCR. The results of drug sensitivity tests showed that the resistant incidence rates of ducks and geese were exhibited to streptomycin （81.58% and 75.43%）, gentamicin （25% and 38.86%）,spectinomycin （21.05% and 74.29%）,kanamycin （38.16% and 54.86%） and amikacin （1.32% and 30.28%）. The occurrences of aadA1 and aph（3＇）-1 genes were ranked the higher （84.6%-91.9%）. It indicated that the antimicrobial resistance genetypes of aadA1 and aph（3＇）-1 were detected frequently among commensal E. coli from waterfowl in Guangdong province. Analysis of resistance genetypes and drug resistance phenotype correlations showed that rmtB gene had significant correlation on the resistance of E. coli to gentamiein,amikacin, kanamycin and spectinomycin,which indicated rmtB gene played an important role in the resistant strains of E. coli. This research played a significant role in prevention of colibacillosis, and provided relevant data for the resistance genes of E. coli.