摘要
采用K-B纸片法对224株大肠杆菌进行5种氨基糖苷类药物的药敏试验,采用微量肉汤稀释法进行庆大霉素和阿米卡星最低抑菌浓度(MIC)的测定,三重PCR法检测全部菌株氨基糖苷类钝化酶基因ant(3’’)-Ia、aac(6’)-Ib和aph(3’)-Ⅱa,普通PCR法检测16S甲基化酶基因。结果显示:山东省禽源大肠杆菌对链霉素、庆大霉素、卡那霉素、新霉素和阿米卡星的耐药率分别为84.4%、57.1%、55.8%、46.9%和40.2%;3种钝化酶基因ant(3’’)-Ia、aac(6’)和Ib、aph(3’)-Ⅱa的检出率依次为49.6%、25.0%和22.8%,介导高水平耐药的16S甲基化酶基因RmtB的检出率为11.6%(26/224),只有1株大肠杆菌检测到armA基因,没有检测到rmtA,且3种甲基化酶基因在低度耐药菌中检出率均为0;所检大肠杆菌中携带2种及2种以上耐药基因的菌株占33.5%(75/224),有1株大肠杆菌同时携带4种耐药基因。结果表明,氨基糖苷类钝化酶及16S甲基化酶广泛存在于禽源大肠杆菌菌中,其耐药性与相关耐药基因的检出率基本呈正相关,部分菌株的耐药性与耐药基因的检出率不一致,表明还存在其他耐药机制。
In order to study the prevalent of aminoglycoside modifying enzymes and 16S rRNA methylases among avian Escherichia coli Strains from Shandong province,a total of 224 strains were tested by K-B（Kirby-Bauer） method to analyze the aminoglycoside susceptibility,by micro-dilution method to evaluate the MICs to gentamicin and amikacin and by PCR to examine the modifying enzyme genes and the 16S rRNA methylase genes which mediated high level resistance to aminoglycosides.The results indicated that the resistant incidence rates were exhibited to streptomycin（84.4%）,gentamicin（57.1%）,kanamycin（55.8%）,neomycin（46.9%） and amikacin（40.2%）;the present ratio of ant（3＇＇）-Ia,aac（6＇）-Ib and aph（3＇）-Ⅱa were 49.6%,25.0% and 22.8% respectively.All of the three genes of 16S rRNA methylase were negative in low-level resistance,and RmtB was the high rate gene of 16S rRNA methylase with 53.1% positive rate among 49 strains of high level resistance to aminoglycosides.Seventy-five strains were detected with at least two genes and only one strain with four genes at the same time.The results revealed that the aminoglycoside modifying enzymes and 16S rRNA methylases were prevalent in avian Escherichia coli strains,and there were the highest coincidence between the resistance to aminoglycoside and the detection rate of the resistance genes.
出处
《中国兽医学报》
CAS
CSCD
北大核心
2011年第9期1279-1282,共4页
Chinese Journal of Veterinary Science
基金
山东省自然科学基金资助项目(Q2006D04)
山东省高等学校科技计划资助项目(J08LF07)
关键词
大肠杆菌
氨基糖苷类钝化酶
16S甲基化酶
耐药性
Escherichia coli
aminoglycoside modifying enzymes
16S rRNA methylases
resistance
