儿科临床分离株中质粒介导喹诺酮类药物耐药基因qnr在产ESBLs或AmpC酶大肠埃希菌和肺炎克雷伯菌中的流行  

The prevalence of qnr-positive clinical isolates in Escherichia coli and Klebsiella pneumoniae producing ESBLs or AmpC-type β-lactamase from five pediatric hospitals in China

作　　者：韩晨曦[1] 王爱华[1] 杨永弘[1] 陆权 王艺[3] 陈沅[4] 邓力[5] 邓秋莲[5] 张泓 王传清[3] 刘岚[4] 徐樨巍[1] 沈叙庄[1] 

机构地区：[1]首都医科大学附属北京儿童医院儿科研究所,北京100045 [2]上海交通大学附属儿童医院 [3]复旦大学附属儿科医院 [4]重庆医科大学附属儿童医院 [5]广州市儿童医院

出　　处：《中国感染与化疗杂志》2009年第6期430-435,共6页Chinese Journal of Infection and Chemotherapy

基　　金：国家科技部十五攻关课题基金资助(2004BA720A09-01)

摘　　要：目的了解质粒介导喹诺酮类药物耐药基因qnr在儿科临床分离产ESBLs或AmpC酶大肠埃希菌和肺炎克雷伯菌中的流行情况与分布特点。方法琼脂稀释法测定抗生素MIC;PCR检测喹诺酮类药物耐药基因qnrA、qnrB和qnrS及相应ESBLs和AmpC酶基因;接合试验检测qnr基因是否可通过质粒转移;肠杆菌基因间重复一致序列-聚合酶链反应(ERIC-PCR)检测qnr阳性菌株的同源性。结果702株儿科临床分离产ESBLs或AmpC酶大肠埃希菌和肺炎克雷伯菌共检出含qnr基因菌株99株(14.1%),其中qnrA、qnrB和qnrS的检出率分别为1.1%(8株)、4.0%(28株)和9.5%(67株),其中3株菌同时含有qnrA和qnrB,1株含qnrB和qnrS。在99株qnr阳性菌株中,有88株(88.9%)检测到至少1种bla基因。20株qnr阳性菌株通过接合试验传递成功。相对于受体菌,接合子对环丙沙星的MIC提高了2～125倍。ERIC-PCR显示99株qnr阳性菌株有不同的DNA条带,提示其可能属于不同的克隆株。结论在702株儿科临床分离产ESBLs或AmpC酶大肠埃希菌和肺炎克雷伯菌中,质粒介导喹诺酮类药物耐药基因qnr携带率为(14.1%),qnrS为最流行的亚型。88.9%的qnr阳性株携带1种或1种以上bla基因。Objective To investigate the prevalence of the plasmid-mediated quinolone resistance genes qnrA, qnrB, and qnrS a- mong clinical isolates of Escherichia coli and Klebsiella pneumoniae producing ESBLs or AmpC β-1actamase. Methods A total of 702 non-duplicate clinical isolates of E. coli and K. pneumoniae phenotypic positive for ESBLs or AmpC β- lactamases were collected from five childrenrs hospitals in China. Isolates were screened for qnrA, qnrB, and qnrS genes by PCR. Transferability was examined by conjugation with the sodium azide-resistant E. coli J53. All qnr-positive isolates were analyzed by ERIC-PCR for DNA-relatedness. Results Totally 99 isolates （14. 1%） were positive for qnr gene, including 8 （1. 1%） of qnrA, 28 （4. 0%） of qnrB, and 67 （9.5%） of qnrS. Eightyeight （88.9%） of the 99 qnr-positive isolates carried at least one bla gene. The ciprofloxacin resistance increased 2- to 125-fold. Different DNA band patterns were obtained from those isolates by ERIC-PCR, indicating that most of them were not clonally related. Conelnsions These results indicate that the most popular plasmid-mediated qnr quinolone resistance gene is qnrS, followed by qnrB and qnrA. Most of the isolates also carried a bla gene encoding ESBLs or ampC gene encoding DHA-1 among E. coli and K. pneumoniae isolated from Chinese pediatric patients.

关 键 词：大肠埃希菌 肺炎克雷伯菌 喹诺酮类药物耐药基因 超广谱Β内酰胺酶 AMPC酶 QNR 

分 类 号：R450[医药卫生—治疗学]