60株肺炎克雷伯菌多重耐药性及主要耐药基因的研究

Study on Multiple Drug-Resistance and Main Drug-Resistant Gene of 60 Klebsiella Pneumoniae Strains

目的:了解临床分离的肺炎克雷伯菌耐药性及主要耐药基因存在状况。方法:采用Microscan微生物鉴定仪,微量肉汤稀释法测定肺炎克雷伯菌对21种抗生素的敏感性。采用聚合酶链反应(PCR)及测序技术分析超广谱β内酰氨酶(ESBLs),质粒介导的AmpC酶和氨基糖苷类修饰酶基因型。结果:肺炎克雷伯菌对亚胺培南全部敏感,对其他抗生素均有不同程度的耐药。60株全部扩增出TEM基因,有25株检出CTX-M-I群基因,有54株扩增出DHA基因,59株检出共3种氨基糖苷类修饰酶基因。且有22株同时携带2～6种耐药基因。对其中4株细菌进行基因型测序,证实CTX-M-I群扩增产物均为CTX-M-3;DHA扩增产物均为DHA-1;氨基糖苷类修饰酶基因分别为aac(3)-Ⅱ、aac(6')-I和ant(3″)-I。其中CTX-M-3(AY635141)、DHA-1(AY635140)已注册GenBank(括号内为GenBank注册号)。结论:临床分离的肺炎克雷伯菌为多重耐药菌,同时存在2～6种耐药基因。

Objective: To study the drug-resistance and drug-resistant gene of clinical Klebiella pneumoniae (Kpn) strains. Methods: Antimicrobial susceptibilities to 21 drugs of Kpn strains were tested by Microscan MIC method and micro-broth dilution. The genotypes of ESBLs, pAmpC and AMEs were analyzed by PCR and DNA seqencing. Results: All Kpn strains were susceptible to imipenem and drug-resistant to other drugs. TEM gene were amplified in 60 strains, CTX-M-I gene were examined in 25 strains, DHA gene were amplified in 54 strains, and 3 AMEs gene were examined in 59 strains. Simultaneously 2～6 drug-resistant gene existed in 22 strains. All CTX-M-I amplificatory productions were proved CTX-M-3, all DHA amplificatory productions were DHA-1, AMEs amplificatory productions were aac (3)-II , aac(6')-I and ant(3'')-I by sequencing in 4 strains. CTX-M-3(AY635141) and DHA-1 (AY635140) had registered GenBank (GenBank register numbers in the brackets). Conclusion: Isolated Kpn is multiple drug-resistant and 2～6 drug-resistant gene are existed.