肺炎克雷伯菌耐碳青霉烯类抗菌药物的基因型研究

Investigation on carbapenem antibiotics resistance gene of Klebsiella pneumoniae

目的探讨肺炎克雷伯菌(Kpn)耐碳青霉烯类药物的耐药基因型。方法收集2011年1月至12月本院分离到的肺炎克雷伯菌,用K-B法进行药敏实验,筛选出6株耐碳青霉烯类抗菌药物的肺炎克雷伯菌(CRKP),采用改良Hodge试验检测菌株产碳青霉烯酶,用乙二胺四乙酸(EDTA)纸片法检测金属酶表型,聚合酶链式反应(PCR)鉴定肺炎克雷伯菌耐碳青霉烯酶(KPC)基因及其他β-内酰胺酶基因。结果 6株CRKP对头孢噻肟、头孢他啶、头孢呋辛、阿莫西林/克拉维酸、氨苄西林、氨苄西林/舒巴坦、庆大霉素、复方新诺明、哌拉西林/三唑巴坦、头孢哌酮/舒巴坦、头孢吡肟、氨曲南、美罗培南、亚胺培南均耐药,对多黏菌素、米诺环素、磷霉素、阿米卡星等敏感,改良Hodge试验提示6株CRKP均产碳青霉烯酶,EDTA纸片法检测显示不产金属酶;PCR鉴定出该6株CRKP均携带blaKPC-2型基因,部分菌株携带blaSHV及blaTEM型广谱β-内酰胺酶耐药基因。结论 BlaKPC-2耐药基因为Kpn对碳青霉烯类药物耐药的主要原因。

Objective To understand the drug resistance genotype of Klebsiella pneumoniae （Kpn） resistant to carbapenems. Methods Klebsiella pneumoniae isolated in our hospital from January to December, 2011 were collected, K-B was used for drug susceptibility test, 6 Klebsiella pneumoniae strains were screened to be resistant to carbapenems. Modified Hodge test was used for the detection of strains producing carbapenemases, ethylene diamine tetraacetic acid （EDTA） disk diffusion method was used for detection of metal enzyme phenotypes, KPC gene and other beta lactamases genes were identiifed by using PCR. Results There were 6 Klebsiella pneumoniae strains resistant to carbapenems drug, they were resistant to cefotaxime, ceftazidine, cefuroxime, amoxicillin, clavulanate, ampicillin, ampicillin, subactam, gentamycin, SMZ/TMP, piperacillin/tazobactam, cefperazone-sulbactam, cefepime, aztreonam, meropenem and imipenem, but sensitive to polymyxin, minocycline, fosfomycin, amikacin. All 6 strains produced carbapenemases but couldn’t produce metal enzyme;all of the 6 strains carried blaKPC-2, part of them carried blaSHV and blaTEM. Conclusions The blaKPC-2 is the main reason for the resistanceof Kpn to carbapenem.