产KPC酶肺炎克雷伯菌检测及耐药性研究

Detection of Klebsiella Pneumoniae Producing KPC Enzymes and Resistance Research

目的探讨我院产肺炎克雷伯菌碳青霉烯酶(KPC)肺炎克雷伯菌对碳青霉烯类药物耐药率升高的原因。方法对2009—2011年我院各类临床标本中分离的肺炎克雷伯菌进行统计及药敏结果分析。对2010年1月—2011年12月间分离的耐碳青霉烯类药物的肺炎克雷伯菌做改良Hodge试验和金属β-内酰胺酶检测,阳性菌株筛查KPC酶及耐药细菌(NDM-1)基因。结果 2009、2010年肺炎克雷伯菌对亚胺培南仍保持高敏感性,对2010年分离的8株耐亚胺培南的肺炎克雷伯菌做改良Hodge试验均为阴性(2009年菌株未保留)。2011年肺炎克雷伯菌对碳青霉烯类药物的耐药性显著升高,47株耐碳青霉烯类药物的肺炎克雷伯菌改良Hodge试验阳性,KPC酶阳性;2株耐碳青霉烯类药物的肺炎克雷伯菌金属β-内酰胺酶阳性;所有菌株NDM-1基因检测均为阴性。结论由KPC酶介导的耐碳青霉烯类药物的肺炎克雷伯菌在临床分离菌株中显著增加。KPC酶基因的出现是碳青霉烯类抗菌药物广泛应用引起的耐药基因突变,携带KPC酶的质粒存在不同种属细菌间进行转移的可能性,临床应加强监控,防止产碳青霉烯酶菌株在医院环境中暴发和流行。

Objective To explore the causes of increased resistance rate of klebsiella pneumoniae producing KPC enzymes to carbapenems.Methods Data of separated klebsiella pneumoniae in clinical collections from 2009 to December 2011 in our hospital were statistically analyzed for drug sensitivity.Separated anti-carbapenems klebsiella pneumoniae separated by our hospital during January 2010 and December 2011 underwent the modified Hodge test,metal bata lactamase detection,KPC enzyme of positive strains screening and NDM-1 encoding genes test.Results There was hypersensitivity of klebsiella pneumoniae to imipenem in 2009 and 2010,and in 2010,only 8 strains of anti-imipenem resistant klebsiella pneumoniae were found negative with the modified Hodge test（no reserved strains in 2009）.The resistance rate of klebsiella pneumoniae to carbapenems drugs significantly increased,47 strains of carbapenem resistant klebsiella pneumoniae were phenotypically positive in the modified Hodge test and the presence of KPC was confirmed in 47 isolates by PCR.Metal bata lactamase expression in 2 strains of carbapenem resistant klebsiella pneumoniae drugs was positive,but NDM-1 gene was negative in all of the strains.Conclusion Klebsiella pneumoniae KPC enzyme-mediated resistance to carbapenems takes a significant increase in clinical isolates.The emergence of the KPC gene is the result of resistance gene mutation due to wide use of carbapenems antibacterial drugs.The KPC gene should be horizontally transmitted by plasmid among different groups of bacteria.It is important to control the transmission of klebsiella pneumoniae KPC enzyme-mediated resistance to carbapenems in hospitals.