产KPC-2 肺炎克雷伯菌的MLST 和wzi 分型分析

目的探讨产KPC-2肺炎克雷伯菌的多位点序列分型(MLST)并确定其wzi分型。方法收集南京鼓楼医院2012—2014年分离的耐碳青霉烯肺炎克雷伯菌108株,采用改良Hodge试验筛选产碳青霉烯酶菌株,PCR和DNA测序技术鉴定KPC-2编码基因。对产KPC-2菌株,用MLST技术分析其遗传相关性,并用PCR技术对其进行wzi分型。结果 108株碳青霉烯类耐药肺炎克雷伯菌中,72株产KPC-2。72株产KPC-2菌株经MLST分型分为9个不同克隆型,其中ST11(61/72,84.7%)最为流行,其次为ST15(4/72,5.6%);72株产KPC-2细菌有7种wzi分型,wzi209(K47荚膜型)最为流行(58/72,80.6%),其次为wzi64(K64荚膜型)(6/72,8.3%)。结论产KPC-2肺炎克雷伯菌ST11型在我院存在克隆播散,大多为wzi209,荚膜型为K47,需加强感染控制措施。

Analysis for MLST and wzi typing of Klebsiella pneumoniae producing KPC-2 carbapenemase

Abstract:Objective To explore multilocus sequence typing (MLST)in KPC-2 producing Klebsiella pneumoniae and detect its wzi types. Methods A total of 108 isolates of carbapenem-resistant K. pneumoniae (CRKP)were collected from Nanjing Drum Tower Hospital from 2012 to 2014. Modified Hodge test was carried out to screen the isolates of carbapenemae. PCR and DNA sequencing were used to detect blaKPC-2 gene. For the KPC-2 positive strains,MLST was implemented to detect the sequence type (ST)and PCR was performed to determine wzi gene typing. Results Seventy-two of 108 CRKP strains were KPC-2-producing. In the identification of MLST 9 different ST types were found among the 72 KPC-2 producing strains in which ST11 (61 / 72,84.7%)was the most prevalent clone,followed by ST15 (4 / 72,5.6%). There were 7 wzi types. Among the 72 KPC-2 producing strains,wzi209 / K47 (n = 58)was the most predominant type accounting for 80.6%,followed by wzi64 / K64 (n = 6,8.3%). Conclusion There was a clonal dissemina-tion of KPC-2 producing K. pneumoniae ST11 in our hospital with the predominant capsular type wzi209 / K47. The relevant control measures for infection should be further strengthened.