新生儿携带IMP-4肺炎克雷伯菌的分子分型特征

Molecular typing characteristics of IMP-4-producing Klebsiella pneumoniae in neonates

目的 分析新生儿产IMP-4肺炎克雷伯菌的分子分型特征。方法从南宁市两家医院住院的新生儿中分离获得49株耐碳青霉烯类肺炎克雷伯菌,筛选出10株携带IMP-4的肺炎克雷伯菌。采用多位点序列分型技术对10株肺炎克雷伯菌进行序列分析,PCR检测β-内酰胺酶耐药基因,并使用eBURST软件进行亲缘分析。结果10株携带IMP-4的肺炎克雷伯菌共有6个序列型,4株序列型为20,2株序列型为1473。所有菌株均检测到耐药基因SHV-11及TEM-1。10株菌株有1个主要克隆复合群(包括序列型20、序列型37、序列型234),属于以序列型11为祖先的复合体。结论南宁市两家医院新生儿携带IMP-4的肺炎克雷伯菌基因序列型别具有多样性,其中序列型20是主要型别,其曾在一家医院新生儿中出现医院感染的暴发。

Objective To analyze the molecular typing characteristics of IMP-4-producing Klebsiella pneumoniae in neonates. Methods Forty-nine strains of carbapenems-resistant Klebsiella pneumoniae were isolated from the neonates in two hospitals of Nanning City,then 10 strains of IMP-4-producing Klebsiella pneumoniae were screened out.Multilocus sequence typing technique was used for sequence analysis of those 10 strains of Klebsiella pneumoniae ,PCR for analysis of β-lactamase resistant genes,and eBURST software for phylogenetic analysis. Results The 10 strains of IMP-4-producing Klebsiella pneumoniae were divided into 6 sequence types(STs),ST20 was found in 4 strains,and ST1473 was found in 2 strains. Resistant genes SHV-11 and TEM-1 were determined in all of the bacterial strains.The 10 strains of IMP-4-producing Klebsiella pneumoniae possessed a main clonal complex group(involving ST20,ST37 and ST234) belonging to the complex confirmed ST11 as the ancestor. Conclusion Among the neonates from the two hospitals of Nanning City,IMP-4-producing Klebsiella pneumoniae obtains diversity of sequence types,ST20 is the dominant type of that bacterial strain and once caused outbreak of hospital infection in the neonates of a hospital.