Outbreak of Klebsiella pneumoniae producing a new carbapenern hydrolyzing class a β-lactamase, KPC-3, in a New York Medical Center
Outbreak of Klebsiella pneumoniae producing a new carbapenern hydrolyzing class a β-lactamase, KPC-3, in a New York Medical Center
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DOI：
10.1128/aac.48.12.4793-4799.2004
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发表时间：
2004-12-01
影响因子：
4.9
通讯作者：
Livermore, DM
中科院分区：
文献类型：
--
作者：
Woodford, N;Tierno, PM;Livermore, DM
从2000年4月到2001年4月，纽约州纽约Tisch医院重症监护室的24名患者，被碳青霉烯类耐药肺炎克雷伯菌感染或定植。脉冲场凝胶电泳确定了一个主要的爆发菌株，但也恢复了其他耐药菌株。详细研究了来自不同患者的三种代表性爆发菌株。所有患者均对亚胺培南、美罗培南、头孢他啶、哌拉西林-他唑巴坦和庆大霉素耐药或敏感性降低，但对四环素仍完全敏感。PCR扩增了一个bla（KPC）等位基因，编码一种新的变体KPC-3，具有KPC-2中未发现的His（272）->Tyr取代;其他碳青霉烯酶基因不存在。在暴发菌株中，KPC-3由一个75-kb质粒编码，该质粒通过电穿孔和接合在体外转移。分离物缺乏OmpK 35孔蛋白，但表达OmpK 36，这意味着作为抗性辅助因子的渗透性降低。这是在肠杆菌科成员中报告的第三种KPC碳青霉烯水解β-内酰胺酶变体，其他变体报告自美国东海岸。虽然这些酶的生产者仍然很少，但这一酶组的进展值得监测。
From April 2000 to April 2001, 24 patients in intensive care units at Tisch Hospital, New York, N.Y., were infected or colonized by carbapenem-resistant Klebsiella pneumoniae. Pulsed-field gel electrophoresis identified a predominant outbreak strain, but other resistant strains were also recovered. Three representatives of the outbreak strain from separate patients were studied in detail. All were resistant or had reduced susceptibility to imipenem, meropenem, ceftazidime, piperacillin-tazobactam, and gentamicin but remained fully susceptible to tetracycline. PCR amplified a bla(KPC) allele encoding a novel variant, KPC-3, with a His(272)-->Tyr substitution not found in KPC-2; other carbapenemase genes were absent. In the outbreak strain, KPC-3 was encoded by a 75-kb plasmid, which was transferred in vitro by electroporation and conjugation. The isolates lacked the OmpK35 porin but expressed OmpK36, implying reduced permeability as a cofactor in resistance. This is the third KPC carbapenem-hydrolyzing beta-lactamase variant to have been reported in members of the Enterobacteriaceae, with others reported from the East Coast of the United States. Although producers of these enzymes remain rare, the progress of this enzyme group merits monitoring.