Samuelsen Ørjan, Naseer Umaer, Tofteland Ståle, Skutlaberg Dag Harald, Onken Annette, Hjetland Reidar, Sundsfjord Arnfinn, Giske Christian G
Reference Centre for Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
J Antimicrob Chemother. 2009 Apr;63(4):654-8. doi: 10.1093/jac/dkp018. Epub 2009 Feb 13.
The class A carbapenemase KPC has disseminated rapidly worldwide, challenging the treatment of Gram-negative infections. This report describes the first KPC-producing Klebsiella pneumoniae isolates identified in Norway (n=6) and the second isolate from Sweden.
Antimicrobial susceptibility profiles were determined using Etest. PCR and sequencing were used to determine the bla(KPC) variant, the surrounding genetic structure and the presence of AmpC and extended-spectrum beta-lactamase genes. PFGE and multilocus sequence typing (MLST) were used for epidemiological comparisons. Localization of bla(KPC) was investigated by S1 nuclease digestion, followed by PFGE and Southern blot hybridization.
All isolates expressed a multidrug-resistant phenotype with some variability in the carbapenem susceptibility profile. The Norwegian isolates carried bla(KPC-2), while the Swedish isolate carried bla(KPC-3). All isolates carried TEM-1, but were negative for bla(CTX-M) and bla(AmpC) genes. SHV-11 and SHV-12 were detected in the Norwegian isolates, while the Swedish isolate carried only SHV-11. Isolates from four patients were associated with import from Greece (n=3) and Israel. The other isolates were probably associated with local transmissions. PFGE and MLST showed that the isolates were clonally related, with three isolates displaying ST258, a single locus variant of ST11 previously associated with the clonal spread of CTX-M-15-producing K. pneumoniae in Hungary. In all isolates, bla(KPC) was located on plasmids as part of isoform a of Tn4401.
The emergence of KPC-producing isolates of K. pneumoniae in Norway and Sweden is associated with multiple import events and probable local transmission of a successful multiresistant ST258 clone, closely related to the CTX-M-15-producing ST11 clone previously described in Hungary.
A类碳青霉烯酶KPC已在全球迅速传播，对革兰氏阴性菌感染的治疗构成挑战。本报告描述了在挪威首次鉴定出的产KPC的肺炎克雷伯菌分离株（n = 6）以及来自瑞典的第二株分离株。
使用Etest测定抗菌药物敏感性谱。采用PCR和测序确定bla(KPC)变体、周围的基因结构以及AmpC和超广谱β-内酰胺酶基因的存在情况。PFGE和多位点序列分型（MLST）用于流行病学比较。通过S1核酸酶消化，随后进行PFGE和Southern印迹杂交研究bla(KPC)的定位。
所有分离株均表现出多药耐药表型，碳青霉烯敏感性谱存在一定差异。挪威分离株携带bla(KPC-2)，而瑞典分离株携带bla(KPC-3)。所有分离株均携带TEM-1，但bla(CTX-M)和bla(AmpC)基因呈阴性。在挪威分离株中检测到SHV-11和SHV-12，而瑞典分离株仅携带SHV-11。来自4名患者的分离株与从希腊（n = 3）和以色列输入有关。其他分离株可能与本地传播有关。PFGE和MLST显示分离株具有克隆相关性，其中3株显示ST258，这是ST11的单一位点变体，先前在匈牙利与产CTX-M-15的肺炎克雷伯菌的克隆传播有关。在所有分离株中，bla(KPC)位于质粒上，作为Tn4401同工型a的一部分。
挪威和瑞典产KPC的肺炎克雷伯菌分离株的出现与多次输入事件以及一个成功的多重耐药ST258克隆的可能本地传播有关，该克隆与先前在匈牙利描述的产CTX-M-15的ST11克隆密切相关。
