Yan J J, Hsueh P R, Ko W C, Luh K T, Tsai S H, Wu H M, Wu J J
Department of Pathology, National Cheng Kung University Medical Center, National Cheng Kung University Medical College, Tainan, Taiwan.
Antimicrob Agents Chemother. 2001 Aug;45(8):2224-8. doi: 10.1128/AAC.45.8.2224-2228.2001.
A total of 209 clinical isolates of Pseudomonas (193 Pseudomonas aeruginosa, 10 P. putida, 4 P. stutzeri, and 2 P. fluorescens isolates) with reduced susceptibilities to imipenem and/or ceftazidime were subjected to PCR assays with primers specific for bla(IMP-1), bla(IMP-2), bla(VIM-1), and bla(VIM-2) and sequence analysis to identify the metallo-beta-lactamases (MBLs) prevalent among these organisms in Taiwan; and 21 isolates gave positive results. Five isolates including two P. putida and three P. stutzeri isolates were found to carry bla(IMP-1), and six isolates including five P. putida and one P. stutzeri isolates harbored bla(VIM-2). The remaining 10 isolates were P. aeruginosa, and all were found to carry a novel variant of bla(VIM-2), designated bla(VIM-3). There are only two nucleotide differences between bla(VIM-2) and bla(VIM-3), leading to two amino acid alterations. Our findings indicate that VIM-2 and its variant have become the most prevalent metalloenzymes in Pseudomonas in Taiwan. Southern hybridization with the bla(VIM-2)-, bla(VIM-3)-, and bla(IMP-1 )-specific probes revealed that only two VIM-2-producing P. putida isolates appeared to carry the MBL gene on plasmids. Pulsed-field gel electrophoresis showed that six VIM-3-producing P. aeruginosa isolates and two IMP-1-producing P. stutzeri isolates were genetically related, suggesting that the spread of these MBL genes in Taiwan could be due to clonal dissemination as well as genetic exchange between different clones.
对209株对亚胺培南和/或头孢他啶敏感性降低的假单胞菌临床分离株（193株铜绿假单胞菌、10株恶臭假单胞菌、4株斯氏假单胞菌和2株荧光假单胞菌分离株），使用针对bla(IMP-1)、bla(IMP-2)、bla(VIM-1)和bla(VIM-2)的引物进行PCR检测，并进行序列分析，以鉴定台湾地区这些菌株中普遍存在的金属β-内酰胺酶（MBL）；21株分离株检测结果呈阳性。发现5株分离株（包括2株恶臭假单胞菌和3株斯氏假单胞菌分离株）携带bla(IMP-1)，6株分离株（包括5株恶臭假单胞菌和1株斯氏假单胞菌分离株）携带bla(VIM-2)。其余10株为铜绿假单胞菌，均被发现携带一种新的bla(VIM-2)变体，命名为bla(VIM-3)。bla(VIM-2)和bla(VIM-3)之间只有两个核苷酸差异，导致两个氨基酸改变。我们的研究结果表明，VIM-2及其变体已成为台湾地区假单胞菌中最普遍的金属酶。用bla(VIM-2)、bla(VIM-3)和bla(IMP-1)特异性探针进行Southern杂交显示，只有2株产VIM-2的恶臭假单胞菌分离株似乎在质粒上携带MBL基因。脉冲场凝胶电泳显示，6株产VIM-3的铜绿假单胞菌分离株和2株产IMP-1的斯氏假单胞菌分离株具有遗传相关性，表明这些MBL基因在台湾地区的传播可能是由于克隆传播以及不同克隆之间的基因交换。
