Yan Jing-Jou, Tsai Shu-Huei, Chuang Chin-Luan, Wu Jiunn-Jong
Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.
J Microbiol Immunol Infect. 2006 Apr;39(2):130-4.
Data on the epidemiology of OXA-type extended-spectrum beta (beta)-lactamases (ESBLs) are limited due to difficulty of identification by routine microbiology laboratories. We determined the prevalence rate of OXA-type beta-lactamases among extended-spectrum cephalosporin (ESC)-non-susceptible Pseudomonas aeruginosa isolates at a university hospital in southern Taiwan.
A total of 1,294 ESC-non-susceptible P. aeruginosa isolates collected between 1989 and 1996 (n = 42) and between December 1999 and December 2002 (n = 1,252) were analyzed by polymerase chain reaction assays with primers specific for bla(OXA) genes and isoelectric focusing.
Forty five isolates (3.5%) were found to produce an OXA-type beta-lactamase. Overall, 2 OXA-type ESBLs, OXA-14 (n = 2) and OXA-17 (n = 35), were detected in 37 (2.9%) isolates, and the OXA-10-type narrow-spectrum beta-lactamase was found in 8 (0.6%) isolates. OXA-10 and the 2 OXA-type ESBLs were detected in 6 (14.3%) and 4 (9.5%) of 42 ESC-non-susceptible isolates collected between 1989 and 1996. OXA-10 and OXA-17 were detected in 2 (0.2%) and 33 (2.6%) of 1,252 ESC-non-susceptible isolates collected between December 1999 and December 2002.
These data indicate that OXA-17 was the most common OXA-type ESBL and that OXA-type beta-lactamases have decreased in ESC-non-susceptible P. aeruginosa at this hospital in recent years. Pulsed-field gel electrophoresis revealed clonal diversity among the OXA-producing isolates.
由于常规微生物实验室难以鉴定，关于OXA型超广谱β-内酰胺酶（ESBLs）的流行病学数据有限。我们测定了台湾南部一所大学医院中对超广谱头孢菌素（ESC）不敏感的铜绿假单胞菌分离株中OXA型β-内酰胺酶的流行率。
采用针对bla(OXA)基因的引物进行聚合酶链反应分析和等电聚焦，对1989年至1996年期间（n = 42）以及1999年12月至2002年12月期间（n = 1,252）收集的总共1,294株对ESC不敏感的铜绿假单胞菌分离株进行分析。
发现45株（3.5%）分离株产生OXA型β-内酰胺酶。总体而言，在37株（2.9%）分离株中检测到2种OXA型ESBLs，即OXA-14（n = 2）和OXA-17（n = 35），在8株（0.6%）分离株中发现了OXA-10型窄谱β-内酰胺酶。在1989年至1996年收集的42株对ESC不敏感的分离株中，分别有6株（14.3%）和4株（9.5%）检测到OXA-10和这2种OXA型ESBLs。在1999年12月至2002年12月收集的1,252株对ESC不敏感的分离株中，分别有2株（0.2%）和33株（2.6%）检测到OXA-10和OXA-17。
这些数据表明OXA-17是最常见的OXA型ESBL，并且近年来该医院对ESC不敏感的铜绿假单胞菌中OXA型β-内酰胺酶有所减少。脉冲场凝胶电泳显示产OXA的分离株之间存在克隆多样性。
