Wang Jann-Tay, Sheng Wang-Huei, Wang Jiun-Ling, Chen Duckling, Chen Mei-Ling, Chen Yee-Chun, Chang Shan-Chwen
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
J Antimicrob Chemother. 2008 Sep;62(3):514-7. doi: 10.1093/jac/dkn208. Epub 2008 May 13.
Chlorhexidine has been widely used for hand hygiene to prevent transmission of nosocomial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). However, data on longitudinal surveillance of the susceptibility of MRSA isolates to chlorhexidine are limited.
A total of 240 nosocomial MRSA isolates obtained in 1990, 1995, 2000 and 2005 at National Taiwan University Hospital (NTUH), a hospital where chlorhexidine gluconate was used for hand hygiene for more than 20 years, were included in the study. Chlorhexidine susceptibility, molecular typing using multilocus sequence typing and distribution of the qacA/B gene of these MRSA isolates were studied.
The proportion of tested MRSA with a high MIC of chlorhexidine (>or=4 mg/L) was 1.7% in 1990, 50% in 1995, 40% in 2000 and 46.7% in 2005. Among these 83 isolates with high chlorhexidine MICs, 55.4% carried the qacA/B gene. MRSA isolates carrying the qacA/B gene were first detected in 1995 and belonged to a single clone at that time. However, the qacA/B gene was detected in MRSA isolates belonging to seven different clones in 2005.
The proportion of tested MRSA isolates with high chlorhexidine MICs at NTUH increased from 1990 to 1995 and remained steady thereafter. The presence of the qacA/B gene may contribute to the spread of specific MRSA clones.
洗必泰已被广泛用于手部卫生，以预防包括耐甲氧西林金黄色葡萄球菌（MRSA）在内的医院病原体传播。然而，关于MRSA分离株对洗必泰敏感性的纵向监测数据有限。
本研究纳入了1990年、1995年、2000年和2005年在台湾大学医院（NTUH）获得的240株医院MRSA分离株，该医院使用葡萄糖酸洗必泰进行手部卫生超过20年。研究了这些MRSA分离株的洗必泰敏感性、使用多位点序列分型的分子分型以及qacA/B基因的分布。
1990年洗必泰高MIC（≥4mg/L）的测试MRSA比例为1.7%，1995年为50%，2000年为40%，2005年为46.7%。在这83株洗必泰高MIC的分离株中，55.4%携带qacA/B基因。携带qacA/B基因的MRSA分离株于1995年首次检测到，当时属于单一克隆。然而，2005年在属于七个不同克隆的MRSA分离株中检测到了qacA/B基因。
NTUH中洗必泰高MIC的测试MRSA分离株比例从1990年到1995年增加，此后保持稳定。qacA/B基因的存在可能有助于特定MRSA克隆的传播。
