Watanabe H, Masaki H, Asoh N, Watanabe K, Oishi K, Furumoto A, Kobayashi S, Sato A, Nagatake T
Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
J Hosp Infect. 2001 Apr;47(4):294-300. doi: 10.1053/jhin.2000.0931.
The objective of this study was to investigate the state of mupirocin resistance in methicillin-resistant Staphylococcus aureus (MRSA) in a community hospital in Japan. Ninety strains of MRSA were isolated from the respiratory tract of 56 patients (group I, Jun 1990-Aug 1996) before introduction of mupirocin in Japan, which were compared with 168 strains from 48 patients (group II, Sept 1996-Jan 1998) and 146 strains from 85 patients (group III, Feb 1999-Dec 1999) isolated after introduction of mupirocin. Comparisons were made by determining the minimum inhibitory concentrations (MIC) against nine antibiotics. Fifty-five MRSA isolates from 27 patients [13 (27.1%) of 48 in group II and 14 (16.5%) of 85 in group III] after introduction of mupirocin showed low-level resistance to mupirocin (MIC, 6.25 to 50 microg/ml) but the remaining isolates were sensitive to mupirocin (MIC < or =3.13 microg/ml). Most patients colonized with low-level mupirocin-resistant MRSA were elderly (> or =65 years of age), on total parenteral nutrition or nasal feeding and had other underlying diseases. The proportion of patients colonized with low-level mupirocin-resistant MRSA following repeated use of mupirocin was higher in patients of group II than those of group III. Molecular typing by pulsed-field gel electrophoresis (PFGE) demonstrated that the pattern of 13 MRSA isolates from 13 patients of group II consisted of three patterns (A, B, C) with predominance of pattern A, while the pattern of 13 MRSA isolates from 13 patients of group III consisted of three patterns (A, C, D) with predominance of patterns A and D. Our results indicated that resistance of MRSA to mupirocin remains at a low level at present in Japan. However, we should be aware of the possible emergence of MRSA highly resistant to mupirocin in the future.
本研究的目的是调查日本一家社区医院耐甲氧西林金黄色葡萄球菌（MRSA）中莫匹罗星耐药情况。在日本引入莫匹罗星之前，从56例患者的呼吸道分离出90株MRSA（第一组，1990年6月 - 1996年8月），并与引入莫匹罗星后从48例患者分离出的168株（第二组，1996年9月 - 1998年1月）以及从85例患者分离出的146株（第三组，1999年2月 - 1999年12月）进行比较。通过测定对9种抗生素的最低抑菌浓度（MIC）进行比较。引入莫匹罗星后，从27例患者分离出的55株MRSA（第二组48例中的13株[27.1%]和第三组85例中的14株[16.5%]）对莫匹罗星表现出低水平耐药（MIC，6.25至50μg/ml），但其余分离株对莫匹罗星敏感（MIC≤3.13μg/ml）。大多数定植有低水平莫匹罗星耐药MRSA的患者为老年人（≥65岁），接受全胃肠外营养或鼻饲，并有其他基础疾病。第二组患者重复使用莫匹罗星后定植有低水平莫匹罗星耐药MRSA的比例高于第三组。通过脉冲场凝胶电泳（PFGE）进行分子分型显示，第二组13例患者的13株MRSA菌株的图谱由三种模式（A、B、C）组成，以模式A为主，而第三组13例患者的13株MRSA菌株的图谱由三种模式（A、C、D）组成，以模式A和D为主。我们的数据表明，目前在日本MRSA对莫匹罗星的耐药性仍处于低水平。然而，我们应意识到未来可能会出现对莫匹罗星高度耐药的MRSA。
