Saderi Horieh, Owlia Parviz, Habibi Mehri
Dept. of Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran.
Med Sci Monit. 2008 Oct;14(10):BR210-3.
The topical agent mupirocin plays a crucial role in strategies designed to control outbreaks of methicillin-resistant Staphylococcus aureus. The rate of high- and low-level mupirocin resistance among S. aureus strains from Iranian hospitals is not known.
MATERIAL/METHODS: Two hundred twenty-two nonduplicate S. aureus strains consecutively isolated in four university hospitals in Tehran, Iran, were tested for mupirocin susceptibility by disc diffusion agar method and minimum inhibitory concentration (MIC) determination by the E-test. Susceptibility to 16 other antimicrobial agents was also determined.
With the disc diffusion agar method, the majority of strains (97.3%) were susceptible to mupirocin and only 2.7% were resistant. The S. aureus strains showed high resistance (>50%) to most antibiotics, including penicillin G, ampicillin-sulbactam, oxacillin, cefoxitin, ciprofloxacin, erythromycin, tetracycline, clindamycin, gentamicin, and rifampicin, but resistance to linezolid, chloramphenicol, cotrimoxazole, and quinupristin/dalfopristin was low and no isolate was resistant to vancomycin. In the E-test, six strains had MICs of >4 mg/l, i.e. five strains had MICs of 8-256 mg/l (low-level mupirocin resistance) and one strain had 1024 mg/l (high-level mupirocin resistance). One strain was resistant to mupirocin in the disc diffusion agar method but showed sensitivity in the E-test (MIC: 0.94 mg/l). The mupirocin-resistant S. aureus isolates were all methicillin resistant and more resistant to the other antimicrobial agents compared with the mupirocin-susceptible strains.
This study is the first report about mupirocin resistance of S. aureus in Iranian hospitals.
外用药物莫匹罗星在控制耐甲氧西林金黄色葡萄球菌暴发的策略中起着关键作用。伊朗医院分离的金黄色葡萄球菌菌株中高水平和低水平莫匹罗星耐药率尚不清楚。
材料/方法：采用纸片扩散琼脂法和E试验测定最低抑菌浓度（MIC），对伊朗德黑兰4所大学医院连续分离的222株非重复金黄色葡萄球菌菌株进行莫匹罗星敏感性检测。同时还测定了对其他16种抗菌药物的敏感性。
采用纸片扩散琼脂法，大多数菌株（97.3%）对莫匹罗星敏感，仅2.7%耐药。金黄色葡萄球菌菌株对大多数抗生素耐药率较高（>50%），包括青霉素G、氨苄西林-舒巴坦、苯唑西林、头孢西丁、环丙沙星、红霉素、四环素、克林霉素、庆大霉素和利福平，但对利奈唑胺、氯霉素、复方新诺明和奎奴普丁/达福普汀耐药率较低，无一株对万古霉素耐药。E试验中，6株菌的MIC>4mg/l，即5株菌的MIC为8～256mg/l（低水平莫匹罗星耐药），1株菌的MIC为1024mg/l（高水平莫匹罗星耐药）。1株菌在纸片扩散琼脂法中对莫匹罗星耐药，但在E试验中敏感（MIC：0.94mg/l）。莫匹罗星耐药的金黄色葡萄球菌分离株均为耐甲氧西林菌株，与莫匹罗星敏感菌株相比，对其他抗菌药物耐药性更强。
本研究是关于伊朗医院金黄色葡萄球菌莫匹罗星耐药性的首次报道。
