title: [In vitro susceptibility of methicillin-resistant Staphylococcus aureus isolates to vancomycin, teicoplanin, linezolide and daptomycin].
abstract: In this study, vancomycin, teicoplanin, linezolide and daptomycin susceptibility rates of 67 methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained from various clinical samples between November 2006 and August 2010 in our laboratories, were investigated by E-test method and MIC values of the drugs were determined. Seventeen (25%) of the samples were from outpatient wards, 50 (75%) from inpatients of which 24 (48%) were from intensive care units. Distribution of MRSA isolated clinical samples were as follows: 16 (23.4%) blood, 28 (42.2%) wound swab, 15 (21.8%) tracheal aspirate, 2 (3.1%) urine, 2 (3.1%) urethral discharge, and one for each (1.6%) cerebrospinal fluid, joint fluid, catheter tip and nasal swab. Except one (1.5%) which was probably intermediate-resistant to vancomycin (since not confirmed by microdilution test or population analysis, this isolate was considered as "probable" intermediate-resistant), all of the isolates were found susceptible to all tested antibiotics. MIC(50) and MIC(90) values were determined as 0.75 and 1.5 µg/ml for vancomycin, 2 and 3 µg/ml for teicoplanin, 0.38 and 0.5 µg/ml for linezolide and 0.094 and 0.19 µg/ml for daptomycin, respectively. The MIC ranges were 0.25-3 µg/ml for vancomycin, 0.125-4 µg/ml for teicoplanin, 0.094-3 µg/ml for linezolide and 0.047-0.25 µg/ml for daptomycin. There was no statistically significant difference between MICs of outpatient, inpatient and intensive care unit isolates for any of the tested drugs (p> 0.05). Based on MIC90 values, daptomycin seems 4-16 times more effective than the other three drugs. It was concluded that considering their in-vitro antibacterial activity, these antibiotics can be used as alternatives to each other for the treatment of MRSA infections.
authors.affiliation: Ankara Atatürk Training and Research Hospital, Clinic of Medical Microbiology, Ankara, Turkey. nevrestec@yahoo.com
authors.forename: Nevreste
authors.initials: N
authors.lastname: Celikbilek
authors.forename: Birsen
authors.initials: B
authors.lastname: Ozdem
authors.forename: Feryal C
authors.initials: FC
authors.lastname: Gürelik
authors.forename: Selda
authors.initials: S
authors.lastname: Güvenman
authors.forename: H Rahmet
authors.initials: HR
authors.lastname: Güner
authors.forename: Ziya Cibali
authors.initials: ZC
authors.lastname: Açıkgöz
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017576:Daptomycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D000069349:Linezolid; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D023303:Oxazolidinones / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D017334:Teicoplanin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D023303:Oxazolidinones; D017334:Teicoplanin; D014640:Vancomycin; D000069349:Linezolid; D017576:Daptomycin