[Evaluation of antibiotic susceptibilities and VISA-VRSA rates among MRSA strains isolated from hospitalized patients in intensive care units of hospitals in seven provinces of Turkey].

The aim of this study was to determine whether vancomycin resistant Staphylococcus aureus (VRSA) and vancomycin intermediate susceptible S.aureus (VISA) strains were present among methicillin-resistant S.aureus (MRSA) strains isolated from patients hospitalised at intensive care units (ICU) of hospitals located at different regions of Turkey and to determine the minimum inhibitory concentration (MIC) values of teicoplanin, linezolid, tigecycline, quinupristin-dalfopristin and daptomycin, which are alternative drugs for the treatment of MRSA infections. A total of 260 MRSA clinical strains (isolated from 113 lower respiratory tract, 90 blood, 24 wound, 17 catheter, 13 nasal swabs, two urine and one CSF sample) were collected from nine health-care centers in eight provinces [Ankara (n= 52), Konya (n= 49), Antalya (n= 40), Istanbul (n= 7), Izmir (37), Diyarbakir (n= 15), Van (n= 12), Trabzon (n= 48)] selected as representatives of the seven different geographical regions of Turkey. Methicillin resistance was determined by cefoxitin disk diffusion in the hospitals where the strains were isolated and confirmed by oxacillin salt agar screening at the Refik Saydam National Public Health Agency. Screening for VISA and VRSA was conducted using the agar screening test and E-test. Susceptibility of the MRSA strains to other antibiotics was also determined by E-test method. None of the 260 MRSA strains were determined to be VRSA or VISA. All were susceptible to teicoplanin and linezolid, and susceptibility rates to daptomycin, tigecycline and quinupristin-dalfopristin were 99.6%, 96.9%, and 95%, respectively. Absence of VISA and VRSA among the MRSA strains surveyed currently seemed hopeful, however, continuous surveillance is necessary. In order to prevent the development of VISA and VRSA strains the use of linezolid, tigecycline, quinupristin-dalfopristin and daptomycin should be encouraged as alternative agents of treatment of MRSA infections.