Various isolated methicillin resistant staphylococcus aureus clinical materials (MRSA) strains of vancomycin investigation activity in vitro

ABSTRACTMethicillin-resistant Staphylococcus aureus (MRSA), are important factors of nosocomial infections have become endemic in many hospitals. Since first vancomycin-resistant Staphylococcus aureus (VRSA) strains isolated from the United States of America, the infections with resistant bacteria would be indicated an important problem in the future. 13 MRSA strains have been reported from 2002 to the present day.In the present study, it was aimed to to investigate the in-vitro activity of vancomycin with microdilution broth method for MRSA strains isolated from clinical specimens in patients of intensive care unit and other clinic and outpatient. The MIC values of vancomycin, the definition of clinical isolates and MRSA were performed according to CLSI criteria.A total of 104 MRSA strains as infectious agent were detected. Distribution of MRSA strains were as follows: 33 (31.7%) reanimation intensive care unit, 14 (13.5%) infectious diseases clinic and 7 (6.7%) plastic surgery clinic. All of the MRSA isolates were found susceptible to vancomycin with microdilution broth method. The MIC values were determined as 0.125 µg /mL for 14 (13.5%)strains, 0.25 µg /mL for 21 (20.2%), 0.5 µg /mL for 52 (50%), 1 µg /mL for 11 (10,6%) and 2 µg /mL for 6 (5,8%) strains. Increased vancomycin MIC values were noted in patients with a history of prior use of vancomycinVancomycin is often used as the only treatment option for infections caused by MRSA because of increase in the infections with MRSA and resistant with many antibiyotics. As a result of the frequent use of vancomycin, increased MIC values of S. aureus strains leads to failures of treatment although within the limits of sensitivity. Heteroresistance-VISA, VISA and MRSA strains which reported increasing frequency suggests that resistance may develop in our country in the near future. Because of that, inappropriate vancomycin using should be avoided and infection control measures should be taken.Key Words: Methicillin-resistant Staphylococcus aureus, Vancomycin, Minimum inhibitory concentration