PREVALENCE OF METHICILLIN RESISTANT STAPHYLOCOCCUS aureus WITH PARTICULAR MENTION OF LOW LEVEL VANCOMYCIN RESISTANCE IN BURNS WOUND INFECTION PATIENTS

Burns wound infection accounts for nearly 75 percentage of deaths following burns. Staphylococcus aureus has been reported as a major cause of community and hospital acquired infections. Wide spread occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) and the use of vancomycin to treat infections has resulted in low level resistance even to vancomycin. The objective of the study was to detect MRSA strains in the wound swabs of the burns patients.These MRSA strains were observed for low level vancomycin resistance.A total of 214 wound swabs was collected from the burns wound infection patients and processed according to standard laboratory techniques.Antimicrobial susceptibility testing was done by KirbyBauer disc diffusion method using the antibiotic discs namely ampicillin (10 micro gm), erythrom y c i n ( 1 5 m i c r o gm),gentamycin(10micro gm),amikacin ( 3 0 m i c r o g m ) , o f l o x a c i n ( 5 m i c r o gm),oxacillin(1micro gm), cefoxitin, (30micro gm ), vancomycin (30 micro gm), linezolid (30 micro gm).. The percentage of staphylococcus aureus isolated in wound swabs was 99 (46 percent). MRSA detection was done by Oxacillin disc diffusion method and Cefoxitin disc diffusion method .Percentage of MRSA detected by both methods was 48 (48.5 percent).VISA was detected by Disc diffusion method,Vancomycin screen agar method and Agar dilution method.In Agar dilution method two strains had MIC 8 micro gm per ml for vancomycin.None of the strains were VRSA with MIC more than 16 micro gm per ml.. In Vancomycin screen agar the same two strains showed visible growth.But in Disc diffusion method all the strains were sensitive to vancomycin. Thus disc diffusion method may not be a reliable method for VISA detection. Vancomycin screen agar results coincides with agar dilution method. Thus vancomycin screen agar may be used as a preliminary screening test for VISA In the present study both the VISA strains showed 100 percent susceptibility to linezolid.In conclusion, though vancomycin intermediate resistant strains were susceptible to linezolid, a strict regulation has to be followed on the usage of glycopeptides like vancomycin to reduce the incidence of VISA and VRSA.