Clinico-microbiological study of community acquired MRSA from skin and soft tissue infections and its antibiogram in a tertiary care hospital in Karnataka

Abstract

Methicillin resistant staphylococcus aureus (MRSA) has always been a worldwide problem, although its prevalence varies considerably among countries. The epidemiology of MRSA has changed over the years and infections are no longer confined to the hospital setting, but appear in healthy community dwelling individuals with no risk factors. From skin and soft tissue infection, common organism isolated is Community associated MRSA (CA-MRSA). Hence the study was done to know the prevalence of MRSA among community associated skin and soft tissue infections in Basaveshwar teaching and general hospital, attached to M.R. Medical College, Gulbarga. Standard techniques were used to isolate Staphylococcus aureus from clinical specimens. Cefoxitin disc diffusion was used to find MRSA. Antibiogram of MRSA was detected by Kirby Bauer disc diffusion method. Inducible Clindamycin resistance was done by Double Disc Diffusion method (D test). From over 200 cases of CA-MRSA, total of (75.5%) staphylococcus aureus was detected. Out of them, CA-MRSA was 27 (17.9%). These showed high sensitivity to Vancomycin (100%), Linezolid (96.2%),Cindamycin (92.59%), moderately susceptible to TMP-SMX(85.1%), Rifampicin (88.1%), Tetracycline(81.4%),Gentamicin (70.3%), ciprofloxacin(62.9%) and a low susceptibility to Erythromycin (48.14%). 14.8% of CA-MRSA strains were D test positive (inducible MLS positive) and 29.63% were D test negative (MS phenotype). 7.4% of CA-MRSA were positive for constitutive MLS resistance. There is a need for judicious selection of antimicrobial agents, as their indiscriminate use can exert pressure in selecting MRSA and other multi-drug resistant organisms. Further spread of community acquired infections can be done by effective infection control programs.