Title of study: Prevalence and Antibiotic Susceptibility Pattern of Methicillin Resistant Staphylococcus aureus isolated from Skin and Soft tissue infections in a Rural Teaching Hospital

Background: Skin and soft tissue infections (SSTI) are ubiquitous and Staphylococcus aureus is almost the universal cause of furuncles, carbuncles and skin abscesses worldwide. Strains resistant to beta-lactam antibiotics, termed Methicillin Resistant Staphylococcus aureus (MRSA), are now causing community-acquired infections. Clinically it is important to distinguish between MRSA and Methicillin sensitive Staphylococcus aureus (MSSA) because their treatments are different.

Objectives: To find the prevalence and antibiotic susceptibility pattern of MRSA and MSSA isolated from SSTIs coming to this tertiary care hospital.

Methodology: This cross-sectional study, conducted in the microbiology department, on pus-samples received from skin and soft tissue infections during the study period had a sample size of of 53 specimens. After obtaining Institutional Scientific Review Board and Ethics committee approval, isolates of Staphylococcus aureus from SSTI were selected by consecutive sampling, cultured, tested and antibiotic susceptibility pattern was obtained by automated and disc diffusion methods

Results: The prevalence of MRSA was 45.3% and MSSA was 54.7%. Out of 53 samples Only 6(11.3%) of the 53 isolates were sensitive to Ampicillin and Penicillin. All MRSA were sensitive to Vancomycin and Linezolid.

Conclusion: About half of Staphylococcus aureus isolated were MRSA. The significant emergence of multi drug resistant Staphylococcus aureus calls for judicious antimicrobial treatment based on Antibiotic Sensitivity Test. Vancomycin and linezolid shows 100% sensitivity, hence are the drugs of choice for treating MRSA. Robust antimicrobial stewardship is advised.

Keywords: MRSA, SSTI, antibiotic susceptibility, Vancomycin, Linezolid.

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Dr Anna Mathew

Professor of Pharmacology, Mepurathu, Mannoor, Keezhillam, Ernakulam, Kerala 682311, India