Coagulase negative staphylococci as a pathogen from wound infections in a Tertiary care Hospital

Abstract

Introduction: Wound infections are a common type of infections that may contribute to longer hospital stay. Most of these infections are superficial and readily treated with a regimen of local care and antibiotics. Determination of the etiologic agent is vital in the final choice of antibiotics. CoNS are previously considered as contaminants and non-pathogenic have been identified as the etiological agents in most hospital acquired infections. These were considered clinically significant when isolated in pure culture from infected sites and in repeated samples. Material and Methods: Retrospective statistical analysis from Jan – Dec 2015. 283 swabs from wound infections were processed by following standard operative procedures. All samples were subjected to direct microscopy (Gram staining) and culture. Culture positive samples were processed by doing Gram staing and Coagulase test. Coagulase negative staphylococcal isolates (CoNS) were subjected for antibiotic susceptibility testing. Results: Of total 283 samples, 159 were culture positive (56.18%). Among 159 isolates 55 were Coagulase negative staphylococci (34.59%). The isolates showed high susceptibility to vancomycin (85.45%). But 80% of CoNS were MRCoNS. Susceptibility to gentamycin was high (69.09%) followed by Amoxiclav (amoxicillin and clavulanic acid - 58.18%), ciprofloxacin (52.72%), ceftriaxone (38.18%), cefaperazone and penicillin (36.36%) and cotrimaxazole (27.27%). Conclusions: 1. CoNS should be considered as an emerging pathogen in wound infections. 2. CoNS is becoming resistant to commonly used antibiotics. 3. CoNS is developing resistance even to vancomycin. Key words: Antibiotic susceptibility testing, Methicillin resistance, Pathogen, Wound infections