Surgical site infection in a coastal tertiary care teaching hospital

Introduction: Surgical site infections are one among the commonly reported nosocomial infections. The present study was aimed at determining the possible risk factors involved in development of SSIs and the microorganisms responsible for SSIs with their antibiogram in a rural tertiary care teaching hospital. Materials and methods: This was a prospective observational study conducted in the Department of Surgery in association with the Department of Microbiology at Vinayaka Missions Medical College and Hospital over a period of six months. Detailed history such as age, sex, operation category (elective/ emergency), history of diabetes were recorded. Swabs were collected from clinically suspected of surgical site infections. Specimens collected were subjected to standard microbiological procedures. Antimicrobial susceptibility of the isolates was determined by Kirby Bauer disk diffusion method on Muller Hinton agar plates according to Clinical and Laboratory Standard Institute (CLSI) guidelines. Results: A total of 342 patients underwent surgery during the study period. 59 cases were clinically diagnosed of surgical site infection, out of which 55 patients' samples yielded growth and accounted for 16% infection rate. The incidence of infection was high in case of emergency surgeries (22%) compared to elective surgeries (13%). SSI rate was low in clean surgeries (7%) whereas contaminated and dirty wounds showed 43% and 75% respectively. Staphylococcus aureus (27.5%) was the predominant pathogen isolated. Linezolide was the most susceptible antibiotic against Gram positive cocci. Second predominant organism was Escherichia coli 14 (20.2%). and showed good susceptibility to imipenem, cefeperazone/ sulbactum and piperacillin/ tazobactum including ESBL producers. Conclusion: In this study, surgical site infection rate was 16%. Staphylococcus aureus (27%) was the most frequently isolated bacteria followed by E.coli (20%). Good susceptibility observed towards linezolide against Gram positive cocci. Imipenem, cefeperazone/ sulbactum and piperacillin/ tazobactum were effective against Gram negative bacilli.