Surgical site infection: Clinico- bacteriological Profile and antibiogram in a tertiary care hospital in Kolkata

Abstract

Surgical site infections (SSIs) are a major health care associated infections and possess a great challenge to clinicians. It increases duration of hospital stay, associated morbidity and mortality and treatment cost. For prompt and appropriate management, it is necessary to understand the appropriate microbial etiology and its antimicrobial susceptibility pattern. To determine the prevalence of SSI along with its clinico-bacteriological profile and antibiogram and to correlate with the risk factors.A cross-sectional study was conducted in the Department of Microbiology of Nil Ratan Sircar Medical College & Hospital, Kolkata for a period of one year (2020-2021). Post-operative surgical site infections within 30 days after surgery were included in the study. All samples were collected from clinically suspected SSI cases and processed in the lab as per standard laboratory protocol. Vitek®2 compact system (BIOMERIEUX) was used for further identification and antimicrobial susceptibility testing. All Gram negative pathogens resistant to 3rd generation cephalosporins were screened for ESBL and AmpC. Carbapenem resistant isolates were subjected to Carba NP test for carbapenemase production. Out of 6582 surgeries, clinically suspected SSIs were detected in 220 cases. Among these 220 patients, 186 patients were confirmed as SSI in the laboratory, SSI rate being 2.83%. In 62.27% cases, growth was mono-microbial. Growth of gram negative organisms were noted in 58.72% cases and gram positive growth was 38.53%. (57.14%) was the predominant isolates followed by (35.94%). Diabetes mellitus, obesity and using prophylactic antibiotic >2 hours prior to surgery were found to be significantly associated. For gram positive organism, Vancomycin and Linezolid were found to be most susceptible antimicrobials and for gram negative organisms, it was Polymyxin B and Meropenem. Most of the gram negative organisms were ESBL producer (67.97%). Rapidly emerging multi drug resistant organisms are complicating the management of surgical site infection day by day and possessing significant burden to health care system. For implementation of appropriate antimicrobial policy, it is important to identify bacteriological profile and antibiogram in every hospital.