Bacteriological profile of post-operative orthopedic implant infections and their antibiotic sensitivity pattern in a tertiary care hospital of southern Odisha

Abstract

Context: Prosthetic replacements and implants are becoming common in orthopedic operations for successfully alleviating the pain and improving the mobility in damaged joints. This sometimes leads to microbial infections contributing to high morbidities and prolonged hospital stay. Aims: This study was aimed to find out (1) the prevalence of bacterial infection in orthopedic implant surgeries; (2) to isolate and identify the bacteriological agents responsible for causing post-operative orthopedic implant infections; and (3) to perform their antimicrobial sensitivity. Methods: This was a prospective study carried out at a tertiary care hospital of southern Odisha, over a period of 24 months. The study was conducted on 112 cases of infected implants from orthopedic wards, from 1st January 2016 to 31st December 2018. Pus samples were collected using three sterile swabs. One was used for Grams stain, one for inoculation on MacConkey and Blood agar, and the 3rd one for inoculation in Robertson's cooked meat (RCM) broth. Blood agar and MacConkey agar plates were processed for culture of aerobic bacteria, while the RCM inoculate was processed for anaerobic bacteria. Biofilm production and Susceptibility testing was performed. Results: Out of the 112 samples processed, culture positivity was observed in 90 specimens. Among them, 78 were aerobic, while 12 were anaerobic infections. Staphylococcus aureus (35.89%) was the predominant aerobic isolate followed by Pseudomonas spp. (28.2%). Among anaerobes, Bacteroides spp. (7.7%) was the most common isolate. Conclusion: The appropriate pre- and post-operative care should be taken to prevent such infections. Staphylococcus spp. was the commonest isolate and its ability to produce biofilm stresses the need for an appropriate antibiotic policy to put in place to eradicate the infection.