Prevalence of Pseudomonas aeruginosa and its antimicrobial sensitivity profile among post-operative wound infections in a tertiary care hospital

Background: Post-operative wound infection or surgical site infection (SSI) is a significant cause of nosocomial infection among patients who have undergone surgery. Objective: The present prospective study was aimed to determine the prevalence of Pseudomonas aeruginosa among the isolates of post-operative wound infection and to study their antimicrobial sensitivity profile. Materials and Methods: The present study was carried out in the department of Microbiology of a teaching tertiary care hospital for a period of six months from January 2021 to June 2021. During this period, a total of 100 post operative wound swabs were processed according to the standard microbiological techniques. The identification of bacterial isolates was done by standard biochemical (HiMedia, Mumbai) and automated (Vitek 2-Compact System, BioMérieux Inc., France) techniques. Antimicrobial Susceptibility Testing (AST) of the isolates was performed on Mueller Hinton agar (HiMedia, Mumbai) by Kirby Bauer’s disc diffusion method. Choice of the antimicrobials and the interpretation of results were done in accordance with the Clinical Laboratory Standard Institute (CLSI) guidelines-2020. Statistical Analysis: The collected data was transferred to the computer and Microsoft Excel 2000 (version 9) Analysis Tool Pack was used for analysis of data. Chi-square test was performed and p ≤ 0.05 was considered statistically significant. Results: Among the 100 wound swabs studied, 93% revealed growth while 7% samples were sterile. Pseudomonas aeruginosa was isolated among highest number of infected wound swabs (26 %) and comparatively higher number (61.53 %) was detected among male patients and those that belonged to 61-80 years of age group (46.15 %). The abscess drainage was the most common type of post operative wound (38.46%) followed by surgery of diabetic foot (30.76%). P.aeruginosa was susceptible to colistin (96.7%) followed by meropenem (76.92%) and imipenem (73.07%).Conclusions: In the present study, Pseudomonas aeruginosa infection was the most common surgical site infection in our healthcare setting and was found to be dependent on age and sex of the individuals who had undergone surgery. Enormous amount of drug resistance was revealed by the isolates. Continuous monitoring of susceptibility pattern of P. aeruginosa through surveillance, formulation of antibiotic policy and infection control practices is essential in individual health care settings in order to prevent further emergence of resistance