Bacteriological Profile of Post-Operative Wound Infections and their Antimicrobial Susceptibility Pattern in a Tertiary Care Hospital

Abstract

Postoperative wound infections or surgical site infection is one of the most commonly Hospital associated infections of patients undergoing surgery. This study was proposed to evaluate the aerobic bacterial isolates and their drug susceptibility patterns in patients with clinically suspected postoperative infection. Samples that were sent to the microbiology laboratory from clinically suspected cases of post-operative wound infections were grown on aerobic culture and their species were identified by standard biochemical tests. Antibiotic sensitivity testing and phenotypic identification of MRSA and ESBL producers were done as per CLSI guidelines 2020. The rate of postoperative wound infection in Rajah Muthiah Medical hospital was 5.59%. Out of 300 infected cases, 145 samples showed culture positivity. The most common organism isolated was Staphylococcus aureus followed by E.coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Coagulase negative staphylococcus aureus (CONS), and Proteus mirabilis. About 84 % of S.aureus were MRSA and 16 % were MSSA. 96% S.aureus were sensitive to Linezolid. ESBL producers were about 41.8 % of which 21.6 % were Enterobacteriaceae and 13.2% were P.aeruginosa. In this study, a higher number of MDR strains was found as the causative agent of wound infection. Thus, to achieve effective therapy for wound infections and to reduce/stop the appearance of multidrug-resistant (MDR) pathogens, continuous monitoring is essential with the appropriate use of antimicrobial agents. So, routine microbiological analysis of the wound specimen and their antibiotic susceptibility testing are recommended that will guide medical practitioners in the empirical treatment of wound infection, to reduce the spread of resistant bacteria.