Etiological Agents and Antimicrobial Susceptibility of Surgical Site Infection Isolates: A Single-Center Experience in Bulgaria

Abstract

Background. Surgical site infections represent the leading complication in surgical departments and are often associated with higher costs, treatment duration and mortality. The present study has evaluated the incidence, the bacteriological profile and the antibiotic resistance pattern of surgical site infection pathogens isolated in the Military Medical Academy in Varna, Bulgaria. Material and methods. A total of 463 isolates were obtained from 957 surgical site samples investigated from January 2019 to December 2021. Their antibiotic susceptibility was determined by the disk diffusion method following the EUCAST guidelines. Results. The most common isolates for the study period were coagulase-negative staphylococci (21.8%) and Escherichia coli (17.3%). Vancomycin, teicoplanin and linezolid were fully effective against staphylococci and enterococci, while colistin, imipenem, meropenem and piperacillin/tazobactam were fully effective against Enterobacteriaceae. Similarly, the most active with 100% retained activity against Pseudomonas aeruginosa and Acinetobacter baumannii was colistin. Conclusions. The etiological structure of surgical site infections in the Military Medical Academy in Varna was comparable to that found in other studies, with a prevalence of staphylococci and enteric bacteria. We found a significant number of isolates resistant to commonly used antibiotics, which limits available treatment options. Strict and active antimicrobial resistance surveillance should be adapted to a larger extent to prevent the emergence of resistant strains.