Antimicrobial Resistance Patterns and Virulence Gene Profiles of Klebsiella pneumoniae Isolated from Surgical Site Infections in Iran.

Background: The prevalence of Klebsiella pneumoniae in surgical site infections (SSIs) has increased recently. This study aimed to evaluate the antimicrobial resistance patterns and biofilm formation capacity of K. pneumoniae strains isolated from SSIs. Methods: A total of 63 K. pneumoniae isolates were obtained from patients with SSIs. Antimicrobial susceptibility testing was determined using the Kirby-Bauer method. Molecular analyses were performed to confirm the presence of virulence and antibiotic resistance genes. Biofilm formation was determined using a semiquantified microtiter plate assay, and optical density measurements were used to classify the isolates into weak, moderate, and strong biofilm producers. Biofilm structure was observed using field-emission scanning electron microscopy. Statistical analyses were performed using SPSS software version 16 (SPSS Inc., Chicago, IL, USA), and data were analyzed and presented in terms of frequency and percentage. Results: The frequencies of fimH, mrkD, mrkA, wcaG, and magA were 98.4%, 96.8%, 77.7%, 61.9%, and 7.9%, respectively. The highest rates of antibiotic resistance were observed for cefazolin, cefuroxime, and piperacillin/tazobactam and 98.4% of the isolates were resistant to at least one antibiotic agent. The most prevalent resistance genes were blaSHV (42.8%), blaCTX-M (31.7%), blaTEM (28.5%), and blaOXA48 (22.2%). All the tested isolates were able to produce biofilms, and 76.2% were classified as strong biofilm producers. Conclusions: Klebsiella pneumoniae is one of the common pathogens in SSIs, and due to its antibiotic resistance and the presence of multiple virulence factors, proper controlling strategies need to be carried out.