Profile of microorganisms and antimicrobial resistance at a tertiary care referral burn centre in Iran: Emergence of Citrobacter freundii as a common microorganism

Infection and antimicrobial resistance are important issues in severe burn. The aims of this prospective study were to investigate the profile of microorganisms and resistance to antimicrobial agents in a tertiary referral burn centre; 113 people aged >10 years, with partial- or full-thickness burns, were included in the study. A total of 733 samples including 275 swabs, 164 tissue biopsies, 258 urine samples, 26 blood samples and 10 sputum samples were collected, from which 124 microorganisms were isolated. Pseudomonas aeruginosa and Citrobacter spp were the most prevalent isolates (57.3% and 35.5%, respectively); 95.5% of Citrobacter. isolates were Citrobacter freundii. Antibiogram results obtained from 15 antimicrobial agents demonstrated that imipenem was the most effective agent against P. aeruginosa, followed by ciprofloxacin and piperacillin/tazobactam (67.9%, 43% and 37.5% sensitive, respectively). At least 60% of all Citrobacter isolates were sensitive to various antimicrobial agents, the highest sensitivity being obtained by ceftazidime and cefepime (81.6% and 78.4%, respectively). Sensitivity of P. aeruginosa isolates to the agents of each antimicrobial class was significantly different (p < 0.001). The incidence of C. freundii and the resistance of P. aeruginosa to anti-pseudomonas agents were exceptionally high.