Prevalence of multidrug-resistant bacteria isolated from patients with burn infection

Abstract

Objectives The aims of the study were to determine bacterial pathogens frequently causing burn infections and their antimicrobial susceptibility patterns, to estimate the prevalence of multidrug resistance (MDR) among the isolated pathogens, and to evaluate the different risk factors for the development of burn wound infection. Background Infection in burn patients remains the significant source of morbidity and mortality. The aggressive use of antimicrobials has improved survival but led to an increased colonization and infection of pathogens that resist current therapies. Materials and methods The study was carried out by collecting swabs from 105 burnt patients during the period from October 2012 to November 2013. Semiquantitative assessment of bacterial growth was performed to distinguish between bacterial colonization and infections. MDR strains were detected including methicillin-resistance and vancomycin-resistance staphylococci and Gram-negative bacilli extended-spectrum b-lactamases and metallo-b-lactamases producers by standardized methods. Results Burn wound infections were polymicrobial in 26.6% of cases. Staphylococcus aureus was the most common aerobic isolate (32.4%). Among S. aureus, 76.5% were MDR strains, 73.5% were methicillin-resistant, and 17.6% were vancomycin resistant. Coagulase-negative staphylococci (CoNS) were represented by 16.2%. About 47% of CoNS strains were MDR strains, 47% were methicillin-resistant CoNS, and 23.6% were vancomycin-resistant CoNS. All Gram-negative bacteria isolated from burn wounds were MDR. Extended-spectrum b-lactamases were detected in 58.5%, whereas metallo-b-lactamases were detected in 43.4% of Gram-negative bacteria. The risk factors for burn wound infections were young age, low socioeconomic status, abuse of invasive procedures and antimicrobial, prolonged hospital stay, and improper control of burn-associated comorbidities. Conclusion The study highlights the high prevalence of MDR bacteria infecting burn wound in our hospitals.