Bacteriological Profile and Antimicrobial Susceptibility Patterns of Isolates From Burn Wounds at a Tertiary Care Hospital in Patna

Abstract

Infection in burn patients is the leading cause of morbidity and mortality, and remains one of the most challenging concerns for the burn team. The bacteriology of burn wounds is often polymicrobial in nature, and the presence of multi-drug resistant organisms is associated with poor response to antimicrobial therapy, high risk of bacterial sepsis, multi-organ failure and death following burn injury. AIM: This study analyzes the bacterial isolates from burn wounds and their antimicrobial sensitivity patterns. MATERIALS AND METHODS: Three hundred randomly selected patients with varying degrees of burn injuries, admitted to the burn unit of a tertiary care hospital in Patna, were included in this study. Wound swab/pus/debrided tissue cultures were assessed at weekly intervals. Seven hundred and thirty six samples were eventually collected and analyzed in this study. The samples were cultured on 5% sheep blood agar and Mac Conkey agar for isolation of organisms. Antimicrobial sensitivity test was performed on Mueller Hinton agar by the disk diffusion method. RESULTS: Patients between 30-40 years of age were more prone to burn injury. Females outnumbered males as regards prevalence of burn cases. Positive wound cultures were obtained in 631 (85.7%) cases. Staphylococcus aureus (40.4%) was the most common isolate in the first week, but was replaced by Pseudomonas spp. in the second (26.0%) and third (28.8%) post-burn weeks. High level resistance to oxacillin was observed in Staphylococcus aureus and Coagulase negative Staphylococci. Vancomycin was the most effective drug for the gram positive isolates. Pseudomonas and Acinetobacter isolates were resistant to most of the drugs tested. Imipenem was effective against all the gram negative isolates. CONCLUSIONS: It is crucial for every burn unit to determine the specific pattern of burn wound microbial colonization, time-related changes in the dominant flora and their antimicrobial sensitivity profiles. This would enable early treatment of imminent septic episodes with proper empirical antibiotics, without waiting for culture reports, thus improving the overall infection-related morbidity and mortality.