Aerobic Bacteriological Isolates of Burn Wound Infections and Their Antimicrobial Sensitivity Pattern in the Burn Unit of a Tertiary Care Hospital in Bihar: A Prospective Observational Study

Abstract

Background: Burn wound infections are among the leading causes of morbidity and mortality in burn patients due to loss of skin barrier, immunosuppression, prolonged hospitalization, and emergence of antimicrobial-resistant organisms. Continuous monitoring of the bacteriological profile and antimicrobial susceptibility pattern is essential for effective management of burn wound infections.
Aim: To study the aerobic bacteriological isolates of burn wound infections and evaluate their antimicrobial sensitivity pattern among patients admitted to the Burn Unit of Patna Medical College & Hospital (PMCH), Patna.
Materials and Methods: A hospital-based prospective observational study was conducted in the Burn Unit of PMCH, Patna, from October 2022 to September 2023. A total of 100 burn wound patients clinically suspected of wound infection were included. Wound swabs/pus samples were collected under aseptic precautions and processed using standard microbiological techniques for aerobic bacterial isolation and identification. Antimicrobial susceptibility testing was performed by Kirby–Bauer disc diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Statistical analysis was performed using SPSS version 25.0.
Results: Among the 100 burn wound samples studied, bacterial growth was obtained in 79 samples, while 21 samples showed no growth. Of the culture-positive samples, 69 (87.34%) demonstrated monomicrobial colonization and 10 (12.66%) demonstrated polymicrobial colonization. A total of 89 bacterial isolates were recovered. Pseudomonas aeruginosa was the predominant isolate accounting for 41.57% of isolates, followed by Staphylococcus aureus (25.84%), coagulase-negative staphylococci (14.60%), Klebsiella pneumoniae (8.98%), Escherichia coli (5.61%), and Proteus mirabilis (3.37%). Gram-negative organisms constituted 59.55% of isolates, whereas Gram-positive organisms accounted for 40.45%. Imipenem demonstrated the highest sensitivity against Gram-negative isolates, while vancomycin and linezolid showed 100% sensitivity against Gram-positive isolates.
Conclusion: Pseudomonas aeruginosa was the predominant aerobic bacterial isolate recovered from burn wound infections in the present study, followed by Staphylococcus aureus. Gram-negative organisms were more common than Gram-positive organisms. Imipenem showed excellent activity against Gram-negative isolates, while vancomycin and linezolid remained highly effective against Gram-positive isolates. Regular bacteriological surveillance and rational antibiotic use are essential for effective management of burn wound infections and prevention of antimicrobial resistance.