# Comparative Study of Swab Culture and Tissue Biopsy in Burn Wound Sepsis: A Tertiary Centre Experience

## TL;DR

This study compares swab and tissue biopsy methods for detecting infections in burn wounds and finds that tissue biopsies are more effective for deeper infections.

## Contribution

The study provides evidence that tissue biopsy culture is superior to swab culture for detecting deeper wound infections in burn patients.

## Key findings

- Tissue biopsy culture showed higher concordance with clinical outcomes compared to swab culture.
- A bacterial load above 10^5 CFU/ml in biopsies was strongly associated with poor patient outcomes.
- Pseudomonas aeruginosa was the most commonly isolated organism in burn wound infections.

## Abstract

Infection remains a critical cause of mortality among patients with burn injuries, with sepsis and subsequent multiorgan failure being the predominant reasons for death in intensive burn care units. The emergence of nosocomial pathogens in this population makes early identification of infection essential for predicting septicemia and reducing mortality rates. This study aimed to compare the efficacy of surface swab culture versus tissue biopsy culture in identifying pathogenic organisms in burn wounds and examine the correlation between bacterial counts and clinical outcomes.​ A prospective study was conducted enrolling 50 burn patients admitted to the burns ward at Thrissur Medical College, Kerala, India. For each patient, surface swabs and tissue biopsies were collected and processed using conventional culture methods. The statistical analysis was performed using chi-square tests.

There was a significant relationship between total body surface area (TBSA) affected and clinical outcome, with a mean TBSA of 45.8%. Notably, 42/50 (84%; p < 0.05) of patients sustained third-degree burns, which was statistically significant in its impact on outcome. Bacterial growth was observed in 48 (96%) of surface swab cultures and 49 (98%) of tissue biopsy samples, with a concordance rate of 19/50 (38%). The most frequently isolated organisms were Pseudomonas aeruginosa 17(34%), Staphylococcus aureus, Klebsiella, and Acinetobacter. A bacterial load greater than 10^5 CFU/ml on quantitative biopsy was significantly associated with poor outcome, as 18/19 (94.7%) patients who died demonstrated counts above this threshold (p < 0.05). In conclusion, both wound surface swab and tissue biopsy cultures were effective in demonstrating pathogen presence, but tissue biopsy was superior in the context of deeper wound invasion. Incorporating tissue biopsy culture into routine management algorithms for high‑risk burn patients may therefore improve prognostication, optimize antibiotic stewardship, and ultimately reduce sepsis‑related deaths in burn units.