PHENOTYPIC AND GENOTYPIC INSIGHTS: ISOLATION OF PROTEUS MIRABILIS FROM BURN WOUNDS INFECTIONS

Abstract

Background: Proteus mirabilis is a Gram-negative, facultatively anaerobic pathogen frequently implicated in burn wound infections. Its ability to form biofilms, produce virulence enzymes such as urease, and acquire antimicrobial resistance genes contributes to its persistence and pathogenicity. The emergence of multidrug-resistant (MDR) P. mirabilis strains, particularly those resistant to β-lactam antibiotics, presents a significant clinical challenge. Identifying resistance mechanisms is crucial for improving therapeutic strategies and mitigating antimicrobial resistance in burn care settings.

Objective: This study aimed to characterize the phenotypic and genotypic resistance mechanisms of P. mirabilis isolated from burn wound infections, with a particular focus on multidrug resistance and β-lactam resistance genes.

Methods: Ethical approval (Approval Certificate #14/2022) was obtained, and informed consent was secured from all participants at Children Hospital Lahore. A total of 80 wound swab samples were collected from burn patients. Bacterial identification was performed using standard microbiological techniques following Clinical and Laboratory Standards Institute (CLSI) guidelines. DNA extraction was conducted using the Miniprep bacterial DNA extraction kit, followed by polymerase chain reaction (PCR) to detect resistance genes, including blaTEM and blaCTX-M. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Statistical correlations between resistance patterns and patient demographics, including age, gender, and clinical severity, were analyzed using SPSS version 22.

Results: Out of 80 samples, 45 (56.2%) P. mirabilis isolates were identified. Phenotypic analysis showed that 75.0% of isolates exhibited multidrug resistance, with marked resistance to β-lactams (71.1%). Ampicillin resistance was observed in 69.0%, while cephalosporin resistance was noted in 64.4%. Genotypic analysis confirmed the presence of blaTEM in 65.0% and blaCTX-M in 60.0% of isolates, demonstrating a strong correlation between genetic determinants and observed resistance profiles (p < 0.05).

Conclusion: Multidrug-resistant P. mirabilis is prevalent in burn wound infections, with β-lactam resistance being particularly concerning. The study underscores the need for alternative therapeutic options, improved antimicrobial stewardship, and continuous surveillance to combat the rising threat of antimicrobial resistance in burn care units.