Multi-antibiotic resistant extended-spectrum beta-lactamase producing bacteria pose a challenge to the effective treatment of wound and skin infections

Introduction: The increasing incidence of antibiotic resistant bacteria is a concern both to the clinicians and the patients due to obvious consequences such as treatment failures, prolonged patients' stay in hospital and nosocomial infections. The choice of the first antibiotic therapy in emergency wards in hospitals is usually not based on patient-specific microbial culture and susceptibility test result.This study is aimed at profiling extended-spectrum beta-lactamase (ESBL) producing bacteria associated with wound injuries and highlighting their multi-antibiotic resistance character.

Methods: Sixty-three wound swab samples were collected and cultured on nutrient agar and on selective media. Evaluation for ESBL production was by phenotypic method while the antibiogram screening was by disc-diffusion.

Results: The wounds evaluated were diabetic sore (14), cancer wounds (12), surgical wounds (17), wounds due to road traffic accidents (10) and wounds from fire burn (10). The result showed that 61 wounds were infected and the prevalence of the infecting pathogens was Escherichia coli 17.46%, Klebsiella Pneumonia 14.28%, Salmonella typhi 12.79%, Pseudomonas Aeruginosa 34.92% and Staphylococcus aureus 17.46%. Thirty four (55.74 %) isolates were ESBL producers, greater than 50% of which being Pseudomonas Aeruginosa. The antibiogram study of the ESBL producers showed multi-drug resistance with resistance highest against ampicillin (100%), followed by cephalosporins: cefuroxime (94.12%) and ceftriaxone (61.76%). No resistance was recorded against the β-lactamase inhibitors: amoxicillin/clavulanate and ceftriaxone/sulbactam. There was a high incidence (55.74 %) of ESBL-producing microbes in the wounds. The isolates were mostly multi-antibiotic resistant.

Conclusion: Multi-drug resistant ESBL-producing bacteria are common in wound infections in the community. However, amoxicillin/clavulanate or ceftriaxone/sulbactam may be used to treat most patients with such infections in the hospital. This may guide antibiotic selection and use in trauma, most especially in resource limited countries where laboratory test is unaffordable for a majority of patients.