Isolation and Identification of Multi-drug resistant Pseudomonas aeruginosa from Burn Wound Infection in Chittagong City, Bangladesh

Abstract

Pseudomonas aeruginosa is an important infectious agent which causes nosocomial infections in immune-compromised patients, especially among burnt patients. In recent times, it has emerged as a far-flung Multi-Drug Resistant (MDR) pathogen which needs regular and periodic antibiotic susceptibility surveillance. The aim of this study was to isolate and identify MDR-P. aeruginosa from the burn patients held in the burn unit of Chittagong Medical College Hospital (CMCH) for ~2 months under treatment andto determine their antimicrobial resistance pattern for some commonly prescribed antibiotics. P. aeruginosa isolates were recovered from ten random wound swab samples of burnt patients through selective growth on MacConkey and Cetrimide agar media. Selected isolates were subjected to cultural, morphological and biochemical characterization. Antibiotic susceptibility patterns of the P. aeruginosa isolates were investigated by standard disk diffusion method of Kirby-Bauer. We assessed their antibiotic sensitivity patterns employing Amoxicillin, Ampicillin, Ceftazidime, Cephalexin, Chloramphenicol, Ciprofloxacin, Gentamicin, and Tetracycline. Two isolates of P. aeruginosa exhibited similar biochemical profiles but differ in cultural characteristics and antibiotypes; hence recognized as separate strains: P. aeruginosa CU1 and P. aeruginosa CU2. P. aeruginosa CU1 was found to be an MDR strain and showed resistance to all the test antibiotics. Not only the isolate exhibited resistance to ampicillin, amoxicillin, cephalexin, ciprofloxacin and tetracycline, but also showed remarkable resistance against two recommended antipseudomonal drugs: gentamicin and ceftazidime. Despite not being an MDR, P. aeruginosa CU2 exhibited resistance against amoxicillin, ampicillin and gentamicin. Though this report covered a small number of samplings and the results represent only a tiny fraction of total burnt patients of the Chittagong city; our findings are auguring enough considering public health concern which might spur care from public health management system of the nation.