Antimicrobial resistance in clinical wound infections: A study on Escherichia coli and Pseudomonas aeruginosa isolates from patients in Imo state, Nigeria

Background: The growing resistance of Escherichia coli and Pseudomonas aeruginosa to antimicrobial treatments poses a major public health concern, particularly in the treatment of hospital-acquired wound infections.
Aim: This study investigated the antimicrobial resistance profile of Escherichia coli and Pseudomonas aeruginosa isolated from patients with wound infections in Imo State, Nigeria.
Study Design: A total of 76 bacterial isolates, comprising Escherichia coli and Pseudomonas aeruginosa, were recovered from patients with clinically infected wounds and subjected to antimicrobial susceptibility testing against a panel of antibiotics representing multiple antibiotic classes, to determine their antimicrobial resistance profiles.
Methodology: Antimicrobial susceptibility testing was performed using the disc diffusion method, as outlined in the Clinical and Laboratory Standards Institute CLSI (2017) guidelines. The isolates were tested against cephalosporins, carbapenems, polymyxins, and quinolones, which include ceftazidime (10μg), ceftriaxone (30μg), cefepime (30μg), imipenem (10μg), meropenem (10μg), colistin (10μg), polymyxin B (30μg), ciprofloxacin (5μg), and levofloxacin (5μg), to determine susceptibility profiles.
Results: Findings revealed a high prevalence of multidrug resistance (MDR) among the gram-negative bacterial isolates, with a substantial proportion of isolates exhibiting resistance to three or more antibiotic classes. Specifically, 43.9% (18) of Pseudomonas aeruginosa and 45.71% (16) of Escherichia coli isolates were identified as MDR.
Notably, a significant number of Escherichia coli and Pseudomonas aeruginosa isolates exhibited resistance to various antibiotic classes, including cephalosporins, carbapenems, polymyxins, and quinolones. However, carbapenems demonstrated remarkable efficacy, with a significant majority of isolates showing susceptibility — 92.68% of Pseudomonas aeruginosa and 90% of Escherichia coli isolates.
Conclusion: The study highlights the urgent need for robust antimicrobial stewardship and infection control practices to preserve the efficacy of available antibiotics in the treatment of clinical wound infections.