Phenotypic screening and antibiotic susceptibility patterns of AmpC β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates obtained from wound samples
Author(s): Esther Chigbaziru Nwojiji, Chijioke Ekpono Ugbala, Ifeoma Precious Ogbonna, Aniokete Ugonna Cassandra, Obinna Okpaga Awoke, Ikemesit Udeme Peter and Ifeanyichukwu Romanus Iroha
Abstract: Background: AmpC β-lactamase-producing strains of
E. coli and
K. pneumoniae have exacerbated treatment challenges, particularly in wound patients, due to their critical resistance phenotype. The lack of awareness among clinicians regarding the clinical significance of AmpC-producing organisms has led to undetected outbreaks and persistent infections in healthcare settings. This study aimed to determine the prevalence of AmpC β-lactamase-producing
E. coli and
K. pneumoniae and their antibiotic susceptibility patterns among wound patients at Alex Ekwueme Federal University Teaching Hospital, Abakaliki.
Methodology: A total of 200 wound swab samples were collected from patients attending the tertiary hospital. The samples were analyzed using standard microbiological techniques for the identification and characterization of Escherichia coli and Klebsiella pneumoniae. Phenotypic screening for AmpC β-lactamase production was performed using the Cefoxitin-Cloxacillin Double Disk Synergy Test (CC-DDST). Antibiotic susceptibility testing was conducted using the Kirby-Bauer disk diffusion method.
Results: Culture-based techniques identified Escherichia coli in 63 cases (31.5%) and Klebsiella pneumoniae in 15 cases (7.5%). Phenotypic confirmation using the CC-DDST method revealed AmpC production in 21 E. coli isolates (10.5%) and 7 Klebsiella pneumoniae isolates (3.5%). AmpC β-lactamase-producing E. coli and K. pneumoniae exhibited high susceptibility to gentamicin and ciprofloxacin (60-100%), while susceptibility to ceftriaxone, imipenem, and trimethoprim-sulfamethoxazole was low (28.6-57.1%).
Conclusion: This study identified AmpC β-lactamase production in E. coli and K. pneumoniae isolates from wound infections, with gentamicin and ciprofloxacin remaining effective treatment options. However, the emergence of these AmpC-producing strains underscores the need for enhanced surveillance to monitor their spread. The findings highlight the importance of establishing efficient antimicrobial resistance (AMR) surveillance systems at local and national levels to track the rise and dissemination of AmpC β-lactamase producers and other multidrug-resistant pathogens in the country.
DOI: 10.22271/27069567.2025.v7.i2a.623Pages: 40-47 | Views: 81 | Downloads: 33Download Full Article: Click Here
How to cite this article:
Esther Chigbaziru Nwojiji, Chijioke Ekpono Ugbala, Ifeoma Precious Ogbonna, Aniokete Ugonna Cassandra, Obinna Okpaga Awoke, Ikemesit Udeme Peter, Ifeanyichukwu Romanus Iroha.
Phenotypic screening and antibiotic susceptibility patterns of AmpC β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates obtained from wound samples. Int J Adv Res Med 2025;7(2):40-47. DOI:
10.22271/27069567.2025.v7.i2a.623
