Antibacterial potential of Anogeissus acuminata against ESBL and carbapenemase-producing multidrug-resistant UPEC

Abstract

Background: The increasing prevalence of antibiotic-resistant Escherichia coli (E. coli) presents significant challenges in managing urinary tract infections (UTIs), particularly in resource-limited settings. Nearly 50% of E. coli isolates are extended-spectrum β-lactamase (ESBL) producers, often harboring resistance genes such as CTX-M-15 and NDM, which confer resistance to last-line antibiotics. Aim: To evaluate the antibacterial efficacy of Anogeissus acuminataextract against genetically confirmed ESBL- and carbapenemase-producing uropathogenic E. coli (UPEC) strains isolated from UTI patients. Methods: A total of 273 UPEC strains were isolated from symptomatic UTI patients (146 females, 127 males). ESBL and carbapenemase production was confirmed using phenotypic and molecular methods per CLSI 2022 guidelines. PCR was used to detect CTX-M and NDM resistance genes. The antibacterial potential of A. acuminata extract was assessed using the Kirby-Bauer disc diffusion method and compared to gentamicin. Results: Among the 273 isolates, 70% exhibited multidrug resistance (MDR); 82 were ESBL producers and 62 were carbapenemase producers. The extract of A. acuminata demonstrated substantial antibacterial activity, with inhibition zones of 20.18 ± 0.89 mm (ESBL-producers) and 20.91 ± 1.3 mm (carbapenemase-producers), comparable to 100% gentamicin. Resistance was more prevalent in hospitalized patients and slightly higher in males. CTX-M and NDM were the most common resistance genes. Conclusion: The study reveals a high prevalence of MDR UPEC strains and emphasizes the urgent need for alternative therapies. A. acuminata showed promising antibacterial activity against resistant UPEC isolates, supporting its potential as an adjunct or alternative treatment for UTIs, especially in low-resource settings.