TITLE:
Characterization of Antibiotic Resistance and Prevalence of Diarrheagenic E. coli Strains Isolated from Stool Samples in a Hospital Setting in Mali
AUTHORS:
Aminata Maiga, Lassina Doumbia, NFaly Tounkara, Tidiani Sinayoko, Rabiatou Sanogo, Ibrahim Keita, Ami Diakite, Moussa Diawara, Oumar Agaly Dicko, Famakan Dembele, Mohamed Ag Baraika, Yacouba Cissoko, Drissa Kone, Aldiouma Guindo, Ibrahim Izetiegouma Maiga, Ousmane Koita
KEYWORDS:
E. coli, DEC, Gene, Multidrug Resistance, Integron, Mali
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.16 No.12,
December
3,
2025
ABSTRACT: Introduction: Antibiotic resistance is a major global health challenge that disproportionately affects low-resource countries, particularly those in West Africa. E. coli, a major pathogen in childhood diarrhea, is both a prominent infectious agent and a reservoir of resistance genes, including resistance to last-resort antibiotics, such as carbapenems. Methodology: The study focused on 98 clinical E. coli isolates collected from stool samples of patients in a hospital setting in Bamako. The analyses included screening for DEC-specific virulence genes, detection of resistance genes across various classes of antibiotics (e.g., beta-lactams, carbapenems, fluoroquinolones), and identification of class 1, 2, and 3 integrons. The blaNDM gene was sequenced to identify mutations associated with carbapenem resistance. Results: Among the isolates, 85.7% carried at least one virulence gene. Of these, half involved co-infections, commonly combining EPEC, EAEC, and ETEC strains. Regarding antibiotic resistance, 94.9% of isolates harbored at least one resistance gene, and 50% were multidrug-resistant. The most frequently detected genes were blaTEM, qnrS1, and aphA3. Class 2 integrons were significantly associated with multidrug resistance (p = 0.01). Sequencing of the blaNDM gene revealed point mutations likely to affect protein function, suggesting an evolution toward increased resistance to carbapenems. Conclusion: The high prevalence of multidrug-resistant diarrheagenic E. coli strains in this study highlights the local antibiotic pressure and the serious health threat it represents. This study shows that the new β-lactamase blaNDM gene has disseminated in the hospital environment of Bamako. It should be noted that this will become a major challenge for clinicians.