Potential Pathogenicity of Escherichia coli Isolated from the Stools of Healthy Children Suffering from Diarrhea Admitted to Hospitals in Southern Benin

Aims: Infant mortality linked to infectious diseases remains a major public health concern, especially in the context of antibiotic resistance. This work aimed to study the potential pathogenicity of Escherichia coli strains isolated from the stools of children suffering from diarrhea and healthy from 0 to 15 years old admitted to hospitals in southern Benin.

Methodology: The isolation and characterization of the strains were carried out according to standard microbiology methods. Molecular characterization was carried out by searching for eight virulence factors (Stx1, Stx2, eaeA, bfpB, LT, InVE, IpaH, AggR) and three antibiotic resistance genes (blaTEM, blaSHV, blaCTX -M) by the PCR technique.

Results: This study shows that 47.06% of the children sampled suffered from diarrhea, against 52.94% who were healthy. A total of 9 species of Enterobacteriaceae were identified in different proportions: Escherichia coli (66.66%), Klebsiella ornithinolytica (13.72%), Klebsiella pneumonia (5.88%), Enterobacter aerogenes (3.92%), Escherichia vulneris (1.96%), Salmonella arizonae (1.96%), Salmonella spp (1.96%), Enterobacter sakazakii (1.96%), Serratia fonticola (1.96%). All E. coli showed total resistance to amoxicillin, ceftazidime, and cefotaxime. In addition, they showed variable resistance to norfloxacin (95.33%), trimethoprim (83.33%), and sulfamethoxazole (95.24%). 70.83% of E. coli strains isolated from apparently healthy children carry resistance genes blaTEM (12.5%), blaSHV (25%), and blaCTX-M (33.33%). While 66.67% of strains of E. coli isolated from children with diarrhea carry resistance genes blaTEM (12.5%), blaSHV (37.5%), and blaCTX-M (16.67%). Only EPEC was isolated and only in diarrheal children, with a frequency of 20.83%.

Conclusion: The relatively high prevalence of ECD in this study is remarkable, and it highlights the fact that E. coli is an important agent of infectious diarrhea and could be the leading cause of gastroenteritis in Benin.