Detection of pathogenic Escherichia coli strains in groundwater in the Yaoundé region (Cameroon, Central Africa)

This study was aimed at assessing the prevalence of pathogenic Escherichiacoli strains, relative to the total count of E.coli, faecal coliforms and other heterotrophic mesophilic aerobic bacteria (HMAB) isolated in groundwater in the equatorial region of Cameroon (Central Africa). Bacteria were isolated using standard methods. Pathogenic E.coli strains were then identified using haemagglutination and antisera tests. The maximum abundance of HMAB, faecal coliforms and E.coli strains were 4.9x10(6), 5.6x10(3) and 1x10(3)colony-forming units (CFU)/100mL, respectively. The count of pathogenic E.coli strains reached 3 CFU/100mL. The counts of commensal and pathogenic E.coli strains underwent temporal and spatial fluctuations. In 21% of sampling sites, the abundance of faecal coliforms was significantly correlated to that of E.coli (P<0.05). However, the isolated bacterial count was not significantly correlated to that of the pathogenic E.coli strains (P>0.05). The bacteria abundance dynamics may be impacted by many interacting factors.