The influence of hydrochemistry on the distribution of pathogenic strains of Escherichia coli in urban groundwater of Yaoundé, Cameroon

Bacteriological and hydrochemical studies of 10 springs, 4 wells and 13 surface waters in Yaounde (Cameroon) were conducted to assess the influence of hydrochemistry on the abundance of pathogenic strains of Escherichia coli. Microbiological analyses were carried out by membrane filtration; physico-chemical analyses used standard analytical techniques. The concentration of thermotolerant coliforms, E. coli and pathogenic E. coli exhibit spatial and temporal fluctuations. The relationship between abundances of these microorganisms and physico-chemical factors such as temperature, electrical conductivity or pH, are weak and variable. The distribution of these bacteria in these aquatic environments depends upon a range of environmental parameters. The presence of the pathogenic strains in groundwater and surface water fed water points exposes users to short-term health risks for which basic precautions like boiling must be considered.