Microbiology Research Journal International

A study was conducted in several households in the Mendong neighborhood of Yaoundé (Cameroon) from January to March 2025 to assess the level of microbiological contamination of groundwater in storage or in use in relation to physicochemical variables. Water samples were collected in sterile 500ml glass bottles for bacterial isolation and in double-sealed polyethylene bottles of 250ml and 1000ml for physicochemical parameters as recommended by standard methods. The bacteria considered were MAHB (Mesophilic Aerobic Heterotrophic bacteria) and some pathogenic bacteria. These bacteria were isolated using PCA and Salmonella-Shigella agar respectively. Pathogenic bacteria were identified using the classical gallery, followed by antibiotic susceptibility testing. Moreover, in addition to the MAHB, the waters sampled in the households and in the water supply sources harbor pathogenic bacteria such as Serratia marcescens, Citrobacter freundii, and Salmonella paratyphi. The densities of these bacteria undergo overall variations depending on the time of water collection, the household, and the water source considered. In addition, the physicochemical parameters considered were taken in situ and in the laboratory using standard techniques. It appears overall that the analyzed waters are acidic and mineralized with a conductivity that varies from 17 µS/cm to 250 µS/cm for an average of 97.59 ± 17.49 µS/cm. The water temperature ranges from 25.1°C to 28.2°C. The mineralization of the water would be due to the presence of Cl^-, Ca²⁺, and Mg²⁺ ions present in the analyzed waters. Similarly, the variation in temperature could be explained by the period of water collection. The physicochemical parameters do not significantly influence the variation in the abundance dynamics of germs over the usage time of the waters. It is therefore recommended that populations use cleaner and better (watertight and non-porous) containers and continue to treat the water regularly before use.