Comparative Approach of Staphylococcus Abundance in 3 Different AquaticEnvironments in Kribi (Coastal Area, Cameroon, Central Africa), andPotential Role of Some Abiotic Factors

A study to compare bacterial populations in sea, ground and stream waters and to assess the importance of some abiotic factors on these populations was carried out in the town of Kribi (on the Cameroonian coast) from January to March 2024. The bacteria sought were Aerobic Mesophilic Heterotrophic Bacteria (AMHB) and staphylococci. They were isolated using the surface spreading technique on Petri dishes on PCA media (Rapid Labs, ref CM-PCASP051) and the membrane filtration technique on Chapman mannitol medium (HIMEDIA, ref MH118-500G), for AMHB and staphylococci respectively. Isolated bacteria were identified by standard methods. Some abiotic parameters were measured using standard analytical techniques. These analyses showed that the abiotic variables varied overall from one sampling period to the next and from one point to the next. It was noted that the water was neutral with low mineral content. The high nitrogen values recorded at all the sampling points attest to the high organic matter content of the water analyzed. Bacteriological analyses revealed that the water contains a high-density bacterial microflora consisting of AMHB and bacteria of the Staphylococcus genus. The average densities of AMHB in log (CFU/100 mL) were 5.62, 5.86 and 5.30 in groundwater, stream waters and seawaters respectively. The waters of this coastal area of Cameroon are populated by Staphylococcus species, Staphylococcus aureus and Staphylococcus epidermidis, with mean densities of 2.66 (log (CFU/100 mL)), 3.30 (log (CFU/100 mL)) and 5, 36 (log (CFU/100 m)) for Staphylococcus aureus and 1.66 (log (CFU/100mL)), 1.06 (log (CFU/100mL)) and 5.02 ( log (CFU/100 mL)) for Staphylococcus epidermidis in groundwater, stream waters and seawaters respectively. Comparatively, the densities of staphylococci in seawaters were more abundant and diverse than those in groundwater and stream waters. The deterioration in the quality of these coastal waters seems to be encouraged by their proximity to point sources of pollution linked to discharges of ballast water without prior treatment. These waters are therefore not recommended for human consumption according to WHO standards.