Spatio-temporal variation of bacteria of the Vibrio and Pseudomonas genera in some underground water points developed in the locality of Ombessa (Department of Mbam-et-Inoubou, Center-Cameroon)

Abstract

A study aimed at evaluating the seasonal variation of Vibrio and Pseudomonas in groundwater in the city of Ombessa, Center region of Cameroon was conducted from January to July 2021. The microorganisms sought were Aerobic Mesophilic Bacteria BHAMs, bacteria of the Vibrio and Pseudomonas genera. These bacteria were isolated from 10 groundwater points by the surface spreading technique for BHAM and the membrane filter method for Vibrio and Pseudomonas. Plate count agar was used for BHAMs, TCBS medium for Vibrio and Cetrimide agar for Pseudomonas. Some abiotic parameters such as temperature, pH, were measured using the usual techniques. The data obtained was analyzed using the appropriate software. Correlation and comparison tests between the variables were carried out. It shows that the water studied has a pH of 5.94 UC to 7.9 UC, the content of dissolved O2 reached 5 mg/L, and there are positive and significant correlations between the density of isolated bacteria and the levels of physicochemical variables. Two species of the genus Pseudomonas (aeruginosa and fluorescens) and four of the genus Vibrio (cholerea, alginolyticus, vulnificus and parahaemolyticus) were isolated, with variable abundance rates ranges from 194 to 898 CFU/100mL for Pseudomonas and from 58 to 683 CFU/100mL for Vibrio. The presence of these germs in groundwater can be explain by the proximity of sources of pollution. This water would be unfit for human consumption without prior treatment according to the World Health Organization standard.