ABSTRACT

The presence of pathogenic bacteria producing biofiJms in drinking water systems in five selected villages of Umudike was determined. Four water samples (4) each were collected from four (4) different households' drinking water systems (storage tanks). A total of forty eight (48) different isolates were obtained from the twenty (20) water samples. These isolates were subjected to three different biofilm screening methods which included Congo red agar method, tube adherence method, and tissue culture plate method. Most of the organisms which were negative in Congo red agar method and tube adherence method gave an optical density (OD) > 0.05nm in the tissue culture plate method and were considered significant. The isolates that were positive in this method were subjected to other biochemical tests for identification. Pseudomonas aeruginosa had the highest percentage of occurrence (22.21%) of the total biofilm forming isolates while, Bacillus spp and Acinetobacter spp had the lowest values (8.88% each). Among the four villages examined, Umujumba and Umundiogu villages' drinking water systems contained the highest values of the total biofilm forming organisms (26.67% and 26.67% respectively) while Ezieke village had the lowest value (11.11 %). The presence of these organisms in drinking water have many implications which include a potential risk in terms of the consumer health while in another view they may indicate the possible presence of other bacteria, viruses or protozoan pathogens.