EVALUATION OF MICROBIAL CONTAMINANTS IN RETAILED BRANDED BOTTLED AND SACHET WATER IN PUBLIC SUPPLY IN THREE UNIVERSITIES SOUTHWEST NIGERIA

Drinking water safety is crucial to public health safety and One-health program being advocated by the world health Organization (WHO) as a means of securing upgrade in the quality of life. A total of twelve retailed branded bottled and sachet water samples were randomly purchased for microbiological analysis from three metropolitan Universities. The physic-chemical properties of these samples were determined prior to microbiological analysis. Standard and conventional methods were followed using the membrane filter technique (diameter 0.45µm) for the isolation of microbial contaminants. Microbial isolates were cultured on nutrient agar (NA), Sabouraud dextrose agar (SDA) and Thiosulphate citrate bile salt sucrose agar (TCBS) simultaneously. Although, biochemical and micro-morphological methods were used for preliminary characterization of these microbial contaminants. The World Health Organization (WHO) and National Food and Drug Administration Council (NAFDAC) standards were the basis of the assessment criteria. Although, the physic-chemical parameters of the analyzed water samples were within the limits stipulated by NAFDAC and WHO, the microbiological quality of the packaged water were compromised. Sachet water samples were found to be more vulnerable to microbial contaminations than bottled water samples. Poor plant sanitation process, Poor handling of products, and poor hygiene among personnel were the reasons for the detection of these contaminants in these products. Molecular characterization of these isolates using the 16S rDNA / ITS method further gave accurate identities of these microbial contaminants. Contrary to previous characterization of some of these contaminants on TCBS medium as Vibrio cholerae, they were identified as Bacillus subtilis (Ascension number AB 862127.1) and Bacillus pumilus (Ascension number EF 491624.1), other isolates included Micrococcus lylae (Ascension number MH 393514.1), Bacillus horneckiae (Ascension number FR 749913.1). Further scientific surveillance on the water processing plants and packaging method would give incontrovertible evidence of the source of the detected contaminants.