Bacteriological evaluation of the drinking water quality in dairy farms in Khartoum state, Sudan

This study was conducted in Khartoum State in order to evaluate the quality of the drinking water in dairy farms based on bacteriological examinations and viable counts. A total of 39 water samples were obtained from dairy farms (13 in Khartoum, 13 in Omdurman and 13 in Khartoum North). All samples were cultured on Blood Agar and MacConkey for bacterial isolation and on nutrient agar for viable counts. The main result revealed that 39 bacterial isolates were detected in drinking water of the dairy farms in Khartoum state. Micrococcus spp., Pseudomonas spp., and Bacillus spp. were dominant in Khartoum, giving a percentage of 7.69 (n=3) for each. Staphylococcus spp. and Corynobacterium spp. were also observed in the samples of dairy farms in Khartoum (5.12%) (n=2) for each. The bacteria isolated from dairy farms in Omdurman were Micrococcus spp. and Aeromonas spp. (5.12%) (n=2) for each. In the same site, Staphylococcus spp., Actenobacillus spp., Moraxella spp. and Flavibacterium spp. were also detected with percentage of 2.56% and frequency of one for each. The most frequent isolate in Khartoum North was Micrococcus spp. (17.95%) (n=7) followed by Aeromonas spp. (10.26%) (n=4) and Staphylococcs spp. (5.12%) (n=2). Regarding bacterial counts, the results have shown high level of contamination of drinking water for all dairy farms in Khartoum State. The results were inter-operated, depending on international critical level (cut-off point) (100 CFU ml-1). For instance, high mean of bacterial counts 6.44 × 108 was observed in dairy farm in Omdurman, followed by Khartoum and Khartoum North, with mean bacterial counts of 4.93 × 108 and 3.81 × 108, respectively. Application of analytical statistic using one way analysis of variance (ANOVA) revealed that there was no statistical significance (F-value = 0.198, p-value > 0.05) for bacterial counts of the drinking water of dairy farms in different sites of Khartoum state.