MICROBIAL RISK ASSESSMENT OF SACHET WATER IN RUMUEPIRIKOM, PORT HARCOURT: FOCUS ON VIRULENCE ATTRIBUTES

Abstract

Population and virulent attributes of bacteria in some commonly consumed sachet water supplies in Rumuepirikom area of Port Harcourt were investigated using Aerobic Plate Count and Most Probable Number (MPN) techniques. Fifty (50) samples of sachet water were analyzed, and comprised of 10 samples each of Bread of Life, Preson, Uzodhu, Judose and Obi Ronix sachet water. Results revealed detectable numbers of heterotrophic bacteria and coliform bacteria in the drinking water samples. However, viable cells of Salmonella, Shigella and Vibrio cholerae were not detected.  Results also showed that the densities of the bacterial contaminants varied with the different brands of sachet water samples. Counts of total heterotrophic bacteria were reasonably high. The MPN results showed presence of coliforms in all brands of water with Uzodhu and Judose sachet waters having the highest counts. Five bacterial species:

Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae were isolated. Among the isolates, Staphylococcus aureus was the most virulent, being able to elaborate lipase, hemolysin, coagulase and DNase on test media while Bacillus subtilis were the least virulent. On the other hand, the isolates demonstrated varying degree of responses to chemotherapeutic agents; Pseudomonas aeruginosa was the most resistant organism isolated from the sachet water samples. The quality assessment of the water samples showed that most of the sachet water supplies analyzed had high coliform and heterotrophic bacterial densities above WHO permissible limits for drinking water. Also virulent bacteria capable of causing disease were isolated. Thus, there is need for regular sanitary inspection of sachet water services so that only those companies which constantly produce water of acceptable bacteriological standards are permitted in the market. banks customers in a caring fashion, understand their needs and also have their best interest at heart.