Abstract

Water borne bacterial pathogens were isolated from sachet water vended in Ogbomoso, Oyo State, Nigeria. The isolates were characterized and identified as Bacillus subtilis, Bacillus alvei, Pseudomonas putida, Pseudomonas fluorescens, Bacillus cereus, Enterobacter aerogenes and Proteus mirabilis. The antibiotic susceptibility profile of the seven isolates was determined and it was discovered that 59.3% was found sensitive to the commercial antibiotic disc used while 40.7% was resistant. The effect of temperature, pH and sodium chloride concentration on the growth rate of isolates was investigated. It was found that as temperature of incubation increased from 50 to 80°C, the rate of growth of all the isolate decreased and as the pH of the growth medium increased from 3 to 9, the rate of growth of all the isolates also increased. As the concentration of sodium chloride increased from 2 to 5%, the rate of growth of isolates also reduced.

Key words: Bacillus subtilis, Bacillus alvei, Pseudomonas putida, Pseudomonas fluorescens, Bacillus cereus, Enterobacter aerogenes and Proteus mirabilis,sachet water, pH, temperature and sodium chloride.