Detection of bacterial load in drinking water samples by 16s rRNA ribotyping and RAPD analysis

Background: Safe and healthy drinking water is inaccessible to more than 20% of the world population. Among some major risks to safety of potable water, contamination with pathogenic microorganisms is the most alarming and harmful Therefore, it is needed to develop and implement fast and accurate methods for the detection of bacterial contamination in water. Methods: Biological analysis of drinking water samples obtained from nine different collection points of Lahore city was carried out and total of six different bacterial strains were isolated. Biochemical characterization was done under standard laboratory conditions. Molecular identification of these isolates was done by using random amplified polymorphic DNA (RAPD) analysis. Results: The drinking water sample collected from Punjab University showed highest bacterial count 1066/0.5 ml of drinking water while residential area of University of the Punjab contained least number of bacterial counts i.e., 38/0.5 ml of drinking water. Amplification patterns of isolates SZ1, SZ3, SZ4 and SZ6 obtained by RAPD were found similar to genus Bacillus. While, SZ2 and SZ5 had unique amplification patterns identical to Bacillus megaterium. All the six bacterial strains were tested for the presence of protease, lipase, cellulase, and amylase. Strain SZ2 gave positive result for all of them except amylase. Conclusion: Tube well water of Punjab University area of Lahore is safe for drinking purpose except admin block tube. It is recommended to monitor the bacteriological load of drinking water at regular intervals in order to control water borne bacterial diseases.