Microbial analysis of bottled mineral water

Contamination of drinking water with disease-causing microorganisms is a growing public health and environmental problem. Microbial analysis of bottled mineral water sold in the surrounding community St. Scholastica’s College and De La Salle University, Manila was conducted to test the potabiIity of these drinking waters. A rapid test using 3M Petrifilm Coliform and Aerobic Count Plates was used in the study. Water samples were tested in three dilutions in three sampling periods. Results showed that out of the eight brands of bottled water studied, only 4 brands passed the test and 3 were defective. Of the defective brands, brand AV attained the highest estimated bacterial count followed by brands K, CS and V. The EAPC (Estimated Aerobic Pl arc Count) and ECC (Estimated Coliform Plate Count) of the three defective brands exceeded the bacteriological standards for bottled water. BrandV which exhibited positive EAPC only in the 3rd sampling should be further tested. On the other hand, the colonies observed growing in the CC medium were not true coliforms but considered as coliform-related bacteria due to the absence of bubbles in the colonies. Furthermore, high EAPC and ECC of the three defective brands indicate that these bottled water were unsafe to drink and should be subjected to further study.