Microbiological investigation of bottled waters from different suppliers in Istanbul

Abstract

Some pathogenic bacteria found in drinking water may cause infections in many countries. The control of these infections is done by water treatment. It's very important to monitor faecal indicator bacteria such as faecal and total coliform in terms of the examination of the bacteriological quality of drinking water. In addition, the determination of total mesophilic aerobic bacteria is also used in measureing bacterial pollution. In our study 88 samples of bottled drinking water belonging to 22 different brands were examined. The water samples that were taken from plastic bottles of 19 L were examined for faecal coliform, total coliform, Pseudomonas aeruginosa, Aeromonas spp., total mesophilic aerobic bacteria, and presence of free-living amoeba. Faecal coliform, total coliform, Pseudomonas aeruginosa, Aeromonas spp., and the existence of free-living amoeba were determined by membrane filtration; and the total mesophilic aerobic bacteria numbers were studied using the pour plate method. It has been found that all of the samples examined in this study are not acceptable according to the standards of TSE and WHO. Although four different water samples were taken from the same brand, it has been shown that their were variations in the bacteriological quality of the water, from one water sample to another. Reusable methods of cleaning the bottles and the unhealthy conditions of filling facilities might cause these differences. In conclusion, the results of the present study have revealed that it is very important to ensure systematic microbiological monitoring and the control of bottled water which is used as drinking water. Also this control should be done by authorized foundations.