Assessment of  microbial quality of bottled water from street vendors and sundry stores in Metro Manila, Philippines

The consumption of bottled drinking water sold by street vendors and sundry stores in Metro Manila has increased because it is expected to be microbiologically safe and is readily available for purchase by commuters, especially in a tropical country with warm and humid weather. Thus, this study investigated the microbial quality of bottled water sold within Metro Manila. Eighty samples representing sixteen brands of bottled water were purchased and analyzed for heterotrophic plate count bacteria (HPC), total coliforms (TC), Escherichia coli and yeast/moulds (YM). The percentage of bottled water samples that did not meet the microbial quality standard was 15%, 24%, and 6% for HPC, YM, and TC, respectively in accordance to the Philippine National Standards for Drinking Water of 2017. HPC bacteria and coliform concentrations were positively correlated with each other (p < 0.01), whereas HPC and YM concentrations were positively correlated with the bottled water's chloride levels (p < 0.05). Coliform isolates from five samples were identified as Klebsiella pneumoniae, with four exhibiting resistance to ampicillin but remaining susceptible to the other 20 tested antibiotics. These findings highlight potential health risks associated with generic bottled water and emphasize the need for stricter quality control to prevent waterborne diseases.