Survival characteristics of pathogens inoculated into bottled mineral water

To assess the risk of contracting a waterborne disease from mineral water and to implement control systems in the mineral water industry, knowledge of the factors affecting the survival and multiplication of non-indigenous bacteria is needed. The survival of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Yersinia enterocolitica inoculated into a Portuguese bottled mineral water was investigated under different conditions: light and dark, different recovery media, presence or absence of autochthonous flora and different ages of water, based on their culturability. For all the pathogenic bacteria higher survival was obtained under dark conditions of storage and when enumeration was performed on non-selective media. Survival of E. coli, Y. enterocolitica and S. typhimurium was longer in fresh water than in old water; results obtained with S. aureus were not conclusive. Survival of E. coli, Y. enterocolitica and S. typhimurium was lower in non-sterile mineral water while the survival of S. aureus was lower in sterilized mineral water.