Random survey of the microbial quality of bottled water in South Africa

Abstract

Due to the increased demand and consumption of bottled water in South Africa, there has been a growing concern about the microbiological quality of this product. Retail outlets sell local as well as imported bottled water to consumers. The microbiological quality of 10 different (8 local and 2 imported) bottled water products were tested over a period of three months on days 1, 30 and 90. Tests for the detection of heterotrophic plate count (HPC) bacteria, total and faecal coliform bacteria, spore-forming Clostridium perfringens, somatic and F-RNA coliphages were performed on the samples. In addition samples were analysed for three selected enteric viruses, caliciviruses, enteroviruses and rotaviruses using the reverse transcriptase-polymerase chain reaction (RT-PCR). The results indicated that 8/10 of the bottled water samples analysed, met the requirements set by the South African Bureau of Standards (SABS) for HPCs in bottled water of less than 100 counts per mℓ. However, in two bottled water samples the average HPC bacteria counts were 2.64 x 10² cfu mℓ^-1 and 8.89 x 10³ cfu mℓ^-1 respectively which exceeded the recommended SABS guideline. HPC counts showed a slight variation during the three-month period in the bottled water samples. Total and faecal coliform bacteria, enterococci, C. perfringens, bacteriophages or enteric viruses were not detected in any of the ten bottled water samples analysed. It can be concluded that the microbial quality of eight of the ten selected bottled water samples analysed was within the acceptable limits set by the SABS guidelines and therefore, was safe for human consumption.


WaterSA Vol.30 (2) 2004: 203-210