Temporal variation of microbiological and chemical quality of noncarbonated bottled drinking water sold in Sri Lanka.

Use of bottled water in Sri Lanka has increased over the last decade, while new brands of bottled water are often introduced to the market. However, the manufacturers' adherence to bottled water regulations is questionable, raising concerns regarding the quality of bottled water. The objective of the current study was to investigate the microbiological and chemical quality of bottled water in Sri Lanka. Thirty bottled water brands were sampled and their chemical and microbiological parameters were analyzed. Microbiological analysis was carried out within 1 to 3, 3 to 6, 6 to 9, and 9 to 12 mo after the date of manufacture. The results indicated that 63% of brands tested exceeded the levels permitted by the Sri Lanka Standards Institution (SLSI) for presumptive total coliforms (TC) (<10 cfu per 100 mL) whereas 97% brands exceeded the World Health Organization (WHO) permitted level. Thirty percent of brands exceeded the limit for presumptive fecal coliforms (FC) (0 cfu per 100 mL in accordance with WHO permitted levels, SLSI and the Sri Lanka Health Ministry requirement). Eighty percent of brands showed higher heterotrophic plate counts (HPC) which exceeded the WHO guidelines for bottled drinking water. Throughout their shelf life, the counts of TC, FC, and HPC bacteria decreased. Bacteria identified were Klebsiella pneumoniae ssp. pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, and Pasteurella haemolytica, the most frequently being P. aeruginosa. The dominant fungi identified were Aspergillus sp. and Penicillium sp. Inorganic chemical parameters were within permitted levels for all brands except for initial content of ammonia. The results of this study show the need for the bottling industry to be monitored closely by relevant authorities, in order to provide safe bottled drinking water to consumers in Sri Lanka.

Proteomic definition of normal human luminal and myoepithelial breast cells purified from reduction mammoplasties.

Normal human luminal and myoepithelial breast cells separately purified from a set of 10 reduction mammoplasties by using a double antibody magnetic affinity cell sorting and Dynabead immunomagnetic technique were used in two-dimensional gel proteome studies. A total of 43,302 proteins were detected across the 20 samples, and a master image for each cell type comprising a total of 1,738 unique proteins was derived. Differential analysis identified 170 proteins that were elevated 2-fold or more between the two breast cell types, and 51 of these were annotated by tandem mass spectrometry. Muscle-specific enzyme isoforms and contractile intermediate filaments including tropomyosin and smooth muscle (SM22) alpha protein were detected in the myoepithelial cells, and a large number of cytokeratin subclasses and isoforms characteristic of luminal cells were detected in this cell type. A further 134 nondifferentially regulated proteins were also annotated from the two breast cell types, making this the most extensive study to date of the protein expression map of the normal human breast and the basis for future studies of purified breast cancer cells.