Abstract
Objective To analyze commercially available bottled water as a possible source of microbial contamination of contact lenses. Methods Two different lots of 23 brands of noncarbonated bottled water were tested for coliforms, total bacteria, fungi, and free-living amebae. A sample consisted of three separate 100-ml aliquots from one lot of each brand (46 samples). Aliquots were vacuum-filtered using a 0.45-μm Nalgene analytical filter unit, and the membrane filter was placed on a filter pad in a Petri dish containing test medium. Plates were examined under a stereomicroscope, and the number of colony-forming units (CFUs) was calculated for each sample. To test for the presence of free-living amebae, three aliquots totaling approximately 3800 ml were concentrated using 8-μm filters, and the filters were placed on non-nutrient agar with live Enterobacter aerogenes. To assess the possibility of contaminating contact lenses, etafilcon lenses were rinsed in 2-ml aliquots of four brands of bottled water and then cultured. Results Seventeen (37%) of 46 samples, representing 11 (48%) of 23 brands, contained viable micro-organisms. Bacteria, including coliforms, were recovered from 12 samples of 8 brands. Yeasts or molds were recovered from seven samples of five brands. Free-living amebae were isolated from two samples, and fresh-water algae were found in both samples of one brand. Nine (20%) of 46 samples, representing 7 (30%) of the 23 brands, had more than 500 CFUs per ml or contained coliforms. Sterile contact lenses became contaminated when exposed for 1 minute to two of four brands of water from which micro-organisms were recovered. Conclusion Some bottled waters contain high numbers of potential ocular pathogens. Bottled water is not safe for routine use with contact lenses.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.