Microbiological Indicators of Water Quality and Water Sustainability
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The provision of high quality, clean water is of paramount importance to both human public health and the welfare of all biodiversity. Maintaining this quality also helps to promote sustainability of water globally through programs involving public health, watershed (ecosystem) protection, water-resource management and water governance and regulation. These initiatives allow for more effective risk assessment and management of the world’s usable water supply. Pathogenic microorganisms such as bacteria, viruses and protozoa which are present in faecal-contaminated water have always been a major threat to human health. Monitoring every single pathogen present in water is impractical, therefore the use of microbial water-quality indicators has been recommended. Escherichia coli (E. coli) and Enterococcus sp. are the main microbial indicators used for assessing fresh and marine water (recreational water), respectively. E. coli testing is conducted all over the world and there are good tests readily available, but tests for Enterococcus are limited, even though these bacteria are often better indicators of faecal contamination. We are developing an Enterococcus test by adapting technology that was developed at Queen’s University for detecting E. coli and Total coliforms. Different growth media types were used and Todd-Hewitt broth (THB) was found to be the most effective media for the Enterococcus test and can be used at full strength or half strength. The test was optimized for temperature; 41oC elicited the best results. In order to promote selective Enterococcus growth, different antibiotics were administered. It was found that 6 mg / L of amikacin in half strength THB was optimal to make the THB media selective to Enterococcus in the presence of potentially interfering E. coli bacteria. This novel test will complement the tools already available for global water-quality monitoring, thereby promoting sustainable water-use, and thus enhancing the protection of the public’s health.