BIOGRAPHY OF A RIVER

Diseases Organisms Associated WithMicroencephalitis Naegleria fowleri Fecal coliform bacteria (Fecals)Typhoid fever Salmonella typhi Contaminated waterCholera Vibrio cholerae Contaminated waterDysentery (gastroenteritis) Staphylococcus aureus Fecals in drinking waterAmoebic dysentery Entamoeba histolytica Fecals in drinking waterBacillary dysentery Shigella Fecals in drinking waterLung fluke Paragonimus westermanni Contaminated fishSchistosomiasis Schistosoma Contaminated waterHistorically, tests have been developed to measure the quality of our water and foods. By testingambient conditions of waters for specific organisms, indicator organisms, water quality managersmonitor the safety of the waters for their specific uses such as drinking water supply, swimming, or fishand wildlife uses. The primary characteristic for indicator organisms is that they are consistently presentin human wastes in substantial numbers. The detection of these organisms in the water is a goodindicator that fecal wastes are entering the water. The indicator organisms should also survive in waterat least as well as other pathogenic organisms would survive. Testing for these organisms is fairlysimple. People with technical training, such as operators of water treatment plants in smallcommunities, do much of the testing.In the U.S., the commonly used indicator organisms are the coliform bacteria. Coliforms are definedas aerobic or facultative anaerobic, gram-negative, non-endospore-forming, rod-shaped bacteria thatoferment lactose to form gas within 48 hours of being placed in a growth medium at 35 C. Coliformbacteria are commensal and are common in the intestines of warm- and cold-blooded animals. Theyaid in food digestion. When animals defecate, the coliform and pathogenic microbes, if present, passout of their bodies with the wastes. If these wastes find their way into a water supply, they bringbacteria and other microbes with them. Large numbers of coliform organisms indicate the possiblepresence of pathogens.oThe fecal coliform bacteria test is easy to do but requires a precise incubation temperature of 44.5 C,onot varying more than 0.2 C either way.Fecal coliform population standards for drinking water are the same for all states and are required bythe EPA. Standards for swimmers and other recreational uses are set by the states and approximatethe water quality criteria given below, with some variability by state.3-67