الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Cryptosporidium, an enteric coccidian protozoan parasite, first recognized as a cause of human gastroenteritis and diarrheal illness in 1976. The illness may be severe in immunocompromised individuals and can ”cause death. The organism is monoxenous, and infective oocysts are shed in the feces of infected host. which are transmitted via the fecal-oral route. Cryptosporidium oocysts have been isolated from many mammals and may be especially prevalent in calves and lambs. Cryptosporidium has been found in association with other enteric pa~hogens such as rotavirus and Giardia, two organisms which have been shown to be waterborne. Therefore, Cryptosporidium mab be a possible etiological agent of water borne diseases. Cryptosporidium and Giardia are both recognized as a cause of traveller’s diarrhea.’-Although the majority of cases of clinical cryptosporidio~is are probably the result of direct transmission. it is possible that this 1 parasite, like Giardia, may be increasingly implicated in waterborne outbreaks. The first reported waterborne outbreaks of crypto sporidiosis occurred in San Antonio, Texas. Sewage con tamination of chlorinated well water was responisble for the outbreak. Cryptosporidium, like Giardia, is more resistant than bacteria to most routine water disinfection practices. The purpose of this study was to examine fresh water, sea water as well as drinking water for the presence of Cryptosporidium oocysts, Giardia lamblia cysts and tradi tional water bacterial indicators (fecal coliforms , and fecal streptococci). A total of 220 water samples were collected from ten beaches of Alexandria (Gleem, Sporting, Cleobatra, Stenly, Ibrahemia, Camp Cizar, El Shatby, EI-Kashafa, EI-Yakht and EI-Anfoushi), six location of Mahmoudia canal and drinking water from taps and tanks of four buildings selected ran . domly. Twenty water samples were examined for the presence of Cryptosporidium spp.oocysts and Giardia lamblia cysts by passing the water through a t ~m polypropylene cartidge filter at a flew rate not greater than 22 liters/min. Sediment trapped in the filter was eluted by back flushing the filter with 2 liters of de-ionized water containing 0.1 Tween 80. The filter was cut and fibers were washed with the original elute in a large beaker. Filter fibers in the elute were agitated and sonicated, then the elute was reconcentrated by centrifugation at 2500 xg for 10 min. and the precipitate was examined for Cryptosporidium oocysts, using the three-step method, and for Giardia cysts by direct saline smear and iodine smear. Isolation and Enumeration of fecal coliforms and fecal streptococci from 200 water samples was carried out using the membrane filtration technique. The mFC was used as a selective medium for fecal coli forms. and the KF and EIA were used for fecal streptococci.