Fresh (36 days old) sporulated oocysts of Eimeria nieschulzi were divided into 7 groups. Control oocysts were maintained at 23 C in 2% aqueous (w/v) K2Cr2O7. The 6 experimental groups were mixed with either Bouin's solution, 10% aqueous (v/v) buffered formalin, Karnovsky's solution, glutaraldehyde, paraformaldehyde, or 70% aqueous (v/v) ethanol (EtOH). After 115 days, oocysts from all 7 groups ...

The association of Cryptosporidium parvum oocysts with suspended particles can alter the oocysts' effective physical properties and influence their transport in aquatic systems. To assess this behavior, C. parvum oocysts were mixed with various suspended sediments under a variety of water chemical conditions, and the resulting settling of the oocysts was observed. Direct microscopic observation...

Toxoplasma gondii oocysts are excreted nonsporulated in the feces of the cats into the environment. These oocysts must undergo sporulation to become infectious. Little is known about the factors that influence sporulation of T. gondii oocysts. The present study examined the survival of nonsporulated oocysts under refrigerated conditions over 11-week observation period. Microscopic examination o...

Cryptosporidium parvum is a zoonotic protozoan parasite that may cause severe neonatal diarrhoea or even mortality in newborn ruminants: its oocysts are extremely resistant to normal environmental conditions and to most common disinfectants. KENO™COX, a patent pending amine-based formula, was tested for its ability to inactivate C. parvum oocysts. The Daugschies assay (2002), a standardized ass...

Cryptosporidium is an important waterborne protozoan parasite that can cause severe diarrhea and death in the immunocompromised. The current methods used to monitor for Cryptosporidium oocysts in water are the microscopy-based USEPA methods 1622 and 1623. These methods assess total levels of oocysts in source waters, but do not determine oocyst viability or genotype. Recently, propidium monoazi...

The potential for the transport of viable Cryptosporidium parvum oocysts through soil to land drains and groundwater was studied using simulated rainfall and intact soil columns which were applied raw slurry or separated liquid slurry. Following irrigation and weekly samplings over a 4-week period, C. parvum oocysts were detected from all soil columns regardless of slurry type and application m...

Between January and March 2001, eight 4- to 8-wk-old camels (Camelus dromedarius) from 2 farms from Dubai area of the United Arab Emirates were submitted for necropsy examination. The camels had diarrhea of 2-5 days duration. Grossly, a severe diphtheroid-to-hemorrhagic colitis was seen in all animals. Gamonts, unsporulated oocysts, sporulating oocysts, and fully sporulated oocysts were present...

We reexamined the finding of Neumann et al. that intact Cryptosporidium parvum oocysts obtained after in vitro excystation were infectious for neonatal CD-1 mice. We used both established excystation protocols and our own protocol that maximized excystation. Although intact oocysts isolated after any of three protocols were infectious for neonatal CD-1 mice, the infectivity of intact oocysts is...

Six genera of rotifers including Philodina, Monostyla, Epiphanes, Euchlanis, Brachionus, and Asplanchna were exposed to oocysts of Cryptosporidium parvum cleaned of fecal debris. Unstained oocysts and those stained with fluorescein-conjugated monoclonal antibody were added to suspensions of viable rotifers and were examined by phase-contrast, differential interference contrast, and fluorescence...

U.S. Environmental Protection Agency method 1623 is widely used to monitor source waters and drinking water supplies for Cryptosporidium oocysts. Matrix spikes, used to determine the effect of the environmental matrix on the method's recovery efficiency for the target organism, require the collection and analysis of two environmental samples, one for analysis of endemic oocysts and the other fo...