Article Abstract:
Cryptosporidium parvum oocysts are capable of survival and infection after freezing, though some of the oocysts are inactivated. Mice injected with oocysts frozen at -20 degrees Celsius (C) for one, three or five hrs contained development-stage parasites indicating oocyst infection. Mice administered oocysts frozen at -70 degrees C for one, eight or 24 hrs had no parasites. Mice injected with oocysts frozen at -20 degrees C for 24 and 168 hrs had no parasites. Mice administered oocysts frozen at -15 degrees C for eight and 24 hrs but not 168 hrs had developmental-stage parasites.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
Experiments on mice reveal that high-temperature-short-time pasteurization of milk and water completely destroys the infectivity of Cryptosporidium parvum oocysts. A temperature of 71.7 degrees celsius sustained for 15 seconds renders oocysts noninfectious. C. parvum, a protozoan parasite, causes enteric infection and diarrhea in 79 species of mammals, including humans. Contaminated water is the main source of infection of the disease cryptosporidiosis which spreads by contact with infected animals or humans through the fecal-oral route.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
Cryptosporidium parvum oocysts obtained from the feces of Peking ducks, innoculated with the oocysts, produces severe infection in neonatal mice. Histological sections of the ducks fail to reveal life-cycle stages of the cryptosporidia. The number of oocyst shells in the feces is less than that of intact oocysts. The number of intact oocyst shells decreases from day two to day five post inoculation. This indicates that the viability and infectivity of the oocysts is unaffected by passage through the duck's intestine.
User Contributions:
Comment about this article or add new information about this topic: