Oocyst


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Related to Oocyst: cryptosporidium

oocyst

[′ō·ə‚sist]
(invertebrate zoology)
The encysted zygote of some Sporozoa.

Oocyst

 

one of the stages in the development of protozoans of the class Sporozoa. The oocyst forms as a result of the encyst-ment of a fertilized egg cell. It is covered with a strong protective membrane. The contents of the oocyst generally divide into several nonmotile spores (in Coccidia) or motile sporozoites (in Gregarinidia). In Hemosporidia the oocyst produces thousands of sporozoites, which subsequently leave the oocyst.

References in periodicals archive ?
Cryptosporidium species have direct life cycles, with oocysts shed in the feces or expelled from the respiratory tract by infected hosts.
Though infectious oocysts can't push through unbroken human skin, parasitologists advise people to wear gloves and wash their hands thoroughly when cleaning litter boxes.
apicomplexa), parasite of the mussel Mytella guyanensis (Mytilidae) from the Amazon Estuary and description of its oocysts.
1] is the total oocyst count on the left side of the counting chamber, [C.
The presence of both oocysts and sporozoites stages confirms that An.
Oocyst populations isolated from water are often of mixed genotype (Jiang et al.
It belongs to the subphylum Apicomplexa, class Sporozoa, and exists in nature in 3 forms: the oocyst (which releases sporozoites), the tissue cyst (which contains and may release bradyzoites), and the tachyzoite.
While there are no standards for the permitted number of cryptosporidium oocyst, and as few as one can make a person ill, it can be eradicated from a water supply by costly municipal filtration.
During the outbreak, the average oocyst density in drinking water was 0.
Oocyst excretion by chicks fed gel-beads or inoculated by oral gavage was 10- to 100-fold greater than that of chicks spray-vaccinated with the Eimeria oocysts mixture (log 6.
More significantly, this study discovered the Imd pathway signal transducing factors and effectors that will mediate a successful reduction of parasite infection at their early ookinete stage, as well as in the later oocyst stage when the levels of infection were similar to those found in nature.