''Cryspovirus'' is a genus of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room ...

, in the family ''

Partitiviridae ''Partitiviridae'' is a family of double-stranded RNA viruses. Plants, fungi, and protozoa serve as natural hosts. It has been suggested that they can also infect bacteria. The name comes from the Latin ''partitius,'' which means divided, a ...

''. Protists serve as natural hosts. There is only one species in this genus: ''Cryptosporidium parvum virus 1''. Cryptosporidium, a genus of Apicomplexan parasites, is known to cause human diarrheal illness. A bi-segmented dsRNA virus linked with Cryptosporidium was discovered and found to have similarities with picobirnaviruses and partitiviruses. This discovery led to the identification of a distinct virus called Cryptosporidium parvum virus 1 (CSpV1). It was suggested to be the sole partitivirus found in a protozoan host. Based on this, a new genus named Cryspovirus was proposed within the Partitiviridae family, which was subsequently approved by the ICTV Executive Committee in 2009. CSpV1, also known as Cryspovirus, is believed to be transmitted intracellularly through Cryptosporidium oocysts and is linked with persistent, mostly non-virulent infections. The virus features isometric virions and has a genome composed of two separate dsRNA molecules encoding RdRp and CP. Notably, the CP of CSpV1 is smaller than that of other partitiviruses, indicating a unique capsid structure. Biologically, CSpV1 appears to be primarily transmitted through intracellular methods and is associated with non-aggressive infections. Its impact on altering Cryptosporidium's pathogenicity remains to be fully understood. CSpV1 exhibits unique genomic and coding characteristics, with its dsRNA segments having distinct nucleotide sequences (often detected via PCR). The virus is believed to employ a non-standard mechanism for translation, and conserved sequences at the 3′ ends of its dsRNAs might be involved in replication or packaging processes. CSpV1 holds practical significance in the detection of Cryptosporidium in contaminated water supplies and in the epidemiological monitoring of Cryptosporidium infections. Vong, M., Ludington, J. G., Ward, H. D., & Nibert, M. L. (2017). Complete cryspovirus genome sequences from Cryptosporidium parvum isolate Iowa. Archives of virology, 162(9), 2875–2879. https://doi.org/10.1007/s00705-017-3385-2

Structure

Viruses in Cryspovirus are non-enveloped, with icosahedral geometries, and T=1 symmetry. The diameter is around 30-35 nm. Genomes are linear and segmented, around 2.1kb in length. The genome codes for 2 proteins.

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. Protists serve as the natural host. Pathway of how double stranded RNA viruses replicate

Pathway of how double stranded RNA viruses replicate

References

External links

ICTV Online Report ''Partitiviridae''

{{Taxonbar, from=Q18820005 Partitiviridae Virus genera Infectious diseases Virology Protista Diarrhea Double-stranded RNA viruses Sanitation Water treatment