title: Fecundity of Cryptosporidium parvum is correlated with intracellular levels of the viral symbiont CPV.
abstract: Differences in the virulence and fecundity of Cryptosporidium parvum isolates have been observed by several researchers studying cryptosporidiosis. The purpose of the present study was to determine if there was a correlation between intracellular levels of the viral symbiont CPV in C. parvum and fecundity of two isolates of the parasite, namely C. parvum Beltsville (B) and C. parvum Iowa (I). Dairy calves infected with 10(6)C. parvum-B excreted 5-fold more oocysts compared with calves infected with the same number of C. parvum-I oocysts. The increased fecundity of the former strain was corroborated by semi-quantitative PCR assay of DNA isolated from cell cultures infected with either C. parvum-B or C. parvum-I. Quantitative reverse transcriptase-PCR analysis of viral RNA revealed a 3-fold greater number of CPV in C. parvum-B compared with C. parvum-I oocysts. These findings may indicate a role for CPV in fecundity and possibly virulence of C. parvum.
authors: Animal Parasitic Diseases Laboratory, ARS, USDA, Beltsville, MD, USA. Mark.Jenkins@ars.usda.gov
authors: M C
authors: MC
authors: Jenkins
authors: J
authors: J
authors: Higgins
authors: J E
authors: JE
authors: Abrahante
authors: K E
authors: KE
authors: Kniel
authors: C
authors: C
authors: O'Brien
authors: J
authors: J
authors: Trout
authors: C A
authors: CA
authors: Lancto
authors: M S
authors: MS
authors: Abrahamsen
authors: R
authors: R
authors: Fayer
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D002470:Cell Survival; D003457:Cryptosporidiosis / Q000469:parasitology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000302:isolation & purification / Q000502:physiology* / Q000821:virology*; D016054:DNA, Protozoan / Q000302:isolation & purification; D005243:Feces / Q000469:parasitology*; D005298:Fertility; D008969:Molecular Sequence Data; D033661:Oocysts / Q000821:virology; D010270:Parasite Egg Count; D012333:RNA, Messenger / Q000302:isolation & purification; D016053:RNA, Protozoan / Q000302:isolation & purification; D012367:RNA, Viral / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013559:Symbiosis
chemical_list: D016054:DNA, Protozoan; D012333:RNA, Messenger; D016053:RNA, Protozoan; D012367:RNA, Viral