Fecundity of Cryptosporidium parvum is correlated with intracellular levels of the viral symbiont CPV

• Published in: International journal for parasitology 2008-07, Vol.38 (8-9), p.1051-1055
• Main Authors: Jenkins, M.C., Higgins, J., Abrahante, J.E., Kniel, K.E., O’Brien, C., Trout, J., Lancto, C.A., Abrahamsen, M.S., Fayer, R.
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Biological and medical sciences; calves; Cattle; Cattle Diseases - parasitology; Cell Survival; cryptosporidiosis; Cryptosporidiosis - parasitology; Cryptosporidiosis - veterinary; Cryptosporidium parvum; Cryptosporidium parvum - isolation & purification; Cryptosporidium parvum - physiology; Cryptosporidium parvum - virology; dairy cattle; DNA, Protozoan - isolation & purification; dsRNA viruses; endosymbionts; Feces - parasitology; Fecundity; Fertility; Fundamental and applied biological sciences. Psychology; General aspects; Life cycle. Host-agent relationship. Pathogenesis; Microbiology; Molecular Sequence Data; Oocysts; Oocysts - virology; Parasite Egg Count; Protozoa; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - isolation & purification; RNA, Protozoan - isolation & purification; RNA, Viral - isolation & purification; strain differences; Symbiosis; Viral symbiont; Virology; Virus
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2007.11.005

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 106C. 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.