A cross-sectional study was carried out to identify species and determine the prevalence of Cryptosporidium sp. shedding in pre-weaned and post-weaned dairy calves and to identify management factors that may be contributing to disease. A total of 240 calf faecal samples were collected from 16 farms in two districts in Johor, Malaysia, and screened by PCR. The overall Cryptosporidium prevalence was 27.1%. The prevalence of Cryptosporidium species in pre-weaned calves was 32.4% for C. parvum, 26.5% for C. bovis, followed by C. andersoni (20.6%), C. ryanae (11.8%) and mixed sp. (8.8%). The prevalence of Cryptosporidium species in post-weaned calves was 35% for C. bovis followed by C. andersoni and C. ryanae (30% each) and mixed sp. (5%). Subtyping analysis of 8 of the 11 C. parvum isolates at the gp60 locus identified five isolates as IIdA15G1, one as IIa18A3R1 and two isolates as IIa17G2R1. Management factors that increased the risk of Cryptosporidium infection included having other cattle farms close by, feeding calves with saleable milk, keeping pre-weaned calves in pens with slatted floors and keeping post-weaned calves in pens with a sand floor.
Matched MeSH terms: Cryptosporidiosis/prevention & control
The phylum Apicomplexa comprises obligate intracellular parasites that infect vertebrates. All invasive forms of Apicomplexa possess an apical complex, a unique assembly of organelles localized to the anterior end of the cell and involved in host cell invasion. Previously, we generated a chicken monoclonal antibody (mAb), 6D-12-G10, with specificity for an antigen located in the apical cytoskeleton of Eimeria acervulina sporozoites. This antigen was highly conserved among Apicomplexan parasites, including other Eimeria spp., Toxoplasma, Neospora, and Cryptosporidium. In the present study, we identified the apical cytoskeletal antigen of Cryptosporidium parvum (C. parvum) and further characterized this antigen in C. parvum to assess its potential as a target molecule against cryptosporidiosis. Indirect immunofluorescence demonstrated that the reactivity of 6D-12-G10 with C. parvum sporozoites was similar to those of anti-β- and anti-γ-tubulins antibodies. Immunoelectron microscopy with the 6D-12-G10 mAb detected the antigen both on the sporozoite surface and underneath the inner membrane at the apical region of zoites. The 6D-12-G10 mAb significantly inhibited in vitro host cell invasion by C. parvum. MALDI-TOF/MS and LC-MS/MS analysis of tryptic peptides revealed that the mAb 6D-12-G10 target antigen was elongation factor-1α (EF-1α). These results indicate that C. parvum EF-1α plays an essential role in mediating host cell entry by the parasite and, as such, could be a candidate vaccine antigen against cryptosporidiosis.
Matched MeSH terms: Cryptosporidiosis/prevention & control