Development and evaluation of an enzyme-linked immunosorbent assay using recombinant p23 for the detection of antibodies to Cryptosporidium parvum in cattle

抄録

An enzyme-linked immunosorbent assay (ELISA) based on the recombinant p23 of Cryptosporidium parvum was established for the detection of antibodies against C. parvum in cattle. The sensitivity and specificity of the ELISA were evaluated with the standard indirect fluorescent antibody test (IFAT) using sporozoites as antigens. Of 77 bovine sera collected from China, 20 (26.0%) were identified as positive by the IFAT. The same samples were tested with the ELISA. The optical densities at 415 nm were compared to the IFAT results and statistically analyzed to designate a provisional cut-off point. As a result, the cut-off point was concluded to be 0.08, which was considered to be the best condition in the light of its sensitivity (80%) and specificity (73.7%). Thus, it was demonstrated that the ELISA could be a useful tool for the diagnosis of C. parvum infection in cattle under field conditions to estimate the magnitude of asymptomatic infection in a cattle population and subsequent risk to humans.