Evaluation of quantitative latex agglutination for detection of Cryptosporidium parvum, E. coli K99, and rotavirus in calf feces.

A new methodology for detection of rotavirus, Escherichia coli K99, and Cryptosporidium parvum in bovine fecal samples was developed based on a quantitative latex agglutination technique (QLAT). Calibrated microspheres coated with specific antibodies to 1 of the enteric pathogens are quantitatively agglutinated by the antigens present in diluted fecal sample. The test is performed in a 96-well flat-bottom plate. The samples were tested with a commercial enzyme-linked immunosorbent assay kit prior to being analyzed by QLAT. The calculated sensitivity and specificity are adequate for field conditions, because the amount of the pathogenic agents is generally high. The overall time to perform the test was about 20 minutes.