Detection of Campylobacter species in foods by indirect competitive ELISA using hen and rabbit antibodies

The competitive enzyme immunoassays for detection of Campylobacter jejuni, C. coli and C. fetus subsp. fetus have been developed. Rabbit and hen immunoglobulins were prepared for these purposes. The working conditions of ELISAs, such as the concentrations of immunoreactants, incubation temperatures and time, and the composition of the substrate have been established. The detection limits were in the range 5.0 104-3.2 106 cfu/ml. The application of chemiluminescent substrates did not result in any significant improvement of the assay's detectability and sensitivity. Prepared antibodies showed rather high specificity and cross-reactivity profiles, and both rabbit and hen immunoglobulins were similar. Only IgY to C. jejuni cross-reacted with seven strains of C. jejuni and two other Campylobacter spp. A limited number of naturally and artificially contaminated food samples were tested. The results obtained by means of an enzyme immunoassay were compared with those obtained from PCR or commercially available Singlepath® Campylobacter GLISA-Rapid Test. Poultry products were naturally contaminated with Campylobacters. The wild species were identified as C. jejuni and C. coli.