Rapid and specific enzyme immunoassay on hydrophobic grid membrane filter for detection and enumeration of thermophilic Campylobacter spp. from milk and chicken rinses.

Six commercially available anti-Campylobacter antibodies were examined for their applicability in an enzyme immunoassay on hydrophobic grid membrane filters, both for the detection and enumeration of Campylobacter spp. When a panel of nine Campylobacter (seven Campylobacter jejuni and two Campylobacter coli) and eight non-Campylobacter strains were used in a dot-blot format enzyme immunoassay to test the specificity of these antibodies, only one polyclonal antibody (Biodesign) detected all Campylobacter strains. Escherichia coli O157:H7 produced weak nonspecific signals due to endogenous peroxidase activity. The specificity of this Biodesign antibody was further tested against 30 more Campylobacter strains and more than 600 non-Campylobacter strains on hydrophobic grid membrane filters grown on modified Campylobacter agar with charcoal and deoxycholate, a Campylobacter selective medium. All the Campylobacter strains were detected, whereas only two (Acinetobacter calcoaceticus, Salmonella Minnesota) of the approximately 130 non-Campylobacter strains, which grew on modified Campylobacter agar with charcoal and deoxycholate, gave false-positive signals. This simple, rapid, and specific enzyme immunoassay also detected Campylobacter spp. from inoculated milk and chicken rinses and naturally contaminated chicken rinses.