Biotin-streptavidin enzyme-linked immunosorbent assay for the detection of antibodies to Campylobacter jejuni and C. coli in chickens.

An enzyme-linked immunosorbent assay (ELISA) was developed in a homologous system with bacterial ultrasonic-treated proteins as the antigen and antisera from chickens infected orally and subcutaneously with the strain Campylobacter jejuni serovar 6 (CJ 6). The cut-off level was determined using antisera from non-infected specific-pathogen-free chickens up to the age of 10 weeks. The suitability of the ELISA system was verified using antisera taken from chickens orally infected at the age of 4 weeks with CJ 1, 6, 28 or 36 or with Campylobacter coli serovar 28 (CC 28). The development of antibodies was monitored up to 6 weeks post-infection (p.i.). Sera from chickens infected with CJ 1, 6, 36 or CC 28 contained specific antibodies to Campylobacter, whereas in those infected with CJ 28 no specific antibodies were found. Distinct cross-reactions were observed between CJ 6, 28 and CC 28 antigens and their antisera 6 weeks p.i., while poor cross-reactions were found with antisera to CJ 1 and 28. Antibodies to strains of all heterologous serovars were successfully detected with an antigen pool comprised of CJ 1, 6 and 36 antigens. In 11 out of the 12 field sera obtained from 5- and 9-week-old broiler chickens suffering from campylobacteriosis, high specific antibody titres to Campylobacter jejuni were found.