Monoclonal antibodies against serogroup B salmonellae: production, characterisation and use in a sandwich ELISA.

Ten monoclonal antibodies (MAbs) against serogroup B salmonellae were obtained after immunisation of BALB/c mice with outer membrane proteins (OMPs) from Salmonella enterica serovar Typhimurium. Affinity constants, measured by enzyme-linked immunosorbent assay (ELISA), ranged from 8×05 to 6×07 l mol-1. Additivity ELISA demonstrated that most MAbs recognise different epitopes. ELISA determined the antigen specificity of the MAbs. The MAbs were more reactive with live Salmonella Typhimurium than with heat-treated cells. Two MAbs were used to develop a sandwich ELISA for rapid detection of Salmonella Typhimurium in experimentally contaminated meats. Its detection limit was 105 CFU ml-1 and it was able to detect 1-10 CFU in post-enrichment broth from 25 g of beef and chicken meat samples. The sandwich ELISA developed was shown to be specific and sensitive for the detection of Salmonella Typhimurium in meat, and produced results comparable to the culture methods in 57 h. [ABSTRACT FROM AUTHOR]