Evaluation of polyclonal and monoclonal antibodies for detection and determination of Clavibacter michiganensis subsp. Sepedonicus.

Iveta Pánková

ipankova@vurv.cz
Department of Bacteriology, Plant Medicine Division, Research Institute of Crop Production, Drnovská 507, Prague 6, 161 06 Czech Republic (Czechia)

Blanka Kokošková

Department of Bacteriology, Plant Medicine Division, Research Institute of Crop Production, Drnovská 507, Prague 6, 161 06 Czech Republic (Czechia)

Abstract

Immunochemical diagnostics of Clavibacter michiganensis subsp. sepedonicus (Spieckerman and Kotthoff) Davis et al., the causal agent of bacterial ring rot of potato, is based on the use of high quality polyclonal and monoclonal antibodies. The specificity and sensitivity of the polyclonal Po-Cs 6 and monoclonal Mn-Cs 1 antibodies for detection and identification of C. m. subsp. sepedonicus in pure culture and extracts of potato tuber samples were compared by double antibody sandwich enzyme-linked immunosorbent assay (DAS ELISA). The polyclonal antibody Po-Cs 6 cross-reacted with strains of several Clavibacter michiganensis subspecies, Pantoea agglomerans, and weakly with Pseudomonas fluorescens and Ralstonia solanacearum (race 3)in all serological tests. After cross-absorption with these bacteria, the threshold level of homologous antigen NCPPB 3467 was 10H⁷ cfu/ml in DAS ELISA. The monoclonal antibody Mn-Cs 1 did not cross react with other michiganensis subspecies or with other plant pathogenic bacteria tested. The monoclonal antibody Mn-Cs 1 cross-reacted very weakly with the saprophytic bacteria P. agglomerans and P. fluorescens. The threshold level of homologous antigen NCPPB 3467 was 10⁴ cfu/ml in DAS ELISA. The monoclonal antibody Mn-Cs 1 proved to be more sensitive and specific than the polyclonal antibody Po-Cs 6 in all serological tests.

Keywords:

bacterial ring rot of potato, DAS ELISA, sensitivity, specificity, cross reactions