Sensitivity and specificity of monoclonal antibody Mn-Cs1 for detection and determination of Clavibacter michiganensis subsp. sepedonicus, the causal agent of bacterial ring rot of potato

Monoclonal antibody Mn-Cs1 with a high level of sensitivity and specificity for detection and determination of Clavibacter michiganensis subsp. sepedonicus was prepared. Strain C. m. subsp. sepedonicus NCPPB 3467 (as whole cell antigen and extracellular polysaccharides) was used for immunisation of four mice Balb/c. After cloning and verifying, two stable hybridoma clones were gained. One monoclonal antibody, designated Mn-Cs1, was used in all tests. It reacted intensely with extracellular polysaccharides from homologous antigen (> 0.5 mg/ml), weakly with proteins from cell walls (> 200 μg/ml) and with whole homologous antigen (concentration 104–103 cfu/ml) in DAS-ELISA. Monoclonal antibody Mn-Cs1 showed a high level of specificity. It reacted neither with bacterial strains of closely related subspecies of Clavibacter michiganensis (C. m. subsp. michiganensis and C. m. subsp. insidiosus) nor with the saprophytic bacteria Pseudomonas fluorescens and Pantoea agglomerans.