Monoclonal antibodies against Yersinia pestis lipopolysaccharide detect bacteria cultured at 28 degrees C or 37 degrees C.

Four monoclonal antibodies were generated against Yersinia pestis lipopolysaccharide by immunising mice with a cell surface preparation from Y. pestis strain 1255. In an ELISA the monoclonal antibodies reacted with live whole cells of Y. pestis strain GB cultured at 28 degrees C or 37 degrees C. The lowest detection threshold for Y. pestis strain GB cultured at 28 degrees C was 4 x 10(5) cfu ml(-1) and for bacteria cultured at 37 degrees C was 1 x 10(4) cfu ml(-1). The monoclonal antibodies did not cross react with other pathogenic Yersinia in an ELISA, but showed some cross reactivity in an immuno-blot. The monoclonal antibodies could be used for the detection of Y. pestis cultured at different temperatures and with varying plasmid profiles as the lipopolysaccharide molecule is not temperature regulated and the genes encoding its biosynthesis are located on the bacterial chromosome.