Molecular detection of Yersinia pestis isolates of Indian origin by using Pla specific monoclonal antibodies

Monoclonal antibodies (MAbs) were generated against the recombinant plasminogen activator (Pla) protein of Yersinia pestis. These MAbs detected Pla in all the 18 isolates of Y. pestis obtained from the sputum of pneumonic plague patients and from the liver and spleen of rodents from plague-affected areas of India during 1994–1995 as well as in seven of the eight isolates obtained from rodents in the surveillance regions of Hosur and Palmner in India during 1998 by simple dot-ELISA. In immunoblotting, the MAbs reacted with the Pla antigen only in Y. pestis isolates at 37 and 35 kDa region. These monoclonal antibodies, being strictly specific, can be used for detecting Y. pestis isolates that are Fraction 1 antigen-negative. Also, the radiolabelled pla fragment hybridized specifically to the representative DNA samples of Y. pestis isolates.