A strategy to verify the absence of the pgm locus in Yersinia pestis strain candidates for select agent exemption

Yersinia pestis is a Department of Health and Human Services select agent as defined in federal regulations. Certain attenuated strains of Y. pestis, such as the pgm− strain, are exempt from these regulations. Herein we describe a strategy to verify the absence of the pgm locus in Y. pestis strains being considered as candidates for select agent exemption by PCR analysis of virulence-associated genes.