Certain circular DNA molecules called plasmids that confer antibiotic resistance in bacteria found in meat and poultry also have been discovered in the plague bacillus Yersinia pestis, according to a research team led by investigators at the Institute for Genomic Research, in Rockville, Md (Welch TJ et al. PLoS ONE. doi:10.1371/journal.pone.0000309 [published online March 21, 2007]).
While the plasmid that confers antibiotic resistance has been associated with only 1 case of the bubonic plague in Madagascar, it is broadly disseminated among bacteria such as Salmonella enterica and Escherichia coli that affect US livestock.
Hampton T. Antibiotic-Resistant Plague. JAMA. 2007;297(17):1870. doi:10.1001/jama.297.17.1870-b