Warning on a new potential for laboratory-acquired infections as a result of the new nomenclature for the plague bacillus.

The new name for the plague bacillus (formerly "Yersinia pestis") is Y. pseudotuberculosis subsp. pestis, while the pseudotuberculosis bacillus is named Y. pseudotuberculosis subsp. pseudotuberculosis. Any tendency to abbreviate these names on labels of cultures, especially by omitting the subspecies epithet, must be avoided because of the risk of confusion between the dangerous plague organism and the pseudotuberculosis bacillus.