Evaluation of a qualitative isocitrate lyase assay for rapid presumptive identification of Yersinia pestis cultures.

Qualitative rapid tests for isocitrate lyase activity were positive for all of 1,695 Yersinia pestis cultures tested but for none of 382 cultures of other gram-negative species. The test is simple, required only commonly available, easily prepared reagents, and provided clear-cut positive or negative results within 20 min.