DESCRIPTION (provided by investigator): The 2001 Anthrax attack confirmed that bioterrorism is a real possibility. Although the attack occurred at a small scale, its impact reached terror proportion. Unfortunately, as former Senator Warren Rudman pointed out, "the likelihood of a terrorist attack in this country in the next several years is more likely than unlikely". Recent study by the Council on Foreign Relations concluded that our nation remains "unprepared to handle a catastrophic attack on American soil, particularly one involving chemical, biological or nuclear agents". With an estimated 100 million plague victims in the last two millennia and the emergence of antibiotic resistance of its causative agent, Yersinia pestis has been identified as a category A bioterrorism agent. In the event of a bioterrorism attack, one of the most important first responses is rapid identification of the biological agent or agents, and timely diagnosis of those who have been infected. Current methods of choice for sensitive detection of Yersinia pestis are those involving polymerase chain reaction (PCR). The organism is then confirmed with culture methods and/or EIA. The use of PCR is not without problems, however. Possible contamination of PCR amplicons necessitates a specialized and highly controlled central laboratory, which in turn necessitates long distance sample shipping. The fact that PCR is susceptible to inhibitory impurities requires lengthy sample preparation and duplicate testing. All these problems had been encountered during the 2001 Anthrax terror attack. We have developed a rapid (approximately 60 minutes) and sensitive (less than 1 bacterium) prototype sepsis test using our microparticle based amplification (MBA) technology and a novel class of bacterial markers. The specific aim for this Phase I application is to study the feasibility of using the same technology but different species of markers to develop a Yersinia pestis test that is (a) rapid (60-90 minutes), (b) sensitive (less than 100 CFU), (c) specific (no cross reactivity with its close relatives), and (d) fully automatic. When fully developed, the only hands-on step for the assay is the loading of clinical samples (not necessarily purified nucleic acids). Because of the dual use of the instruments, the Yersinia pestis test could be widely available in clinical laboratories and thus offer a first-line diagnosis testing in the event of a bioterrorism.