rodent and rabbit assay data sheet
code: B0065 - Ultrasensitive qualitative detection of
Yersinia pestis, the
etiologic agent of plague, by real time polymerase chain
Yersinia pestis is a gram-negative rod-shaped bacterium belonging to the family
Enterobacteriaceae. Formerly called
Pasteurella pestis, it
is a facultative anaerobe that can infect humans and other
animals. Stained, it has a “safety pin” appearance.
main forms of infection can occur in humans, referred to as
pneumonic plague, septicemic plague and bubonic plague. All
three forms have caused high mortality rates in epidemics
throughout human history, including the Black Death (the bubonic
form) that accounted for the death of at least one-third of the
European population in 1347 to 1353.
America, fleas infected with
Yersinia pestis have
been found on wild rodents and other animal species from the
Pacific Coast to the Great Plains, and from southwestern Canada
to Mexico. Most human cases in the United States occur in two
regions: 1) northern New Mexico, northern Arizona, and southern
Colorado; and 2) California, southern Oregon, and far western
Nevada (Adjemian et al., 2007)
Rodents are a common reservoir of these bacteria; their fleas
help disseminate the disease. When humans live in close
proximity to infected rodents, the bacteria can pass to humans
via flea bites. Once the bacteria enter the bloodstream, they
migrate to the lymph nodes. The ability of Yersinia pestis
to inhibit phagocytosis allows it to avoid destruction by immune
system cells such as macrophages and thereby to proliferate in
lymph nodes, causing lymphadenopathy.
Airborne transmission to humans results in pneumonic plague,
whereas patients infected by the bubonic or septicemic forms
seldom exhibit pneumonic characteristics. After an incubation
period, patients with pneumonic plague show sudden onset of
coughing, high temperature, and lack of energy; these symptoms
increase in severity over time. Due to its high replication
rates, plague proves fatal in roughly 50% of human cases even
with medical treatment, and is almost universally fatal without
Traditionally, the "gold standard" for testing fleas for Y.
pestis infection has been the inoculation of mice with
ground flea suspensions. Inoculated mice are monitored for
death, which usually takes at least 21 days; tissues from these
dead mice are then tested by fluorescent antibody
analysis for evidence of Y. pestis infection. This
testing approach, however, requires considerable time and
personnel involvement. False negative results can
occur when death is used as the assay endpoint, because
some mice occasionally survive the infection. Molecular
detection is a rapid, sensitive, specific and safer alternative
for identification of Y. pestis.
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
diagnosis of Y. pestis
Help ensure that rodent colonies and populations are free of
Early prevention of spread of these bacteria among a
Minimize personnel exposure to these bacteria
Safety monitoring of biological products that derive
Adjemian, J.C., Foley, P., Gage, K.L. and Foley, J.E. (2007)
Initiation and spread of traveling waves of plague,
Yersinia pestis, in
the western United States. Am J Trop Med Hyg. 76:365-375.
Engelthaler, D.M., Gage, K.L., Montenieri, J.A., Chu, M. and Carter, L.G.
Detection of Yersinia
pestis in fleas: Comparison with mouse inoculation. J. Clin.
0.2 ml whole blood in EDTA (purple top) or ACD (yellow top)
types other than those listed here, please call to confirm
specimen acceptability and shipping instructions.
specimen types, if there will be a delay in shipping, or during
very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain
frozen in transit. See shipping
instructions for more information.
2 business days
real time PCR