Yersinia pestis PCR test
dog and cat assay data sheet
B0065 - Ultrasensitive qualitative detection of
Yersinia pestis, the
etiologic agent of plague, by real time polymerase chain reaction.
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.
it has a “safety pin” appearance.
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
Rodents are a common reservoir of these bacteria; their fleas help
disseminate the disease. When humans or other animals live in close
proximity to infected rodents, the bacteria can be transmitted 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
In North 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)
Domestic cats and
dogs in endemic areas can easily be infected with these bacteria if
exposed to infected rodents. Dogs are generally resistant to plague.
Although they may become infected, they usually develop very mild
symptoms, such as swollen lymph nodes, and they can become carriers of
the bacteria. Wild and domestic cats can become infected and develop
any of the three forms of the disease (bubonic, septicemic or
pneumonic). About 50% of cats infected with
Y. pestis will die soon after developing the disease.
Airborne transmission 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.
In pneumonic form,
Y. pestis can be transmitted
person-to-person or cat-to-person through aerosols from coughing (Gage
et al., 2000). Due to its high replication rates, plague proves
fatal in roughly 50% of cases even with medical treatment, and is
almost universally fatal without treatment.
"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
Help confirm the disease causing agent
Shorten the time required to confirm a clinical
diagnosis of Yersinia pestis
Help ensure that animals and facilities are free of
Early prevention of spread of
Minimize human exposure to
Safety monitoring of biological products that derive
from susceptible animals
References:Gage, K.L., Dennis, D.T., Orloski, K.A., Ettestad, P., Brown, T.L.,
Reynolds, P.J., Pape, W.J., Fritz, C.L., Carter, L.G.., and Stein,
J.D. (2000) Cases of human plague associated with exposure to
infected domestic cats. Clin. Infect. Dis. 30:893-900.
J.C., Foley, P., Gage, K.L. and Foley, J.E. (2007) Initiation and
spread of traveling waves of plague,
pestis, in the western United States. Am J Trop Med Hyg.
Engelthaler, D.M., Gage, K.L., Montenieri, J.A., Chu, M. and
Carter, L.G. (1999) PCR
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) tube, or
nasal swab, or skin swab, or lesion swab.
For specimen types
other than those listed here, please call to confirm specimen
acceptability and shipping instructions.
For all 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
2 business days
polymerase chain reaction