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What 2 Rickettsia are known to infect mice?
1. Eperythrozoon coccoides
2. Hemobartonella muris
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-Eperythrozoon coccoides and Hemobartonella muris are common blood parasite of rodents and the etiological agent of a chronic infection present in many mouse colonies. After primary infection, mice develop a parasitemia and anemia followed by a chronic, latent infection.
-They are also known as chemotropic mycoplasmas:
Eperythrozoon coccoides as Mycoplasma coccoidesHemobartonella muris as Mycoplasma hemomuris
-Have a trophic for red blood cells
-Diagnose with blood smears and PCR
Giardia muris
Hymenolepis nana causes weight loss and focal enteritis. Cinical disease is rare. Can be treated with benzimidazoles.
Name 1-2 important features about the dwarf tapeworm, Hymenolepis nana (Rodentolepis):
-Can directly infect humans
-Has a direct life cycle
When you clinically see the oily hair effect with jaundice and wasting, your presumptive diagnosis of what virus would this be?
Mammalian Orthoreovirus (Reovirus 1, 2, 3)
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Reovirus Infections:
-ds RNA virus
-2 members of this family infect laboratory mice:
1. Mammalian Orthoreovirus
2. Rotavirus A (aka Epizootic diarrhea of infant mice, EDIM)
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1. Mammalian Orthoreovirus:
-Reovirus 3 is a serotype of Mammalian Orthoreovirus. Mice can be infected with any serotype but Reovirus 3 is emphasized because it has been associated with naturally occurring disease.
-Acute disease affects sucklings at 2 weeks of age. Severe pan tropic infection in infant mice (liver, brain, heart, pancreas, spleen, LN, blood vessels)
-Subclinical infection in adults
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2. Rotavirus A (aka Epizootic diarrhea of infant mice, EDIM)
-Replicates in epithelial cells of the small intestine
-species specific
-Clinical signs seen in infant mice < 2 weeks old. Only in offspring of non immune dams=maternal immunity needed.
-Cardinal signs: bloated abdomen with fecal soiling or perineum
-Presence of milk might help differentiate from other diseases because nursing ceases with others not EDIM
What are the long lived infections that can be expressed in 2 ways of Eperythrozoon coccoides (hemotropic mycoplasma) infection?
1. acute febrile anemia and latent
or
2. subclinical infection that can be reactivated by splenectomy
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-carrier state may be lifelong with hemotropic mycoplasmas
-Can be transmitted via bio products such as tumors or blood
What cell type is needed to suppress infection with Pneumocystis?
T lymphocytes
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Pneumocystosis
P. murina (Pm)
- subclinical
-severe in immunodeficient mice, infection proceeds slowly
-pneumonia
-ubiquitous organism
-transmitted via aerosol
-establishes a persistent, quiescent infection of lungs
-detected with silver methenamine staining
Name the organs that Toxoplasma gondii causes necrosis and inflammation in. (there are about 11)
intestine
mesenteric LN
eyes
heart
adrenals
spleen
brain
lung
liver
placenta
muscles
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- mouse is the intermediate host
Syncytia is the HALLMARK LESION on pathology of this mouse virus that has prevalence and severity that is dependent on age, strain, and immunological status of infect mice:
Murine Coronavirus (Mouse Hepatitis Virus, MHV)
What is the primary vector for Eperythrozoon coccoides?
Polyplax serrata, the mouse louse
T or F: Spironucleus muris infection causes poor hair coat, sluggish behavior, weight loss, diarrhea. Usually is subclinical. 0.1% dimetridazole to drinking water for 14 days is the treatment. What other parasitic disease is Spironucleus muris clinical signs similar to?
Giardia
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-Giardia and Spironucleus both inhabit the duodenum and both have the same clinical signs of poor hair coat, sluggish behavior, weight loss, diarrhea. Both have the same treatment with dimetridazole.
-Spironucleus muris is smaller than Giardia, lacks a sucking disk, an moves in a zigzag
Polyplax serrata, otherwise known as the mouse louse and a vector of Mycoplasma coccoides. What are my clinical signs?
Pruritis, dermatitis anemia
What procedure is performed in order to detect rickettsial infection in mice?
splenectomy
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-Diagnosis is by splenectomy or inoculation of test material into splenectomized mice, which is most sensitive!!
-Romanowsky stained blood smears or IMF prepared every 6 hours, 48hours after splenectomy
-Treatment is not practical.
-Cull
Tritrichomoniasis, the parasitic disease caused by Tritrichomonas muris is non pathogenic in lab mice. Does it inhabit the cecum, colon, small intestine, two of the locations, or all three of the locations? If so, which ones?
Cecum, colon and small intestine
What serovar of Leptospira has been reported in mice?
Leptospira interrogans serovar ballum
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-One of the most common zoonoses transmissible from rodents
-Persistent infection in renal tubules
-Vascular, hepatic and renal lesions
-exceedingly rare in lab mice
-periodically excreted in the urine
-natural infection is usually subclinical. Experimental can result in severe vascular, hepatic and renal lesions, dependent on server, strain of mouse and immunocompetancy.
What pathogenic agent is the Nigg agent associated with?
Chlamydia trachomatis or Chlamydia muridarum
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-One strain historically referred to as the "Nigg agent" after Clara Nigg is more recently classified as C. muridarum and is a model for human chlamydia infection
-Known as the mouse pneumonitis agent due to severe acute infection, labored respiration and interstitial pneumonitis and death in 24 hours
-typically subclinical but persistent
What pinworm is detected by perianal tape test? What pinworm is detected by fecal examination?
Choices:
Syphacia obvelata
Aspicularis tetraptera
Hymenolepis nana
(There is only one answer for each question; so one answer choice will be left out)
Syphacia obvelata is detected by tape test, as eggs are laid on the perianal hairs.
Aspiculuris tetraptera is detected by fecal examination.
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Syphacia obvelata (mouse pinworm)
-subclinical
-causes rectal prolapse, intussusception, enteritis, and fecal impaction.
-Tape test
Aspicularis tetraptera:
-coinfection with syphacia obveleta
-longer lifecycle, so appear in somewhat older mice
-Similar clinical signs to Syphacia obvelata
-Easier to treat
Proteus mirabilis, is a gram negative rod, aerobic, motile flagellete. It is ubiquitous in environment. Can inhabit the respiratory and intestinal tract. Generally there are no clinical signs but in immune dysfunction, can cause sepsis, diarrhea, weight loss, death.
If you were transporting mice to another university (or vice versa), would this pathogen be of general concern to screen and why?
No; Commonly found in research mice unless specifically excluded