LAM3_93-133_JS Flashcards
Staphylococcus to the end of the chapter
What are the two most common species of Staphylococcus that infect mice?
S. aureus - can be highly pathogenic
S. epidermidis - generally nonpathogenic
What is a common cause of botryomycosis?
S. aureus
Staphylococcus is a gram_________, coagulase____________ organism.
positive, positive
Most streptococcal infections is laboratory mice are caused by ___________ hemolytic organisms in Lancefield’s group ____________.
β, C
A common Strep. syndrome in mice is _________ lymphadenitis with fistulous drainage to the ___________.
cervical; neck
T/F Escherichia coli is highly pathogenic organism that causes disease in immunocompetent mice.
False: Escherichia coli is a gram neg. rod that is a normal inhabitant of the mouse intestine, but may cause hyperplastic typhlocolitis in SCID mice.
Name two species of Klebsiella found in laboratory mice.
K. pneumoniae, K. oxytoca
T/F K. pneumoniae and K. oxytoca are significant causes of disease in mice.
False
Clostridia are large rod/cocci shaped, gram positive/negative, anaerobic/aerobic bacteria.
rod; positive; anaerobic
Naturally occurring clostridial infection in mice is rare, but what species of Clostridium has been associated with high mortality in suckling mice?
C. perfringens type D
T/F Mycobacteria are gram-negative, acid-fast, obligate intracellular bacteria.
False: Mycobacteria are gram-positive, acid-fast, intracellular bacteria.
Name two species of Mycobacterium that are known to be pathogenic in laboratory mice.
M. avium-intracellulare (extremely rare) and M. lepraemurium
What is the etiologic agent of murine leprosy?
M. lepraemurium. It has been used as a model for human leprosy.
What are clinical signs and gross lesions associated with murine leprosy?
Clinical signs include alopecia, thickening of skin, subcutaneous swelling, and cutaneous ulceration. Disease can lead to death or clinical recovery. Gross lesions include nodules in SQ tissues and organs (lung, spleen, lymph nodes, bone marrow, and thymus).
What is the histologic hallmark of murine leprosy?
The histologic hallmark is perivascular granulomatosis with accumulation of large, foamy epithelioid macrophages (lepra cells) filled with acid-fast bacilli.
T/F Clinical disease resulting from Proteus mirabilis infection is typically only seen in association with stress or immunosuppression (induced or innate).
True
T/F Leptospirosis usually causes clinically apparent disease in mice.
False: Leptospirosis in mice is generally asymptomatic
Leptospirosis in mice is primarily associated with what organism?
Leptospira interrogans serovar ballum
How is Leptospirosis diagnosed in mice?
PCR & isolation of the organism from kidney.
What two rickettsia are known to infect mice?
Mycoplasma coccoides, Mycoplasma muris
Formerly Epyerythizoon coccoides, and Hemobartonella muris
How are M. coccoides & M. muris transmitted?
M. coccoides is transmitted by the mouse louse Polyplax serrata, and M. muris is transmitted by the rat louse Polyplax spinulosa.
What are two possible clinical outcomes in mice infected with M. coccoides?
Mice may remain clinically normal, or develop febrile, hemolytic anemia and splenomegaly, which may be fatal.
Latent infection with M. coccoides can be reactivated by _______________.
Splenectomy. Splenectomy or inoculation of test material into splenectomized mice is the most sensitive means to detect infection.
T/F Chlamydia trachomatis has been known to cause disease in mice.
True, but typically natural infections are asymptomatic but persistent; A strain, called the Nigg agent, has been associated with natural infection in mice.
Causes ocular and urogenital infections in people!
Pneumocystis carinii was originally classified as a ___________, but is now characterized as a _______________.
protozoan; fungus
What clinical signs of pneumocystosis are seen in immunocompetent mice vs. immunodeficient mice?
immunocompetent: generally asymptomatic. immunodeficient: dyspnea, hunched posture, wasting, and scaly skin. Severe cases may be fatal.
What type of stains are used to visualize Pneumocystis cysts?
silver-based stains
What virus has been shown to accelerate the development of Pneumocystosis in SCID mice?
Pneumonia virus of mice.
________________ is the most common fungal agent of mice.
Trichophyton mentagrophytes
T/F T. mentagrophytes frequently causes clinical disease in infected mice, and organisms can be detected using a Wood’s lamp.
False; Infection rarely causes disease, and T. mentagrophytes rarely fluoresces under uv light.
Name two common flagellates that inhabit the duodenum of mice, rats, and hamsters.
Giardia muris and Spironucleus muris
T/F Giardia muris infection is usually asymptomatic, but if organisms proliferate extensively, it can cause weight loss, rough hair coat, and abdominal distension.
True; additionally, clinical signs usually don’t include diarrhea, and heavy infestations may be fatal in immunodeficient mice.