Companion Guide to Infectious Diseases of Mice and Rats (1991) / Chapter Skim
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Part II: Disease Agents
Part II: Disease Agents
Pages 9-69
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From page 9... ...
Control. Cesarean derivation and barrier maintenance may be necessary for eliminating either virus strain.
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From page 10... ...
Subclinical infection is probably more common than clinical disease (commonly called Tyzzer's disease)
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From page 11... ...
Diagnosis of clinical disease is based on finding typical gross and microscopic lesions and characteristic organisms in silver-stained histologic sections. Both the IFA and the CF tests have been used for the diagnosis of subclinical infections, but neither test is available commercially in the United States.
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Laboratory rats and mice, wild rats (Rattus norvegicus) , African white-tailed rats (Mystromys albicaudatus)
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Control. The infection probably can be eliminated by cesarean derivation, but definitive data are not available.
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From page 14... ...
Persistent subclinical infections are thought to be common in conventionally reared stocks and rare in barrier-maintained stocks. The main sites of infection are probably the oropharynx, submaxillary lymph nodes, and large intestine, with transmission mainly by the fecal-oral route.
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Cesarean derivation and barrier maintenance are effective means of control. Interference with Research.
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From page 16... ...
These methods may prove useful for monitoring laboratory mice for cytomegalovirus infection in selected situations. Virus isolation can be accomplished using mouse embryo fibroblasts or other tissue culture systems.
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From page 17... ...
Quarantine and testing of incoming mice and mouse tissues from sources other than commercial barrier facilities are the best way to prevent the introduction of infection. In the past, the accepted practice for eradicating ectromelia virus was elimination of infected mouse colonies and all infected biologic materials,
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From page 18... ...
Suggested Reading AALAS (American Association of Laboratory Animal Science)
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From page 19... ...
E cuniculi can contaminate transplantable tumors and alter host responses during tumor passage in mice.
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in Eastern Europe and Scandinavia; urban and laboratory rat viruses, Rattus norvegicus, moderate disease found mostly in people in Asia but occasionally also in Europeans; Girard Point and other viruses from North and South America, Rattus norvegicus, no disease recognized in humans, although serologic evidence of infection has been found; and Prospect Hill virus, the meadow vole Microtus pennsylvanicus, no disease recognized in humans. Naturally infected laboratory rats have been the source of Hantavirus infections in research personnel in Japan, Belgium, the United Kingdom, and France.
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From page 21... ...
Hantavirus infections can be prevented by obtaining animals, transplantable tumors, and other biologic materials that have been tested and found to be free of infection. Contamination of laboratory rodent stocks by wild rodents must be prevented.
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From page 22... ...
MHV is a frequent contaminant of transplantable tumors and cell lines. Clinical.
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From page 23... ...
Transplantable tumors and other biologic materials can be screened by virus isolation or by the MAP test. Control.
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Common infection of wild and laboratory rats; prevalence exceeds 50% in some populations. Epizootiological characteristics are generally assumed to be similar to those of Kilham rat virus infection.
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KRV is a frequent contaminant of cultured cell lines and transplantable tumors. Clinical.
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Immunosuppression can cause clinical disease in inapparently infected rats. Suggested Reading Coleman, G
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From page 27... ...
Diagnosis is usually based on the presence of increased plasma LDH activity. Transplantable tumors, virus inocula, and other biologic materials can be screened for LDV contamination by inoculating pathogen-free mice with the test material and performing a plasma or serum LDH assay 72-96 hours later.
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From page 28... ...
1987. Delayed increase in plasma lactic dehydrogenase activity in mouse hepatitis virus-infected mice subsequently infected with lactic dehydrogenase virus.
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From page 29... ...
Thus, an awareness of the incidence of spontaneous tumors in different mouse strains or the ability of specific test chemicals to induce tumors can be useful in designing some expenments. Active MuLV infection can cause suppression of humoral and cellular immunity without causing clinical disease.
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Since 1960 three epidemics involving at least 236 human cases have occurred in the United States, and all have been associated with Syrian hamsters, either as laboratory animals bearing transplantable tumors or as pets.* Clinical.
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From page 31... ...
LCMV is a frequent contaminant of biologic materials, including transplantable tumors of mice, hamsters, and guinea pigs; tissue culture cell lines; virus stocks, including leukemia viruses, distemper virus, rabies virus, and mouse poliomyelitis virus; and Toxoplasma gondii sublines. LCMV infection has an inhibitory effect on tumor induction by polyomavirus, Rauscher virus, and mammary tumor virus.
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From page 32... ...
1987. Mechanism of recovery from acute virus infection: Treatment of lymphocytic chonomeningitis virusinfected mice with monoclonal antibodies reveals that Lyt-2+ T lymphocytes mediate clearance of virus and regulate the antiviral antibody response.
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MMTV infection can be a complicating factor in experimental carcinogenesis studies. Suggested Reading Bentvelzen, P., and J
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Virus isolation can be done by using rat embryo tissue culture. The MAP test is commonly used for detection of MVM in transplantable tumors and other biologic materials.
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From page 35... ...
M arthritidis can contaminate transplantable tumors of rats, causing arthritis and/or abscesses at the injection site in recipients.
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Infection and disease are common in conventionally reared rats and mice. Subclinical infection occurs in some cesarean-derived, barrier-maintained stocks.
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From page 37... ...
In mice infection can activate natural killer cells, contaminate transplantable tumors, and cause arthritis in the recipients. Subclinical infection can be exacerbated by some experimental procedures (e.g., deficiencies of vitamin A or E, administration of hexarnethylphosphorarnide)
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From page 38... ...
Pp. 1481-1550 in Pathology of Laboratory Animals, vol.
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From page 39... ...
Rats and mice show no clinical signs unless they are immunodeficient or immunosuppressed. Clinical signs include weight loss, cyanosis, rough hair coat, and dyspnea.
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From page 40... ...
Cesarean derivation and barrier maintenance are effective methods of controlling infection. Interference with Research.
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From page 41... ...
Cesarean derivation and barrier maintenance are usually effective in eliminating the virus because transplacental transmission does not occur. Strict isolation from polyomavirus-infected stocks and exclusion of wild mice from animal facilities are essential for preventing infection.
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A paralytic disease in nude mice associated with polyoma virus infection.
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From page 43... ...
Pathology. There are no pathologic changes associated with natural infections.
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From page 44... ...
Reovirus-3 is an occasional contaminant of and may interfere with research involving transplantable tumors and cell lines. Suggested Reading Hartley, J
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From page 45... ...
Epizootiology. Prevalence in laboratory rodents is unknown, but there is evidence that subclinical infections caused by weakly virulent strains are common in the United States.
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From page 46... ...
Enzootically infected breeding colonies can have alternating periods of inapparent infection and overt clinical disease. Litter sizes and birth weights can be reduced.
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From page 47... ...
Prevalence is considered high in colonies of laboratory mice and rats worldwide. Natural infection occurs via the respiratory tract.
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From page 48... ...
Clinical disease caused by natural SV infection in mice falls into one of two patterns. Enzootic (subclinical)
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From page 49... ...
The MAP test can be used for determining contamination of transplantable tumors and other biologic materials. Control.
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From page 50... ...
The submaxillary and parotid salivary, exorbital lacrimal, Harderian, and intraorbital lacrimal glands are the major target organs. There are also mild changes in the cervical lymph nodes, thymus, and respiratory tract.
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From page 51... ...
1987. Exacerbation of murine respiratory mycoplasmosis by sialodacryoadenitis virus infection in gnotobiotic F344 rats.
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From page 52... ...
aureus-induced renal abscesses. Suggested Reading Clarke, M
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From page 53... ...
Cesarean derivation, barrier maintenance, and regular monitoring for rodent pathogens by a comprehensive health surveillance program are the best methods of control. Mice should not be housed in the same room as rats that have not been monitored for S
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From page 54... ...
Control. Cesarean derivation and barrier maintenance are extremely effective methods of control.
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From page 55... ...
In naturally infected mice, there is a low titer of virus in intestinal mucosa; intestinal contents; feces; and, less frequently, mesenteric lymph nodes. Virus shedding in the feces has been documented to occur as long as 154 days postinfection.
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From page 56... ...
The MAP test can be used for screening biologic materials. Definitive diagnosis usually is made by isolating the virus from the spinal cords or brains of mice with clinical disease, but it is also possible to isolate the virus from the intestinal contents of mice with asymptomatic infections.
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From page 57... ...
Infections are rare, and when they do occur, they are usually subclinical. Clinical disease has been seen more frequently in mice than in rats.
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From page 58... ...
1980. Laboratory animals as apossible source of dermatophytic infections inman.
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From page 59... ...
Cesarean derivation and barrier maintenance are the most effective methods for eradication of mite infestations. Insecticides can be used, but they may alter experimental results.
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From page 60... ...
Other Ectoparasites For more in-depth coverage or information on less common ectoparasites of mice and rats, consult comprehensive reference works on the subject. Suggested Reading Flynn, R
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From page 61... ...
Cesarean derivation and barrier maintenance are effective. Infection can be controlled to some extent by using hygienic methods, such as frequent cage and room sanitization.
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From page 62... ...
Control. Entamoeba muris can be eliminated by cesarean derivation and barrier maintenance; however, infection with this agent is generally considered inconsequential, and control measures are usually not necessary.
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From page 63... ...
Cesarean derivation is required to eliminate the parasite from infected stocks. Metronidazole can be used for treatment of infected animals but does not completely eradicate infection.
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From page 64... ...
nana. Cesarean derivation and barrier maintenance are the most effective methods for eliminating infection.
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From page 65... ...
Other possible causes of digestive tract disease (e.g., enterotrophic strains of mouse hepatitis virus) must be ruled out.
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From page 66... ...
Control. Cesarean derivation and barrier maintenance are recommended for control of the organism.
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From page 67... ...
Control. Cesarean derivation and barrier maintenance are effective methods of control.
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From page 68... ...
Cleveland: CRC Press. Other Endoparasites Numerous other endoparasites have been reported in wild mice and rats and are encountered occasionally in laboratory animals maintained by conventional methods.
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From page 69... ...
1974. Diseases of laboratory animals parasitic.
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