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PSITTACOSIS : II. EXPERIMENTALLY INDUCED INFECTIONS IN MICE
1Hospital of The Rockefeller Institute for Medical Research.
Abstract:
The work presented in this communication concerning psittacosis in mice confirms Krumwiede's observations that mice inoculated intraperitoneally with emulsified livers and spleens containing the virus develop the disease and that the malady can in this way be passed serially through a number of mice. Furthermore, it has been shown that mice are susceptible to the virus administered intracerebrally and that the active agent can be propagated indefinitely by means of brain to brain inoculations. Moreover, by the use of mice, the presence of the virus of psittacosis in the sputum of a patient with the disease has for the first time been demonstrated. It follows that the mouse is available for diagnostic purposes. The pathological findings in infected mice consist of enlarged fatty livers that frequently show areas of necrosis infiltrated with polymorphonuclear and mononuclear cells; enlarged spleens with areas of necrosis and cellular infiltrations involving the pulp and lymphoid follicles; and, finally, in intracerebrally infected animals, a meningoencephalitis. The "minute bodies" described by other observers were not found in all animals, but they were seen with sufficient frequency in smears of peritoneal and meningeal exudates and in smears and sections of livers and spleens to demand serious consideration as the possible etiological agent of the disease. Neutralizing and protective antibodies were not found in convalescent human sera when the mouse was used as the test animal.
Insights
Mice can be used to study psittacosis, a disease caused by a specific virus. This research demonstrates the effectiveness of using mice for diagnosing psittacosis and understanding its pathological effects.
Area of Science:
- Veterinary Pathology
- Infectious Diseases
- Microbiology
Background:
- Psittacosis is an infectious disease that affects various species.
- Previous research established mice as a model for psittacosis, but further investigation was needed.
Purpose of the Study:
- To confirm and expand upon Krumwiede's findings regarding psittacosis in mice.
- To investigate the efficacy of intracerebral inoculation and serial propagation of the psittacosis virus in mice.
- To demonstrate the presence of the psittacosis virus in patient sputum using a mouse model and assess its diagnostic utility.
Main Methods:
- Intraperitoneal inoculation of mice with emulsified infected livers and spleens.
- Intracerebral inoculation of mice for serial propagation.
- Examination of pathological findings in infected mice, including liver, spleen, and brain tissue.
- Microscopic analysis of peritoneal and meningeal exudates, as well as tissue smears and sections.
- Testing for neutralizing and protective antibodies in convalescent human sera using mice.
Main Results:
- Mice inoculated intraperitoneally developed psittacosis, confirming serial transmissibility.
- Intracerebral inoculation allowed for indefinite propagation of the psittacosis virus.
- The psittacosis virus was successfully identified in the sputum of a patient using the mouse model.
- Pathological findings included enlarged, necrotic livers, enlarged spleens with necrosis, and meningoencephalitis in intracerebrally infected mice.
- "Minute bodies," potentially the etiological agent, were observed in various infected tissues and exudates.
- No neutralizing or protective antibodies were detected in convalescent human sera when mice were used for testing.
Conclusions:
- Mice serve as a viable model for studying psittacosis and are suitable for diagnostic purposes.
- The mouse model facilitates the study of psittacosis pathogenesis and viral propagation.
- Further investigation is warranted regarding the "minute bodies" as the etiological agent of psittacosis.
