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EXPERIMENTAL STUDIES WITH A SPIRAL ORGANISM FOUND IN A WILD RAT AND IDENTICAL WITH THE ORGANISM CAUSING RAT-BITE
1American Hospital, Mexico City, Mexico.
Abstract:
1. The spiral organism isolated from a wild rat has proved identical with that from a human case of rat-bite fever in Mexico City. 2. Rabbits can easily be infected with these organisms. 3. The subcutaneous inoculation of them is followed after 3 to 5 days by a local edema, induration, and inflammation: primary lesion. 4. About 8 days after the appearance of the primary lesion, edematous swellings and inflammation appear on the head and genitals: secondary lesions. 5. The organism can be transmitted from rabbit to rabbit by coitus. 6. Protective antibodies are to be found in the blood of infected rabbits at a time when the local lesions are still active. The peculiar character of certain of the lesions is probably due to the escape of the antibodies from the blood stream. 7. The organism belongs to the genus Treponema.
Insights
A spiral organism causing rat-bite fever in humans and rats was identified as Treponema. This bacterium can be transmitted between rabbits, causing distinct primary and secondary lesions.
Area of Science:
- Microbiology
- Infectious Diseases
- Veterinary Medicine
Background:
- Rat-bite fever is a zoonotic disease with human and animal reservoirs.
- The causative agent of rat-bite fever has been historically challenging to characterize.
- Understanding the transmission and pathogenesis of this organism is crucial for public health.
Purpose of the Study:
- To identify and characterize the spiral organism responsible for rat-bite fever.
- To establish an animal model for studying the disease progression and host response.
- To investigate the transmission dynamics of the organism.
Main Methods:
- Isolation and identification of the spiral organism from infected rats and humans.
- Experimental infection of rabbits via subcutaneous inoculation.
- Observation of lesion development and characterization (primary and secondary).
- Transmission studies between rabbits through coitus.
Main Results:
- The spiral organism from wild rats was identical to that from a human case, identified as Treponema.
- Rabbits developed characteristic primary lesions (local edema, induration, inflammation) 3-5 days post-inoculation.
- Secondary lesions (edematous swellings, inflammation) appeared on the head and genitals around day 8.
- The organism was transmissible between rabbits via coitus.
- Protective antibodies were detected in infected rabbits while lesions were still active.
Conclusions:
- The identified spiral organism belongs to the genus Treponema.
- Rabbits serve as a viable model for studying rat-bite fever, exhibiting similar lesion development.
- The transmission of Treponema via coitus in rabbits suggests a potential transmission route.
- The presence of antibodies during active lesions indicates a complex host-pathogen interaction.
