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Host-parasite relationships in experimental Streptobacillus moniliformis arthritis in mice
Abstract:
Several variables of host and parasite, relating to the establishment of the chronic Streptobacillus moniliformis-induced arthritis, were studied. Results from these studies indicated (i) that intravenous inoculation of the organism produced a progressive bacteremia and a polyarthritis, whereas subcutaneous inoculation into the top of the back foot produced an intermittent bacteremia and arthritis only in that foot, (ii) that serum-broth-grown cells were more virulent than serum-agar-grown cells, (iii) that young animals were more susceptible to infection than old, and (iv) that the organism apparently had a predilection for joints. It was also determined that the leukocyte and antibody responses of mice to infection were minimal with a slight neutrophilia and a maximum antibody titer of 1:640 detected after infection. Measurements of the effectiveness of antibody and leukocytes in prevention or resolution of infection indicated (i) that the presence of homologous antibody prior to infection prolonged the incubation period for development of the lesion, (ii) that the opsonic index was 1.2 to 1.4, and (iii) that the organism was apparently resistant to destruction by in vitro phagocytosis and actually increased in number in the presence of phagocytes. It was concluded that these represented some of the prime factors contributing to the establishment of the infection and its chronicity.
Insights
Streptobacillus moniliformis causes chronic arthritis by establishing infection in joints. Factors like inoculation route and bacterial growth influence disease severity and host immune response.
Area of Science:
- Microbiology
- Immunology
- Veterinary Pathology
Background:
- Streptobacillus moniliformis is a bacterium known to cause infectious arthritis in various hosts.
- Understanding host-parasite interactions is crucial for managing chronic infections like S. moniliformis-induced arthritis.
Purpose of the Study:
- To investigate key host and parasite variables influencing the establishment and chronicity of Streptobacillus moniliformis-induced arthritis.
- To elucidate the role of inoculation route, bacterial virulence, host age, and immune responses in disease pathogenesis.
Main Methods:
- Inoculation of mice via intravenous and subcutaneous routes with S. moniliformis.
- Comparison of bacterial virulence based on growth medium (serum-broth vs. serum-agar).
- Assessment of host immune responses, including leukocyte and antibody titers, and evaluation of antibody and leukocyte effectiveness in controlling infection.
Main Results:
- Intravenous inoculation led to progressive bacteremia and polyarthritis, while subcutaneous inoculation caused localized infection.
- Serum-broth-grown bacteria were more virulent; younger animals were more susceptible.
- Host immune responses were minimal, with low antibody titers and limited effectiveness of phagocytosis against S. moniliformis.
Conclusions:
- Bacterial virulence, inoculation site, and host susceptibility significantly impact S. moniliformis infection.
- The bacterium's resistance to phagocytosis and minimal host immune response contribute to the establishment and chronicity of arthritis.
- These factors are critical in understanding the pathogenesis of S. moniliformis-induced chronic arthritis.