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Experimental arthritis induced by a clinical Mycoplasma fermentans isolate
Antonio Rivera1, Antonio Yáñez, Gloria León-Tello
1Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, México. jart70@starmedia.com
Background:
Mycoplasma fermentans has been associated with rheumatoid arthritis. Recently, it was detected in the joints and blood of patients with rheumatoid arthritis, but it is not clear yet how the bacteria enter the body and reach the joints. The purpose of this study was to determine the ability of M. fermentans to induce experimental arthritis in rabbits following inoculation of the bacteria in the trachea and knee joints.
Methods:
P-140 and PG-18 strains were each injected in the knee joints of 14 rabbits in order to evaluate and compare their arthritogenicity. P-140 was also injected in the trachea of 14 rabbits in order to test the ability of the bacteria to reach the joints and induce arthritis.
Results:
M. fermentans produced an acute arthritis in rabbits. Joint swelling appeared first in rabbits injected with P-140, which caused a more severe arthritis than PG-18. Both strains were able to migrate to the uninoculated knee joints and they were detected viable in the joints all along the duration of the experiment. Changes in the synovial tissue were more severe by the end of the experiment and characterized by the infiltration of neutrophils and substitution of adipose tissue by connective tissue. Rabbits intracheally injected with P-140 showed induced arthritis and the bacteria could be isolated from lungs, blood, heart, kidney, spleen, brain and joints.
Conclusion:
M. fermentans induced arthritis regardless of the inoculation route. These findings may help explain why mycoplasmas are commonly isolated from the joints of rheumatic patients.
Insights
Mycoplasma fermentans can cause arthritis in rabbits, even when introduced through the trachea. This finding helps explain how these bacteria may reach the joints of rheumatoid arthritis patients.
Area of Science:
- Microbiology
- Immunology
- Rheumatology
Background:
- Mycoplasma fermentans is linked to rheumatoid arthritis.
- This bacterium has been found in the joints and blood of rheumatoid arthritis patients.
- The route of infection and joint colonization by M. fermentans remains unclear.
Purpose of the Study:
- To investigate the arthritogenic potential of M. fermentans.
- To determine if M. fermentans can induce experimental arthritis in rabbits.
- To assess bacterial migration to joints after tracheal inoculation.
Main Methods:
- Two strains of M. fermentans (P-140 and PG-18) were injected into rabbit knee joints.
- The P-140 strain was also inoculated into the tracheas of rabbits.
- Arthritogenicity and bacterial presence in joints and other organs were evaluated.
Main Results:
- M. fermentans induced acute arthritis in rabbits, with P-140 being more virulent than PG-18.
- Bacteria migrated to uninoculated joints and remained viable throughout the experiment.
- Tracheal inoculation led to arthritis and systemic bacterial dissemination, including to the joints.
Conclusions:
- M. fermentans can induce arthritis irrespective of the inoculation site (knee joint or trachea).
- These results provide a potential mechanism for mycoplasma isolation from the joints of rheumatic disease patients.
