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Association of lysogenic bacteriophage MAV1 with virulence of Mycoplasma arthritidis
L L Voelker1, K E Weaver, L J Ehle
1Department of Microbiology, University of South Dakota School of Medicine, Vermillion 57069-2390, USA.
Abstract:
Mycoplasma arthritidis causes a severe polyarthritis under natural conditions in rats and under experimental conditions in both rats and mice. Although the disease itself has been extensively studied, M. arthritidis virulence factors remain uncharacterized. Comparison of relative arthritogenicity of 20 strains of M. arthritidis revealed that the strains tended to fall into two groups, a highly arthritogenic group, inducing maximum arthritis scores of > or = 11 in rats, and a low-virulence group, inducing maximum scores of < 6. Chromosomal DNA from the more highly arthritogenic strains possessed sequences that hybridized by Southern analysis with a probe prepared from lysogenic M. arthritidis bacteriophage MAV1, while DNA from low-virulence strains did not. One of the low-virulence strains, 158, was experimentally lysogenized with MAV1. Lysogenized 158 showed a significant increase in arthritogenicity over nonlysogenized 158. These data suggest that MAV1 carries a factor that is important in pathogenesis of M. arthritidis-induced arthritis of rats.
Insights
Mycoplasma arthritidis bacteriophage MAV1 is linked to increased arthritis severity in rats. Highly arthritogenic strains possess MAV1 DNA sequences, suggesting MAV1 carries a key virulence factor.
Area of Science:
- Microbiology
- Immunology
- Pathogenesis
Background:
- Mycoplasma arthritidis is a known cause of severe polyarthritis in rats.
- Virulence factors contributing to M. arthritidis pathogenesis remain largely uncharacterized.
- Arthritogenicity varies significantly among different strains of M. arthritidis.
Purpose of the Study:
- To investigate the genetic basis for varying arthritogenicity in M. arthritidis strains.
- To identify potential virulence factors associated with severe M. arthritidis-induced arthritis.
- To explore the role of bacteriophage MAV1 in M. arthritidis pathogenesis.
Main Methods:
- Comparative analysis of arthritogenicity across 20 M. arthritidis strains in rats.
- Southern blot hybridization using MAV1 bacteriophage DNA as a probe against chromosomal DNA of different strains.
- Experimental lysogenization of a low-virulence M. arthritidis strain (158) with MAV1.
Main Results:
- M. arthritidis strains were classified into highly arthritogenic (scores >= 11) and low-virulence (scores < 6) groups.
- Highly arthritogenic strains contained DNA sequences hybridizing with the MAV1 probe, unlike low-virulence strains.
- Experimental lysogenization of strain 158 with MAV1 significantly increased its arthritogenicity.
Conclusions:
- The M. arthritidis bacteriophage MAV1 is associated with increased arthritogenicity.
- MAV1 likely carries a factor crucial for the pathogenesis of M. arthritidis-induced arthritis in rats.
- Targeting MAV1 or its associated factors may offer therapeutic strategies for M. arthritidis arthritis.