title: Analysis of mechanisms associated with loss of infectivity of clonal populations of Borrelia burgdorferi B31MI.
abstract: Numerous studies have provided suggestive evidence that the loss of plasmids correlates with the loss of infectivity of the Lyme disease spirochetes. In this study we have further investigated this correlation. Clonal populations were obtained from the skin of a mouse infected for 3 months with a clonal population of Borrelia burgdorferi B31MI. The complete plasmid compositions of these populations were determined using a combination of PCR and Southern hybridization. The infectivities of clones differing in plasmid composition were tested using the C3H-HeJ murine model for Lyme disease. While several clones were found to be noninfectious, a correlation between the loss of a specific plasmid and loss of infectivity in the clones analyzed in this report was not observed. While it is clear from recent studies that the loss of some specific plasmids results in attenuated virulence, this study demonstrates that additional mechanisms also contribute to the loss of infectivity.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Medical College of Virginia at Virginia Commonwealth University, Richmond 23298-0678, USA.
authors.forename: J V
authors.initials: JV
authors.lastname: McDowell
authors.forename: S Y
authors.initials: SY
authors.lastname: Sung
authors.forename: M
authors.initials: M
authors.lastname: Labandeira-Rey
authors.forename: J T
authors.initials: JT
authors.lastname: Skare
authors.forename: R T
authors.initials: RT
authors.lastname: Marconi
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D015748:Borrelia burgdorferi Group / Q000235:genetics* / Q000472:pathogenicity*; D002999:Clone Cells; D004195:Disease Models, Animal; D008193:Lyme Disease / Q000382:microbiology / Q000503:physiopathology; D051379:Mice; D008809:Mice, Inbred C3H; D010957:Plasmids; D016133:Polymerase Chain Reaction; D014774:Virulence / Q000235:genetics