Restoration of cytoadherence to an adherence-deficient mutant of Mycoplasma arthritidis by genetic complementation

Academic Article


  • Mycoplasma arthritidis causes a severe septic arthritis in rats under natural and experimental conditions. An earlier study implicated a membrane lipoprotein designated MAA1 in cytadherence of M. arthritidis. In addition, a spontaneous adherence-deficient mutant was shown to contain a nonsense mutation in the gene encoding MAA1, resulting in production of a truncated product, MAA1Δ. In the present study, a wild-type maa1 gene carried on transposon Tn4001T was introduced into the low-adherence mutant by polyethylene glycol-mediated transformation. The presence of the tranposon and the wild-type maa1 gene in the chromosome of transformants was confirmed by PCR and Southern hybridization. The latter procedure also confirmed that each transformant contained a single copy of the transposon. Western immunoblotting showed that transformants produced both wild-type MAA1 and MAA1Δ, indicating that the introduced wild-type maa1 gene was functional. This phenotype was stably maintained after multiple subcultures even in the absence of antibiotic selection. Finally, transformants were shown to adhere to rat L-2 lung cells in culture at wild-type levels, providing confirmation for an important role for MAA1 in adherence.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Washburn LR; Bird DW; Dybvig K
  • Start Page

  • 671
  • End Page

  • 675
  • Volume

  • 71
  • Issue

  • 2