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Evidence that mycoplasmas, gram-negative bacteria, and certain gram-positive bacteria share a similar protein antigen

T Sasaki1

  • 1Department of General Biologics Control, National Institute of Health, Tokyo, Japan.

Journal of Bacteriology
|April 1, 1991
PubMed

Insights

A shared protein antigen between 42-48 kDa was identified in mycoplasmas, gram-negative bacteria, and some gram-positive bacteria. This antigen was detected using an antibody specific to Mycoplasma fermentans, aiding in bacterial classification.

Area of Science:

  • Microbiology
  • Immunology
  • Bacteriology

Background:

  • Mycoplasmas and various bacteria possess shared antigens.
  • Identifying conserved antigens aids in bacterial taxonomy and diagnostics.

Purpose of the Study:

  • To investigate a shared protein antigen among Mycoplasma species, gram-negative bacteria, and gram-positive bacteria.
  • To characterize the distribution and location of this antigen.

Main Methods:

  • Western blotting (immunoblotting) was employed.
  • An antibody specific to a 43-kDa membrane protein of Mycoplasma fermentans was used.
  • Proteins were analyzed in cytoplasmic and membrane fractions.

Main Results:

  • A conserved protein antigen (42-48 kDa) was detected in all 14 Mycoplasma spp. tested, Acholeplasma laidlawii, and 8 species of gram-negative bacteria.
  • Staphylococcus aureus was the only gram-positive species showing cross-reactivity.
  • Ureaplasma urealyticum and mammalian cells did not cross-react.
  • The antigen was present in cytoplasmic and membrane fractions but not on the cell surface.

Conclusions:

  • A conserved antigen exists across Mycoplasma, gram-negative bacteria, and some gram-positive bacteria.
  • This antigen is located intracellularly and in membranes, not extracellularly.
  • The findings support the use of this antigen in bacterial identification and serological studies.

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