The virulence of animal-passaged Mycoplasma arthritidis (158) was demonstrated to be enhanced in rats by growth in oleic acid-enriched broth. The virulence of a laboratory-maintained culture of the same strain was unaffected by similar growth conditions. No differences either in the immune response as measured by complement-fixing (CF) antibodies or in the histogenesis of the disease were detected when rats were injected with animal-passaged M. arthritidis grown either in the presence or in the absence of oleic acid. All tests for metabolism-inhibiting (MI) antibodies in the rat were negative.

A Mycoplasma-associated immunosuppression of the primary and of the secondary hemagglutinin (HA) response to a common Gram negative antigen (CA-) of Escherichia coli (014) was demonstrated in the rabbit when pre-incubated mixtures of CA(-) and M. arthritidis membranes were injected iv. A similar immunosuppression was demonstrated only for the secondary HA response to a common Gram positive antigen (CA+) of Staphylococcus aureus when pre-incubated mixtures of CA(+) and M. arthritidis membranes were employed as immunizing materials. Mixtures containing CA(+) appeared to interfere with MI antibody production in the rabbit.

The findings suggest 1) that oleic acid may play a role in the virulence of animal-passaged M. arthritidis in the rat# 2) that MI antibody synthesis may be subject to competitive inhibition by (CA+) in the rabbit, and 3) that the immunosuppressive effect of M. arthritidis is associated with membrane components and is not limited to the host in which arthritogenic properties are manifested.

LLU Discipline





Graduate School

First Advisor

Ben H. S. Lau

Second Advisor

Charles E. Winter

Third Advisor

Robert L. Nutter

Fourth Advisor

Dick H. Koobs

Fifth Advisor

Walter E. Roop

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Mycoplasmatales; Arthritis -- etiology; Antibody Formation



Page Count

ill; 128

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives