Adherence and colonization of Mycoplasma pulmonis to genital epithelium and spermatozoa in rats.

Mycoplasma pulmonis is the etiological agent of a naturally occurring genital disease in rats. Transmission and scanning electron microscopic evaluations of the genital tracts of naturally and experimentally infected female rats show M. pulmonis in close association with both squamous and nonsquamous epithelial cells, although more frequently with the latter. In contrast to other species of mycoplasmas, M. pulmonis adhesion to epithelial cells appears to be mediated by a generalized interaction of the mycoplasma membrane with the host cell membrane, rather than by a specialized attachment tip. Extensive studies of all levels of the male genital tract have not yet been performed, but M. pulmonis can be demonstrated in the urethra and epididymis in animals showing evidence of chronic inflammation. Adherence of M. pulmonis to rat spermatozoa in vitro is associated with a decrease in motility. Addition of anti-M. pulmonis antibody following organism attachment results in marked agglutination of the spermatozoa. Further study of mechanisms involved in M. pulmonis adherence and subsequent mycoplasma host cell interactions is expected to contribute to an understanding of mechanisms involved in reproductive failure.