Adhesion onto and invasion into mammalian cells by mycoplasma penetrans: a newly isolated mycoplasma from patients with AIDS.

The newly identified mycoplasma, Mycoplasma pentrans shows remarkable pathobiologic properties: it adheres to cell surfaces, deeply penetrates into the cell, strongly hemadsorbs human red blood cells, and cytadsorbs human CD4+ lymphocytes and monocytes. These in vitro biologic activities of mycoplasmas have been previously shown to be associated with pathogenic virulence in vivo. Both adhesion and invasion clearly involve the organism's unique tip-like structure. Invading mycoplasmas often have their tip-like structure deeply buried in the cytoplasm of infected mammalian cells. Extensive invasion of the mycoplasma into the cytoplasm may kill the cells. The same pathobiologic processes of adhesion and invasion using the specialized tip-like structure are found on the epithelium in the patient's urogenital tract infected by M. penetrans. Both in vitro and in vivo findings suggest a possible pathogenic role of this newly discovered human mycoplasma and call for careful evaluation of its role in human diseases.