Mycoplasma penetrans sp. nov., from the urogenital tract of patients with AIDS.

An unusual mycoplasma, which was isolated from the urine of a human immunodeficiency virus-positive male homosexual patient, has an elongated flask shape and two unique sharply divided internal compartments. The tiplike compartment is densely packed with fine granules, and the body compartment is loosely filled with coarse granules consistent with ribosomal structures. The organism has properties of adherence, hemadsorption, and cytadsorption and invades many different types of mammalian cells. Adhesion and penetration apparently involve the terminally located tiplike structure. Cholesterol is required for growth, and the mycoplasma ferments glucose and hydrolyzes arginine, but does not hydrolyze urea. The results of DNA homology studies revealed that this organism is not genetically related to previously described mycoplasma species that have the same biochemical properties. The results of serologic studies demonstrated that this organism is antigenically distinct from all previously described mycoplasmas. We propose that this new mollicute species should be named Mycoplasma penetrans sp. nov. The type strain is strain GTU-54-6A1 (= ATCC 55252).