Strain BV1 was isolated from the exudate of the footpad abscess of a black vulture (Coragyps atratus). The colonies had a "fried-egg" appearance consistent with that of mycoplasmal species. Electron microscopic examination of the cells revealed irregular elongated or elliptical forms and smaller circular budding processes. Profuse growth was observed in Frey medium supplemented with 20% swine serum at 37°C in a humidified atmosphere of 10% CO, and air. Typical of mycoplasma, strain BV1 required sterol for growth and catabolized glucose but did not hydrolyze arginine or urea. The guanine-plus-cytosine content of the DNA was 28 mol%. The organism demonstrated the ability to hemolyze, absorb onto, and agglutinate the elythrocytes from several animal species. Strain BV1 was serologically unrelated by the growth inhibition test to previously established Mycoplusmu, Achokplasnw, Entomoplasma, and Mesoplusma species, as well as to strains belonging to these genera but not identified to species level. Moreover, BV1 had a 16s rRNA gene with a nucleotide sequence distinct from reported sequences of other mycoplasmas. This organism represents a new species for which the name Mycoplusmu corogypsi is proposed. Strain BV1 (ATCC 5114sT) is the type strain of Mycophmu corogypsi sp. nov.Cell wall-less procaryotes (in the class Mollicutes) have been previously isolated from a variety of domestic and free-living avian species (2, 9, 17, 18, 25,34,38). Most of the known pathogenic and nonpathogenic species of Mollicutes isolated from avian hosts belong to the family Mycoplasmataceae and the genus Mycoplasma (16, 27). Species belonging to the genera Acholeplasma (34) and Ureaplasma (20) have been isolated less frequently from birds, and their role as pathogens remains vague.We describe the characteristics of a mycoplasma isolated from the footpad abscess of a black vulture, Coragyps atratus. The black vulture is native to North America and subsists chiefly or entirely on carrion (33). On the basis of proposed standards for the description of new species of the class Mollicutes (15), we find that the mycoplasma isolated from the vulture possesses distinctive characteristics that differentiate it from other previously classified mycoplasma species. We therefore propose the recognition of strain BV1 (Mycoplasma corogypsi) as a new species in the genus Mycoplasma . MATERLALS AND METHODSMycoplasma. The mycoplasma designated strain BV1 was isolated from an abscess in the footpad of a black vulture which was presented to the Raptor Rehabilitation Center, Auburn University, Auburn, Alabama. The abscess was incised surgically, and the exudate was initially cultured on blood agar base (Bacto Tryptose Blood Agar Base with yeast extract; Difco Laboratories, Detroit, Mich.) supplemented with 5% bovine blood. Other avian mycoplasma type cultures used for comparison in this study (Mycoplasma gallisepticum ATCC 19610T, Mycoplasma synoviae ATCC * Corresponding author.25204T, Mycoplasma gallinarum ATCC 19708T, Mycoplasma gallinaceum ATCC 33550T, Myco...

Western blots of proteins of 14 Mycoplasma iowae strains and isolates resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were probed with three monoclonal antibodies (MAbs), MI6, MI7, and MI8. MAb MI6 reacted with one or more antigens with apparent molecular weights of 60,000, 70,000, and 94,000. In three strains (N-PHN-D13, R-D2497, and K 1805), antigens located on a single peptide band were recognized, while in others additional epitopes at different molecular-weight positions were revealed. A similar pattern was observed with MAb MI7, although it reacted with fewer antigens than did MAb MI6 and failed to recognize antigens in strains N-PHN-D13 and R-D2497. MAb MI8 reacted with an antigen at an apparent molecular-weight position of 28,000 in four of the 14 strains and isolates. The diverse reaction patterns observed with the MAbs in the 14 M. iowae strains and isolates confirms the occurrence of antigenic variation within this species. Antigenic variation in M. iowae may be pivotal in determining host-parasite interactions, pathogenesis, and the outcome of disease.

An agglutinating monoclonal antibody (MAb S2) specific for a 55,000-molecular-weight surface protein of Mycoplasma synoviae was developed by fusion of spleen cells from immunized BALB/c mice with P3X63 Ag8.653 myeloma cells. Immunogold labeling experiments confirmed the cell surface location of the MAb-recognized antigen. MAb S2-coated Staphylococcus aureus was used in a rapid slide coagglutination assay. Eleven M. synoviae strains, including the type strain WVU 1853, coagglutinated with MAb-coated S. aureus, but five M. gallisepticum strains (PG31, S6, R, F, and A5969) did not.