Experimental Infection of Pig-Tailed Macaques (Macaca nemestrina) with Mycoplasma genitalium.

Mycoplasma genitalium is an underappreciated cause of human reproductive tract disease, characterized by persistent, often asymptomatic, infection. Building on our previous experiments using a single female pig-tailed macaque as a model for M. genitalium infection (G. E. Wood, S. L. Iverson-Cabral, D. L. Patton, P. K. Cummings, Y. T. Cosgrove Sweeney, and P. A. Totten, Infect Immun 81:2938-2951, 2013, https://doi.org/10.1128/IAI.01322-12), we cervically inoculated eight additional animals, two of which were simultaneously inoculated in salpingeal tissue autotransplanted into abdominal pockets. Viable M. genitalium persisted in the lower genital tract for 8 weeks in three animals, 4 weeks in two, and 1 week in one; two primates resisted infection. In both animals inoculated in salpingeal pockets, viable M. genitalium was recovered for 2 weeks. Recovery of viable M. genitalium from lower genital tract specimens was improved by diluting the specimen in broth and by Vero cell coculture. Ascension to upper reproductive tract tissues was not detected, even among three persistently infected animals. M. genitalium-specific serum antibodies targeting the immunodominant MgpB and MgpC proteins appeared within 1 week in three animals inoculated both cervically and in salpingeal pockets and in one of three persistently infected animals inoculated only in the cervix. M. genitalium-specific IgG, but not IgA, was detected in cervical secretions of serum antibody-positive animals, predominantly against MgpB and MgpC, but was insufficient to clear M. genitalium lower tract infection. Our findings further support female pig-tailed macaques as a model of M. genitalium infection, persistence, and immune evasion.