Patricia A. Totten, PhD
Research Associate Professor, Department of Medicine
Research in the Totten group focuses on the discovery, epidemiology, and molecular pathogenesis of novel bacteria associated with idiopathic reproductive tract diseases in men and women. For example, in collaborative studies with clinicians and epidemiologists, we have shown that Mycoplasma genitalium and Ureaplasma urealyticum, two newly recognized bacterial species, are associated with urethritis in men from whom no known pathogen was identified. Significantly, we have also shown that Mycoplasma genitalium is associated with cervicitis, endometritis, pelvic inflammatory disease, HIV shedding, and preterm birth. Our studies have also demonstrated that this organism can persist for months, if not years, in infected women and as a result we have proposed that antigenic variation within surface-exposed proteins in its unique and complex attachment organelle contributes to this persistence. Supporting this hypothesis, we demonstrated that the genes encoding these proteins are extremely heterogeneous in vivo and in vitro and vary by reciprocal recombination with archived DNA sequences on its minimal chromosome. The identification and regulation of recombination genes required for this variation, the effect of gene variation on the antigenicity of the resulting proteins, and the role of antigenic variation on immune evasion are ongoing studies in the Totten laboratory.