Stefanie L Iverson-Cabral

Publications (3)11.55 Total impact

• Article: Detection of Mycoplasma genitalium-reactive cervicovaginal antibodies among infected women.

  Stefanie L Iverson-Cabral, Lisa E Manhart, Patricia A Totten
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  ABSTRACT: Mycoplasma genitalium-reactive cervicovaginal IgA and IgG antibodies were detected in 51.9% and 70.4% of 27 infected women and 22.2% and 18.5% of 27 uninfected controls, respectively. The predominance of MgpB- and MgpC-reactive antibodies at the site of infection is consistent with their hypothesized role in selecting antigenic variants during persistent infection.
  Clinical and vaccine immunology: CVI 08/2011; 18(10):1783-6. · 2.37 Impact Factor
• Article: mgpB and mgpC sequence diversity in Mycoplasma genitalium is generated by segmental reciprocal recombination with repetitive chromosomal sequences.

  Stefanie L Iverson-Cabral, Sabina G Astete, Craig R Cohen, Patricia A Totten
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  ABSTRACT: Mycoplasma genitalium is associated with sexually transmitted infections in men and women that, if untreated, can persist, suggesting that mechanism(s) exist to facilitate immune evasion. Approximately 4% of the limited M. genitalium genome contains repeat sequences termed MgPar regions that have homology to mgpB and mgpC, which encode antigenic proteins associated with attachment. We have previously shown that mgpB sequences vary within a single strain of M. genitalium in a pattern consistent with recombination between mgpB and MgPar sequences (Iverson-Cabral et al.). In the current study, we show that mgpC heterogeneity similarly occurs within the type strain, G-37(T), cultured in vitro and among cervical specimens collected from a persistently infected woman. In all cases, alternative mgpC sequences are indicative of recombination with MgPar regions. Additionally, the isolation of single-colony M. genitalium clonal variants containing alternative mgpB or mgpC sequences allowed us to demonstrate that mgpB and mgpC heterogeneity is associated with corresponding changes within donor MgPar regions, consistent with reciprocal recombination. Better-defined systems of antigenic variation are typically mediated by unidirectional gene conversion, so the generation of genetic diversity observed in M. genitalium by the mutual exchange of sequences makes this organism unique among bacterial pathogens.
  Molecular Microbiology 11/2007; 66(1):55-73. · 5.01 Impact Factor
• Article: Intrastrain heterogeneity of the mgpB gene in Mycoplasma genitalium is extensive in vitro and in vivo and suggests that variation is generated via recombination with repetitive chromosomal sequences.

  Stefanie L Iverson-Cabral, Sabina G Astete, Craig R Cohen, Eduardo P C Rocha, Patricia A Totten
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  ABSTRACT: Mycoplasma genitalium is associated with reproductive tract disease in women and may persist in the lower genital tract for months, potentially increasing the risk of upper tract infection and transmission to uninfected partners. Despite its exceptionally small genome (580 kb), approximately 4% is composed of repeated elements known as MgPar sequences (MgPa repeats) based on their homology to the mgpB gene that encodes the immunodominant MgPa adhesin protein. The presence of these MgPar sequences, as well as mgpB variability between M. genitalium strains, suggests that mgpB and MgPar sequences recombine to produce variant MgPa proteins. To examine the extent and generation of diversity within single strains of the organism, we examined mgpB variation within M. genitalium strain G-37 and observed sequence heterogeneity that could be explained by recombination between the mgpB expression site and putative donor MgPar sequences. Similarly, we analyzed mgpB sequences from cervical specimens from a persistently infected woman (21 months) and identified 17 different mgpB variants within a single infecting M. genitalium strain, confirming that mgpB heterogeneity occurs over the course of a natural infection. These observations support the hypothesis that recombination occurs between the mgpB gene and MgPar sequences and that the resulting antigenically distinct MgPa variants may contribute to immune evasion and persistence of infection.
  Infection and Immunity 08/2006; 74(7):3715-26. · 4.16 Impact Factor