Macrolide Resistance inTreponema pallidumin the United States and Ireland

An HIV-infected patient in San Francisco with primary syphilis was treated with azithromycin, but the lesion did not resolve. The authors of this case report confirmed resistance to azithromycin and identified a mutation in the 23S rRNA genes of T. pallidum. The mutation was also found in samples collected in Baltimore, Seattle, and Dublin.