Activities of first-choice antimicrobials against gamma interferon-treated Chlamydia trachomatis differ in hypoxia.

Gamma interferon (IFN-γ)-mediated host responses play a central role in resolving genital Chlamydia trachomatis infections but may also result in persistence of the pathogen, which shows reduced susceptibility to antimicrobials. The antichlamydial function of IFN-γ is oxygen dependent, and the efficacy of antimicrobials against C. trachomatis is reduced in a low-oxygen environment. In this study, we show that the antichlamydial efficacies of azithromycin and doxycycline differ in IFN-γ-treated cells under hypoxia.