Post-exposure prophylaxis (PEP) with doxycycline has been shown to reduce rates of bacteria sexually transmitted infections in clinical trials, and while formal guidance from CDC has not been issued, it is recommended by some public health departments in the United States. Doxycycline PEP is less effective against gonorrhea due to tetracycline resistance among circulating N. gonorrheoae lineages. Selection imposed by doxycycline use may also select for multi-drug resistant lineages.
In our study, we used our curated collection of N. gonorrhoeae genomes and minimum inhibitory concentrations to assess the impact of doxycycline PEP on antimicrobial resistance in the near term. We found that this impact will depend on the strength of selection for chromosomally-encoded tetracycline resistance, which is often linked to resistance to other antimicrobials, or tetM, which most often occurs in lineages that are not resistant to other gonorrhea therapies. Genomic surveillance will be critical for differentiating between these outcomes and for monitoring antimicrobial resistance prevalence among populations using doxycycline PEP.
This project is now published in Clinical Infectious Diseases!