Induction of the Chlamydia muridarum stress/persistence response increases azithromycin treatment failure in a murine model of infection

Antimicrob Agents Chemother. 2014;58(3):1782-4. doi: 10.1128/AAC.02097-13.

Abstract

Viable but noninfectious (stressed/persistent) chlamydiae are more resistant to azithromycin (AZM) in culture than are organisms in the normal developmental cycle. Chlamydia muridarum-infected mice were exposed to amoxicillin to induce the organisms to enter the persistent/stressed state and subsequently treated with AZM. AZM treatment failure was observed in 22% of persistently infected mice, with an average of 321,667 inclusion-forming units (IFU) shed after AZM treatment. Productively infected mice had a 9% rate of AZM treatment failure and shed an average of 12,083 IFU. These data suggest that stressed chlamydiaeare more resistant to frontline antichlamydial drugs in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin / pharmacology
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use*
  • Azithromycin / pharmacology
  • Azithromycin / therapeutic use*
  • Chlamydia Infections / drug therapy*
  • Chlamydia muridarum / drug effects*
  • Drug Resistance, Bacterial
  • Female
  • Mice
  • Mice, Inbred BALB C
  • Stress, Physiological / drug effects
  • Treatment Failure

Substances

  • Anti-Bacterial Agents
  • Amoxicillin
  • Azithromycin