Toxin Induction or Inhibition of Transcription or Translation Posttreatment Increases Persistence to Fluoroquinolones
Annabel S. Lemma, Mark P. Brynildsen
Abstract
Overabundances of toxins have been shown to increase the antibiotic tolerances of bacteria. Largely, these effects have been attributed to the abilities of toxins to inhibit bacterial growth before and during antibiotic exposure. In this study, we assessed to what extent toxins can influence bacterial survival following antibiotic treatment, rather than before or during. Using two mechanistically distinct toxins, we show that their accumulations after antibiotic exposure have the capacity to increase the abundances of fluoroquinolone persisters from nongrowing populations. Further, we show with wild-type and uropathogenic E. coli that chemical inhibition of growth, not just that induced by toxins, produces analogous results. These observations reveal another dimension of how toxins influence antibiotic tolerance and highlight the importance of postantibiotic physiology on bacterial survival.