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Stationary-Phase Persisters to Ofloxacin Sustain DNA Damage and Require Repair Systems Only during Recovery.

Völzing KG, Brynildsen MP - MBio (2015)

Bottom Line: Persister survival is attributed to a transient state of dormancy in which a cell's growth and metabolism are significantly reduced and many essential processes are thought to be inactive.In this work, we show that in nongrowing populations, persisters to ofloxacin experience the same level of antibiotic-induced damage as cells that succumb to the treatment and that their survival critically depends on repair of this damage after the conclusion of treatment.We hypothesize that effective antipersister therapies may be developed on the basis of this knowledge.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA.

No MeSH data available.


Related in: MedlinePlus

RecA and the SOS response are critical to persistence only during recovery from ofloxacin treatment (OFL tx). (A) Ofloxacin persisters decreased >1,000-fold in the absence of RecA expression (dashed purple) relative to when RecA was expressed from 2 h pretreatment with ofloxacin through recovery (dashed blue). RecA induction on LB plates during recovery only (red) was sufficient to restore persisters to WT levels. (B) Ofloxacin persisters decreased 25-fold with LexA3 (blue) relative to the WT (black). LexA3 induction on LB plates only (red) maintained this reduced survival. We note that LexA3 induction only during recovery reduced the overall viability in both ofloxacin-treated and untreated samples, and this was accounted for by plotting the surviving fraction. Data are average values ± standard errors from at least three biological replicates. Numbers of CFU per milliliter for all samples and controls are provided in Fig. S7 in the supplemental material.
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fig6: RecA and the SOS response are critical to persistence only during recovery from ofloxacin treatment (OFL tx). (A) Ofloxacin persisters decreased >1,000-fold in the absence of RecA expression (dashed purple) relative to when RecA was expressed from 2 h pretreatment with ofloxacin through recovery (dashed blue). RecA induction on LB plates during recovery only (red) was sufficient to restore persisters to WT levels. (B) Ofloxacin persisters decreased 25-fold with LexA3 (blue) relative to the WT (black). LexA3 induction on LB plates only (red) maintained this reduced survival. We note that LexA3 induction only during recovery reduced the overall viability in both ofloxacin-treated and untreated samples, and this was accounted for by plotting the surviving fraction. Data are average values ± standard errors from at least three biological replicates. Numbers of CFU per milliliter for all samples and controls are provided in Fig. S7 in the supplemental material.

Mentions: To determine when stationary-phase ofloxacin persisters require DNA repair machinery, we enumerated persisters from samples with RecA expression induced prior to ofloxacin treatment, during treatment, and during recovery only. We found that while persisters were 10,000-fold less abundant in recA-deficient cells than in WT cells (Fig. 4), induction of RecA only during recovery was sufficient to restore persister levels to those with RecA expressed prior to and during treatment in stationary-phase cultures (Fig. 6A). RecA was used in these experiments because it was found to be the most important DNA repair system for persister survival from ofloxacin treatment (Fig. 4).


Stationary-Phase Persisters to Ofloxacin Sustain DNA Damage and Require Repair Systems Only during Recovery.

Völzing KG, Brynildsen MP - MBio (2015)

RecA and the SOS response are critical to persistence only during recovery from ofloxacin treatment (OFL tx). (A) Ofloxacin persisters decreased >1,000-fold in the absence of RecA expression (dashed purple) relative to when RecA was expressed from 2 h pretreatment with ofloxacin through recovery (dashed blue). RecA induction on LB plates during recovery only (red) was sufficient to restore persisters to WT levels. (B) Ofloxacin persisters decreased 25-fold with LexA3 (blue) relative to the WT (black). LexA3 induction on LB plates only (red) maintained this reduced survival. We note that LexA3 induction only during recovery reduced the overall viability in both ofloxacin-treated and untreated samples, and this was accounted for by plotting the surviving fraction. Data are average values ± standard errors from at least three biological replicates. Numbers of CFU per milliliter for all samples and controls are provided in Fig. S7 in the supplemental material.
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Related In: Results  -  Collection

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fig6: RecA and the SOS response are critical to persistence only during recovery from ofloxacin treatment (OFL tx). (A) Ofloxacin persisters decreased >1,000-fold in the absence of RecA expression (dashed purple) relative to when RecA was expressed from 2 h pretreatment with ofloxacin through recovery (dashed blue). RecA induction on LB plates during recovery only (red) was sufficient to restore persisters to WT levels. (B) Ofloxacin persisters decreased 25-fold with LexA3 (blue) relative to the WT (black). LexA3 induction on LB plates only (red) maintained this reduced survival. We note that LexA3 induction only during recovery reduced the overall viability in both ofloxacin-treated and untreated samples, and this was accounted for by plotting the surviving fraction. Data are average values ± standard errors from at least three biological replicates. Numbers of CFU per milliliter for all samples and controls are provided in Fig. S7 in the supplemental material.
Mentions: To determine when stationary-phase ofloxacin persisters require DNA repair machinery, we enumerated persisters from samples with RecA expression induced prior to ofloxacin treatment, during treatment, and during recovery only. We found that while persisters were 10,000-fold less abundant in recA-deficient cells than in WT cells (Fig. 4), induction of RecA only during recovery was sufficient to restore persister levels to those with RecA expressed prior to and during treatment in stationary-phase cultures (Fig. 6A). RecA was used in these experiments because it was found to be the most important DNA repair system for persister survival from ofloxacin treatment (Fig. 4).

Bottom Line: Persister survival is attributed to a transient state of dormancy in which a cell's growth and metabolism are significantly reduced and many essential processes are thought to be inactive.In this work, we show that in nongrowing populations, persisters to ofloxacin experience the same level of antibiotic-induced damage as cells that succumb to the treatment and that their survival critically depends on repair of this damage after the conclusion of treatment.We hypothesize that effective antipersister therapies may be developed on the basis of this knowledge.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA.

No MeSH data available.


Related in: MedlinePlus