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. 2022 Feb 23;77(3):641-645.
doi: 10.1093/jac/dkab445.

Effect of RecA inactivation and detoxification systems on the evolution of ciprofloxacin resistance in Escherichia coli

S Diaz-Diaz  1   2   3   4 , E Recacha  1   2   3   4 , A García-Duque  1 , F Docobo-Pérez  2   3   4 , J Blázquez  5 , A Pascual  1   2   3   4 , J M Rodríguez-Martínez  2   3   4
Affiliations

Effect of RecA inactivation and detoxification systems on the evolution of ciprofloxacin resistance in Escherichia coli

S Diaz-Diaz et al. J Antimicrob Chemother. .

Abstract

Background: Suppression of SOS response and overproduction of reactive oxygen species (ROS) through detoxification system suppression enhance the activity of fluoroquinolones.

Objectives: To evaluate the role of both systems in the evolution of resistance to ciprofloxacin in an isogenic model of Escherichia coli.

Methods: Single-gene deletion mutants of E. coli BW25113 (wild-type) (ΔrecA, ΔkatG, ΔkatE, ΔsodA, ΔsodB), double-gene (ΔrecA-ΔkatG, ΔrecA-ΔkatE, ΔrecA-ΔsodA, ΔrecA-ΔsodB, ΔkatG-ΔkatE, ΔsodB-ΔsodA) and triple-gene (ΔrecA-ΔkatG-ΔkatE) mutants were included. The response to sudden high ciprofloxacin pressure was evaluated by mutant prevention concentration (MPC). The gradual antimicrobial pressure response was evaluated through experimental evolution and antibiotic resistance assays.

Results: For E. coli BW25113 strain, ΔkatE, ΔsodB and ΔsodB/ΔsodA mutants, MPC values were 0.25 mg/L. The ΔkatG, ΔsodA, ΔkatG/katE and ΔrecA mutants showed 2-fold reductions (0.125 mg/L). The ΔkatG/ΔrecA, ΔkatE/ΔrecA, ΔsodA/ΔrecA, ΔsodB/ΔrecA and ΔkatG/ΔkatE/ΔrecA strains showed 4-8-fold reductions (0.03-0.06 mg/L) relative to the wild-type. Gradual antimicrobial pressure increased growth capacity for ΔsodA and ΔsodB and ΔsodB/ΔsodA mutants (no growth in 4 mg/L) compared with the wild-type (no growth in the range of 0.5-2 mg/L). Accordingly, increased growth was observed with the mutants ΔrecA/ΔkatG (no growth in 2 mg/L), ΔrecA/ΔkatE (no growth in 2 mg/L), ΔrecA/ΔsodA (no growth in 0.06 mg/L), ΔrecA/ΔsodB (no growth in 0.25 mg/L) and ΔrecA/ΔkatG/ΔkatE (no growth in 0.5 mg/L) compared with ΔrecA (no growth in the range of 0.002-0.015 mg/L).

Conclusions: After RecA inactivation, gradual exposure to ciprofloxacin reduces the evolution of resistance. After suppression of RecA and detoxification systems, sudden high exposure to ciprofloxacin reduces the evolution of resistance in E. coli.

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Figures

Figure 1.
Figure 1.
MIC (orange) and MPC (blue) of ciprofloxacin for the catalase mutants group (a) and superoxide dismutase mutants group (b) at 96 h. The wild-type (E. coli BW25113) MIC of ciprofloxacin is 0.015 mg/L. CIP, ciprofloxacin. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.
Figure 2.
Figure 2.
Curves showing culture growth of (a) the katG gene group, and (b) the katE gene group with increasing concentrations of antibiotics. Representation of the number of viable cultures over time. Sixteen populations of each strain were propagated under increasing concentrations of ciprofloxacin, starting with 6.25 × 10−5 mg/L of antibiotic on day 1 and doubling the antibiotic concentration each day. The dashed vertical line represents the wild-type (BW25113) MIC of ciprofloxacin. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.
Figure 3.
Figure 3.
Curves showing culture growth of (a) the sodA gene group, and (b) the sodB gene group with increasing concentrations of antibiotics. Representation of the number of viable cultures over time. Sixteen populations of each strain were propagated under increasing concentrations of ciprofloxacin, starting with 6.25 × 10−5 mg/L of antibiotic on day 1 and doubling the antibiotic concentration each day. The dashed vertical line represents the wild-type (BW25113) MIC of ciprofloxacin. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.
See this image and copyright information in PMC

References

    1. Baharoglu Z, Mazel D.. SOS, the formidable strategy of bacteria against aggressions. FEMS Microbiol Rev 2014; 38: 1126–45. - PubMed
    1. Blázquez J, Rodríguez-Beltrán J, Matic I.. Antibiotic-induced genetic variation: how it arises and how it can be prevented. Annu Rev Microbiol 2018; 72: 209–30. - PubMed
    1. Little JW, Edmiston SH, Pacelli LZ. et al. Cleavage of the Escherichia coli lexA protein by the recA protease. Proc Natl Acad Sci USA 1980; 77: 3225–9. - PMC - PubMed
    1. Luo Y, Pfuetzner RA, Mosimann S. et al. Crystal structure of LexA: a conformational switch for regulation of self-cleavage. Cell 2001; 106: 585–94. - PubMed
    1. Fernández De Henestrosa AR, Ogi T, Aoyagi S. et al. Identification of additional genes belonging to the LexA regulon in Escherichia coli. Mol Microbiol 2000; 35: 1560–72. - PubMed

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