From OMPwiki
Jump to: navigation, search

Thi, TD, López, E, Rodríguez-Rojas, A, Rodríguez-Beltrán, J, Couce, A, Guelfo, JR, Castañeda-García, A and Blázquez, J (2011) Effect of recA inactivation on mutagenesis of Escherichia coli exposed to sublethal concentrations of antimicrobials.J. Antimicrob. Chemother. 66:531-8


Low concentrations of some antibiotics have been reported to stimulate mutagenesis and recombination, which may facilitate bacterial adaptation to different types of stress, including antibiotic pressure. However, the mutagenic effect of most of the currently used antibiotics remains untested. Furthermore, it is known that in many bacteria, including Escherichia coli, stimulation of mutagenesis is mediated by the SOS response. Thus, blockage or attenuation of this response through the inhibition of RecA has been proposed as a possible therapeutic adjuvant in combined therapy to reduce the ability to generate antibiotic-resistant mutants. The aim of this work was to study the capacity of sublethal concentrations of antimicrobials of different families with different molecular targets to increase the mutant frequency of E. coli, and the effect that inactivation of recA would have on antibiotic-mediated mutagenesis.


PubMed Online version:10.1093/jac/dkq496


Anti-Bacterial Agents; Escherichia coli; Gene Deletion; Humans; Mutagenesis; Mutagens; Mutation; Rec A Recombinases

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.

Phenotype of Taxon Information Genotype Information (if known) Condition Information OMP ID OMP Term Name ECO ID ECO Term Name Notes Status

a mutation or genetic difference within a strain

  • Taxon: Escherichia coli
  • Strain: K-12
  • Substrain: ME12 recA(del)::kan
  • NCBI Taxon ID: 8333
  • Genotype of Reference Strain: recA+
  • Genotype of Experimental Strain : recA(del)::kan
  • Reference Condition: no antibiotic
  • Experimental Condition: sublethal concentration of antibiotic

decreased mutation frequency

ME12 = MG1655 lacZ(del)C-lacZ(del)N-yfp

Fig. 1 shows results for mutants with increased resistance to rifampicin and fosfomycin. Largest effects seen for sublethal conc. of trimethoprim, sulfamethoxazole, and trimethoprim + sulfamethoxazole.

a mutation or genetic difference within a strain

  • Taxon: Escherichia coli
  • Strain: K-12
  • Substrain: ME12
  • NCBI Taxon ID: 8333
  • Genotype of Reference Strain:
  • Reference Condition:no antibiotic
  • Experimental Condition: antibiotic

decreased binary fission

Figure 3: Treatment for 4 h with mitomycin C, ceftazidime, ciprofloxacin, or trimethoprim caused filamentation.

ME12 = MG1655 lacZ(del)C-lacZ(del)N-yfp



See Help:References for how to manage references in OMPwiki.