Salmonella Typhimurium exhibits fluoroquinolone resistance mediated by the accumulation of the antioxidant molecule H2S in a CysK-dependent manner
Cargando...
Archivos
Fecha
2016
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Oxford University Press
Nombre de Curso
Licencia CC
Licencia CC
Resumen
Objectives
To evaluate the contribution of cysK and cysM to the fluoroquinolone (ofloxacin) antibiotic resistance in Salmonella Typhimurium, and their impact on H2S and cysteine production through targeted mutagenesis.
Methods
Salmonella Typhimurium 14028s and its cysK and cysM mutants were tested for their susceptibility to ofloxacin, as determined by a broth microdilution test (to determine the MIC) and survival curves. H2S levels were measured by the Pb(AC)2 method and cysteine levels were determined using 5,5-dithio-bis-2-nitrobenzoic acid. DNA damage induced by antibiotic treatment was determined by PFGE. Finally, expression of cysK and cysM genes under antibiotic treatment was determined by real-time reverse transcription PCR.
Results
As determined by MIC, the ΔcysK strain was more resistant to ofloxacin, a reactive oxygen species (ROS)-producing fluoroquinolone, than the WT and ΔcysM strains, which correlates with survival curves. Moreover, the ΔcysK strain exhibited higher H2S levels and lower cysteine levels than the WT strain. Finally, the ΔcysK strain exhibited lower DNA damage upon challenge with ofloxacin than the WT and ΔcysM strains. These results are in accordance with lower expression of cysK under ofloxacin treatment in the WT strain.
Conclusions
This work demonstrated that cysteine metabolism in Salmonella Typhimurium modulated H2S levels, conferring resistance to second-generation fluoroquinolones.
Notas
Indexación: Scopus.
Palabras clave
Antibiotics, Antioxidants, Polymerase Chain Reaction, Metabolism, Antibiotic Resistance, Bacterial, Cysteine, Dna Damage, Electrophoresis, Gel, Pulsed-field, Fluoroquinolones, Genes, Ofloxacin, Reactive Oxygen Species, Salmonella Typhimurium, Survival Curve, Multi-Antibiotic resistance, Molecule
Citación
Journal of Antimicrobial Chemotherapy. Volume 71, Issue 12, Pages 3409 - 3415. 2016
DOI
10.1093/JAC/DKW311