Molecular insights into fosfomycin resistance in Escherichia coli
| Autor: | Fernando Docobo-Pérez, L. Racero, M. S. Ramos-Guelfo, Álvaro Pascual, José-Manuel Rodríguez-Martínez, Jesús Blázquez, M. Ballestero-Téllez, Jesús Rodríguez-Baño, I Portillo-Calderón |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Instituto de Salud Carlos III, Junta de Andalucía, Red Española de Investigación en Patología Infecciosa, European Commission, Universidad de Sevilla |
| Rok vydání: | 2017 |
| Předmět: |
DNA
Bacterial 0301 basic medicine Microbiology (medical) genetic structures 030106 microbiology Mutant Microbial Sensitivity Tests Fosfomycin medicine.disease_cause 03 medical and health sciences Drug Resistance Bacterial Escherichia coli medicine Humans Pharmacology (medical) Pharmacology Chemistry Escherichia coli Proteins biochemical phenomena metabolism and nutrition cyaA Molecular biology In vitro Anti-Bacterial Agents Infectious Diseases Mutation Resistant mutants Genes MDR Clearance medicine.drug |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | [Objectives] Fosfomycin activity in Escherichia coli depends on several genes of unknown importance for fosfomycin resistance. The objective was to characterize the role of uhpT, glpT, cyaA and ptsI genes in fosfomycin resistance in E. coli. [Methods] WT E. coli BW25113 and null mutants, ΔuhpT, ΔglpT, ΔcyaA, ΔptsI, ΔglpT-uhpT, ΔglpT-cyaA, ΔglpT-ptsI, ΔuhpT-cyaA, ΔuhpT-ptsI and ΔptsI-cyaA, were studied. Susceptibility to fosfomycin was tested using CLSI guidelines. Fosfomycin mutant frequencies were determined at concentrations of 64 and 256 mg/L. Fosfomycin in vitro activity was tested using time–kill assays at concentrations of 64 and 307 mg/L (human Cmax). [Results] Fosfomycin MICs were: WT E. coli BW25113 (2 mg/L), ΔglpT (2 mg/L), ΔuhpT (64 mg/L), ΔcyaA (8 mg/L), ΔptsI (2 mg/L), ΔglpT-uhpT (256 mg/L), ΔglpT-cyaA (8 mg/L), ΔglpT-ptsI (2 mg/L), ΔuhpT-cyaA (512 mg/L), ΔuhpT-ptsI (64 mg/L) and ΔptsI-cyaA (32 mg/L). In the mutant frequency assays, no mutants were recovered from BW25113. Mutants appeared in ΔglpT, ΔuhpT, ΔcyaA and ΔptsI at 64 mg/L and in ΔuhpT and ΔcyaA at 256 mg/L. ΔglpT-ptsI, but not ΔglpT-cyaA, ΔuhpT-cyaA or ΔuhpT-ptsI, increased the mutant frequency compared with the highest frequency found in each single mutant. In time–kill assays, all mutants regrew at 64 mg/L. Initial bacterial reductions of 2–4 log10 cfu/mL were observed for all strains, except for ΔuhpT-ptsI, ΔglpT-uhpT and ΔuhpT-cyaA. Only ΔglpT and ΔptsI mutants were cleared using 307 mg/L. [Conclusions] Fosfomycin MIC may not be a good efficacy predictor, as highly resistant mutants may appear, depending on other pre-existing mutations with no impact on MIC. This work was supported by the Ministerio de Economía y Competitividad, Instituto de Salud Carlos III (PI13/01885 and PI 13/01282) and the Consejería de Igualdad, Salud y Políticas Sociales, Junta de Andalucía (PI-0044-2013), Spain. It was partly supported by the Plan Nacional de I + D+i and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD12/0015)—co-financed by the European Development Regional Fund ‘A way to achieve Europe’ ERDF. F. D.-P. is supported by a VPPI-US fellowship from the University of Sevilla. |
| Databáze: | OpenAIRE |
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