RT Conference Proceedings
T1 Post-Antibiotic Effect of Moxifloxacin in Streptococcus pneumoniae: DNA-cleavage and Reactive Oxygen Species Production
A1 García Esteban, María Teresa
A1 Valenzuela, Myriam
A1 Ferrándiz, María José
A1 De la Campa, Adela G.
AB Background: Streptococcus pneumoniae is cause of community acquired pneumonia, meningitis,  otitis media, sinusitis and conjunctivitis. Moxifloxacin (MFX) is a fluoroquinolone used for  pneumococcal infections. The post-antibiotic effect (PAE) is useful to determine optimal dosage  regimens for antibiotics. MFX forms intermediates of DNA-MFX-topoisomerase complexes, which  generates double-stranded DNA breaks. Its lethality is enhanced by the production of reactive oxygen species (ROS), via the up-regulation of genes that increases pyruvate and stimulate the  Fenton reaction. Objectives: To study the factors involved in PAE of MFX in S. pneumoniae. Methods: Streptococcus pneumoniae R6 strain was analyzed during the postantibiotic phase. Growth curves by viable counting, level of chromosome fragmentation by Pulse Field Gel Electrophoresis,  ROS production by dihydrorhodamine 123 dye and gene expression by q-RT-PCR, were determined Results: Treatment of 1 h with MFX at (2.5 −5 – 10)  MIC induced PAE of 0.76 h, 1.33 h and 1.99 h,  respectively. DNA breakage induced by the treatment decreased more than 3-fold after the PAE phase. Increase up to 3-fold of ROS level induced by the treatment reverted after the PAE-phase.  MFX up-regulated the expression of fba and gpdA genes involved in the conversion of fructose 6- phosphate to pyruvate by glycolytic pathway. MFX also up-regulated the expression of pmi and tktA genes, which encode for enzymes that funnel phosphate sugars into the glycolytic pathway. MFX  induces significant PAE representing the time necessary for the bacteria to recover their normal  levels of ROS and intact DNA.
YR 2019
FD 2019
LK https://hdl.handle.net/20.500.14352/129870
UL https://hdl.handle.net/20.500.14352/129870
LA eng
NO Maria Teresa Garcia Esteban, Valenzuela, M., María José Ferrándiz, & Adela G. de la Campa. (2019). Post-Antibiotic Effect of Moxifloxacin in Streptococcus pneumoniae: DNA-cleavage and Reactive Oxygen Species Production. En FEMS2019: 8th Congress of European Microbiologists. Federation of European Microbiological Societies.
DS Docta Complutense
RD 17 ene 2026