Prieto Prieto, JoséAguilar, LorenzoFuentes, FernandoGiménez, María JoséAlou Cervera, LuisDal-Ré, RafaelSörgel, FritzFrı́as, J.2024-07-232024-07-232001-09Prieto J, Aguilar L, Fuentes F, Giménez MJ, Alou L, Dal-Ré R, Sörgel F, Frías J. Influence of diminished susceptibility of Streptococcus pneumoniae to ciprofloxacin on the serum bactericidal activity of gemifloxacin and trovafloxacin after a single dose in healthy volunteers. Int J Antimicrob Agents. 2001 Sep;18(3):231-8.0924-857910.1016/s0924-8579(01)00392-2https://hdl.handle.net/20.500.14352/107049The serum bactericidal activity against 2 Streptococcus pneumoniae strains (ciprofloxacin MIC 1 and 4 mg/l) was measured in 12 volunteers who received oral single doses of gemifloxacin 320 mg and trovafloxacin 200 mg in a crossover fashion. The 4-fold increase in ciprofloxacin MIC from the susceptible to the resistant strain resulted in a 2-fold increase in MIC (from 0.015 to 0.03 mg/l), a 2-fold decrease in C(max)/MIC (104 vs 52) and in AUC(0-24 h)/MIC (532 vs 266), but a 5.6-fold decrease in area under the bactericidal curve (AUBC: 168 vs 30) for gemifloxacin. Trovafloxacin showed a 4-fold higher MIC (0.25 vs 0.06 mg/l), a 4-fold lower C(max)/MIC (8.6 vs 36), a 4-fold lower AUC(0-24 h)/MIC (85 vs 356) and a 11-fold lower AUBCs (2 vs 22) against the resistant isolate compared with the susceptible one. Trovafloxacin serum bactericidal titres against the ciprofloxacin-resistant strain were measurable generally only at 1 h after dosing (median titre=2). Gemifloxacin showed similar ex vivo bactericidal activity against the ciprofloxacin-resistant strain to that of trovafloxacin against the ciprofloxacin-susceptible strain.engjournal articlehttps://doi.org/10.1016/S0924-8579(01)00392-2https://www.sciencedirect.com/science/article/pii/S0924857901003922restricted access611.02Streptococcus pneumoniaeSerum bactericidal activityGemifloxacinMicrobiología médica2414 Microbiología