title: Antimicrobial activity against Gram-positive and Gram-negative bacteria during gatifloxacin degradation by hydroxyl radicals.
abstract: Gatifloxacin, an antimicrobial drug belonging to the fluoroquinolone family, is active against Gram-positive and Gram-negative bacteria and is extensively used for the control of infections in humans. The presence of the drug in environmental matrices has already been reported. This study investigated the degradation of gatifloxacin in water by hydroxyl radicals generated by the UV254 nm/H2O2process ([Formula: see text] 0.4-2.4 mmol L-1) and evaluated the capacity of the radicals to reduce the antimicrobial activity against Gram-positive and Gram-negative bacteria. Acute toxicity assays were performed with Vibrio fischeri, and the degradation products were proposed. The hydroxyl radicals formed in the processes were able to degrade the fluoroquinolone and remove the antimicrobial activity from the aqueous solution. Approximately 97 % gatifloxacin degradation was observed after applying 2.4 mmol L-1of initial H2O2concentration and 20 min of UVC254nmirradiation (130 J s-1). The acute toxicity assays showed that the toxicity of the treated solution for V. fischeri increased as the gatifloxacin concentration in the solution decreased.
authors.affiliation: School of Civil Engineering, Architecture and Urban Design, University of Campinas, P.O. Box 6143, 13083-889, Campinas, Brazil.
authors.forename: Marlon
authors.initials: M
authors.lastname: Caianelo
authors.affiliation: Institute of Chemistry, Department of Analytical Chemistry, University of Campinas, P.O Box 6154, 13084-971, Campinas, SP, Brazil. caio.rodrigues@iqm.unicamp.br.
authors.forename: Caio
authors.initials: C
authors.lastname: Rodrigues-Silva
authors.affiliation: School of Civil Engineering, Architecture and Urban Design, University of Campinas, P.O. Box 6143, 13083-889, Campinas, Brazil.
authors.forename: Milena Guedes
authors.initials: MG
authors.lastname: Maniero
authors.affiliation: School of Civil Engineering, Architecture and Urban Design, University of Campinas, P.O. Box 6143, 13083-889, Campinas, Brazil. jorober@fec.unicamp.br.
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Guimarães
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D024841:Fluoroquinolones / Q000737:chemistry* / Q000494:pharmacology* / Q000633:toxicity; D000077734:Gatifloxacin; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry*; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D000077734:Gatifloxacin
keywords: Acute toxicity; Advanced oxidation process; Antimicrobial activity; Drinking water; Fluoroquinolone degradation products; UV/H2O2