Antimicrobial activity against Gram-positive and Gram-negative bacteria during gatifloxacin degradation by hydroxyl radicals

• Published in: Environmental science and pollution research international 2017-03, Vol.24 (7), p.6288-6298
• Main Authors: Caianelo, Marlon, Rodrigues-Silva, Caio, Maniero, Milena Guedes, Guimarães, José Roberto
• Format: Article
• Language: English
• Subjects: Acute toxicity; Aliivibrio fischeri - drug effects; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - toxicity; Antimicrobial agents; AOPs: Recent Advances to Overcome Barriers in the Treatment of Water; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Degradation products; Drinking water; Drugs; E coli; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fluoroquinolones - chemistry; Fluoroquinolones - pharmacology; Fluoroquinolones - toxicity; Gram-negative bacteria; Gram-Negative Bacteria - drug effects; Gram-positive bacteria; Gram-Positive Bacteria - drug effects; Humans; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Hydroxyl Radical - chemistry; Hydroxyl radicals; Irradiation; Microbial Sensitivity Tests; Mineral water; Mineralization; Oxidation; Pharmaceuticals; Studies; Toxicity; Vibrio fischeri; Waste Water Technology; Wastewater and Air; Water Management; Water Pollution Control; Water treatment plants
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-6972-y

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 UV 254 nm /H 2 O 2 process ( C H 2 O 2 initial =  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 −1 of initial H 2 O 2 concentration and 20 min of UVC 254nm irradiation (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.