title: Toxic concentrations of metronidazole to Microcystis protocystis.
abstract: Antimicrobials are among the most commonly used drugs and have become a class of contaminants with great environmental importance. Metronidazole is an antimicrobial used for the therapeutic management of several human diseases. The toxicity of antimicrobials on aquatic species may affect sensitive microorganisms and reduce metabolic processes. Cyanobacteria is a group of organisms that are of great ecological importance in aquatic environments. Studies indicate that cyanobacteria are very sensitive to some antimicrobials. Therefore, it is necessary to evaluate the effects of metronidazole contamination on phytoplankton. The aim of this study was to investigate the effects of metronidazole on the growth of the cyanobacterium Microcystis protocystis and to evaluate the stability of this antimicrobial agent in the culture medium over a period of 96 hours. M. protocystis was resistant to growth inhibition by metronidazole. The EC50 of this antimicrobial for M. protocystis was 117.3 mg L(-1). Under the growth inhibition test conditions, neither a significant change in the MNZ concentration nor the presence of drug metabolites or degradation products was observed. These results indicate low cellular uptake of the antimicrobial agent and its persistence in the culture medium.
authors: Department of Social Pharmacy, School of Pharmacy, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: S M S
authors: SM
authors: Magalhães
authors: Department of Social Pharmacy, School of Pharmacy, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: C M
authors: CM
authors: Brêtas
authors: Department of Pharmaceutical Products, School of Pharmacy, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: J M
authors: JM
authors: Brêtas
authors: Department of Pharmaceutical Products, School of Pharmacy, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: G A
authors: GA
authors: Pianetti
authors: Department of General Biology, Biological Science Institute, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: M W
authors: MW
authors: Franco
authors: Department of General Biology, Biological Science Institute, Federal University of Minas Gerais - UFMG, Belo Horizonte, MG, Brazil.
authors: F A R
authors: FA
authors: Barbosa
mesh_terms: D004305:Dose-Response Relationship, Drug; D008795:Metronidazole / Q000633:toxicity*; D046931:Microcystis / Q000145:classification / Q000187:drug effects*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D008795:Metronidazole