Antimicrobials in the environment: occurrence, depletion and remediation strategy.

Abstract

Antibiotics are widely used to treat diseases caused by bacterial infections in humans, plants and animals. The use of these drugs on a large scale has generated considerable concern and relevance, as their widespread administration can lead to the development of resistant pathogenic bacteria, which has hampered the treatment of infectious diseases worldwide. Conventional sewage treatment plants do not have the ability to completely eliminate antimicrobials. Therefore, the accurate and sensitive determination of antimicrobial residues in different environmental matrices is a necessity that can help in the establishment of measures of preservation, conservation or intervention. Likewise, depletion studies are important to measure or predict internal drug concentrations, helping to understand their dynamics in environmental biological matrices. The investigation of alternative and low-cost ways to remove these contaminants is paramount to environmental health. Thus, the objective of this project is determine antimicrobial residues in different environmental matrices, in addition to performing a depletion study in Astianax sp and Eisenia andrei using 14C radiolabeled compounds, and to evaluate the remediation potential of species Pistia stratiotes and Canavalia. ensiformis to remove these contaminants. To this end, chromatographic methods will be adapted and validated for the detection of twelve antibiotics of veterinary origin: tetracycline (TTC), sulfadimethoxine (SDT), enrofloxacin (EFX), chloramphenicol (CFC), oxytetracycline (OTC), chlortetracycline (CTC), ciprofloxacin (CFX), sarafloxacin (SAR), norfloxacin (NFX), sulphathiazole (STZ), florfenicol (FF) sulfamethazine (SMZ). The samples will be carried out in the Rio Piracicaba, SP and on a farm with a 12-year history of swine manure application. The highest concentrations determined, via liquid chromatography (LC-MS/MS), will be used to carry out the depletion studies and analysis of antimicrobial removal using plants. It is expected that the research will serve as a guiding basis for the inclusion of the drugs studied in environmental monitoring programs, as well as to understand how the mechanism of depletion (absorption and elimination) of antimicrobials in organisms occurs, in addition to determining the potential of Pistia stratiotes and Canavalia ensiformis in accelerating the degradation of antimicrobials.