Produção e avaliação de toxicidade de nanomateriais com potencial aplicação da medicina veterinária

Abstract

Mastitis is one of the principal diseases that affects dairy herds around word. According WHO, Staphylococcus aureus, the main etiological agent of this disease, was recently included in global priority list of antibiotic-resistant bacteria. This pathogen causes extreme threats to health and therefore, requires extensive research and efforts for development of new and effective drugs and vaccines. The biofilm, an important factor of virulence produced by this bacteria, has as the main component the exopolysaccharide (PNAG). Thus, the present research proposes the vibrational spectroscopy evaluation of S. aureus PNAG and its application as non - destructive alternative to determine the degree of polymer deacetylation, and the possible polymer cellular toxicity. The PNAG characterization was performed by nuclear magnetic resonance, Raman, infrared and dynamic light scattering. Biological tests were accomplished using bovine peripheral blood mononuclear cells to evaluate the compound acute toxicity. The polysaccharide was toxic to lymphocytes only at highest concentration (7.5 mg / mL), suggesting that the higher degree of deacetylation, higher the rate of fagocytosis. This study has potential application for the development of immunostimulators for bovine mastitis treatment.