Navegando por Autor "Fontoura, Inglid"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Antibacterial activity of silver nanoparticles functionalized with amikacin applied against multidrug-resistant acinetobacter baumannii
    (Elsevier) Camargo, Larissa de Oliveira; Fontoura, Inglid; Veriato, Thaís da Silva; Raniero, Leandro José; Castilho, Maiara Lima
    Background: Multidrug-resistant bacteria are one of the world's biggest health problems; therefore, improving the spectrum of action of antibiotics could be necessary to reverse this situation. Amikacin and silver salts have well-known antimicrobial properties. However, both drugs lost their effectiveness against some bacteria, such as Acinetobacter baumannii. This work aims to develop a nanodrug from silver nanoparticles (AgNPs) functionalized with Amikacin against multidrug-resistant Acinetobacter baumannii. Methods: AgNPs were produced using the bottom-up methodology and functionalized with Amikacin modified by the carbodiimide-based chemistry, forming AgNPs@Amikacin. Susceptibility tests were performed using Amikacin-resistant Acinetobacter baumannii strains to assess the bacteriostatic and bactericidal potential of the developed nanodrug. The clinical strains were induced to form a biofilm, and biomass quantification and the metabolic activity were determined. Results: The AgNPs have a hydrodynamic diameter of the particles with a bimodal distribution, with a size of 37.84 nm. The FT-IR spectrum of AgNPs@Amikacin exhibits vibrational modes corresponding to Amikacin, confirming the conjugation to AgNPs. Susceptibility testing demonstrated a minimal inhibitory and bactericidal concentration of < 0.5 µg/mL. The AgNPs@Amikacin reduced the biofilm metabolic activity of Acinetobacter baumannii at rates ≥ 50%, characterized by the minimal biofilm inhibition concentrations. Conclusions: Results demonstrate a promising development of a new nanodrug with lower concentrations, less toxicity, and greater efficacy against multidrug-resistant Acinetobacter baumannii.
  • Imagem de Miniatura
    Item
    Biochemical characterization of the strict anaerobic Gram-negative bacteria Tannerella forsythia by infrared micro-spectroscopy
    (Elsevier) Abreu, Geraldo Magno Alves de; Fontoura, Inglid; Castilho, Maiara Lima; Sibelino, Sônia Khouri; Soto, Claudio Alberto Téllez; Martin, Aírton Abrahão
    Tannerella forsythia is a fastidious S-layer Gram-negative, strict anaerobic, and highly pleomorphic bacterium associated with periodontal inflammatory processes, bone loss, cardiovascular mortality, systemic sequelae, sepsis, and preterm birth. One of the purposes of this study was to characterize, for the first time, Tannerella forsythia (ATCC 43037) using Fourier transform infrared micro-spectroscopy. The analysis aimed to establish a suitable methodology for obtaining reproducible spectra for the characterization of this microorganism, as well as to assign the vibrational bands using techniques such Fourier self-deconvolution analysis (FSD) and second derivative spectral followed by Gaussian band fitting. The study was carried out in triplicate, yielding a total of 25 spectra per culture and 75 spectra across replicates. This methodology can be applied to the biochemical identification and characterization of Tannerella forsythia.