Banca de DEFESA: JULIO CESAR SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JULIO CESAR SILVA
DATE: 13/03/2024
TIME: 09:00
LOCAL: CCAB
TITLE:

FTIR analysis and antimicrobial activity of molybdic acid, potassium molybdate, calcium tungstate and sodium tungstate

KEY WORDS:

ATR-FTIR; Molybdates; Polyoxometalates; Bacterial resistance Tungstates

PAGES: 112
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

The discovery and use of bacteria allowed the treatment of infections and the reduction of mortality rates associated with bacterial pathogens. However, simultaneously, bacterial pathogens progressed to antibiotic resistance. Added to this, today antibiotics are no longer produced as they were in the previous century and this is due to costs and profitability compared to the manufacture of other medicines. These determinants raise the need to develop new therapeutic alternatives. For a long time, public health policies have resorted to drugs of last resort or increasing the pharmacological concentrations of antibiotics, but these strategies, despite being immediate, are insufficient and make the treatment of infections more expensive, in addition to resulting in an increase in adverse effects. Therefore, to be considered promising, a medicine needs to have a well-defined structure. Polyoxometalates (POM’s) represent a class of inorganic compounds with a diversity of functions, sizes and chemical composition, characteristics currently being targeted. The writing plan for this study is divided into two important axes: 1- an integrative and bibliometric review of the literature and 2- carrying out chemical characterization and microbiological activity tests. The integrative and bibliometric survey was carried out using the Scopus and Web of Science databases using the descriptors “Polyoxometalates” and “Polyoxometalates and antibacterial activity”. From this, 38 and 36 articles were selected, respectively, for each indexed database. Bibliometrics presented the relationship between the keywords of the selected articles and data about bibliographic coupling. The latter demonstrated that, of the total number of studies surveyed, 27 were correlated in Scopus and 31 in Web of Science. The predominance graphs allowed us to verify that the bacteria most used in studies are Escherichia coli and Staphylococcus aureus, using the microdilution method. The chemical characterization of the compounds occurred by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), revealing a pattern of bands for the compounds that were located between 84-1915 cm^-¹. Using serial microdilution methodology, with colorimetric development, microbiological studies investigated the direct effect of the compounds on the clinically important bacteria Escherichia coli and Staphylococcus aureus, and the subinhibitory effect combined with traditional antibiotics was also verified. To evaluate the inhibition of beta-lactamase activity, the ability of the compounds to reduce the MIC of ampicillin against multiresistant strains of Staphylococcus aureus K-4414 and K-4100 was verified. Molybdates and tungstates did not present direct antibacterial activity, however they potentiated the effect of the traditional antibiotics ampicillin and gentamicin, in different circumstances against the bacteria Escherichia coli 06 and Staphyloccocus aureus 10. Molybdic acid, potassium molybdate, calcium tungstate and calcium tungstate inhibited the resistance effect presented by the bacteria S. aureus-K4100 and K4414. Given the current resistance scenario, these results represent new alternatives for the treatment of bacterial infections, allowing a better understanding of the properties of POMs. These results are pioneering in terms of publication.

COMMITTEE MEMBERS:
Presidente - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Externa à Instituição - JANAÍNA ESMERALDO ROCHA
Interna - KAMILA CAMARA CORREIA
Externa à Instituição - MARIA KAROLLYNA DO NASCIMENTO SILVA LEANDRO
Externo à Instituição - THIAGO SAMPAIO DE FREITAS