Banca de DEFESA: ALESSANDRA RODRIGUES DE SANTANA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALESSANDRA RODRIGUES DE SANTANA
DATE: 19/07/2023
TIME: 09:30
LOCAL: https://conferenciaweb.rnp.br/webconf/lucia-19
TITLE:

Analysis of Enterococcus in swine manure samples treated by anaerobic digestion: evaluation of sensitivity to antimicrobials used in swine farming

PAGES: 95
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

The use of pig manure, treated by anaerobic biodigestion, as fertilizer is a sustainable practice of using solid waste. In pig farming, antimicrobials are used, which favors the selection of resistant microorganisms in the intestinal tract of animals and enables the dissemination of multiresistant variants to other living beings. Enterococcus are present in the intestine of animals and are characterized as one of the bacteria that most cause infections, being a public health concern. Considering the relevance of pig farming in Brazilian agribusiness, and the importance of technical-scientific knowledge about resistance to antibiotics in this branch of livestock, the objective of this study was to analyze the presence of microorganisms of the genus Enterococcus in samples from swine manure, which underwent anaerobic digestion treatment. For this purpose, the following steps were performed: presumptive microbiological tests to identify the genus of Enterococcus bacteria; identification of Enterococci through molecular analysis to confirm presumptive tests; verification of the resistance of identified microorganisms to the recommended antibiotic for all stages of swine production: amoxicillin; and carrying out microbiological tests with amoxicillin adding the food additives used in pig farming, in order to verify possible changes in the resistance of microorganisms. The manure samples were collected in a pig farm in the municipality of Ibiúna (São Paulo), with eight collections carried out between 2022 and 2023. The liquid samples were effluents collected from the subsurface of a biodigester settling tank; solid samples obtained from the decanted effluent after having passed through the dewatering system and having been left in a covered drying bed. The experimental tests were carried out in laboratories with the determination of the variables pH and solids (total, fixed and volatile); microbiological analyzes included Gram staining, catalase test, primary bacterial isolation of samples in saline solution (incubated at 37 ºC for 24 hours) and, afterwards, cultivation in azide broth culture media (37 ºC for 24 hours), Brain Heart Infusion (BHI) (37°C for 24h), Enterococcus selective agar medium (37°C for 24h); the antibiogram was performed with amoxicillin discs (2µg and 10µg) in culture media with and without food additives. From the microorganism isolated in BHI broth with Tris-HCl pH 7.8 buffer solution, the conventional polymerase chain reaction (PCR) molecular biology test was performed with specific primers for the genus Enterococcus; the PCR product was analyzed by electrophoresis in a 1.5% agarose gel, stained with GelRed® and visualized in an ultraviolet light transilluminator. The positive control was the strain ATCC 29212. Of the total of 16 samples collected (8 liquid + 8 solid), the study indicated the presence of Enterococcus in the majority (93.75%), confirmed by molecular tests. The antibiogram did not show microorganisms resistant to amoxicillin in bacteria isolated and cultivated in both types of culture media - with and without the addition of food additives.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1814655 - LUCIA HELENA GOMES COELHO
Membro Titular - Examinador(a) Externo ao Programa - 1675714 - MARCIA APARECIDA SPERANCA
Membro Titular - Examinador(a) Externo à Instituição - SILVANA LIMA GORNIAK - USP
Membro Suplente - Examinador(a) Interno ao Programa - 2342998 - RODRIGO DE FREITAS BUENO
Membro Suplente - Examinador(a) Externo ao Programa - 1222415 - MERCIA REGINA DOMINGUES MORETTO