Banca de DEFESA: PAULA FERNANDA ALVES FERREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PAULA FERNANDA ALVES FERREIRA
DATE: 05/03/2021
TIME: 09:00
LOCAL: https://zoom.us/j/96337540658
TITLE:

Effect of composting from animal production wastes to ensure safety

KEY WORDS:

Animal wastes, Antimicrobials, Bacterial resistance, Pathogens, Public health.

PAGES: 84
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Microbiologia e Bioquímica do Solo
SUMMARY:

The increase in the generation of animal production waste it is a concern of the agricultural sector which increasingly seeks more sustainable alternatives for its disposal. These residues are promising for use in agricultural production as an organic fertilizers or soil conditioners. However, they can be a source of pathogenic microorganisms and determinants of antimicrobial resistance. Thus, when not properly managed, they can contaminate the soil and plants used for human consumption, what can result in public health risk. In this sense, it is recommended to seek for management alternatives that result in the reduction or elimination of pathogens and undesirable compounds to ensure the safety of their use as fertilizer. In this context, this study aimed to evaluate effect of composting in animal wastes to reduce the microbiological and parasitic load, as well as the distribution of bacteria and their antimicrobial resistance profile throughout of process. For such, was assembled a composting experiment with horse bedding and organic and conventional poultry litter. The samples were collected in the times 0, 14, 32, 60, 90 and 125 days. Were determined the presence of Salmonella sp., the quantification of thermotolerant coliforms and the presence of helminth eggs. The bacteria isolated during the composting process were identified through MALDI-TOF proteomic technique and then it was performed disk diffusion test for phenotypic detection of antimicrobial resistance. Salmonella sp. was absent in both the raw materials and the final compost. Composting was effective in the elimination of helminth eggs and in the reduction of thermotolerant coliforms, however, the final composts retained a higher thermotolerant coliforms load than that required by the current legislation. Were isolated 158 bacterial strains during the composting process of the three residues. The Enterobacteriaceae family was the more abundant and Proteus mirabilis and Escherichia coli were the species with higher percentage at the residues and those that presented multi-resistance profile. The bacteria Klebsiella pneumoniae and P. mirabilis, both with pathogenic potential, were found throughout all the composting. Despite composting have been effective in eliminating strains of E. coli, the same did not occur with strains of P. mirabilis. Therefore, even if the use of animal waste in agriculture be a sustainable alternative, the presence of pathogenic organisms with a multi-resistant profile represents a public health risk, since they can increment pathogenic bacteria and resistant to antimicrobials us soils and vegetable and consequently favor the dissemination and the transfer the same for commensal and pathogenic bacteria of humans and animals. Thus, this work reinforces the importance the studies that address management strategies that reduce and/or eliminate the contaminants from animal residues, aiming your safe use in agriculture, besids promoting the discussion about parameters of quality and safety of these residues.

BANKING MEMBERS:
Presidente - 1815763 - IRENE DA SILVA COELHO
Externa ao Programa - 1722406 - SHANA DE MATTOS DE OLIVEIRA COELHO
Externo à Instituição - EDNALDO DA SILVA ARAÚJO - UFRRJ