Extrato de Punica granatumL. (romã): análise das propriedades para uso como sanitizante no manejo da ordenha bovina

Abstract

The standards provided for by current legislation for agricultural production adapt production systems to ensure food safety and quality, which encompasses hygienic-sanitary aspects and good production practices on the part of cow caretakers, milkers and animal handlers. Bovine mastitis is an important challenge as infectious agents often isolated from cases of mastitis are resistant to antibiotics, making their eradication difficult. The use of conventional disinfectants and antibiotics has faced bacterial resistance, which leads to the search for alternatives such as phytosubstances and their derivatives. Therefore, the objective of this work is to compare the effect of the ethanolic extract of peels from the fruits of Punica granatum L., pomegranate, with commercial disinfectants against strains of Escherichia coli and Staphylococcus aureus. The phytochemical analysis of the extract was carried out using mass spectrometry. Membrane integrity was analyzed by propidium iodide impregnation by flow cytometry using the fluorescence intensity parameter (FL3) and by quantification of DNA in the supernatant using the FastDNA spin for soil typical workflow kit. Analysis of the bacterial surface and ultrastructure was performed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Phytochemical analysis of the extract indicated punicalagin as the majority substance. The results showed an action of the P. granatum extract in altering the membrane integrity observed by the incorporation of propidium iodide after treatment with 50 mg/mL, 25 mg/mL and 10mg/mL of the extract in just 30 seconds for both strains tested. The results of DNA release into the supernatant corroborated the results of changes in membrane integrity and extravasation of intracellular content. The changes on the surfaces were evident in the SEM and TEM images, in which it is possible to observe membrane rupture and extravasation of intracellular contents. Comparison of the effect of the extract with traditionally used commercial disinfectants (hypochlorite and chlorhexidine) carried out by macrodilution in broth and the determination of colony forming units per milliliter corroborated the promising nature of the hydroalcoholic extract of P. granatum bark, given its effectiveness against the strains of Gram-negative and Gram-positive bacteria (E. coli and S. aureus, respectively) associated with bovine mastitis.