ABSTRACT
To evaluate the antibacterial, antibiofilm and antivirulence potential of the main diterpenes from Copaifera spp. oleoresins against multidrug-resistant (MDR) bacteria. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration of Biofilm (MICB50), as well as synergistic and antivirulence assays for eight diterpenes against MDR. The tests revealed that two diterpenes (named 1 and 5) showed the best results, with MIC and MBC between 12.5 and 50 µg/mL against most MDR bacteria. These diterpenes exhibited promising MICB50 in concentration between 3.12-25 µg/mL but showed no synergistic antimicrobial activity. In the assessment of antivirulence activity, diterpenes 1 and 5 inhibited only one of the virulence factors evaluated (Dnase) produced by some strains of S. aureus at subinhibitory concentration (6.25 µg/mL). Results obtained indicated that diterpenes isolated from Copaifera oleoresin plays an important part in the search of new antibacterial and antibiofilm agents that can act against MDR bacteria.
ABSTRACT
Este estudo objetivou avaliar os efeitos da inoculação de proteína isolada de soja (P.I.S.) em ovos embrionados de matrizes semipesadas com diferentes idades. Foram utilizados 320 ovos embrionados de matrizes semipesadas da linhagem Rhode Island Red com 35 e 70 semanas de idade. Ao 17º dia de incubação, os ovos foram inoculados com 0,5mL de solução diretamente na cavidade alantoide. O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial (2 x 4), constituído por dois fatores: idades das matrizes (matrizes jovens e matrizes velhas) e soluções inoculadas (ovo íntegro; 0,5% de solução salina; 1% de P.I.S. + 0,5% de solução salina; e 2% de P.I.S. + 0,5% de solução salina), totalizando oito tratamentos contendo 40 ovos cada. Os dados coletados foram analisados pelo teste de Tukey a 5% de significância. A inoculação de proteína isolada de soja apresentou efeito positivo sobre a relação pinto-ovo, porém sem proporcionar melhora nos rendimentos de incubação, no desenvolvimento dos órgãos e no desempenho de pintos na fase pré-inicial. A idade da matriz influenciou diretamente as variáveis avaliadas, em que ovos oriundos de aves velhas apresentaram maior peso, maior mortalidade embrionária na fase tardia, pintos mais pesados e pior conversão alimentar.(AU)
This study aimed to evaluate the influence of inoculation of isolated soy protein (P.I.S.) in embryonated eggs of semi-heavy with different ages. 320 embryonated eggs were used from semi-heavy breeders of Rhode Island Red lineage with 35 and 70 weeks of age. In the 17th day of incubation, the eggs were inoculated with 0.5 ml of solution in the allantoic cavity. The experimental method was completely randomized in factorial scheme (2 x 4), consisting of two factors: matrices ages (young and old matrices) and inoculation solutions (non-inoculated eggs; 0.5% of saline solution; 1% of P.I.S. + 0.5% of saline solution; and 2% of P.I.S. + 0.5% of saline solution, totalling eight treatments containing 40 eggs each. The inoculation of isolated soy protein showed positive effect on the chick-egg relation, albeit without improving incubation yields, organ development and chicks's performance in the pre-initial phase. The age of the breeder directly influenced the variables evaluated, with eggs from older breeder showing better weight, higher embryonic mortality in late phase, heavier chicks and worse feed conversion.(AU)