RESUMEN
O gênero Saccharomyces tem sido usado como indutor de resistência ou para controle biológico em muitos patossistemas. Neste trabalho objetivou-se a indução de fitoalexinas em mesocótilos de sorgo e cotilédones de soja pela levedura Saccharomyces boulardii na forma do produto comercial Floratil (Merck) (com 2 x 106 células/mg produto comercial - pc) e massa de células obtidas de meio líquido YEPG (primeiramente com 14 dias de cultivo e, posteriormente, com 7, 14, 21, 28 e 35 dias) ambos em concentrações de 0,005; 0,05; 0,5; 5; 15 e 25 mg/mL, além de filtrado desse meio nas concentrações de 0,01; 0,1; 1; 5; 10 e 20%. Como tratamentos controle utilizou-se água e S. cerevisiae (25 mg/mL de pc) para soja e água e acibenzolar-S-metil (ASM) (125 mg i.a./L) para sorgo. Em soja os três produtos apresentaram efeito dose-dependente, com ajustes de equações de 1° grau e R2 de 0,64; 0,94 e 0,98 não tendo efeito do tempo de cultivo da levedura na indução de fitoalexinas. Em sorgo apenas o filtrado e Floratil tiveram efeito dose-dependente com equação de 1° grau e R2 de 0,63 e 0,94 respectivamente e obteve-se nos diferentes dias de cultivo R2 de 0,62 com a massa de células somente. Portanto, pode-se evidenciar o potencial indutor de fitoalexinas dos produtos a base de S. boulardii para ensaios com indução de resistência em patossistemas envolvendo sorgo e soja.
Saccharomyces yeast compounds have been used as a resistance elicitor or for biological control in many pathosystems. Thus, the aim of this research was to verify the induction of phytoalexins in sorghum mesocotyls and soybean cotyledons by using Saccharomyces boulardii in the form of the commercial product Floratil (Merck) (with 2 x 106 cells/mg) and yeast-cell mass obtained from liquid culture in YEPG medium (with 7, 14, 21, 28 and 35 days old), both at concentrations of 0.005, 0.05, 0.5, 5, 15 and 25 mg/mL, as well as the filtrate of this medium in concentrations of 0.01, 0.1, 1, 5, 10 and 20%. The control treatments consisted of distilled water and S. cerevisiae (25 mg of commercial product per mL) for the soybean tests and distilled water and acibenzolar-S-methyl (125 mg of active ingredient per L) for the sorghum tests. In soybeans the three tested S. boulardii products presented a dose-dependent effect with R2 of 0.64, 0.94 and 0.98 for the culture filtrate, cell suspension and commercial product of S. boulardii, respectively, with no effect of culture time of yeasts on phytoalexin induction. In sorghum, only the culture filtrate and Floratil presented a dose-dependent effect, with R2 of 0.63 and 0.94, respectively, and the cell suspension of S. boulardii showed dependence of culture time with R2 of 0.62. Thus, S. boulardii and its derivates induce phytoalexins and have potential to be used as an elicitor for assays with induction resistance in pathosystems involving sorghum and soybean plants.
Asunto(s)
Glycine max/fisiología , Cotiledón/microbiología , Sorghum/fisiología , Saccharomyces boulardiiRESUMEN
ABSTRACT Saccharomyces yeast compounds have been used as a resistance elicitor or for biological control in many pathosystems. Thus, the aim of this research was to verify the induction of phytoalexins in sorghum mesocotyls and soybean cotyledons by using Saccharomyces boulardii in the form of the commercial product Floratil (Merck) (with 2 x 106 cells/mg) and yeast-cell mass obtained from liquid culture in YEPG medium (with 7, 14, 21, 28 and 35 days old), both at concentrations of 0.005, 0.05, 0.5, 5, 15 and 25 mg/mL, as well as the filtrate of this medium in concentrations of 0.01, 0.1, 1, 5, 10 and 20%. The control treatments consisted of distilled water and S. cerevisiae (25 mg of commercial product per mL) for the soybean tests and distilled water and acibenzolar-S-methyl (125 mg of active ingredient per L) for the sorghum tests. In soybeans the three tested S. boulardii products presented a dose-dependent effect with R2 of 0.64, 0.94 and 0.98 for the culture filtrate, cell suspension and commercial product of S. boulardii, respectively, with no effect of culture time of yeasts on phytoalexin induction. In sorghum, only the culture filtrate and Floratil presented a dose-dependent effect, with R2 of 0.63 and 0.94, respectively, and the cell suspension of S. boulardii showed dependence of culture time with R2 of 0.62. Thus, S. boulardii and its derivates induce phytoalexins and have potential to be used as an elicitor for assays with induction resistance in pathosystems involving sorghum and soybean plants.
RESUMO O gênero Saccharomyces tem sido usado como indutor de resistência ou para controle biológico em muitos patossistemas. Neste trabalho objetivou-se a indução de fitoalexinas em mesocótilos de sorgo e cotilédones de soja pela levedura Saccharomyces boulardii na forma do produto comercial Floratil (Merck) (com 2 x 106 células/mg produto comercial - pc) e massa de células obtidas de meio líquido YEPG (primeiramente com 14 dias de cultivo e, posteriormente, com 7, 14, 21, 28 e 35 dias) ambos em concentrações de 0,005; 0,05; 0,5; 5; 15 e 25 mg/mL, além de filtrado desse meio nas concentrações de 0,01; 0,1; 1; 5; 10 e 20%. Como tratamentos controle utilizou-se água e S. cerevisiae (25 mg/mL de pc) para soja e água e acibenzolar-S-metil (ASM) (125 mg i.a./L) para sorgo. Em soja os três produtos apresentaram efeito dose-dependente, com ajustes de equações de 1° grau e R2 de 0,64; 0,94 e 0,98 não tendo efeito do tempo de cultivo da levedura na indução de fitoalexinas. Em sorgo apenas o filtrado e Floratil tiveram efeito dose-dependente com equação de 1° grau e R2 de 0,63 e 0,94 respectivamente e obteve-se nos diferentes dias de cultivo R2 de 0,62 com a massa de células somente. Portanto, pode-se evidenciar o potencial indutor de fitoalexinas dos produtos a base de S. boulardii para ensaios com indução de resistência em patossistemas envolvendo sorgo e soja.
RESUMEN
The safety and immunogenicity of Haemophilus influenzae type b-tetanus toxoid conjugate vaccine (Hib-TT) were evaluated in 77 healthy infants receiving injections at 3, 5, 7, and 18 months of age. No serious local or systemic reactions were noted. After the first injection the geometric mean Hib antibody level rose to 0.55 micrograms/ml, and each subsequent injection elicited a statistically significant rise in the geometric mean. The percentage of vaccinees with Hib antibody levels greater than 0.15 micrograms/ml serum was 75.5% after the first, 97.4% after the second, and 100% after the third Hib-TT injection. This percentage fell to 90.9% at 18 months of age but rose again to 100% after the fourth injection. Control infants (n = 10) injected with diphtheria-tetanus toxoid-pertussis vaccine only had nondetectable levels after the second injection. Hib-TT elicited increases of Hib antibody in all isotypes: IgG greater than IgM greater than IgA. Among IgG subclasses the highest increases were of IgG1. All vaccinated subjects had greater than 0.01 U/ml of TT antibody (estimated protective level) throughout the study. We conclude that Hib-TT, injected at 3, 5, 7, and 18 months, is safe and induces protective levels of antibodies during the age of highest incidence of meningitis caused by Hib.