ABSTRACT
Conocer las características biológicas de una cepa de Trypanosoma cruzi, procedente de Tiabaya, Arequipa, Perú,y determinar la supervivencia de los ratones inoculados con relación a la dosis infectante y al sexo. Se utilizaron 14 ratones BALB/C-53 (machos y hembras) de 30 días. Los grupos I y II fueron inoculados por vía intraperitoneal con 1,8 x 105 y 1,8 x 104 trypomastigotes metacíclicos de T. cruzi, respectivamente; el grupo III con 1,5 x 107 trypomastigotes sanguíneos. El grupo control (IV) recibió solo solución salina fisiológica al 0,9 por ciento. Los parásitos fueron evaluados en sangre periférica de los ratones. El análisis de supervivencia fue realizado por el método de Kaplan-Meier, test deLogaritmo de rangos y Wilcoxon al 95 por ciento de nivel de confianza. Se encontraron formas delgadas y gruesas de T. cruzi. La letalidad fue 100 por ciento al día 40 postinfección (pi). La parasitemia fue detectada desde el 6to hasta el 40mo día pi y el pico máximo global (6747 parásitos) fue observado al 29no día pi. Existen diferencias significativas en la supervivenciade los ratones inoculados de acuerdo a la dosis por la prueba de Logaritmo de rangos (p = 0,0202). La cepa de T. cruzi,procedente de Tiabaya, Arequipa es de mediana virulencia. La supervivencia de los ratones infectados está relacionadaa la dosis de inoculación.
To know the biological characteristics of a strain of Trypanosome cruzi, coming from the district of Tiabaya, Arequipa,Peru, and to determine the survival of inoculated mice relating the infecting dose ante and sex. Were used 14 BALB/C-53 mice (males and females) of 30 days of age as biological model. The groups I and II were inoculated via intraperitoneum with 1,8 x 105 and 1,8 x 104 meta-cyclic trypomastigotes of T. cruzi, respectively; group III with 1,5 x 107 sanguine trypomastigotes. Control group (IV) received only physiologic saline solution at 0.9 por ciento. The parasites were searched in peripheral blood of the mouse. The analysis of survival was carried out by Kaplan-Meier method, Logrank test andWilcoxon to 95 por ciento of confidence level. Were find thin and thick forms of T. cruzi. The fatality rate was 100 por ciento groups at day 40 -post-infection- (pi). The parasitemy was detected from the 6th until the 40th day pi and the global maximum pick (6747parasites) was observed on the 29th day pi. Significant differences exist in the survival of inoculated mice according to the dose by the Logrank test (p = 0,0202). The strain of T. cruzi, coming from Tiabaya, Arequipa is of medium virulence. The survival of the infected mice is related to the dose of inoculation.
Subject(s)
Humans , Disease Models, Animal , Mice , Trypanosoma cruzi , Virulence , PeruABSTRACT
"Crespera" is an infectious disease of coffee plants that affects both the coffee production and the economy of the coffee producer countries. This disease affects morphologically the plant: long and narrow leaves with wavy borders and marginal necrosis; strong chlorosis results in drying of the leave, and leads to bad conditions of the plant. The internodes are short, producing the appearance of multiple sprouts in the axial sprout, the flowers can turn greenish, and the plant can present branches with severe symptoms, and branches without apparent symptoms at the same time. As a result, the coffee bean production decreases strikingly. The aim of this work was to determine the occurrence of the possible causative agent in the coffee plants using transmission electron microscopy. Normal and infected plants were compared looking at the leaves, central vein, lateral veins and petiole. It was determined that xylematic vessels show the presence of gram negative bacilliform bacteria (of thick-wavy walls), with dimensions of 0.3-0.5 micron diameter and 1-4 microns, length. The control plants did not show bacteria in the xylem.