Isolation, viability in low temperatures and axenic culture of cysts og Giardia duodenalis of patients of the region the northwest of the Paraná

Abstract

Giardiosis is a serious public health problem. The objective of this work was to isolate cysts of Giardia duodenalis taken from human stools, in order to verify the viability of the cysts in function of the time of stockage in low temperature, as well as to obtain trophozoites for axenic culture. The isolated cysts were isolated and purified using the technique of Roberts-Thompson et al. The samples were divided in two groups; one was used to verify the viability of the stored cysts in low temperature, while the other was submitted to axenization, excystation and culture. For excystation, two techniques were used. The viability of the cysts’ stockage in low temperature decreased with storage time. Statistically significant changes in the viability of the isolated samples were not observed after 24, 48, 72 hours, and in the following two months. From the third to the fifth month, there was a decrease in the percentage of viable cysts, and the ninth month total loss of viability occurred. Growth in vitro of the axenic samples was not observed. This study will be able to contribute to expanding the knowledge of this parasite and, later aid in the detection of differences between types.