International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 2 Number 8 (2013) pp. 263-271 
Encystment and encystations of Entamoeba invadens In-Vitro as a model to test amebicides against Entamoeba histolytica to the public health problem Entamoeba dispar 
Ruvalcaba Ledezma Jesus Carlos1* , Latorre Cervantes Samantha2 , GarcĂ­a Romero Evelyn3 , Susana Ramirez Roma4 and Juan Mora Galindo5 
1Doctor of Science in Public Health, Full-time Research Professor in ICSA-UAEH, Institute of Health Sciences, Autonomous Universityof the State of Hidalgo, Pachuca Hidalgo, Mexico, academic area of Medicine and Master of Public Health. Pachuca Hidalgo, Mexico. 2Lic. In UAEH Medicine, Autonomous University of the State of Hidalgo, Pachuca Hidalgo, Mexico. 3Lic. In UAEH Medicine, Autonomous University of the State of Hidalgo, Pachuca Hidalgo, Mexico. 4Accountant CIBOIMSS, Guadalajara Jalisco, Mexico. Science and Research 5Doctor retired CIBO-IMSS, Guadalajara Jalisco, Mexico - University of Guadalajara, Mexico *Corresponding author e-mail: 
The life cycle of Entamoeba invadens implies the cyst formation who infest to new guests and that excystation and reproduction cause amebiasis; the excystation process is poorly understood and it hasn`t been systematically studied in vitro.The objective of this study was to quantify the excystation of cysts of E. invadens IP-1 strain, previously obtained in axenic conditions for incubation in medium AEM with inoculums of 2 x 10 5 trophozoites / ml for 72 hours. The excystation was caused to transfer the cysts to the growth medium Bl-S- 33, the first trophozoites were observed after 12 hours of incubation and after 72 hours, the 13% of the inoculated cyst were excystation: the most range of excystation was observed at 48 hours. It was obtained as cultives of trophozoites, who after six weeks it had similar growth curves to the original strain. These results demonstrated the quantitatively excystation of Entamoeba invadens and confirmed the possibility of provoke the life cycle in vitro of this amoeba in axenic conditions for facilitating the study, and it was necessary to determine the optimum conditions to induce the massive and synchronize excystation. The model obtained in Entamoeba invadens IP-1 could even reduce unnecessary exposure to drugs, in the case of E. dispar and E. histolytica, increases the costs to the patient and family, health institutions, and the risks of exposure to drugs, as E. dispar is not parasitic amoeba 
Entamoeba invadens; cysts; trophozoites; E. dispar; exposue to drugs; axenic conditions; E. histolytica