More productive in vitro culture of Cryptosporidium parvum for better study of the intra- and extracellular phases Pérez-Cordón, Gregorio Marín Sánchez, Clotilde Romero, D. Sánchez Moreno, Manuel Rosales Lombardo, María José Cryptosporidium In vitro Culture extracellular stages The great difficulties in treating people and animals suffering from cryptosporidiosis have prompted the development of in vitro experimental models. Due to the models of in vitro culture, new extracellular stages of Cryptosporidium have been demonstrated. The development of these extracellular phases depends on the technique of in vitro culture and on the species and genotype of Cryptosporidium used. Here, we undertake the molecular characterization by polymerase chain reaction-restriction fragment lenght polymorphism of different Cryptosporidium isolates from calves, concluding that all are C. parvum of cattle genotype, although differing in the nucleotide at positions 472 and 498. Using these parasites, modified the in vitro culture technique for HCT-8 cells achieving greater multiplication of parasites. The HCT-8 cell cultures, for which the culture had not been renewed in seven days, were infected with C. parvum sporozoites in RPMI-1640 medium with 10% IFBS, CaCl2 and MgCl2 1 mM at pH 7.2. Percentages of cell parasitism were increased with respect to control cultures (71% at 48 h vs 14.5%), even after two weeks (47% vs 1.9%). Also, the percentage of extracellular stages augmented (25.3% vs 1.1% at 96 h). This new model of in vitro culture of C. parvum will enable easier study of the developmental phases of C. parvum in performing new chemotherapeutic assays. 2014-07-24T11:17:41Z 2014-07-24T11:17:41Z 2007 info:eu-repo/semantics/article Pérez Cordón, G.; et al. More productive in vitro culture of Cryptosporidium parvum for better study of the intra- and extracellular phases. Memoria do Instituto Oswaldo Cruz, 102(5): 567-571 (2007). [http://hdl.handle.net/10481/32767] 0074-0276 1678-8060 http://hdl.handle.net/10481/32767 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Instituto Oswaldo Cruz