Triatomine's embryo extracts promote growth of culture forms of Trypanosoma cruzi.

A m o n g 59 s tu d ie d c h ro n ic c h a g a s ic patients, in four of them it was only possible to is o la te T r y p a n o s o m a c r u z i u s in g haemoculture, but not xenodiagnosis1. This fa ilu re in i s o la t in g T. c r u z i u s in g xenodiagnosis performed with three different triatomine species, represents an opportunity to evaluate the interaction between T. cruzi and its infection within the triatomine vector. Based on observation that a triatomine embryo-cell-line allows the differentiation of the p arasite to m etacic lic form s5 and the i n d u c t i o n o f p a r a s i t e g r o w t h a n d differentiation in cultures, when supplemented with triatomines’ intestinal extracts2 we argue that som e of the questions related to triatomine’s susceptibility and infection could be answered by studding the influence of the vector’s organ extracts on parasite growth in culture media. The present study is being conducted to a n a l y z e t he ro l e of d i f f e r e n t o r ga n homogenates, from embryos to adult stages of triatomines, on the growth and differentiation of two T. cruzi strains (Herm and Fran) isolated only by hem oculture from two chagasic patients and frozen immediately after isolation. The isolates were used after five passages in LIT media. Suspensions of four and three days old embryos, of Dipetalogaster maxim us and Rhodnius prolixus respectively, were obtained from ground eggs in PBS (pH 7.2). The extracts were filtered either with 0.22 or 0.45pm Millipore filters, in order to observe possible differences in the flagellates growrth due to the