Biomaterial Database

Insect-borne and culture-derived metacyclic Trypanosoma cruzi: differences in infectivity and virulence. 1987

F Villalta, and F Kierszenbaum

We report in this paper significant differences in the virulence of insect-derived and cultured metacyclic forms of Trypanosoma cruzi which are morphologically indistinguishable. Mice infected intraperitoneally with 10(3) metacyclic T. cruzi isolated from Rhodnius prolixus showed average parasitemia levels greater than 2 X 10(5) organisms/ml around day 10 post-infection (when first measured) and peak levels recorded on day 16 post-infection exceeded 4 X 10(7) organisms/ml. None of these animals survived after 30 days post-infection. In contrast, in mice infected with 10(3) or 10(4) metacyclic forms from axenic cultures the highest average parasitemia was approximately 10(4) organisms/ml and occurred around day 19 post-infection. In these animals, parasitemias declined with time to become undetectable and no mortality was recorded over the 100-day observation period. There was also a marked difference in the 50% lethal dose of insect- and culture-derived metacyclics. The value for the former was 670 parasites whereas none of the mice infected intraperitoneally with up to 10(6) cultured metacyclics died. These results point to a marked difference in the biological properties of insect-borne and cultured T. cruzi metacyclics under our experimental conditions and caution against extending results obtained with the latter to vector-transmissible metacyclics, at least in infectivity and virulence studies.

UI	MeSH Term	Description	Entries
D007928	Lethal Dose 50	The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.	LD50,Dose 50, Lethal
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012239	Rhodnius	A genus of the subfamily TRIATOMINAE. Rhodnius prolixus is a vector for TRYPANOSOMA CRUZI.
D014225	Triatominae	A subfamily of assassin bugs (REDUVIIDAE) that are obligate blood-suckers of vertebrates. Included are the genera TRIATOMA; RHODNIUS; and PANSTRONGYLUS, which are vectors of TRYPANOSOMA CRUZI, the agent of CHAGAS DISEASE in humans.
D014349	Trypanosoma cruzi	The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.	Trypanosoma cruzus,cruzi, Trypanosoma
D014355	Chagas Disease	Infection with the protozoan parasite TRYPANOSOMA CRUZI, a form of TRYPANOSOMIASIS endemic in Central and South America. It is named after the Brazilian physician Carlos Chagas, who discovered the parasite. Infection by the parasite (positive serologic result only) is distinguished from the clinical manifestations that develop years later, such as destruction of PARASYMPATHETIC GANGLIA; CHAGAS CARDIOMYOPATHY; and dysfunction of the ESOPHAGUS or COLON.	Trypanosomiasis, South American,American Trypanosomiasis,Chagas' Disease,Trypanosoma cruzi Infection,Infection, Trypanosoma cruzi,Infections, Trypanosoma cruzi,South American Trypanosomiasis,Trypanosoma cruzi Infections,Trypanosomiasis, American
D014774	Virulence	The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.	Pathogenicity
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus