RESUMEN
Severe chronic damage to the heart and gastrointestinal tract in patients with Chagas' disease are often observed 10-20 years after the acute phase. The course of long-lasting infection with the Colombian strain of Trypanosoma cruzi was studied in seven rhesus monkeys infected for 15-19 years. Subpatent parasitemia was detected in all studied animals, using hemoculture (two of seven), artificial xenodiagnosis (three of seven), and a polymerase chain reaction PCR (six of six). High titers of specific IgG antibody to T. cruzi persisted throughout the chronic phase of infection. Abnormal electrocardiographic (three of six) and echocardiographic (one of six) patterns detected in the T. cruzi-infected monkeys were possibly related to parasite-triggered myocardial damage. The results suggest that rhesus monkeys experimentally infected with T. cruzi, besides reproducing the acute phase of Chagas' disease, also develop chronic chagasic cardiomyopathy.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Cardiomiopatía Chagásica , Enfermedad de Chagas/fisiopatología , Modelos Animales de Enfermedad , Parasitemia/parasitología , Trypanosoma cruzi/patogenicidad , Animales , Cardiomiopatía Chagásica/diagnóstico por imagen , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/fisiopatología , Enfermedad de Chagas/parasitología , Enfermedad Crónica , Ecocardiografía , Electrocardiografía , Humanos , Inmunoglobulina G/sangre , Macaca mulatta , Masculino , Reacción en Cadena de la Polimerasa , Radiografía , Trypanosoma cruzi/genética , Trypanosoma cruzi/aislamiento & purificaciónRESUMEN
The infection pattern in Swiss mice and Triatomine bugs (Rhodius neglectus) of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically charcterized. The clones and the original isolate were in the same zymodeme (Z1) except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice enfected bugs well while only the original stock and one of the clones (F8). All clones and the original isolate enfected bugs well while only the original isolate and clones E2 and F3 yiedlded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade of I.E. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.