The Effect of Sulphaquinoxaline on the Feeding and Breeding Performance of the Tick Rhipicephalus appendiculatus Neumann (Acarina: Ixodidae)

Abstract

31,000 and 21,000 were clearly defined, although the resultant bands were less intense. Based on the presence of antibodies in at least 2 of the 5 test sera examined, the extracts of T. cruzi and T. rangeli shared a minimum of 5 prominent antigens of m.w. of about 72,000, 61,000, 54,000, 44,000, and 32,000 daltons. However, the antisera failed to detect in the T. rangeli extract the 92,000 dalton antigen which in the T. cruzi extract appeared as a wide, faint band. The results described above have identified the antigens present in the extract of T. rangeli that are recognized by antibodies in the serum of patients with chronic chagasic cardiomyopathies. Qualitative and quantitative differences (indicated by the intensity of the bands) were observed between the patients' sera. The data are consistent with the observation that T. cruzi and T. rangeli are similar antigenically (Afchain et al., 1979, J. Parasit. 65: 507-514; Bronzina et al., 1980, Medicina (Buenos Aires) 40: 45-49; Anthony et al., 1981, Am. J. trop. Med. Hyg. 30: 1192-1197). However, it is not in contradiction with the existence of species-specific antigens and antigenic differentiation of T. cruzi and T. rangeli (Ebert et al., 1978, Tropenmed. Parasit. 29: 115-118; Afchain et al., 1979, loc. cit.; Muhlpfordt and Schottelius, 1977, Tropenmed. Parasit. 28: 1-7; Anthony et al., 1981, loc. cit.). Afchain et al. (1979, loc. cit.) showed that T. cruzi and T. rangeli share many common antigens (18 precipitin lines with an isology index of 0.6), and Bronzina et al. (1980, loc. cit.) also using immunoprecipitation techniques identified a flagellar and a cytoplasmic antigen common to the epimastigote life stage of both trypanosomes. Recently, Benavides and Kuhn (pers. comm.) have found that there is a possibility that T. rangeli has an intracellular stage in mammals. In addition, it is not known what role T. rangeli plays in concomitant or sequential infections in the pathogenesis of Chagas' disease. The identification and characterization of cross-reacting antigens can be of importance in epidemiological studies to examine the effect, if any, of T. rangeli infection on the course of Chagas' disease. In addition, the characterization of species-specific antigens is of importance in developing serodiagnostic procedures to distinguish T. cruzi and T. rangeli infections in man. It is conceivable that the 92,000 dalton antigen of T. cruzi may prove useful for this purpose. This research received financial support from the UNDP/WB/WHO Special Program for Research and Training in Tropical Diseases and the United States Army Medical Research and Development Command. . : 1-7; Anthony et al., 1981, lo . cit.). Af-