Antonia Maria Ramos Franco

Feeding preference of the sand flies Lutzomyia umbratilis and L. spathotrichia (diptera: Psychodidae, Phlebotominae) in an urban forest patch in the city of Manaus, Amazonas, Brazil

Precipitin tests were performed on blood meals of 199 sand flies (161 Lutzomyia umbratilis, 34 L. spathotrichia, two Lutzomyia of group shannoni, one L. anduzei) in a non-flooded upland forest on the Campus of the Universidade Federal do Amazonas. This is the second largest forest fragment in an urban setting in Brazil. Results on L. umbratilis, which is considered to be the principal leishmaniasis vector in this region, indicated rodents as its predominant blood source in contrast to previous reports in which blood meal analysis indicated that this species fed principally on Xenarthra (particularly sloths).

Characterization of Endotrypanum (Kinetoplastida: Trypanosomatidae), a Unique Parasite Infecting the Neotropical Tree Sloths (Edentata)

This article reviews current concepts of the biology of Endotrypanum spp. Data summarized here on parasite classification and taxonomic divergence found among these haemoflagellates come from our studies of molecular characterization of Endotrypanum stocks (representing an heterogenous population of reference strains and isolates from the Brazilian Amazon region) and from scientific literature. Using numerical zymotaxonomy we have demonstrated genetic diversity among these parasites. The molecular trees obtained revealed that there are, at least, three groups (distinct species?) of Endotrypanum, which are distributed in Central and South America. In concordance with this classification of the parasites there are further newer molecular data obtained using distinct markers. Moreover, comparative studies (based on the molecular genetics of the organisms) have shown the phylogenetic relationships between some Endotrypanum and related kinetoplastid lineages.

Enzyme polymorphism in Endotrypanum and numerical analysis of isoenzyme data

In this study, we have analysed enzyme polymorphism among a group of protozoan parasites of the genus Endotrypanum (Kinetoplastida: Trypanosomatidae). Seventeen stocks of Endotrypanum spp. isolated from sloths (Choloepus didactylus and C. juruanus) in the Amazon Region of Brazil were analysed by enzyme electrophoresis, and their electromorphic profiles were compared with reference strains reported previously. The 16 enzymic loci were analysed, and the strains were classified into zymodemes, each representing parasites with unique enzyme profiles. Each zymodeme was considered as an elementary taxon, and using numerical analyses (cladistic, agglomerative hierarchical and ordination techniques) the genus was shown to be monophyletic and the 12 zymodemes characterized could be divided into 3 groups (A, B, C). The heterogeneous population (which may represent a complex of parasite species or strains variants) showed, however, no correlation with the origin (i.e. host species involved or geographic area of isolation) of Endotrypanum stocks. Eight isolates of Endotrypanum sp. from Rondônia State (Brazil) and a parasite strain from Panama were clustered together into a zymodeme, which was phenetically closely related to the E. monterogeii from Costa Rica. The data indicate that E. schaudinni is a species complex.

Minicircle kDNA microheterogeneity in Endotrypanum indicate diversity within this genus

A comparison of kDNA restriction-endonuclease fragment patterns from strains representing selected Endotrypanum zymodemes was done by schizodeme analysis. As the degree of heterogeneity within mini-circles varied among species or strains of Endotrypanum, the fingerprint obtained with each of the restriction enzymes was unique for each of these parasites. The data have revealed that this trypanosomatid genus is much more complex than it was originally thought to be.

Single and concomitant experimental infections by Endotrypanum spp. and Leishmania (Viannia) guyanensis (Kinetoplastida: Trypanosomatidae) in the neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae).

Lutzomyia longipalpis females received single and mixed infections with Endotrypanum and Leishmania. Two biological parameters were analyzed: the percentage of infected females and the distribution of flagellates in the gut of the females. The principal comparisons were performed between (1) two strains of Endotrypanum, (2) cloned versus primary sample of one strain of Endotrypanum, (3) Endotrypanum versus Leishmania guyanensis, and (4) the pattern of flagellates behaviour by optical microscopy in females with single or mixed infection versus the identification of parasites isolated from digestive tracts by isoenzyme electrophoresis. Flagellates of Endotrypanum showed distinct patterns of infection suggesting that there is variation between and within strains. The distribution of Endotrypanum and L. guyanensis differed significantly in relation to the colonization of the stomodeal valve. In co-infection with L. guyanensis, a large number of flagellates were seen to be plentifully infecting the stomodeal valve in significantly more specimens than in females infected by Endotrypanum only. However, the electrophoretic profiles of isoenzymes of parasites recovered from all co-infected specimens corresponded to Endotrypanum. This suggests that the mere correlation sand fly infection-biochemical analysis of isolates may induce parasitological incorrect consideration.

Characterization of Endotrypanum parasites using specific monoclonal antibodies

A large number of Endotrypanum stocks (representing an heterogeneous population of strains) have nbeen screened against a panel of monoclonal antibodies (MAbs) derived for selected species of nEndotrypanum or Leishmania, to see whether this approach could be used to group/differentiate further namong these parasites. Using different immunological assay systems, MAbs considered specific for the ngenus Endotrypanum (E-24, CXXX-3G5-F12) or strain M6159 of E. schaudinni (E-2, CXIV-3C7-F5) nreacted variably according to the test used but in the ELISA or immunofluorescence assay both reacted nwith all the strains tested. Analyses using these MAbs showed antigenic diversity occurring among the nEndotrypanum strains, but no qualitative or quantitative reactivity pattern could be consistently related nto parasite origin (i.e., host species involved) or geographic area of isolation. Western blot analyses of nthe parasites showed that these MAbs recognized multiple components. Differences existed either in the nepitope density or molecular forms associated with the antigenic determinants and therefore allowed nthe assignment of the strains to specific antigenic groups. Using immunofluorescence or ELISA assay, nclone E-24 produced reaction with L. equatorensis (which is a parasite of sloth and rodent), but not with nother trypanosomatids examined. Interestingly, the latter parasite and the Endotrypanum strains crossreacted with a number of MAbs that were produced against members of the L. major-L. tropica complex.