Abstract The Japanese invasive jumping snail Ovachlamys fulgens is a pest of ornamental plants and an intermediate host of a nematode that causes eosinophilic meningitis. We expand its distribution to eight municipalities from Rio de Janeiro State, and one locality from the Paraná State, and generated for the first time partial sequences of the cytochrome c oxidase subunit I (COI) gene for Brazilian populations. External morphology, reproductive system, shell, radula, and jaw were also analyzed and described. Twenty-one lots were collected from Rio de Janeiro, Niterói, Magé, Miguel Pereira, Petrópolis, Teresópolis, Nova Friburgo, Bom Jardim and Paraty, in Rio de Janeiro State, and from Foz do Iguaçu, Paraná State. External morphology, shell and reproductive system were typical of O. fulgens, with some peculiarities found in the shell and radula. A single haplotype was found, which was 100% similar to sequences of COI available in GenBank for specimens from Japan and Argentina. The species seems to be adapted to many habitats and be rapidly expanding its distribution in Southeastern and Southern Brazil, and other South America countries. We highlight the importance of monitoring O. fulgens, considering its potential to compete with native mollusks, attack several plants, and be a transmitter of diseases.

Os autores descreveram as características morfológicas de Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 pertencente ao grupo de espécies que compõem o "complexo T. oliveirai". Até o presente tem sido difícil separar essas espécies com base nas características ninfais, o que justifica o desenvolvimento deste trabalho. Os espécimes foram coletados em frestas de rochas no morro Malavok na localidade de Linha Brasil, município de Nova Petrópolis, no Estado do Rio Grande do Sul. O local de captura dos triatomíneos situa-se entre 700 e 800 m de altitude (29º18'38''S, 51º04'57''W). Juntamente com T. oliveirai (Neiva, Pinto & Lent, 1939), espécie morfologicamente mais próxima, são as únicas do complexo que não foram encontradas, até o momento, no Estado do Mato Grosso, Mato Grosso do Sul e Goiás, Brasil. Em condições experimentais, já foi testada e comprovada a sua susceptibilidade à infecção pelo Trypanosoma cruzi (Chagas, 1909) e Trypanosoma rangeli (Tejera, 1920). A análise comparativa das ornamentações do exocório dos ovos e de três estádios ninfais de T. klugi por microscopia óptica e microscopia eletrônica de varredura mostrou algumas particularidades morfológicas, com destaque para: a face ventral da cabeça, o sulco estridulatório e os últimos segmentos abdominais (IX, X - futura genitália e XI - tubo anal). Esses dados contribuem para a ampliação dos parâmetros diferenciais visando à diagnose de T. klugi durante o seu desenvolvimento ninfal.

The authors had described the morphologic characteristics of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 to the group of species belonging to "T. oliveirai complex". Until the moment it has been difficult to separate on the nymphs characteristics basis these species, what it justifies the development of this work. The specimens had been collected in openings of rocks in the Malavok mount in the locality of Linha Brazil, city of Nova Petrópolis, in the State of Rio Grande do Sul. The local of capture of the Triatominae is placed enters 700 and 800 m of altitud (29º18'38''S, 51º04'57''W). Together with T. oliveirai (Neiva, Pinto & Lent, 1939), its morphologically related species, is the only ones of the complex that had not been found, until the moment, in the State of Mato Grosso, Mato Grosso do Sul and Goiás, Brazil. In experimental conditions, already it was tested and proven its susceptibilities to the infection for Trypanosoma cruzi (Chagas, 1909) and Trypanosoma rangeli (Tejera, 1920). The comparative analysis of the ornaments of the exocorium of eggs and of three nymphs of T. klugi by optic microscopy and scanning electron microscopy showed some morphologic particularities, with prominence for: the ventral face of the head, the stridulatory sulcus and the last abdominal segments (IX, X - future genitalia and XI - anal duct). These data contribute for the magnifying of the distinguishing parameters aiming at diagnosis of T. klugi during its nymphal development.

Ultrastructural analysis of the ventral region of the head - rostrum, buccula and stridulatorium sulcus - of 1st, 3rd and 5th instars of Triatoma klugi Carcavallo et al, Triatoma vandae Carcavallo et al, and Triatoma williami Galvão et al, are described in here. Morphological differences in the analyzed structures for all three Triatoma species studied were detected under scanning electron microscopy, allowing their grouping by their morphological similarities. Species-specific differences at each nymphal development stage were analyzed as well.

The present paper summarizes new approaches regarding the progress done to the understanding of the interaction of Trypanosoma cruzi-cardiomyocytes. Mannose receptors localized at the surface of heart muscle cell are involved in binding and uptake of the parasite. One of the most striking events in the parasite-heart muscle cells interaction is the disruption of the actin cytoskeleton. We have investigated the regulation of the actin mRNA during the cytopathology induced in myocardial cells by the parasite. T. cruzi invasion increases calcium resting levels in cardiomyocytes. We have previously shown that Ca2+ ATPase of the sarcoplasmic reticulum (SERCA) is involved in the invasion of T. cruzi in cardiomyocytes. Treating the cells with thapsigargin, a drug that binds to all SERCA ATPases and causes depletion of intracellular calcium stores, we found a 75% inhibition in the T. cruzi-cardiomyocytes invasion.

Macrophages and muscle cells are the main targets for invasion of Trypanosoma cruzi. Ultrastructural studies of this phenomenon in vitro showed that invasion occurs by endocytosis, with attachment and internalization being mediated by different components capable of recognizing epi-or trypomastigotes (TRY). A parasitophorus vacuole was formed in both cell types, thereafter fusing with lysosomes. Then, the mechanism of T. cruzi invasion of host cells (HC) is essentially similar (during a primary infection in the abscence of a specific immune response), regardless of wether the target cell is a professional or a non-professional phagocytic cell. Using sugars, lectins, glycosidases, proteinases and proteinase inhibitors, we observed that the relative balance between exposed sialic acid and galactose/N-acetyl galactosamine (GAL) residues on the TRY surface, determines the parasite's capacity to invade HC, and that lectin-mediated phagocytosis with GAL specificity is important for internalization of T. cruzi into macrophages. On the other hand, GAL on the surface to heart muscle cells participate on TRY adhesion. TRY need to process proteolytically both the HC and their own surface, to expose the necessary ligands and receptors that allow binding to, and internalization in the host cell. The diverse range of molecular mechanisms which the parasite could use to invade the host cell may correspond to differences in the available "receptors"on the surface of each specific cell type. Acute phase components, with lectin or proteinase inhibitory activities (a-macroglobulins), may also be involved in T. cruzi-host cell interaction.