An Investigation on the Ecology of Triatoma vitticeps (Stal, 1859) and its Possible Role in the Transmission of Trypanosoma cruzi, in the Locality of Triunfo, Santa Maria Madalena Municipal District, State of Rio de Janeiro, Brazil

From January 1989 to April 1995, 465 specimens of Triatoma vitticeps were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district, State of Rio de Janeiro. The bugs were found indoors by local residents with predominance of adults. The flight activity was high in hot months when the incidence in the domicile also increased. Two hundred and two bugs (111 alive and 91 dead) were examined for Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34%) and 88 (79%) of the live bugs examined. With a view to investigate the possible vertebrate hosts of the T. cruzi isolates, the blood of 122 mammals was examined through Giemsa-stained smears, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens of Didelphis marsupialis and T. (M.) theileri was detected in one specimen of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as antigens. These results show that T. vitticeps is still a sylvatic species although nymphs have been found inside the domicile. Thus, an epidemiological vigilance is necessary to know the behaviour of this species following the continuous modifications promoted by the presence of man.

Trypanosoma cruzi infection in Didelphis marsupialis in Santa Catarina and Arvoredo Islands, southern Brazil

Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis) was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI), in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI), located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9% of the opossums captured in SCI and 45.2% among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed.

Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae) resistant to Schistosoma mansoni

Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil) is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant) and B. tenagophila from Joinville, state of Santa Catarina (susceptible) was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

Anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl)-2-propen-1-one derivatives

A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl)-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E)-3-(3,4,5-trimethoxy-phenyl)-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl)-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.

Paleoparasitological results for rodent coprolites from Santa Cruz Province, Argentina

The aim of this study was to examine the parasite remains present in rodent coprolites collected from the archaeological site Alero Destacamento Guardaparque (ADG) located in the Perito Moreno National Park (Santa Cruz Province, 47º57'S 72º05'W). Forty-eight coprolites were obtained from the layers 7, 6 and 5 of ADG, dated at 6,700 ± 70, 4,900 ± 70 and 3,440 ± 70 years BP, respectively. The faecal samples were processed and examined using paleoparasitological procedures. A total of 582 eggs of parasites were found in 47 coprolites. Samples were positive for eggs of Trichuris sp. (Nematoda: Trichuridae), Calodium sp., Eucoleus sp., Echinocoleus sp. and an unidentified capillariid (Nematoda: Capillariidae) and for eggs of Monoecocestus (Cestoda: Anoplocephalidae). Quantitative differences among layer for both coprolites and parasites were recorded. In this study, the specific filiations of parasites, their zoonotic importance, the rodent identity, on the basis of previous zooarchaeological knowledge, and the environmental conditions during the Holocene in the area are discussed.

Paleoparasitologic, paleogenetic and paleobotanic analysis of XVIII century coprolites from the church La Concepción in Santa Cruz de Tenerife, Canary Islands, Spain

We present the results of a paleoparasitologic, paleogenetic and paleobotanic analysis of coprolites recovered during the excavation of the church La Concepción in Santa Cruz de Tenerife. Coprolites (n = 4) were rehydrated and a multidisciplinary analysis was conducted. The paleobotanic analysis showed numerous silicates, seeds and fruits of the family Moraceae. In the paleoparasitologic study, Ascaris sp. eggs (n = 344) were identified. The paleogenetic results confirmed the Ascaris sp. infection as well as the European origin of human remains. These findings contribute to our knowledge of ancient helminthes infections and are the first paleoparasitological record of Ascaris sp. infection in Spain.

Spotted fever group Rickettsia infecting ticks (Acari: Ixodidae) in the state of Santa Catarina, Brazil

During 2006-2008, a total of 260 adult ticks were collected from domestic and wild animals in different regions of the state of Santa Catarina (SC), Brazil, including areas where human cases of Brazilian spotted fever have been reported. Collected ticks belonging to nine species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma ovale, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus) were tested by polymerase chain reaction (PCR) for rickettsial infection. Overall, eight (3.1%) ticks were found to be infected with Rickettsia species. After sequencing the PCR products, we determined that the sequences generated from three A. aureolatum, one A. ovale and one R. sanguineus from the municipality of Blumenau, one A. ovale from the municipality of Águas Mornas and one A. ovale from the municipality of Urussanga were identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia parkeri strain Atlantic rainforest. The sequence generated from one A. longirostre from Blumenau was 100% identical to the corresponding partial rickettsial ompA gene sequence of Rickettsia amblyommii strain AL. Because R. parkeri strain Atlantic rainforest was recently shown to have caused two cases of human spotted fever in other states of Brazil, the role of this rickettsial agent as a possible etiological agent of spotted fever in SC is discussed.

Biological, biochemical and molecular features of Trypanosoma cruzi strains isolated from patients infected through oral transmission during a 2005 outbreak in the state of Santa Catarina, Brazil: its correspondence with the new T. cruzi Taxonomy Consensus (2009)

We examined strains of Trypanosoma cruzi isolated from patients with acute Chagas disease that had been acquired by oral transmission in the state of Santa Catarina, Brazil (2005) and two isolates that had been obtained from a marsupial (Didelphis aurita) and a vector (Triatoma tibiamaculata). These strains were characterised through their biological behaviour and isoenzymic profiles and genotyped according to the new Taxonomy Consensus (2009) based on the discrete typing unities, that is, T. cruzi genotypes I-VI. All strains exhibited the biological behaviour of biodeme type II. In six isolates, late peaks of parasitaemia, beyond the 20th day, suggested a double infection with biodemes II + III. Isoenzymes revealed Z2 or mixed Z1 and Z2 profiles. Genotyping was performed using three polymorphic genes (cytochrome oxidase II, spliced leader intergenic region and 24Sα rRNA) and the restriction fragment length polymorphism of the kDNA minicircles. Based on these markers, all but four isolates were characterised as T. cruzi II genotypes. Four mixed populations were identified: SC90, SC93 and SC97 (T. cruzi I + T. cruzi II) and SC95 (T. cruzi I + T. cruzi VI). Comparison of the results obtained by different methods was essential for the correct identification of the mixed populations and major lineages involved indicating that characterisation by different methods can provide new insights into the relationship between phenotypic and genotypic aspects of parasite behaviour.