Live-cell three-dimensional single-molecule tracking reveals modulation of enhancer dynamics by NuRD.

To understand how the nucleosome remodeling and deacetylase (NuRD) complex regulates enhancers and enhancer-promoter interactions, we have developed an approach to segment and extract key biophysical parameters from live-cell three-dimensional single-molecule trajectories. Unexpectedly, this has revealed that NuRD binds to chromatin for minutes, decompacts chromatin structure and increases enhancer dynamics. We also uncovered a rare fast-diffusing state of enhancers and found that NuRD restricts the time spent in this state. Hi-C and Cut&Run experiments revealed that NuRD modulates enhancer-promoter interactions in active chromatin, allowing them to contact each other over longer distances. Furthermore, NuRD leads to a marked redistribution of CTCF and, in particular, cohesin. We propose that NuRD promotes a decondensed chromatin environment, where enhancers and promoters can contact each other over longer distances, and where the resetting of enhancer-promoter interactions brought about by the fast decondensed chromatin motions is reduced, leading to more stable, long-lived enhancer-promoter relationships.

First case of canine visceral leishmaniasis in the midwestern of Santa Catarina State, Brazil.

Canine visceral leishmaniasis (CVL) caused by Leishmania (Leishmania) infantum is transmitted by phlebotomine sandflies and a major zoonotic disease in Brazil. Due to the southward expansion of the disease within the country and the central role of dogs as urban reservoirs of the parasite, we have investigated the occurrence of CVL in two municipalities Erval Velho and Herval d'Oeste in the Midwest region of Santa Catarina state. Peripheral blood samples from 126 dogs were collected in both cities and tested for anti-L. infantum antibodies by indirect enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence reaction (IIF) and for the presence of parasite DNA by polymerase chain reaction (PCR) in peripheral blood. From examined dogs, 35.71% (45/126) were positive for at least one of the three tests and two (1.6%) were positive in all performed tests. Twelve dogs (9.5%) were positive for both ELISA and IIF, while 21 dogs were exclusively positive for ELISA (16.7%), and 15 (11.9%) for IIF. L. infantum k-DNA was detected by PCR in 9 out of 126 dogs (7.1%) and clinical symptoms compatible with CVL were observed for 6 dogs. Taken together, these results indicate the transmission of CVL in this region, highlighting the needs for epidemiological surveillance and implementation of control measures for CVL transmission in this region.

Biological activities of marine invertebrates extracts from the northeast brazilian coast.

This paper reports the in vitro antiproliferative effects, antiprotozoal, anti-herpes and antimicrobial activities of 32 organic extracts of 14 marine sponges and 14 corals collected in northeast Brazilian coast. The ethanolic extracts of the sponges Amphimedon compressa and Tedania ignis, and the acetone extract of Dysidea sp. showed relevant results concerning the antiproliferative effects against A549, HCT-8, and PC-3 cell lines by sulforhodamine B assay, but also low specificity. Concerning the antiprotozoal screening, the ethanolic extract of Amphimedon compressa and the acetone and ethanolic extracts of Dysidea sp. were the most active against Leishmania amazonensis and Trypanosoma cruzi expressing ß-galactosidase in THP-1 cells. In the preliminary anti-HSV-1 (KOS strain) screening, the ethanolic extracts of the sponges Amphimedon compressa, Haliclona sp. and Chondrosia collectrix inhibited viral replication by more than 50%. The most promising anti-herpes results were observed for the ethanolic extract of Haliclona sp. showing high selective indices against HSV-1, KOS and 29R strains (SI> 50 and >79, respectively), and HSV-2, 333 strain (IS>108). The results of the antibacterial screening indicated that only the ethanolic extract of Amphimedon compressa exhibited a weak activity against Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli by the disk diffusion method. In view of these results, the extracts of Amphimedon compressa, Tedania ignis and Dysidea sp. were selected for further studies aiming the isolation and identification of the bioactive compounds with antiproliferative and/or antiprotozoal activities. The relevant anti-herpes activity of the ethanolic extract of Haliclona sp. also deserves special attention, and will be further investigated.

Efficacy of benznidazol treatment for asymptomatic chagasic patients from state of Rio Grande do Sul evaluated during a three years follow-up.

The efficacy of benznidazol on the treatment of chagasic patients from the state of Rio Grande do Sul was evaluated during a three-year follow-up. A cohort of 80 asymptomatic chronic chagasic patients or blood bank donors (49 male and 31 female) was studied. Their ages varied from 17-42 years, with a mean and a median of 30 and 35 years, respectively. The 80 patients presented positive serology, hemoculture and polymerase chain reaction (PCR). They were treated with 5 mg/Kg benznidazol twice a day for 60 days. Serological, parasitological and PCR methods were used to evaluate response. Serology was performed using commercial ELISA and indirect immunofluorescence (IFI) tests, parasitemia was monitored by hemoculture in LIT medium and PCR with primers S35/S36 was used to amplify a Trypanosoma cruzi 330 bp kDNA repetitive sequence. PCR positivity of 240 seropositive individuals was compared using DNA preparations from whole blood/guanidine EDTA (GE), buffy-coat/GE and frozen buffy-coat. Fifty non-chagasic individuals were used as negative controls. PCR positivity was 86.7% for the frozen buffy-coat, 71.7% for the GE/buffy-coat and 69.2% for the GE/whole blood. The hemocultures became negative just after treatment and remained negative during the three years of follow-up. In the third year after treatment, 9/80 (11.3%) patients presented negative PCR and, from those, four also presented negative serological tests. Furthermore, a reduction in three serological titers was observed in 27/80 (33.8%) of the patients treated. Taken together, the results show that four of the 80 (5.0%) chronic chagasic patients from the state of Rio Grande do Sul were cured after treatment with benznidazol.

First case of canine visceral leishmaniasis in the midwestern of Santa Catarina State, Brazil / Primeiros casos de leishmaniose visceral canina no Meio-oeste do Estado de Santa Catarina, Brasil

Canine visceral leishmaniasis (CVL) caused by Leishmania (Leishmania) infantum is transmitted by phlebotomine sandflies and a major zoonotic disease in Brazil. Due to the southward expansion of the disease within the country and the central role of dogs as urban reservoirs of the parasite, we have investigated the occurrence of CVL in two municipalities Erval Velho and Herval d'Oeste in the Midwest region of Santa Catarina state. Peripheral blood samples from 126 dogs were collected in both cities and tested for anti-L. infantum antibodies by indirect enzymelinked immunosorbent assay (ELISA) and indirect immunofluorescence reaction (IIF) and for the presence of parasite DNA by polymerase chain reaction (PCR) in peripheral blood. From examined dogs, 35.71% (45/126) were positive for at least one of the three tests and two (1.6%) were positive in all performed tests. Twelve dogs (9.5%) were positive for both ELISA and IIF, while 21 dogs were exclusively positive for ELISA (16.7%), and 15 (11.9%) for IIF. L. infantum k-DNA was detected by PCR in 9 out of 126 dogs (7.1%) and clinical symptoms compatible with CVL were observed for 6 dogs. Taken together, these results indicate the transmission of CVL in this region, highlighting the needs for epidemiological surveillance and implementation of control measures for CVL transmission in this region.

A Leishmaniose Visceral Canina (LVC) causada pela Leishmania (Leishmania) infantum e transmitida por flebotomíneos e é uma das principais zoonoses do Brasil que se encontra em expansão em estados da região sul do país, sendo os cães o principal reservatório urbano do parasito. O presente estudo investigou a ocorrência de LVC em dois municípios, Erval Velho e Herval d'Oeste localizados no meio-oeste de Santa Catarina. Para tanto, amostras de sangue periférico de 126 cães foram coletadas em ambas as cidades e submetidas à detecção de anticorpos anti-L. infantum por meio de testes de ELISA e imunofluorescência indireta (IFI), bem com a detecção de k-DNA pela reação em cadeia de polimerase (PCR). Além disso, também foram observados os sintomas clínicos e as condições ambientais associadas a esses animais. Dos cães examinados, 35,7% (45/126) foram positivos para pelo menos um dos três testes, dois cães (1,6%) foram positivos em todos os três testes, 12 cães (9,5%) foram positivos tanto no ELISA quanto na IFI, enquanto 21 cães (16,7%) foram positivos para ELISA e 15 (11,9%) para o IFI. A amplificação do k-DNA de L. infantum foi positiva em 9 dos 126 cães (7,1%). Entre os cães positivos seis apresentaram um ou mais sintomas clínicos correlacionados com a LVC. Esses resultados confirmaram a ocorrência de LVC na região e destacaram a importância do monitoramento e implementação de medidas de controle para a LVC nessa região.

First case of canine visceral leishmaniasis in the midwestern of Santa Catarina State, Brazil / Primeiros casos de leishmaniose visceral canina no Meio-oeste do Estado de Santa Catarina, Brasil

Canine visceral leishmaniasis (CVL) caused by Leishmania (Leishmania) infantum is transmitted by phlebotomine sandflies and a major zoonotic disease in Brazil. Due to the southward expansion of the disease within the country and the central role of dogs as urban reservoirs of the parasite, we have investigated the occurrence of CVL in two municipalities Erval Velho and Herval d'Oeste in the Midwest region of Santa Catarina state. Peripheral blood samples from 126 dogs were collected in both cities and tested for anti-L. infantum antibodies by indirect enzyme linked immunosorbent assay (ELISA) and indirect immunofluorescence reaction (IIF) and for the presence of parasite DNA by polymerase chain reaction (PCR) in peripheral blood. From examined dogs, 35.71% (45/126) were positive for at least one of the three tests and two (1.6%) were positive in all performed tests. Twelve dogs (9.5%) were positive for both ELISA and IIF, while 21 dogs were exclusively positive for ELISA (16.7%), and 15 (11.9%) for IIF. L. infantum k-DNA was detected by PCR in 9 out of 126 dogs (7.1%) and clinical symptoms compatible with CVL were observed for 6 dogs. Taken together, these results indicate the transmission of CVL in this region, highlighting the needs for epidemiological surveillance and implementation of control measures for CVL transmission in this region.

A Leishmaniose Visceral Canina (LVC) causada pela Leishmania (Leishmania) infantum e transmitida por flebotomíneos e é uma das principais zoonoses do Brasil que se encontra em expansão em estados da região sul do país, sendo os cães o principal reservatório urbano do parasito. O presente estudo investigou a ocorrência de LVC em dois municípios, Erval Velho e Herval d’Oeste localizados no meio-oeste de Santa Catarina. Para tanto, amostras de sangue periférico de 126 cães foram coletadas em ambas as cidades e submetidas à detecção de anticorpos anti-L. infantum por meio de testes de ELISA e imunofluorescência indireta (IFI), bem com a detecção de k-DNA pela reação em cadeia de polimerase (PCR). Além disso, também foram observados os sintomas clínicos e as condições ambientais associadas a esses animais. Dos cães examinados, 35,7% (45/126) foram positivos para pelo menos um dos três testes, dois cães (1,6%) foram positivos em todos os três testes, 12 cães (9,5%) foram positivos tanto no ELISA quanto na IFI, enquanto 21 cães (16,7%) foram positivos para ELISA e 15 (11,9%) para o IFI. A amplificação do k-DNA de L. infantum foi positiva em 9 dos 126 cães (7,1%). Entre os cães positivos seis apresentaram um ou mais sintomas clínicos correlacionados com a LVC. Esses resultados confirmaram a ocorrência de LVC na região e destacaram a importância do monitoramento e implementação de medidas de controle para a LVC nessa região.

First case of canine visceral leishmaniasis in the midwestern of Santa Catarina State, Brazil

Abstract Canine visceral leishmaniasis (CVL) caused by Leishmania (Leishmania) infantum is transmitted by phlebotomine sandflies and a major zoonotic disease in Brazil. Due to the southward expansion of the disease within the country and the central role of dogs as urban reservoirs of the parasite, we have investigated the occurrence of CVL in two municipalities Erval Velho and Herval dOeste in the Midwest region of Santa Catarina state. Peripheral blood samples from 126 dogs were collected in both cities and tested for anti-L. infantum antibodies by indirect enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence reaction (IIF) and for the presence of parasite DNA by polymerase chain reaction (PCR) in peripheral blood. From examined dogs, 35.71% (45/126) were positive for at least one of the three tests and two (1.6%) were positive in all performed tests. Twelve dogs (9.5%) were positive for both ELISA and IIF, while 21 dogs were exclusively positive for ELISA (16.7%), and 15 (11.9%) for IIF. L. infantum k-DNA was detected by PCR in 9 out of 126 dogs (7.1%) and clinical symptoms compatible with CVL were observed for 6 dogs. Taken together, these results indicate the transmission of CVL in this region, highlighting the needs for epidemiological surveillance and implementation of control measures for CVL transmission in this region.

Resumo A Leishmaniose Visceral Canina (LVC) causada pela Leishmania (Leishmania) infantum e transmitida por flebotomíneos e é uma das principais zoonoses do Brasil que se encontra em expansão em estados da região sul do país, sendo os cães o principal reservatório urbano do parasito. O presente estudo investigou a ocorrência de LVC em dois municípios, Erval Velho e Herval dOeste localizados no meio-oeste de Santa Catarina. Para tanto, amostras de sangue periférico de 126 cães foram coletadas em ambas as cidades e submetidas à detecção de anticorpos anti-L. infantum por meio de testes de ELISA e imunofluorescência indireta (IFI), bem com a detecção de k-DNA pela reação em cadeia de polimerase (PCR). Além disso, também foram observados os sintomas clínicos e as condições ambientais associadas a esses animais. Dos cães examinados, 35,7% (45/126) foram positivos para pelo menos um dos três testes, dois cães (1,6%) foram positivos em todos os três testes, 12 cães (9,5%) foram positivos tanto no ELISA quanto na IFI, enquanto 21 cães (16,7%) foram positivos para ELISA e 15 (11,9%) para o IFI. A amplificação do k-DNA de L. infantum foi positiva em 9 dos 126 cães (7,1%). Entre os cães positivos seis apresentaram um ou mais sintomas clínicos correlacionados com a LVC. Esses resultados confirmaram a ocorrência de LVC na região e destacaram a importância do monitoramento e implementação de medidas de controle para a LVC nessa região

Internal transcribed spacers (ITS) of Trypanosoma rangeli ribosomal DNA (rDNA): a useful marker for inter-specific differentiation.

The internal transcribed spacers (ITS) flanking the 5.8S subunit of the ribosomal RNA genes (rDNA) of Trypanosoma rangeli strains isolated from distinct geographical regions and hosts were studied. The results revealed the sequence variability of the ITS spacers showing the presence of microsatellite repeats and single nucleotide polymorphisms (SNP), which were also observed within the 5.8S rDNA sequence. ITS-2 spacer was the most phylogenetically informative region due the presence of a higher number of parsimonious sites in both inter- and intra-specific analysis. Sequence analysis of both ITS spacers plus the 5.8S rDNA of T. rangeli strains allowed a clear inter-specific differentiation from Trypanosoma cruzi strains representative of the parasite zymodemes.

Biological activities of marine invertebrates extracts from the northeast brazilian coast / Atividades biológicas de extratos de invertebrados marinhos da costa nordeste do Brasil

Abstract This paper reports the in vitro antiproliferative effects, antiprotozoal, anti-herpes and antimicrobial activities of 32 organic extracts of 14 marine sponges and 14 corals collected in northeast Brazilian coast. The ethanolic extracts of the sponges Amphimedon compressa and Tedania ignis, and the acetone extract of Dysidea sp. showed relevant results concerning the antiproliferative effects against A549, HCT-8, and PC-3 cell lines by sulforhodamine B assay, but also low specificity. Concerning the antiprotozoal screening, the ethanolic extract of Amphimedon compressa and the acetone and ethanolic extracts of Dysidea sp. were the most active against Leishmania amazonensis and Trypanosoma cruzi expressing β-galactosidase in THP-1 cells. In the preliminary anti-HSV-1 (KOS strain) screening, the ethanolic extracts of the sponges Amphimedon compressa, Haliclona sp. and Chondrosia collectrix inhibited viral replication by more than 50%. The most promising anti-herpes results were observed for the ethanolic extract of Haliclona sp. showing high selective indices against HSV-1, KOS and 29R strains (SI> 50 and >79, respectively), and HSV-2, 333 strain (IS>108). The results of the antibacterial screening indicated that only the ethanolic extract of Amphimedon compressa exhibited a weak activity against Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli by the disk diffusion method. In view of these results, the extracts of Amphimedon compressa, Tedania ignis and Dysidea sp. were selected for further studies aiming the isolation and identification of the bioactive compounds with antiproliferative and/or antiprotozoal activities. The relevant anti-herpes activity of the ethanolic extract of Haliclona sp. also deserves special attention, and will be further investigated.

Resumo Este artigo reporta as atividades in vitro antiproliferativa, atiprotozoárica, anti-herpética e antimicrobiana de 32 extratos orgânicos provenientes de 14 esponjas marinhas e 14 corais coletados no litoral nordestino brasileiro. Os extratos etanólicos das esponjas Amphimedon compressa e Tedania ignis, e o extrato acetônico de Dysidea sp. demonstraram resultados promissores em relação aos efeitos antiproliferativos frente as linhagens celulares A549, HCT-8, PC-3 pelo método da sulforrodamina B, mas sem especificidade. Em relação à atividade antiprotozárica, os extratos etanólico de Amphimedon compressa e acetônico e etanólico de Dysidea sp. apresentaram atividade contra Leishmania amazonensis e Trypanosoma cruzi através do método de expressão de β-galactosidase em células THP-1. Na investigação preliminar de atividade antiviral frente ao vírus Herpes simplex tipo 1 (cepa KOS), os extratos etanólicos das esponjas Amphimedon compressa, Haliclona sp. e Chondrosia collectrix inibiram mais de 50% da replicação viral. O extrato etanólico da esponja Haliclona sp. demonstrou resultados promissores para atividade anti-herpética com altos índices de seletividade para as cepas KOS (IS >50) e 29R (IS>79) frente ao VHS-1 e cepa 333 (IS>108) frente ao VHS-2. O extrato etanólico da esponja Amphimedon compressa exibiu uma pequena atividade contra Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli pelo método de difusão em disco. De acordo com os resultados apresentados, os extratos das esponjas Amphimedon compressa, Tedania ignis e Dysidea sp. serão selecionados para futuros estudos de isolamento e identificação dos compostos bioativos para as atividades antiproliferativa e antiprozoárica. O extrato etanólico de Haliclona sp. será investigado por possuir atividade relevante anti-herpética.

Random amplified polymorphic DNA analysis of Trypanosoma cruzi strains.

DNA extracted from 32 isolates of Trypanosoma cruzi was subjected to polymerase chain reaction amplification using 4 arbitrary primers resulting in relatively complex DNA profiles that include polymorphic markers known as random amplified polymorphic DNAs (RAPDs). The RAPD profiles of 18 strains belonging to zymodeme 1 (Z1) collected from various regions of South America exhibited a consistant pattern and 59 (59%) of the bands produced were present in all Z1 strains. A similar level of consistency was seen in the number of bands shared between 5 Z2 strains, 4 ZB strains and 2 ZC strains. A phenetic analysis of the 5 most different Z1 strains based on band sharing showed that their interrelationships mirrored their geographical origin. Comparison of the RAPD profiles of strains from different zymodemes showed that less than 7% of bands of strains in one zymodeme are present in strains of another zymodeme. Analysis of band sharing using bands present in all strains of a given zymodeme showed ZB and ZC to be closely related and Z1 and Z2 to form distinct groups.

The use of RAPDs for the analysis of parasites.

There is a lack of sequence information concerning polymorphic loci in parasite genomes. Thus, the use of arbitrary PCR primers under low temperature annealing conditions to generate random amplified polymorphic DNAs (RAPDs) represents an important approach to the study of the structure of parasite populations, their genetic variation as well as improved diagnosis of the diseases they cause. Following the examination of all variables and their effect on the reproducibility of the reaction, we have established a protocol for the analysis of RAPDs that involves amplification at two separate DNA concentrations followed by polyacrylamide gel electrophoresis and silver staining. We find the technique to be sensitive, reproducible, simple and relatively cheap. It has already provided insight into the genetic variation in populations of schistosomes and trypanosomes and is being used to study various other endemic infections. We also use specific primers under low stringency conditions in situations where the objective of the amplification is the detection of a particular sequence and where normal high stringency conditions give a positive/negative answer such as sex determination or diagnosis of blood born infections. Under low stringency conditions, specific amplification products persist but products of low stringency priming are also apparent and serve as a perfect internal control for negative samples.

The use of RAPDs for the study of the genetic diversity of Schistosoma mansoni and Trypanosoma cruzi.

Arbitrary primers have been used for the production of complex, PCR generated DNA profiles in order to undertake a preliminary random amplified polymorphic DNA (RAPD) analysis of strains (and related species) of two parasitic organisms that are responsible for important diseases endemic in Brazil: Schistosoma mansoni that causes schistosomiasis, and Trypanosoma cruzi that causes Chagas' disease. A relatively low level of polymorphism was found in S. mansoni when strains isolated from different regions of Brazil were compared, with less than 10% of bands exhibiting polymorphism. Comparison of different schistosome species, on the other hand, showed them to be distantly related with very few bands shared by even the more closely related species. Trypanosome strains were found to be much more variable. When strains were compared between zymodemes (groups of parasite strains with the same isoenzyme profiles), a maximum of 7% of bands were found to be common whereas among strains in the same zymodeme a clear characteristic pattern was observed. In the zymodeme most thoroughly studied, it was found that 59% of bands were shared. Band sharing analysis showed that the relationships of strains within a zymodeme correlate with their geographical origin and that the relationship between zymodemes correlates closely with that previously determined by isoenzyme analysis. These preliminary data indicate the ready applicability of RAPD analysis to the study of parasites where largely unexplored genetic variations may have an important bearing on the complexity and diversity of diseases.

Trypanosoma cruzi: parasitaemia produced in mice does not seem to be related to in vitro parasite-cell interaction.

The interaction of Trypanosoma cruzi strains producing subpatent or high parasitaemia in mice with mouse macrophages, Vero and L929 cells was evaluated using tissue culture trypomastigotes. Macrophages were the cells most readily infected while Vero cells presented the highest parasite intracellular multiplication rates. Subpatent strains were equal or more infective than the high parasitaemia. Due to the small number of strains, no correlation could be established between the zymodemes and parasitaemia or parasite-cell interaction in vitro. However parasitaemia in mice does not seem to be related to in vitro parasite-cell interaction.

Differential susceptibility of triatomines of the genus Rhodnius to Trypanosoma rangeli strains from different geographical origins.

The susceptibility of four Rhodnius species to different Trypanosoma rangeli strains was evaluated using both intracoelomic inoculation and oral infection. Rhodnius prolixus, Rhodnius domesticus, Rhodnius neglectus and Rhodnius nasutus were infected with Trypanosoma rangeli Macias (Venezuela), Choachi (Colombia) and SC-58 (Brazil) strains, revealing distinct haemolymph and salivary glands infection rates. The obtained infection rates were revealed to be dependent on the method of infection and the triatomine species. Our results suggest the existence of a high adaptation between the strain and the local vector.

Biological and isoenzymatic characterization of Trypanosoma cruzi strains isolated from sylvatic reservoirs and vectors from the state of Santa Catarina, Southern Brazil.

Sixty eight Trypanosoma cruzi strains were isolated in the state of Santa Catarina, Southern Brazil, from sylvatic reservoirs or naturally infected vectors and characterized by their biological behaviour in mice, morphology of bloodstream forms and isoenzyme profiles. Twenty eight strains were isolated from the triatomine bug (Panstrongylus megistus), 2 from rodents (Echimys dasythrix and Akodon sp) and 38 from opossums (Didelphis marsupialis). The infectivity in mice of 48 T. cruzi strains showed that 2 (4.2%) were of high virulence, 19 (39.6%) of medium virulence, 15 (31.2%) of low virulence and 12 (25.0%) produced subpatent parasitemia in mice. A morphological study of bloodstream trypomastigotes from 8 T. cruzi strains showed a predominance of stout forms. The isoenzyme pattern of 59 T. cruzi strains showed that 54 (91.5%) belonged to zymodeme Z1, 3 (5.1%) to zymodeme Z2 and 2 (3.4%) to mixed zymodemes, Z1 and Z2. All 34 T. cruzi strains analyzed from opossums were Z1. Three out of 5 strains isolated from adults of P. megistus collected inside houses, belonged to zymodeme Z2 and two strains exhibited mixed zymodemes, Z1 and Z2, in 5 out of 6 enzymes studied. Although the State of Santa Catarina is a non endemic region for human Chagas'disease, the presence of zymodeme Z2 parasites in the sylvatic vector, P. megistus, captured in domiciliary environments suggests the possibility of human and/or domestic mammal infection by T. cruzi.

Characterization of Leishmania sp. strains isolated from autochthonous cases of human cutaneous leishmaniasis in Santa Catarina State, southern Brazil.

Four Leishmania sp. samples were isolated from autochthonous human cases of American cutaneous leishmaniasis (ACL) in Santa Catarina State, southern Brazil. These strains were characterized using indirect immunofluorescence with a panel of Leishmania-specific monoclonal antibodies (MAbs), and by PCR amplification and hybridization assay of the mini-exon gene with group specific probes. The results obtained with the MAbs were in agreement with the genetic marker. Two isolates (MHOM/BR/89/JSC89-H1 and MHOM/BR/89/JSC89-H2) were identified as L. (Leishmania) amazonensis and two (MHOM/BR/96/LSC96-H3 and MHOM/BR/97/LSC97-H4) as L. (Viannia) braziliensis. The southernmost autochthonous cases of ACL in Brazil are due to two different Leishmania sp. species, confirming the spreading of ACL on the American continent.

Besnoitia sp. (Protozoa:Toxoplasmatinae) from Akodon montensis (Rodentia:Cricetidae) in Santa Catarina State, Brazil.

Tissue cysts of Besnoitia sp. were found in muscles and several organs from a naturally infected Akodon montensis captured in the rural area of the municipality of Timbó, Santa Catarina State, in southern Brazil. Indirect fluorescence and enzyme-linked immunosorbent assays carried out with sera from mice chronically infected with Toxoplasma gondii and Besnoitia sp. showed, as expected, a stronger reaction against homologous than heterologous antigens. No cross-protection was observed in mice immunized with T. gondii when challenged with Besnoitia sp. This is the first description of a natural infection of A. montensis by parasites of the genus Besnoitia sp. in Brazil.

Characterization of trypanosomes from the subgenus Schizotrypanum isolated from bats, Eptesicus sp. (Chiroptera: Vespertilionidae), captured in Florianópolis, Santa Catarina State, Brazil.

Seven Trypanosoma spp. isolates obtained from bats (Eptesicus sp.) were characterized using experimental infection in mice, triatomines, and culicines; complement lysis; indirect fluorescence assays; as well as isoenzyme and random-amplified polymorphic DNA (RAPD) profiles. The Trypanosoma sp. isolates were compared with Trypanosoma cruzi, Trypanosoma rangeli. and 2 other bat trypanosomes species, Trypanosoma vespertilionis and Trypanosoma hastatus. Trypanosoma sp. isolates were different from the other species in all experiments, except in complement lysis. Experimental infection of triatomines and culicines with Trypanosoma sp. proved to be transitory. These parasites were noninfective for both normal and immunosuppressed mice. Isoenzyme and RAPD profiles obtained for Trypanosoma sp. were quite distinct from T. cruzi and T. rangeli and closely related to T. vespertilionis and T. hastatus. No cross-reaction was observed between sera from mice infected with Trypanosoma sp. and the other trypanosomatids and vice-versa. Trypanosoma sp. induced no protection against T. cruzi infection in mice. The very low, or nonsimilarity between Trypanosoma sp. isolates and the other species used in this study suggests that they might be members of a distinct bat trypanosome species. However, further studies should be done to prove their affinities with Trypanosoma cruzi-marinkellei, another trypanosome species from bats.

Ultrastructure of the salivary glands of Rhodnius domesticus Neiva & Pinto, 1923 (Hemiptera: Reduviidae).

The fine structure of the salivary glands of the triatomine bug Rhodnius domesticus was investigated. Stereomicroscopy and scanning electron microscopy showed that each salivary gland pair contains two close and independent units: the larger is reddish and elongated (principal gland), while the smaller is round and translucent (accessory gland). The accessory gland opens at the base of the main excretion duct, which arises at the medial portion of the principal gland. An accessory duct emerges at the base of the main excretion duct, above the accessory gland opening, and runs towards the digestive tract. Transmission electron microscopy showed that both gland units are formed by a single layer of epithelial gland cells, surrounded by a thick basal lamina containing tracheolae and muscle cell fibers. Adjacent gland cells are interconnected by interdigitations of their lateral plasma membranes and by septate junctions. Microvilli are present at the apical domain of the gland cell plasma membrane, which allow faster diffusion of the saliva towards the gland lumen. Several mitochondria, abundant endoplasmic reticulum profiles and usually one elongated nucleus are observed in the gland cells. According to standard nomenclatures, the salivary gland cells can be classified as type I cells, secreting the saliva into a large gland lumen.