Abundancia y diversidad de vectores (Diptera: Psychodidae) en área de transmisión antigua de Leishmaniasis Cutánea en el nuevo mundo después de la construcción del gasoducto Bolivia-Brasil / Abundance and diversity of vectors (Diptera: Psychodidae) in an old transmission area of cutaneous leishmaniasis in the new world after Bolivia-Brazil gas pipeline construction

The objective of this study was to determine the abundance and diversity of the species and their presumed vectorial role in the transmission of Cutaneous Leishmaniasis (CL). Research on sand flies (Diptera: Psychodidae) was carried out in two municipalities in the Ribeira River Valley in the State of Paraná, southern Brazil. One, Adrianópolis, is an endemic area of CL and the other is a recent outbreak area (Cerro Azul). A total of 432 specimens were collected from residential, peri-domestic and wild environments. According to the data obtained, for each ecotope studied, the statistical analysis has shown that two lines of the Lutzomyia intermedia population coexist and that the quantity of specimens from L. intermedia s.l. is significantly different from L. intermedia s.s. in all environments (χ2=9.943; DF=2; p=0.07). The prevalence of L. intermedia (93.28%) in the ecotopes studied suggests that it is the main vector of leishmaniasis. The succession of vector species and their involvement in the epidemiological cycle of L. braziliensis is discussed in this article(AU)

El objetivo de este trabajo fue determinar la abundancia y diversidad de las especies y su supuesto papel vectorial en la transmisión de Leishmaniasis Cutánea (LC). La investigación sobre flebótomos (Diptera: Psychodidae) se llevó a cabo en dos municipios en el Valle del Río Ribeira en el Estado de Paraná, sur de Brasil. Las regiones estudiadas fueron Adrianópolis, área endémica de LC, y Cerro Azul, que se reporta como zona de brote reciente. Se recolectaron un total de 432 especímenes de ambientes residenciales, peri-domésticos y silvestres. El análisis estadístico realizado, a partir de los datos obtenidos para cada ecotopo estudiado, mostró que coexistían dos linajes de la población de Lutzomyia intermedia y que la cantidad de especímenes de L. intermedia s.l. fue significativamente diferente de L. intermedia s.s. en todos los entornos (χ2=9,943; GL=2; p=0,07). La prevalencia de L. intermedia (93,28%) en los ecotopos estudiados sugiere que es el principal vector de la leishmaniasis. La sucesión de especies de vectores y su participación en el ciclo epidemiológico de L. braziliensis se discute en este artículo(AU)

Limiar de positividade e sensibilidade dos métodos de Faust et al. e Lutz para detecção de cistos de Giardia duodenalis / Positivity threshold and sensitivity of methods of Faust et al. and Lutz for detection of Giardia duodenalis cysts

Objetivo: O presente estudo teve como objetivo determinar e comparar o limiar de positividade e a sensibilidade dos métodos de centrífugo-flutuação em sulfato de zinco (Faust et al.) e sedimentação espontânea (Lutz) para o diagnóstico de cistos de Giardia duodenalis. Métodos: Para obtenção de amostras fecais com quantidades conhecidas de cistos de G. duodenalis, amostras positivas para o parasito foram purificadas e quantificadas, e posteriormente alíquotas com diferentes quantidades foram adicionadas a amostras fecais negativas para parasitos. Após a contaminação de oito amostras negativas com quantidades variando entre 1.000 e 200.000 cistos por grama de fezes (c/g/f), as mesmas foram submetidas aos métodos de Faust et al. e Lutz, onde o primeiro se mostrou mais sensível para a detecção de cistos de G. duodenalis. Resultados: O limiar de positividade do método de Faust et al. foi de 11.000 c/g/f, e do método de Lutz foi de 100.000 c/g/f, portanto, cargas parasitárias inferiores a esses limiares levariam a resultados falso-negativos. Conclusão: O método de Lutz não é adequado para o diagnóstico de giardíase, portanto deve ser sempre utilizado em conjunto com o método de Faust et al.

Objective: The present study aimed to determine and compare the positivity threshold and sensitivity of the methods of zinc sulfate centrifugal flotation (Faust et al.) and spontaneous sedimentation (Lutz) for the diagnosis of Giardia duodenalis. Methods: To obtain fecal samples containing known amounts of G. duodenalis cysts, the samples with the parasite were purified and quantified, then aliquots with different amounts were added to fecal samples negative for parasites. After the contamination of eight negative samples with amounts ranging between 1.000 and 200.000 cysts per gram of feces, they were subjected to methods of Faust et al. and Lutz, where the first was more sensitive for the detection of G. duodenalis cysts. Results: The positivity threshold of the method of Faust et al. was 11.000 c/g/f, and the method of Lutz was 100.000 c/g/f, so parasitic loads below those thresholds would lead to false-negative results. Conclusion: The method of Lutz is not suitable for the diagnosis of giardiasis, therefore must always be associated with the method Faust et al.

Trypanosoma cruzi vector infection rate is underestimated in some localities in the state of Bahia

Bahia was the last Brazilian state declared free of Chagas disease transmission by Triatoma infestans in 2006. The program designed to control vector transmission of Chagas is currently active, and all potential triatomines collected by the Bahia State Department of Health officials are most frequently diagnosed as negative for Trypanosoma cruzi when analyzed by the conventional parasitological direct method. The aim of the current study was to investigate whether triatomines from Bahia are free of T. cruzi infection using a more sensitive diagnostic methodology, namely the kinetoplastid-DNA polymerase chain reaction (kDNA-PCR). With the help of health officials, 51 triatomines were analyzed from peridomicile areas within the central north region of the state of Bahia. The majority (60.8%) were Triatoma brasiliensis, 29.4% were Triatoma pseudomaculata, and 9.8% were unidentified nymphs. Only one insect tested potentially positive for T. cruzi by the conventional parasitological direct method, and 31.4% were positive for T. cruzi DNA by kDNA-PCR. Almost half the infected insects (41.9%) were T. brasiliensis, a species with high potential for T. cruzi transmission. These results demonstrate that the number of infected triatomines with high transmission potential of T. cruzi may be greater than expected in four localities in the state of Bahia

Detection of Streptococcus mutans using padlock probe based on Rolling Circle Amplification (RCA)

The aim of this study was to develop and evaluate a padlock probe based on the Rolling Circle Amplification (RCA), which targeted to 16S-23S rDNA region of S. mutans. The specificity of developed padlock probe was tested for DNA within a panel strains, including S. mutans isolated from the saliva and reference strains of the genus Streptococcus, as well as total DNA samples of biofilm and saliva. The results were positive either for DNA samples of S. mutans or DNA samples recovered from the biofilm and saliva revealing the specificity of designed padlock probe. The padlock probe based on the RCA was proved to be an effective, reproducible method for S. mutans detection and demonstrated the possibility of a rapid detection and accurate identification of S. mutans infection.

High occurrence of Calodium hepaticum (syn. Capillaria hepatica) spurious infection in a village in the Atlantic Forest of southern Brazil

Calodium hepaticum (syn. Capillaria hepatica) is a nematode of the Capillariidae family that infects rodents and other mammals. In Brazil, human spurious infections of C. hepaticum have been detected in indigenous or rural communities from the Amazon Basin, but not in the southern states of the country. Here, we report the highest occurrence (13.5% of 37 residents) of C. hepaticum human spurious infection detected in Brazil and the first record in a southern region, Guaraqueçaba. The finding is explained by the area being located in the Atlantic Forest of the state of Paraná, surrounded by preserved forests and because the inhabitants consume the meat of wild mammals.

Phenetic analysis of Panstrongylus megistus Burmeister, 1835 (Hemiptera: Reduviidae: Triatominae) in the State of Paraná-Brazil

Panstrongylus megistus is an important Chagas Disease vector and is said to be one of the species that might replace Triatoma infestans as the main vector of that disease in Brazil. The different degrees of P. megistus domiciliation in Brazil and its epidemiological relevance draw forth the need for the development of genetic studies that make it possible to analyze and understand the interchange of individual and gene fluxes among different populations. Thus, the present work aimed at studying the genetic variability of P. megistus in the State of Paraná - south of Brazil- and at comparing it with populations of the same species from five other states in Brazil (SP, MG, SC, RS, SE). In order to attain the proposed objective, 25 populations were studied using fifteen isoenzymatic systems (6PGD, G6PD, ME¹, ME², ICD, PGM, GPI, GOT¹, GOT², NP¹, NP², DIA, MPI, F, and MDH). The phenetic analysis allowed the individuation of 22 electromorphs and five zymodemes. The G6PD enzyme was the only polymorphic one presenting four electromorphs for the studied populations, all of them described for the State of Paraná-BR. The P. megistus populations from other states grouped with those from Paraná-BR, evidencing a low genetic variability in that species. Despite the existing geographic barriers, sub-samples - away from one another by at most 570km - were grouped in one and the same zymodeme. The epidemiological implications of such results are discussed in the present work.

Panstrongylus megistus é um importante vetor da Doença de Chagas e é apontado como uma das espécies com potencial para substituir Triatoma infestans como principal vetor desta doença no Brasil. Os diferentes graus de domiciliação por P. megistus - no Brasil - e sua importância epidemiológica evocam a necessidade de estudos com bases genéticas que possibilitem analisar e compreender os intercâmbios de indivíduos e os fluxos gênicos entre as distintas populações. Assim, o presente trabalho tem como objetivo estudar a variabilidade genética de P. megistus no Estado do Paraná e compará-los com populações da mesma espécie de cinco estados do Brasil (SP, MG, SC, RS, SE). Para atingir o objetivo proposto, 25 populações foram estudadas empregando quinze sistemas isoenzimáticos (6PGD, G6PD, ME¹, ME², ICD, PGM, GPI, GOT¹, GOT², NP¹, NP², DIA, MPI, FH e MDH). A análise fenética permitiu a individualização de 22 eletromorfos e quatro zimodemas. A enzima G6PD foi a única polimórfica que apresentou quatro eletromorfos para as populações estudadas, todas descritas para o Estado do Paraná. As populações de P. megistus procedentes dos outros estados agruparam-se com as do Paraná, demonstrando haver baixa variabilidade genética na espécie. Apesar das barreiras geográficas existentes, sub-amostras - distantes entre si por até 570 km - ficaram reunidas num mesmo zimodema. As implicações epidemiológicas destes resultados são discutidas no presente trabalho.