RESUMEN
Chagas disease is a neglected tropical disease caused by Trypanosoma cruzi parasite with an estimated 70 million people at risk. Traditionally, parasite presence in triatomine vectors is detected through optical microscopy which can be low in sensitivity or molecular techniques which can be costly in endemic countries. The aim of this study was to evaluate the ability of a reagent-free technique, the Near Infrared Spectroscopy (NIRS) for rapid and non-invasive detection of T. cruzi in Triatoma infestans body parts and in wet/dry excreta samples of the insect. NIRS was 100% accurate for predicting the presence of T. cruzi infection Dm28c strain (TcI) in either the midgut or the rectum and models developed from either body part could predict infection in the other part. Models developed to predict infection in excreta samples were 100% accurate for predicting infection in both wet and dry samples. However, models developed using dry excreta could not predict infection in wet samples and vice versa. This is the first study to report on the potential application of NIRS for rapid and non-invasive detection of T. cruzi infection in T. infestans in the laboratory. Future work should demonstrate the capacity of NIRS to detect T. cruzi in triatomines originating from the field.
Asunto(s)
Insectos Vectores/parasitología , Espectroscopía Infrarroja Corta/métodos , Triatoma/parasitología , Trypanosoma cruzi/patogenicidad , Animales , Heces/parasitología , Intestinos/parasitología , Límite de Detección , Espectroscopía Infrarroja Corta/normas , Trypanosoma cruzi/aislamiento & purificaciónRESUMEN
Over the last three decades, it has been progressively assumed that morphology has become obsolete for trypanosomatid systematics. Traditional taxonomy, based on the occurrence of specific kinds of cell morphotypes during life cycles and the morphometry of such cells, is often rejected by molecular phylogenies inferred mostly from 18S rDNA alone or combined with GAPDH. In such context, we hypothesized the affinities of 35 representatives of seven trypanosomatid genera from separated and combined cladistics analyses of morphological and 18S matrices. Morphology is shown to be more consistent and to have stronger synapomorphy retention than the 18S data. The strict consensus of cladograms from separated analyses was mostly unresolved, while combined analysis produced a meaningful and robust phylogenetic pattern, as evidenced by partition congruence index, Bremer support and frequencies of groups present/contradicted. The results (1) corroborate the separation of Angomonas and Strigomonas from Crithidia, which is now shown to be monophyletic, (2) support the revalidation of the genus Wallaceina, and (3) place the genera Herpetomonas, Leptomonas and Phytomonas within a single clade. Overall, we demonstrate the belief that morphological characters are inferior to molecular ones for trypanosomatid systematics is a consequence of neglecting their inclusion in phylogenetic analyses.
RESUMEN
Tilapia fingerlings were reared at densities of 90, 120 and 150 fish in circular tanks (0.5m³), submitted to two full water exchanges (0 and 60 minutes), in a raceway system. Costs, profitability and productive performance were evaluated. The incidence of costs (IC) increased with fish stocking density increase, for water exchange in 60 minutes (R$0,98 to 1.07/kg); the best IC was obtained with 120 fish/m³ for water exchange in 30 minutes (R$0,90/kg). The partial net income (PNI) ranged from R$11,11 to R$22,65, respectively for water exchange in 60 minutes/90 fish and for water exchange in 30 minutes/120 fish. In this research, the highest PNI could be R$90,60/m³/year, in two annual yields. The best economic performance occurred in the best productive performance system: 30 minutes/120 fish/m³.
Alevinos de tilápia foram criados nas densidades de 90, 120 e 150 peixes em tanques circulares (0,5m³), submetidos a duas trocas totais de água (30 e 60 minutos), no sistema raceway. Avaliaram-se os custos, a lucratividade e o desempenho produtivo. A incidência de custo (IC) aumentou com o aumento da densidade de estocagem dos peixes, na troca de água feita em 60 minutos (R$0,98 a R$1,07/kg); a melhor IC foi obtida com 120 peixes/m³ na troca de água em 30 minutos (R$0,90/kg). A renda líquida parcial (RLP) variou de R$11,11 a R$22,65, respectivamente, para a troca de água em 60 minutos/90 peixes e para a troca de água em 30 minutos/120 peixes. A maior RLP foi de R$90,60/m³ por ano, extrapolando-se para duas produções/ano. O melhor desempenho econômico ocorreu no tratamento com 120 peixes/m³ e troca de água em 30 minutos, que apresentou também o melhor desempenho produtivo.
RESUMEN
Tilapia fingerlings were reared at densities of 90, 120 and 150 fish in circular tanks (0.5m³), submitted to two full water exchanges (0 and 60 minutes), in a raceway system. Costs, profitability and productive performance were evaluated. The incidence of costs (IC) increased with fish stocking density increase, for water exchange in 60 minutes (R$0,98 to 1.07/kg); the best IC was obtained with 120 fish/m³ for water exchange in 30 minutes (R$0,90/kg). The partial net income (PNI) ranged from R$11,11 to R$22,65, respectively for water exchange in 60 minutes/90 fish and for water exchange in 30 minutes/120 fish. In this research, the highest PNI could be R$90,60/m³/year, in two annual yields. The best economic performance occurred in the best productive performance system: 30 minutes/120 fish/m³.
Alevinos de tilápia foram criados nas densidades de 90, 120 e 150 peixes em tanques circulares (0,5m³), submetidos a duas trocas totais de água (30 e 60 minutos), no sistema raceway. Avaliaram-se os custos, a lucratividade e o desempenho produtivo. A incidência de custo (IC) aumentou com o aumento da densidade de estocagem dos peixes, na troca de água feita em 60 minutos (R$0,98 a R$1,07/kg); a melhor IC foi obtida com 120 peixes/m³ na troca de água em 30 minutos (R$0,90/kg). A renda líquida parcial (RLP) variou de R$11,11 a R$22,65, respectivamente, para a troca de água em 60 minutos/90 peixes e para a troca de água em 30 minutos/120 peixes. A maior RLP foi de R$90,60/m³ por ano, extrapolando-se para duas produções/ano. O melhor desempenho econômico ocorreu no tratamento com 120 peixes/m³ e troca de água em 30 minutos, que apresentou também o melhor desempenho produtivo.