Accumulation of oocysts of Cryptosporidium parvum in Biomphalaria glabrata (Pulmonata: Planorbidae) under experimental conditions

Abstract INTRODUCTION: Cryptosporidium oocysts are easily transported to various aquatic environments. The objective of this study was to evaluate B. glabrata mollusks exposed to food containing C. parvum oocysts. METHODS: Six experimental groups were used with B. glabrata either exposed or not to C. parvum oocysts. Microscopic and molecular diagnostics were conducted in water samples and tissues of B. glabrata. RESULTS: By light microscopy, C. parvum oocysts were identified in the water of the exposed groups. C. parvum DNA was not detected in water but was detected in tissue samples. CONCLUSIONS: Further studies should be conducted under natural conditions.

Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails

ABSTRACT The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

Alterations in the oxidative metabolism of Rhipicephalus (Boophilus) microplus ticks in response to exposure to the insect growth regulator fluazuron / Alterações no metabolismo oxidativo de carrapatos Rhipicephalus (Boophilus) microplus em resposta à exposição ao regulador de crescimento fluazuron

Abstract Aiming to characterize the potential off-target effects of fluazuron on ticks, biochemical analyses were conducted to evaluate changes in the carbohydrate metabolism of Rhipicephalus (Boophilus) microplus ticks after exposure to fluazuron. Hemolymph and fat body were collected from female ticks before and after (4, 8 and 15 days) exposure to fluazuron. Spectrophotometric analyses were done to quantify glucose concentration and lactate dehydrogenase (LDH) activity in the hemolymph and the concentration of glycogen in the tick’s fat body. High Performance Liquid Chromatography (HPLC) was employed to determine the concentration of carboxylic acids in the hemolymph and to evaluate changes in intermediary metabolic processes requiring oxygen consumption. Increases in the levels of LDH activity and lactic acid concentration indicated that fluazuron enhanced fermentative metabolism in ticks. Exposure to fluazuron was also found to increase glucose concentrations in the hemolymph over time, although no significant differences were noted daily. In addition to expanding the body of knowledge about the mode of action of fluazuron, investigations into these mechanisms may also be useful in discovering new and as yet unexplored secondary effects.

Resumo Com o objetivo de caracterizar os efeitos não-alvo da ação do fluazuron, foram realizados testes bioquímicos para analisar possíveis alterações no metabolismo de carboidratos em carrapatos Rhipicephalus (Boophilus) microplus após sua exposição ao composto. Foram coletados hemolinfa e corpo gorduroso de fêmeas ingurgitadas antes e após (4, 8 e 15 dias) a exposição ao fluazuron. Análises espectrofotométricas foram usadas para quantificar a concentração de glicose e a atividade da lactato desidrogenase (LDH) na hemolinfa e concentração de glicogênio no corpo gorduroso. Cromatografia Líquida de Alta Eficiência (CLAE) foi usada para determinação das concentrações de ácidos carboxílicos na hemolinfa e avaliar possíveis alterações em metabolismo intermediário em relação ao consumo de oxigênio. Aumento na atividade de LDH e concentração de ácido lático indicaram que o fluazuron pode regular o metabolismo fermentativo em carrapatos. A exposição ao fluazuron também aumentou a concentração de glicose na hemolinfa, apesar de não ter havido diferença significativa na comparação entre as médias no mesmo dia de avaliação. Além de aumentar o conhecimento sobre o modo de ação do fluazuron, investigações sobre tais mecanismos também são úteis no descobrimento de novos efeitos secundários ainda não explorados.

Histopathological changes in the kidneys of vertebrate hosts infected naturally and experimentally withParatanaisia bragai (Trematoda, Digenea)

Paratanaisia bragai is a trematode parasite that reaches sexual maturity in the kidney collecting ducts of domesticated and wild fowl and whose intermediate hosts are the snails Subulina octona and Leptinaria unilamellata. There are some discrepancies in descriptions of the pathology of this parasite in bird kidneys. Therefore, the purpose of this study was to analyze the kidneys of rock pigeons (Columba livia) naturally infected and of chickens (Gallus gallus) experimentally infected with Paratanaisia bragai, by means of macroscopic observation and by light and scanning electron microscopy. Both bird species showed significantly dilated collecting ducts. In addition, lymphocyte infiltration was observed in the kidneys of C. livia and metaplasia in the epithelial lining of the kidney collecting ducts of G. gallus.

Paratanaisia bragai é um trematódeo que atinge sua maturidade sexual nos ductos coletores de rins de aves domésticas e silvestres, tendo os moluscos Subulina octona e Leptinaria unilamellata como hospedeiros intermediários. A patologia descrita no rim das aves apresenta uma série de divergências. Dessa forma, o presente estudo teve como objetivo analisar rins de Columba livia, naturalmente infectada, e de Gallus gallus infectados experimentalmente por Paratanaisia bragai. Através das análises, verificaram-se alterações macroscópicas, por microscopia de luz e eletrônica de varredura, sendo caracterizada significativa dilatação dos túbulos coletores. Essas alterações foram observadas nas aves infectadas naturalmente e experimentalmente. Por outro lado, foi observada infiltração linfocitária nos rins de C. livia, naturalmente infectada, e ocorrência de metaplasia no revestimento epitelial dos túbulos coletores dos rins de G. gallus, experimentalmente infectados.

Biochemical and histological changes in liver of Nectomys squamipes naturally infected by Schistosoma mansoni / Alterações na bioquímica e histologia do fígado de Nectomys squamipes naturalmente infectado por Schistosoma mansoni

The South American water rat Nectomys squamipes is a wild mammal reservoir of Schistosoma mansoni in Brazil. In the present study, wild rodents were collected in the field and categorized into two groups: infected and uninfected by S. mansoni. Blood was collected to analyze changes in the serum glucose level (mg/dL) and liver fragments were used to determine the hepatic glycogen content (mg of glucose/g tissue). The histological examination showed inflammatory granulomatous lesions in different phases of development in the liver of rodents naturally infected with S. mansoni, in some cases with total or partial occlusion of the vascular lumen. Early lesions were characterized by the presence of inflammatory infiltrate around morphologically intact recently deposited eggs. Despite the significance of these histological lesions, the biochemical changes differed in extent. N. squamipes naturally infected by S. mansoni showed no variation in hepatic glycogen reserves. These findings were accompanied by a significant increase in plasma glucose contents, probably as a consequence of amino acids deamination, which are degraded, resulting in the formation of intermediates used as precursors for the glucose formation, without compromising the reserves of liver glycogen. In the wild, naturally infected N. squamipes can maintain S. mansoni infections without undergoing alterations in its carbohydrate metabolism, which minimizes the deleterious effects of S. mansoni.

Nectomys squamipes é um mamífero silvestre reservatório de Schistosoma mansoni no Brasil. No presente estudo, os roedores silvestres, colhidos no campo, foram classificados em dois grupos: infectado e não infectado por S. mansoni. O sangue foi colhido para análise da alteração no nível de glicose sérico (mg/dL) e fragmentos de fígado foram usados para determinar o conteúdo de glicogênio hepático (mg de glicose/g tecido). A análise histológica demonstrou lesões granulomatosas em diferentes fases de desenvolvimento no tecido hepático dos roedores naturalmente infectados com S. mansoni, localizados principalmente na região periportal, com total ou parcial oclusão do lúmen vascular. As lesões foram caracterizadas por presença de infiltrado inflamatório ao redor de ovos morfologicamente intactos recentemente depositados. Apesar da grande significância das lesões histológicas, as alterações bioquímicas não diferiram no mesmo grau. N. squamipes naturalmente por S. mansoni não apresentaram variação na reserva de glicogênio hepático. Esses achados foram acompanhados pelo aumento significativo nos conteúdos de glicose plasmática, provavelmente como consequência ao processo desaminativo de aminoácidos, que passam a ser degradados notadamente para a formação de glucose, sem contudo comprometer a reserva de glicogênio hepático. Em condições naturais a infecção de S. mansoni pode ser mantida usando N. squamipes como hospedeiro definitivo, sem alterações significativas nos conteúdos de glicogênio hepático, minimizando os efeitos deletérios causados por S. mansoni nos roedores N. squamipes naturalmente infectados.

Cyathostomin larvae: presence on Brachiaria humidicola grass during the rainy and dry seasons of Brazil / Larvas de ciatostomíneos: disponibilidade em gramínea Brachiaria humidicola nas estações chuvosa e seca do Brasil

The presence of cyathostomin larvae is directly associated to climatic conditions of each region. This study aimed to evaluate the ecology of infective larvae on Brachiaria humidicola during the dry and rainy seasons from October 2007 to September 2008 in a tropical region, Rio de Janeiro state, southeastern Brazil. Stools were collected from the rectum of horses naturally infected with cyathostomins at the beginning of the rainy season (October to March) and dry season (April to September). They were divided into four samples of 500 g and deposited on a grass patch of B. humidicola. Seven days later and every 15 days thereafter samples of feces and grass were collected and processed by the Baermann technique. The mean number of larvae recovered from the grass varied according to the season, with greater recovery of larvae during the peak of the dry season (14,700 L3.kg-¹ DM). There was a statistically significant difference between L3 recovered from feces and grass, but not between L3 recovered from the grass base and apex. These results show that the region’s climate favors the development and survival of infective cyathostomin larvae throughout the year, with a greater number of larvae during the dry season.

A disponibilidade de larvas de ciatostomíneos está diretamente relacionada com as condições climáticas de cada região. Para avaliar o comportamento das larvas infectantes nos períodos seco e chuvoso em gramínea Brachiaria humidicola, realizou-se um estudo, no período de outubro/2007 a setembro/2008, na região da Baixada Fluminense, RJ, de clima tropical. Amostras de fezes foram coletadas diretamente do reto de equinos naturalmente infectados por ciatostomíneos, no início do período chuvoso (outubro a março) e seco (abril a setembro), divididas em quatro amostras de 500 g e depositadas em um canteiro formado por gramínea B. humidicola. Sete dias após o depósito e, posteriormente, a cada 15 dias, amostras de fezes e gramíneas, foram coletadas às 8 horas e processadas pela técnica de Baermann. O número médio de larvas recuperadas da gramínea variou conforme os períodos, ocorrendo maior recuperação no ápice do período seco (14.700 L3.kg-1. MS). Diferença significativa ocorreu entre a contagem de L3 recuperadas das fezes e gramínea e não significativa entre as de L3 recuperadas nas duas alturas da gramínea. Concluiu-se que as condições climáticas da região favorecem o desenvolvimento e a sobrevivência de larvas infectantes de ciatostomíneos durante todo o ano, com maior disponibilidade no período seco.

A Mobilização do cálcio em biomphalaria glabrata exposta a diferentes quantidades de carbonato de cálcio / Calcium mobilization in biomphalaria glabrata exposed to different quantities of calcium carbonate

O cálcio é essencial na vida dos moluscos, pois está relacionado com a formação da concha e com vários processos metabólicos fundamentais para manter a sua homeostase. O objetivo deste trabalho foi verificar a mobilização do cálcio na hemolinfa e na concha de Biomphalaria glabrata exposta a diferentes soluções de carbonato de cálcio. Para este estudo, foram utilizados caramujos com 60 dias de vida, distribuídos em cinco grupos, quatro expostos a diferentes soluções (20, 40, 60 e 80mg/L) de carbonato de cálcio e um controle. O tempo total de exposição foi de 45 dias. Quinzenalmente, os caramujos eram sacrificados por meio de punção cardíaca para extração da hemolinfa. A concentração de cálcio na hemolinfa foi determinada usando-se kits de diagnóstico (Doles Reagentes) e o conteúdo de cálcio nas conchas, pelo método de volumetria de complexação modificada. Os resultados demonstraram que houve aumento de cálcio na hemolinfa e diminuição de cálcio na concha aos 15 dias de exposição a 20mg/L de carbonato de cálcio. Nos demais grupos expostos, verificou-se que a concentração de cálcio na hemolinfa é inversamente proporcional à quantidade de cálcio na concha. Concluiu-se que, em moluscos expostos a diferentes quantidades de cálcio, ocorre uma mobilização frequente do cálcio na hemolinfa e na concha de acordo com a quantidade de cálcio disponível.

Calcium is essential to mollusk’s life, because is associated with shell formation and metabolic processes that are essential to maintain their homeostasis. The aim of this work was to verify the mobilization of calcium in the haemolymph and shell of Biomphalaria glabrata (strain BH) exposed to different calcium carbonateconcentrations. Sixty days old snails were used for this study, distributed in five groups: four groups exposed to different concentrations (20, 40, 60, 80 mg/L) of calcium carbonate and one control group. The exposition time was forty-five days. Fortnightly, the snails were sacrificed by cardiac puncture for haemolymph extraction. The concentration of calcium was determined in the haemolymph, using diagnosis kits (Doles Reagentes®) and for the calcium content in the shell,a modified volumetric method of complexing was employed. The results showed an increase of the calcium content in haemolymph and a decrease in shell of snails exposed to 15 days of 20mg/L of calcium carbonate. In the other exposed groups, the calcium concentration in the haemolymph was inversely proportional to the amountof calcium in the shell. We conclude that in snails exposed to different amounts ofcalcium, mobilization in the hemolymph and in the shell occurs according to theamount of calcium available.

Carbohydrate metabolism alterations in Biomphalaria glabrata infected with Schistosoma mansoni and exposed to Euphorbia splendens var. hislopii latex

This paper evaluates the alterations in the glycogen content of tissues (digestive gland and cephalopedal mass) and glucose in the haemolymph of Biomphalaria glabrata BH strain infected with Schistosoma mansoni BH strain and exposed to the latex of Euphorbia splendens var. hislopii. A reduction in the glycogen deposits was observed in infected snails exposed and not exposed to latex. However, the exposure to latex caused a greater depletion of the glycogen levels in both sites analysed, especially from the third week onward. The utilisation of latex as a molluscicide to control the population of infected B. glabrata selectively is proposed.

An improvement of calcium determination technique in the shell of molluscs

The complexometric method is usually applied to quantitative calcium determination in different materials; however the application of this method to calcium determination in molluscs shells infers significant interferences to the results. The snail Bradybaena similaris, a terrestrial gastropod, was used as experimental model to the improvement of this method. The shells were calcinated and dissolved in nitric acid, the hydrogen peroxide was also used to clarify the medium after the acid addition. The calcination procedure and the use of nitric acid reduced the significantly the interferences, allowing a major degree of destruction of the organic substances of the shell. The improvement of the calcium determination technique usually employed showed calcium content of 874.24 ± 56.617 mg of CaCO3/g of ash in comparison to the conventional technique that allowed the determination of 607.79 ± 67.751 mg of CaCO3/g of shell, wet weight.

O método complexométrico é geralmente utilizado para determinação quantitativa de cálcio em diferentes materiais; contudo a aplicação deste método à determinação de cálcio em conchas de moluscos infere significativas interferências aos resultados obtidos. O molusco Bradybaena similaris, um gastrópode terrestre, foi utilizado como modelo para aperfeiçoar este método. As conchas foram calcinadas e dissolvidas em ácido nítrico, o peróxido de hidrogênio também foi empregado para clarificar o meio após a adição do ácido. O processo de calcinação e o uso do ácido nítrico reduziram significativamente as interferências, permitindo um maior grau de destruição das substâncias orgânicas da concha. O aperfeiçoamento da técnica para determinação de cálcio empregado resultou em uma quantidade maior de cálcio igual a 874.24 ± 56.617 mg de CaCO3/g de cinzas em comparação com a técnica convencional que permitiu a determinação de 607.79 ± 67.751 mg de CaCO3/g de concha, peso fresco.

Forma isolada do miocárdio não-compactado / Isolated noncompaction of the myocardium

Miocárdio não-compactado (MNC) é uma cardiopatia congênita com incidência rara, sendo o seu primeiro relato feito há 15 anos e com poucos casos publicados. O objetivo deste artigo é descrever um caso de MNC. É apresentada descrição dos achados clínicos e dos exames complementares de imagem de uma paciente com 37 anos, portadora de MNC de forma isolada. A paciente queixava-se de palpitações, apresentava extra-sístoles no exame clínico e, no eletrocardiograma de 12 derivações, bigeminismo ventricular. Realizou ecocardiograma Doppler tridimensional que revelou a presença de numerosas e proeminentes trabéculas com recessos intertrabeculares profundos com fluxo de sangue que se comunicavam com a cavidade ventricular e que se acentuavam na região septo-apical. A ressonância nuclear magnética de coração corroborou os achados do ecocardiograma. A clínica e os resultados dos exames complementares dessa paciente confirmaram o diagnóstico de MNC de forma isolada. O conhecimento de achados ecocardiográficos dessa doença permite um diagnóstico precoce e tratamento mais adequado.

Noncompacted myocardium (NCM) is a rare congenital heart disease, first reported 15 years ago and with only a few published cases. In this paper, we report the main clinical findings and the complementary exams that suports NCM diagnostic. Discretion of anamnesis and physical examination, together with characteristic image complementary exams findings of symptomatic NCM. (Case report). The clinical assessment and the electrocardiogram at the admission found bigeminism ventricular. A tridimensional Doppler echocardiogram was performed and showed numerous and prominent myocardium trabeculations and deep intertrabecular recess filled with blood that communicate with the ventricular cavity, more present in the septal-apical area. Magnetic resonance imaging supported the echocardiographic findings and ruled out the presence of others cardiac malformations. The clinical and imaging complementary exams filled out the touchstones that support isolated NCM diagnose. Is important to know that suggestive NCM findings permits an earlier diagnostic and treatment.

Physiological changes in Biomphalaria glabrata say, 1818 (Pulmonata: Planorbidae) caused by sub-lethal concentrations of the latex of Euphorbia splendens var. hislopii N.E.B (Euphorbiaceae)

Molluscides have been used as one of the strategies to control schistosomiasis. Many plant extracts with molluscidal effects have been tested, but the action of the latex of Euphorbia splendens var. hislopii is considered the most promising because it meets the recommendations of the World Health Organization (WHO). The objective of this study was to determine the lethal dose and identify the effects of the different doses of latex of E. splendens var. hislopii on the physiology of Biomphalaria glabrata submitted to treatment for 24 h. The concentrations of glucose, uric acid and total proteins in the hemolymph and of glycogen in the digestive gland and cephalopodal mass were determined. The LD50 value was 1 mg/l. The highest escape index was found to be at a concentration of 0.6 mg/l. The results showed that the latex of E. splendens var. hislopii caused a sharp reduction in the reserves of glycogen in the digestive gland and elevation of the protein content in the hemolymph of B. glabrata.

Aminotransferases activity in the hemolymph of Bradybaena similaris (Gastropoda, Xanthonychidae) under starvation

Aminotransferases (GOT and GPT) activities in the hemolymph of Bradybaena similaris under experimental condition of starvation were studied. At the 10th day of starvation, GOT activity was 416.6 percent higher than that observed in the fed snails, being reduced and ranging values near to that shown by the control group onwards. GPT activity only varied significantly at the day-30 of starvation. The results were discussed

The influence of starvation and Eurytrema coelomaticum infection on the nitrogenous products of degradation in the hemolymph of Bradybaena similaris

The urea and uric acid contents in the hemolymph of Bradybaena similaris were analyzed under starvation and Eurytrema coelomaticum infection during 30 days. The urea and uric acid contents in the uninfected and fed snails were 15.090 mg/dl and 9.399 mg/dl, respectively, being the urea/uric acid ratio 1.6. The urea content in starved snails increased to a maximum of 363.237 mg/dl at 15 days, and the uric acid varied to a maximum of 11.470 mg/dl. The urea content in infected snails was reduced to a minimum of 2.123 mg/dl at 30 days of infection and the uric acid increased significatively at 25 days post exposure, being 13.820 mg/dl. A significative relation was not observed between the time of starvation and time of E. coelomaticum infection and the uric acid content in the hemolymph of B. similaris.

O conteúdo de uréia e de ácido úrico na hemolnfa de Bradybaena similaris foi analisado em função da inanição e da infecção com Eurytrema coelomaticum ao longo de 30 dias. O conteúdo destas substâncias em moluscos não infectados e alimentados foi, respectivamente, 15.090 mg/dl e 9.399 mg/dl, sendo a relação uréia/ácido úrico 1.6. A concentração de uréia nos moluscos em inanição aumentou até um valor máximo de 363.237 mg/dl, aos 15 dias de inanição e o conteúdo de ácido úrico variou até um valor máximo de 11.761 mg/dl, aos 10 dias de jejum. A concentração de uréia em moluscos infectados foi reduzida até um valor mínimo 2.123 mg/dl, aos 30 dias de infecção, e o conteúdo de ácido úrico aumentou significativamente aos 25 dias de infecção, sendo 13.820 mg/dl. Não foram observadas relações significativas entre o tempo de inanição e o tempo de infecção com estágios larvais de E. coelomaticum e o conteúdo de ácido úrico na hemolinfa de B. similaris.

Eurytrema coelomaticum: influence of the infection on the reproduction and nucleic acids contents in the albumen gland and ovotestis of Bradybaena similaris

The number of eggs laid per snail in Bradybaena similaris and the nucleic acids (DNA and RNA) in the albumen gland and ovotestis were quantified in snails infected with sporocysts of the digenetic trematode Eurytrema coelomaticum. The total number of eggs laid per mollusc was reduced by 96.32 por cento at the end of the larval development. The DNA concentration increased by 700 por cento and the RNA concentration was reduced by 8,38 por cento by the time when the daughter sporocysts of E. coelomaticum were released from B. similaris. The relation between these values and the inhibition of the reproduction observed in infected molluscs is discussed.

Eurytrema coelomaticum (Digenea, Dicrocoeliidae): the effect of infection on carbohydrate contents of its intermediate snail host, Bradybaena similaris (Gastropoda, Xanthonychidae)

The interface Eurytrema coelomaticum/Bradybaena similaris was studied by quantifying the amount of glucose on the hemolymph and the content of glycogen in the cells of the digestive gland and the cephalopedal mass of infected and uninfected snails. Samples were analyzed on days 0, 30, 90 and 150 post-infection. The infected snails had less glucose in the hemolymph, with a reduction of 67.05 por cento at 30 days, and 62.09 por cento at 90 days post-infection. The reduction in glycogen content was 86.41 por cento in the digestive gland and 79.1 por cento in the cephalopedal mass at 30 days, and 92.71 por cento and 90.89 por cento in these organs respectively at 90 days post-infection. It is proposed that the sporocysts absorb glucose directly from the hemolymph.