Changes in hemocytes of Biomphalaria glabrata infected with Echinostoma paraensei and exposed to glyphosate-based herbicide.

The immune system of snails is highly sensitive to pollutants, which can suppress its immune response. We investigated the effects of exposure to the glyphosate-based herbicide Roundup® Original on the snail Biomphalaria glabrata infected by the platyhelminth Echinostoma paraensei by evaluating changes in the snail's internal defense system. Four cohorts were studied: control group, infected snails, snails treated with Roundup®, and snails infected and treated with Roundup®. The hemocyte viability was assessed, morphological differentiation of cells was observed and flow cytometry was performed to determine the morphology, viability and the lectin expression profiles. The frequencies of dead hemocytes were lower in the infected group and higher in both pesticide treated groups. Three cell types were identified: blast-like cells, hyalinocytes and granulocytes. The highest number of all types of hemocytes, as well as the highest number of dead cells, were observed in the infected, pesticide-treated group. The association between infection and herbicide exposure greatly increased the frequency of dead hemocytes, suggesting that this condition impairs the internal defense system of B. glabrata making the snails more vulnerable to parasitic infections.

Morphological effects on helminth parasites caused by herbicide under experimental conditions.

Helminth parasites have been studied as potential accumulators for different pollutants. Echinostoma paraensei is a foodborne trematode whose vertebrate host, the rodent Nectomys squamipes, is naturally exposed to environmental pesticides. However, little information exists regarding the pesticide's effects on helminths. This study investigated the morphological effects on the trematode, E. paraensei, after experimental Roundup® herbicide exposure, in concentrations below those recommended for agricultural use. After two hours of exposure, scanning electron microscopy (SEM) showed changes to the tegument, such as furrowing, shrinkage, peeling, spines loss on the peristomic collar, and histopathological evidence of altered cells in the cecum and acinus vitelline glands with vacuoles and structural changes to the muscular layers. Glycidic content was decreased, primarily in the connective tissue. As E. paraensei is an intestinal parasite of the semi-aquatic wild rodent, N. squamipes, it is predisposed to pesticide exposure resulting from agricultural practices. Therefore, we emphasize the need to evaluate its impact on helminth parasites, due to their pivotal role in regulating host populations.

Morphological effects on helminth parasites caused by herbicide under experimental conditions / Efeitos morfológicos em helminto parasito causado por herbicida em condições experimentais

Abstract Helminth parasites have been studied as potential accumulators for different pollutants. Echinostoma paraensei is a foodborne trematode whose vertebrate host, the rodent Nectomys squamipes, is naturally exposed to environmental pesticides. However, little information exists regarding the pesticide's effects on helminths. This study investigated the morphological effects on the trematode, E. paraensei, after experimental Roundup® herbicide exposure, in concentrations below those recommended for agricultural use. After two hours of exposure, scanning electron microscopy (SEM) showed changes to the tegument, such as furrowing, shrinkage, peeling, spines loss on the peristomic collar, and histopathological evidence of altered cells in the cecum and acinus vitelline glands with vacuoles and structural changes to the muscular layers. Glycidic content was decreased, primarily in the connective tissue. As E. paraensei is an intestinal parasite of the semi-aquatic wild rodent, N. squamipes, it is predisposed to pesticide exposure resulting from agricultural practices. Therefore, we emphasize the need to evaluate its impact on helminth parasites, due to their pivotal role in regulating host populations.

Resumo Helmintos parasitos tem sido estudados como acumuladores potenciais para diferentes poluentes. O trematódeo E. paraensei tem como hospedeiro vertebrado o roedor Nectomys squamipes naturalmente exposto a pesticidas no meio ambiente. No entanto, pouca informação está disponível sobre os efeitos dos pesticidas em helmintos parasitos. O presente estudo investigou, em condições experimentais, os efeitos morfológicos no trematódeo E. paraensei após a exposição ao herbicida Roundup®, em concentrações abaixo das recomendadas para a utilização agrícola. A microscopia eletrônica de varredura (MEV) mostrou após duas horas de exposição, alterações no tegumento, como enrugamento, contração e descamação com perda de espinhos no colar peristômico e análise histopatológica evidenciou células do ceco alteradas, as glândulas vitelínicas com vacúolos e mudanças estruturais nas camadas musculares. Diminuição do conteúdo glicídico, principalmente no tecido conjuntivo, também foi observado. Considerando a predisposição à exposição a pesticidas agrícolas de N. squamipes infectado por E. paraensei, são necessários estudos para avaliar o impacto de tais resíduos frente aos helmintos e seus hospedeiros.

Intestinal parasitic infections in a lowincome urban community: prevalence and knowledge, attitudes and practices of inhabitants of Parque Oswaldo Cruz, Rio de Janeiro, Brazil

Intestinal parasitic infections (IPIs) are present in Brazil from upper-to low-income communities, with varying infection estimates; however, they affect those living in urban and rural poverty more severely, without adequate access to consistently safe drinking water, sanitation, waste disposal, medical access and education. Estimates show the need for establishing infection prevalence and socioeconomic features, along with population knowledge, attitudes and practices (KAP) regarding IPIs. The purpose of this study is to assess the prevalence and KAP regarding IPIs of residents of an urban low-income community (Parque Oswaldo Cruz/Amorim) of the Complexo de Manguinhos, Rio de Janeiro, Brazil. The Lutz sedimentation technique was used for parasite detection (n=1,121) and, to obtain data on community KAP regarding IPIs, a KAP survey, adapted from Mello et al. was applied (n=505). An overall prevalence of 20.7% was detected with protozoa composing 92.9% (n=235) of the positive samples. Questionnaires revealed generally correct knowledge but with several inconsistencies, unawareness of the association between the etiological agent and the disease, and uncertainty regarding own knowledge of the subject. The population understood the importance of prevention and was willing to utilize prevention strategies despite being unsure of how to prevent infection. Further studies are required to investigate best practices for improving health equity, community health empowerment and IPIs prevention in Rio de Janeiro, Brazil.

Association between clinical indications and coproparasitological tests carried out at the Pedro Ernesto University Hospital (HUPE/UERJ) in Rio de Janeiro, Brazil

Enteroparasitosis is a public health problem in Brazil. Clinical indications and the appropriate stool examination are essential to obtain an adequate result. This study aims to evaluate whether the clinical indications and the choice of coproparasitological tests requested by the medical services may influence the diagnosis of enteroparasitosis. The data was obtained from the records in the Laboratory of Parasitology at the Pedro Ernesto University Hospital (HUPE/ UERJ) of the State University of Rio de Janeiro (UERJ) from 2009 to 2014. The qualitative variables were grouped in medical services (medical surgery, infectious and parasitic diseases, gastroenterology, pediatrics and rheumatology); types of tests requested (parasitological stool examination (PSE), merthiolate-iodine-formaldehyde (MIF), and sodium-acetate acetic acidformaldehyde (SAF)) and clinical indications (anemia, diarrhea, abdominal pain, eosinophilia, routine tests, HTLV patients, HIV patients, parasitosis and transplantation research). The chi square (X²) and the Spearman coefficient correlation tests were performed to calculate the association between the clinical indications and the coproparasitological tests. A significant association was evident in the clinical indication: parasitosis found among the MIF tests and Trichrome Wheatley (ρ = 0.980). In other clinical indications such as anemia, surgery/ transplant, diarrhea, patients with HIV, HTLV and eosinophilia (despite the PSE tests and MIF having presented a strong link (ρ = 0.802), there was no significant association among the tests. Clinical indications are essential and they have a great influence on the parasitological diagnosis, requiring a combination of diagnostic methods for the detection of protozoa and helminths of medical interest.

In vivo and in vitro effects of the herbicide Roundup(®) on developmental stages of the trematode Echinostoma paraensei.

The exposure of wildlife and humans to toxic residues of Roundup(®) through agricultural practices or the food chain has been reported since the herbicide was found contaminating rivers. Glyphosate, N-(phosphonomethyl)glycine acid, is a nonselective post-emergent herbicide and is formulated as an isopropylamine salt with the surfactant taloamine polyethoxylate (POEA) representing the commercial formulation of Roundup(®). There is little knowledge about the effects of the herbicide on helminth parasites, particularly those whose life cycle is related to water bodies. Here we investigated the effects of the Roundup(®) on the food-borne trematode Echinostoma paraensei in experimental conditions using different developmental stages (eggs, miracidia, cercariae, metacercariae, newly excysted larvae (NEL), helminths at seven days and helminths at fourteen days). Three different herbicide concentrations were tested based on concentrations typically applied in the field: 225, 450 and 900 mg/L. Specimens were analyzed in vitro for hatching miracidia, mortality and excystment rate of metacercariae and in vivo for parasitic load and egg production. There was a significant difference in the hatching miracidia rate only for the newly embryonated eggs. The mortality of specimens and excystment rate of metacercariae were concentration-dependent. There was a significant difference in the miracidia mortality with respect to concentration until 56.3 mg/L. The same effect was observed for cercariae, and mortality was observed from 15 min onwards at concentrations of 225-900 mg/L. At low concentrations, mortality was detected after 30 min. The effects of the herbicide concentration on NEL and on helminths at seven and fourteen days showed a significant difference after 24 h. There was no significant difference in parasitic load and egg production after infection of rodents with exposed metacercariae. All developmental stages of the trematode E. paraensei were affected by Roundup(®) exposure under experimental conditions. These results suggest that dynamics of transmission of the trematode could be affected in the natural environments. The study also reinforces the usefulness of this trematode as a good model organism to test pesticides regarding human and environmental health.

The influence of exposure to Euphorbia splendens var. hislopii latex on the concentrations of total proteins and nitrogen products in Biomphalaria glabrata infected with Schistosoma mansoni.

The aim of this work was to analyze the content of total protein and nitrogen degradation products in Biomphalaria glabrata infected with Schistosoma mansoni and exposed to Euphorbia splendens var. hislopii latex. The LC(50) of this latex was 1.0mg/l. Concentrations of uric acid, urea and total proteins were determined in the hemolymph of B. glabrata infected with five S. mansoni miracidia and exposed to a sublethal concentration of E. splendens var. hislopii latex for 24h. The exposure to this molluscicide caused total depletion of the alterative sources of energy (total proteins) and significant variation in the nitrogen degradation products. The urea content increased while the uric acid level decreased. These results reflect a disturbance in the snails regulation of their metabolism due to intoxication caused by the latex exposure.

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.

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.

Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex.

The reproductive activity of Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex was evaluated. Parameters related to fecundity and fertility were observed. The snails were exposed to the LD50 (1 mg/l) of crude latex. At the first week post exposure (p.e.), the egg laying was reduced. After the fourth week p.e., an increase of the number of eggs/snail occurred. The results showed a marked reduction in the hatching of the snails, revealing an interference of latex exposure with the reproductive process of B. glabrata of E. splendens var. hislopii. The LD50 of the latex may be used as an alternative method to control the size of the populations of B. glabrata in field.

Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex

The reproductive activity of Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex was evaluated. Parameters related to fecundity and fertility were observed. The snails were exposed to the LD50 (1 mg/l) of crude latex. At the first week post exposure (p.e.), the egg laying was reduced. After the fourth week p.e., an increase of the number of eggs/snail occurred. The results showed a marked reduction in the hatching of the snails, revealing an interference of latex exposure with the reproductive process of B. glabrata of E. splendens var. hislopii. The LD50 of the latex may be used as an alternative method to control the size of the populations of B. glabrata in field.

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.

[Intestinal parasitic helminths in institutionalized dogs of Rio de Janeiro, Brazil]. / Parasitas gastrointestinais em cães institucionalizados no Rio de Janeiro, RJ.

The occurrence of intestinal parasitic helminths in dogs from a public institute of veterinary medicine in Rio de Janeiro was assessed. Samples of fresh feces were collected in March 2004 and analyzed by Willis and centrifugal-flotation in sucrose solution methods. Of 204 samples, 45.6% were positive for helminths.

Parasitas gastrointestinais em cães institucionalizados no Rio de Janeiro, RJ / Intestinal parasitic helminths in institutionalized dogs of Rio de Janeiro, Brazil

Foi estudada a ocorrência de parasitas gastrointestinais em cães recolhidos e mantidos em instituto público de medicina veterinária no Rio de Janeiro, RJ. Amostras de fezes frescas foram coletadas em março de 2004 e analisadas pelos métodos de flutuação de Willis e centrífugo-flutuação em solução de sacarose. De 204 amostras, 45,6 por cento estavam positivas para helmintos gastrointestinais.

Lymnaea truncatula Muller, 1774 (Pulmonata: Lymnaeidae) infected with Fasciola hepatica (Linnaeus, 1758) (Trematoda: Digenea), in Moscow districts, Russian Federation

Estudou-se a abundância sazonal e taxas de infecção naturais por Fasciola hepatica em Lymnaea truncatula em áreas rurais endêmicas da região de Moscou. As coletas de campo foram realizadas mensalmente entre maio e outubro de 2002 em duas fazendas de gado do distrito de Naro-Fominsk e duas do distrito de Dmitrov. A abundância de caramujos foi máxima em maio (189 caracóis na primavera) e mínima em julho, (5 caracóis no verão), provavelmente devido às condições apropriadas dos biótopos ao desenvolvimento do molusco durante a primavera. A prevalência dos caramujos infectados durante o período estudado foi de 14,3por cento, sendo mais alta (12,5por cento) e mais baixa (0,53por cento) em setembro e maio, respectivamente.

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.

First report of Lymnaea cousini Jousseaume, 1887 naturally infected with Fasciola hepatica (Linnaeus, 1758) (Trematoda: Digenea) in Machachi, Ecuador

We report the first finding of Lymnaea cousini naturally infected with Fasciola hepatica in Ecuador. A sample of 70 snails was collected in April 2005 from a wetland located in a valley at approximately 3000 m a.s.l., near the locality of Machachi, Pichincha Province. The prevalence of natural infection in L. cousini was 31.43 percent, which is the highest value ever recorded for naturally infected lymnaeid species.

First report of Lymnaea cousini Jousseaume, 1887 naturally infected with Fasciola hepatica (Linnaeus, 1758) (Trematoda: Digenea) in Machachi, Ecuador.

We report the first finding of Lymnaea cousini naturally infected with Fasciola hepatica in Ecuador. A sample of 70 snails was collected in April 2005 from a wetland located in a valley at approximately 3000 m a.s.l., near the locality of Machachi, Pichincha Province. The prevalence of natural infection in L. cousini was 31.43%, which is the highest value ever recorded for naturally infected lymnaeid species.

Activity of Euphorbia splendens var. hislopii N.E.B. (Euphorbiaceae) latex against Lymnaea columella (Say, 1817) (Pulmonata: Lymnaeidae), intermediate host of Fasciola hepatica, Linnaeus, 1758 (Trematoda: Fasciolidae). 2: limited field-testing

The molluscicidal evaluation of Euphorbia splendens var. hislopii (Crown of thorns) against Lymnaea columella snails, intermediate host of Fasciola hepatica, in irrigation ditches of the Pisciculture Station at Universidade Federal Rural do Rio de Janeiro, was studied under limited field conditions. An aqueous solution of the latex at 5 mg/l was tested in two irrigation ditches (experimental and control ditches), after initial sampling of the snail population present. Twenty-four hours after application of the product, it was verified that 97.4 percent of free L. columella snails and 100 percent of snails of the same species captive in cages and used as sentinels at three points equidistant from the application site in the experimental ditch, died. For Biomphalaria tenagophila and Melanoides tuberculata snails, present in the experimental ditch, the mortality was 100 percent, for the species Pomacea spp. the mortality was 40 percent. No mortality was verified in the free mollusks, or in the sentinels in the ditch used as control. E. splendens var. hislopii latex is thus an efficient natural molluscicide, which may be used as an alternative control agent against L. columella.