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.

Allozyme analysis of the temporal populations of Echinostoma revolutum collected from domestic ducks in Khon Kaen Province, Thailand.

Four temporal populations of Echinostoma revolutum (ER1, ER2, ER3, ER4) were collected from domestic ducks in Khon Kaen Province, Thailand during February-October 2008. The ER1, ER2, ER3 and ER4 were collected in February, April, June and October, respectively. The 12 enzymes encoding 15 loci were examined. Two loci were found in each of 3 enzymes, namely glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and peptidase valine-leucine (PEPA). Of these, three loci, namely, G6pd-1, Me-1 and PepA-2, were polymorphic. Genotypes were assigned for the specific allelic profiles detected at these three polymorphic loci. Twenty-eight genotypes were observed in the 4 temporal populations of E. revolutum. Three genotypes, Er22, Er23 and Er25, were found in all populations. The Er6 genotype occurred had the highest frequency of all the populations. These 28 genotypes were clustered into 3 groups with genetic differences of 2-12% among the loci. A cluster of genotypes (Er1, Er3, Er9 and Er12) showed the greatest genetic difference among the genotypes (12% difference). These results show intraspecific variation exists in E. revolutum populations in domestic ducks from Khon Kaen Province, Thailand.

In vitro culture of rediae of Echinostoma caproni.

Rediae of Echinostoma caproni (Egyptian strain) were dissected from Biomphalaria glabrata snails at intervals from 13-34 days post-exposure and co-cultured for up to 51 days with cells of the B. glabrata embryonic (Bge) cell line. Rediae readily ingested Bge cells and survived longer when co-cultured with cells than in cell-free cultures. Rediae released mostly motile cercariae throughout the observation period when in Bge medium and cells. Rediae cultured in 199 medium with Bge cells also produced progeny throughout most of the observation period. In the latter medium, progeny were much more likely to include rediae as well as cercariae. Some cercariae produced in vitro encysted as metacercariae. Rediae consumed cercariae released into culture but were not observed to attack one another or rediae of a different echinostome species.

Ocorrência de Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae), no Estado de Goiás. Consideraçöes sobre os parasitos por ela transmitidos / Occurrence of Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae) in the State of Goiás and commentes about the ralationships of the molluc with the transmission of some parasites

Os autores relatam a primeira ocorrência de Lymnaea columella (Say, 1817) no Estado de Goiás, ressaltando a importância da espécie como hospedeiro intermediário de vários parasitos dos animais domésticos, dos quais, alguns são agentes de zoonoses no Brasil e em outros países. Também fazem considerações sobre os parasitos transmitidos ou possivelmente transmitidos por este molusco, já assinalados no Brasil