Biological control of sheep parasite nematodes by nematode-trapping fungi: In vitro activity and after passage through the gastrointestinal tract

The main method used for the control of gastrointestinal nematodes in sheep production is the application of chemotherapeutic agents, which often lead to the selection of parasites resistant to given active principles. Biological control can be considered a promising alternative, contributing to an increase in the efficacy of verminous control. We determined the in vitro activity and in situ survival of the predatory fungi Arthrobotrys musiformis and Arthrobotrys conoides during passage through the gastrointestinal tract of sheep after oral administration of conidia in microencapsulated form and as a liquid in natura. Initial in vitro tests showed that both fungi were efficient in the predation of trichostrongylid L3 larvae present in the faeces of sheep naturally infected with gastrointestinal nematodes. The fungi presented high nematophagous activity, which was 99.3% for A. conoides and 73.7% for A. musiformis. A. conoides did not survive passage through the gastrointestinal tract under the conditions of the present experiment. On the other hand, A. musiformis was reisolated after administration in either microencapsulated or liquid form, suggesting that this species is a promising alternative for the control of nematodes in sheep since it survives without any protection (in natura). © Springer 2005.

Brazilian catfish parasitized by Epistylis sp. (Ciliophora, Epistylididae), with description of parasite intensity score

The determination of mean intensity of parasitism for colony-forming sessile protozoan such as Epistylis has been a great problem in parasitological studies. Some alternatives have been proposed by researchers for laboratory and field conditions. This study describes the criteria to establish the parasitic intensity score for epistylidid infestation in fish. Parasite distribution and the host-parasite relationship in four species of Brazilian cultured catfish and their hybrids are discussed. The highest prevalence rates were found in the hybrid jundiara, Leiarius marmoratus male × Pseudoplatystoma reticulatum female (96.4 %), followed by jurupoca, Hemisorubim platyrhynchos (60 %), and the hybrid surubim, Pseudoplatystoma corruscans male × P. reticulatum female (52.7 %). Positive correlation between parasitic intensity score and the fish size, weight, and relative condition factor were also observed. These findings indicate that Epistylis infestation in Brazilian catfish is an emerging disease in cultured fish. © 2012 Springer-Verlag.

Calling behavior and parasite intensity in Treefrogs, Hypsiboas prasinus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Paratrichodina africana (Ciliophora): A pathogenic gill parasite in farmed Nile tilapia

Trichodinids are ciliated protozoa that are widely known as one of the main groups of fish parasites. The genus Trichodina presents the greatest species diversity. However, records of Paratrichodina species are scarce, and little is known about their pathogenicity in hosts. The present study provides new records of Paratrichodina africana Kazubski and El-Tantawy (1986) in Nile tilapia from South America and descriptions of pathological changes and seasonality. A total of 304 farmed fish were examined. From gill scraping, parasites were identified using Klein's nitrate impregnation method. Gill samples were fixed for histopathological analysis. Small trichodinid found in this study have a prominent blade apophysis and narrow central part and blade shape that corresponds to the characteristics of P. africana Kazubski and El-Tantawy (1986). Gill lesions were proportional to parasite intensity, in which the gill tissue was compromised in heavy infestation. Proliferative disturbances were found, including epithelial hyperplasia, desquamation, and mononuclear and eosinophilic infiltrate that culminated in necrosis. We did not observe a seasonality effect on the occurrence of P. africana. This ciliated protozoan causes compromised respiratory capacity that leads to severe gill lesions and currently is an important pathogen that afflicts intensive tilapia cultures in Brazil. © 2013 Elsevier B.V.

Nonlinear dynamics of within-host parasite competition

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aedes aegypti on Madeira Island (Portugal): genetic variation of a recently introduced dengue vector

The increasing population of Aedes aegypti mosquitoes on Madeira Island (Portugal) resulted in the first autochthonous dengue outbreak, which occurred in October 2012. Our study establishes the first genetic evaluation based on the mitochondrial DNA (mtDNA) genes [cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4)] and knockdown resistance ( kdr ) mutations exploring the colonisation history and the genetic diversity of this insular vector population. We included mosquito populations from Brazil and Venezuela in the analysis as putative geographic sources. The Ae. aegyptipopulation from Madeira showed extremely low mtDNA genetic variability, with a single haplotype for COI and ND4. We also detected the presence of two important kdr mutations and the quasi-fixation of one of these mutations (F1534C). These results are consistent with a unique recent founder event that occurred on the island of Ae. aegyptimosquitoes that carry kdr mutations associated with insecticide resistance. Finally, we also report the presence of the F1534C kdr mutation in the Brazil and Venezuela populations. To our knowledge, this is the first time this mutation has been found in South American Ae. aegypti mosquitoes. Given the present risk of Ae. aegypti re-invading continental Europe from Madeira and the recent dengue outbreaks on the island, this information is important to plan surveillance and control measures.

Endohelminths in Cichla piquiti (Perciformes, Cichlidae) from the Paraná River, São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Helminth parasite communities of allopatric populations of the frog Leptodactylus podicipinus from Pantanal, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Immune response to Haemonchus contortus and Haemonchus placei in sheep and its role on parasite specificity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Phylogeny, ultrastructure and histopathology of Myxobolus lomi sp nov., a parasite of Prochilodus lineatus (Valenciennes, 1836) (Characiformes: Prochilodontidae) from the Peixes River, Sao Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vitamin B6-Dependent Enzymes in the Human Malaria Parasite Plasmodium falciparum: A Druggable Target?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological changes and parasite load of the adrenal from dogs with visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Social Parasite Evolved Reproductive Isolation from Its Fungus-Growing Ant Host in Sympatry

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Immunization of Wistar female rats with 255-Gy-irradiated Toxoplasma gondii: Preventing parasite load and maternofoetal transmission

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Trichodina heterodentata (Ciliophora) infestation on Prochilodus lineatus larvae: a host-parasite relationship study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)