ATP-binding cassette (ABC) transporters, including P-glycoproteins (PGP), have been implicated in drug resistance in different organisms including Haemonchus contortus. This study confirmed the resistance status of H. contortus isolates selected for ivermectin (IVM) and oxfendazole (OXF) resistances using the fecal egg count reduction test and evaluated the gene expression of seven ABC transporters using RT-qPCR for two biological scenarios: the effect of selection for anthelmintic resistance and the effect of drug exposure on gene expression.
View Article and Find Full Text PDFRev Bras Parasitol Vet
June 2023
Parasitism by gastrointestinal nematodes is a challenge for small ruminant farming worldwide. It causes productive and economic losses, especially due to parasite resistance to conventional anthelmintics. Natural compounds with antiparasitic activity are a potential alternative for controlling these parasites especially when considering the widespread occurrence of anthelmintic resistance.
View Article and Find Full Text PDFRev Bras Parasitol Vet
June 2021
The aim of this study was to characterize the anthelmintic resistance (AR) of a sheep gastrointestinal nematode population, named Caucaia, from northeastern Brazil. Phenotypic tests performed were: egg hatch (EHT), larval development (LDT) and fecal egg count reduction (FECRT). Benzimidazoles (BZs) genotypic evaluation was by frequency of single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A, and for levamisole (LEV), by frequency of resistance alleles of Hco-acr-8 gene.
View Article and Find Full Text PDFRev Bras Parasitol Vet
April 2020
The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep.
View Article and Find Full Text PDFParasitism by Haemonchus contortus is one of the main limiting factors in small ruminant production around the globe. Although several studies suggest the use of integrated management practices, these parasites have been controlled essentially with synthetic anthelmintic drugs. The resistance mechanism against the imidazothiazole derivative levamisole in Haemonchus contortus has not been fully described.
View Article and Find Full Text PDFIn this study, we evaluated in two trials a protocol designed to protect hair sheep using Barbervax®, a vaccine containing Haemonchus contortus gut membrane glycoprotein antigens. Results indicated that naturally infected vaccinated sheep had significant egg count reductions (90.2 ± 4.
View Article and Find Full Text PDFVet Parasitol
December 2017
Parasitism by Haemonchus contortus is one of the main limiting factors in small ruminant production in tropical areas. Benzimidazoles (BZ) and macrocyclic lactones (ML) are the most used anthelmintic classes in gastrointestinal nematodes control. There is considerable scientific evidence of a possible relation between the anthelmintic resistance to BZ and ML.
View Article and Find Full Text PDFCoccidiosis is a disease that limits the production and marketing of gallinaceous birds in North America, especially quails, pheasants and chukar partridges. Virtually no research has been conducted in South America on the causative agents of diseases among these birds, including coccidia. The aim of this work was to make first observations on Eimeria spp.
View Article and Find Full Text PDFVet Parasitol
January 2014
Haemonchus contortus is the most prevalent nematode in Brazil. The objective of this study was to select 6 populations of H. contortus of known or suspected benzimidazole resistance status and characterize these using quantitative real-time polymerase chain reaction (qPCR) for single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A in the β-tubulin isotype 1 gene.
View Article and Find Full Text PDFHere, we show the morphological events associated with organelle segregation and their timing in the cell cycle of a reference strain of Leishmania (L.) amazonensis promastigotes, the main causative agent of Tegumentary leishmaniasis in the Americas. We show evidences that during the cell cycle, L.
View Article and Find Full Text PDFTwelve white peafowl (Pavo cristatus) affected by an outbreak of an intestinal disease were referred for more detailed examination at the Universidade Estadual de Santa Cruz-BA, Brazil. During the course of the disease, peachicks were severely affected, with enteric signs such as diarrhea plus dehydration, decreased feed intake and progressive weight loss. After examination, 8 of 12 samples (66.
View Article and Find Full Text PDFThis study compares both versions of the nutritional requirement system determined by the National Research Council (NRC) version 1985 (NRC85) and NRC version 2007 (NRC07), for finishing lambs in feedlots. Nineteen crossbred lambs were divided in four groups representing four experimental treatments: one diet according to NRC85 and three diets according to NRC07. The diets recommended by NRC07 considers crude protein intake relative to ruminal undegradable protein at 20, 40, and 60 % levels (NRC07/20, NRC07/40, and NRC07/60).
View Article and Find Full Text PDFBackground: Paracoccidioides is the causative agent of paracoccidioidomycosis, a systemic mycosis endemic to Latin America. Infection is initiated by inhalation of conidia (C) or mycelial (M) fragments, which subsequently differentiate into yeast (Y). Epidemiological studies show a striking predominance of paracoccidioidomycosis in adult men compared to premenopausal women.
View Article and Find Full Text PDFThe focus of this work is to determine the distribution and identify species of Eimeria parasites of dairy goats in the livestock of the National Goat and Sheep Research Center in Sobral, State of Ceará, Northeast Brazil. Results showed the presence of multiple species in 196 of 215 analyzed samples (91.2%).
View Article and Find Full Text PDFThe present review intends to summarize the, yet preliminary, but very important emerging data underlining the functions exerted by the nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase SIRT1 on protein homeostasis. The main focus of the discussion is the cooperation between SIRT1 and the heat shock factor 1 (HSF1) responsible for activating the transcription of molecular chaperones, the protein-protective factors that resolve damaged/misfolded and aggregated proteins generated by heat stress or metabolism. SIRT1, a mammalian ortholog of the yeast silent information regulator 2, is a stress activated protein deacetylase that contributes to life-span extension by regulating different cell survival pathways, including replicative senescence, inflammation and resistance to hypoxic and heat stress.
View Article and Find Full Text PDFBackground: The genus Arachis comprises 80 species and it is subdivided into nine taxonomic sections (Arachis, Caulorrhizae, Erectoides, Extranervosae, Heteranthae, Procumbentes, Rhizomatosae, Trierectoides, and Triseminatae). This genus is naturally confined to South America and most of its species are native to Brazil. In order to provide a better understanding of the evolution of the genus, we reconstructed the phylogeny of 45 species using the variation observed on nucleotide sequences in internal transcribed spacer regions (ITS1 and ITS2) and 5.
View Article and Find Full Text PDFDiversity in 26 microsatellite loci from section Caulorrhizae germplasm was evaluated by using 33 accessions of A. pintoi Krapov. & W.
View Article and Find Full Text PDFParacoccidioides brasiliensis is a thermally dimorphic fungus, and causes the most prevalent systemic mycosis in Latin America. Infection is initiated by inhalation of conidia or mycelial fragments by the host, followed by further differentiation into the yeast form. Information regarding gene expression by either form has rarely been addressed with respect to multiple time points of growth in culture.
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