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1.
Exp Parasitol ; 205: 107734, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31394093

RESUMO

Parasitism 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. Recently, resistance was associated with a 63bp deletion in the Hco-acr-8b gene that encodes a subunit for a nicotinic acetylcholine receptor. This study aimed to standardize a real time PCR (qPCR) protocol for levamisole resistance diagnosis in H. contortus populations based on this polymorphism and use it to characterize 23 field H. contortus populations obtained from different localities of Ceará State, Northeast Brazil. In addition, two populations of H. contortus were used as a standard of susceptibility and resistance, Inbred Strain Edinburgh (ISE) and Kokstad, respectively. Larval development tests (LDT) were performed on five field isolates and both EC50 and EC95 were estimated. LDT EC95 values provided a wider interval between susceptible and resistant populations than EC50 values (EC95 = 1.96-57.93 µM; EC50 = 0.05-0.39 µM), and were found to be more appropriate for differentiating them. Real time PCR results showed resistance allele frequencies ranged from 20.9 to 76.7%. Our results suggest that levamisole resistance may be present in field populations but it is not as widespread as benzimidazole resistance. This methodology may be useful to monitor levamisole resistance in field populations of H. contortus.


Assuntos
Antinematódeos/farmacologia , Resistência a Medicamentos/genética , Haemonchus/efeitos dos fármacos , Levamisol/farmacologia , Animais , Benzimidazóis/farmacologia , DNA de Helmintos/isolamento & purificação , Fezes/parasitologia , Frequência do Gene/genética , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Hemoncose/veterinária , Haemonchus/genética , Haemonchus/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Receptores Colinérgicos/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Alinhamento de Sequência/veterinária , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Tetramizol/farmacologia
2.
Vet Parasitol ; 271: 64-67, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31303206

RESUMO

The present study aimed to evaluate the viability of Haemonchus placei parasitism in experimentally infected goats. For that, 14 75 days old kids male Saanen kids were placed in one of the four experimental groups: GI - infected with 5000 H. placei L3 (n = 4); GII - infected with 5000 H. contortus L3 (n = 4); GIII - infected with 2500 H. contortus L3 + 2500 H. placei L3 (n = 4), and GIV - control, inoculated with distilled water (n = 2). Each kid received, orally, the infective dose in a single inoculum. Based on daily fecal egg counts, the average pre-patent period was determined as 24 days for H. contortus, and 31 days for H. placei. Regarding the Haemonchus spp. recovered at necropsy, the experimental groups GI, GII, and GIII had, respectively, an average of 25.5, 619.5, and 724.75 (120 H. placei, and 604.75 H. contortus) adult specimens, and no immature forms. Under the conditions of this study, the viability of goat infection by H. placei was confirmed, although, with low susceptibility. Nevertheless, the parasitism of this helminth species was more intense when associated with H. contortus. This fact indicates that in common grazing between cattle and young goats, when the latter end up ingesting both Haemonhcus species, especially in a mixed infection, H. placei may also parasitize them.


Assuntos
Doenças das Cabras/parasitologia , Hemoncose/veterinária , Haemonchus/fisiologia , Animais , Coinfecção , Fezes/parasitologia , Cabras/parasitologia , Hemoncose/parasitologia , Masculino , Contagem de Ovos de Parasitas
3.
Parasitol Res ; 118(8): 2383-2388, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203449

RESUMO

In 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 ± 4.03%) compared with controls, although blood parameters remained relatively unchanged probably because the level of challenge was low. Vaccination prevented the periparturient rise in egg shedding of ewes, as well as egg shedding in lambs (37.1%). In the second trial, sheep which were experimentally exposed to higher artificial challenge also showed an efficient response to the vaccine as confirmed by high antibody levels and reduced egg counts and worm burdens (87 ± 5.4% and 79%) respectively. Thus, we believe that the vaccine should be integrated with other management practices for meat hair sheep as it has the advantages of adequate efficacy, reducing anthelmintic utilization and avoiding milk and environmental contamination with chemical residues.


Assuntos
Hemoncose/veterinária , Haemonchus/imunologia , Doenças dos Ovinos/prevenção & controle , Vacinação/métodos , Vacinas/administração & dosagem , Animais , Anticorpos Anti-Helmínticos/imunologia , Feminino , Hemoncose/imunologia , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/genética , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Vacinas/imunologia
4.
BMC Vet Res ; 15(1): 184, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164118

RESUMO

BACKGROUND: Since pastoralists in South Darfur, Sudan, had complained about lack of albendazole (ABZ) efficacy to control nematodes in goats, the frequency of infection with gastrointestinal helminths was studied before in vivo faecal egg count reduction tests (FECRT) were conducted using ABZ orally either at the dose recommended for sheep, 5 mg/kg body weight (bw) or at 10 mg/kg bw. Experiments included goats naturally infected with gastrointestinal nematodes or experimentally infected with local Haemonchus contortus isolates. Three study areas (Nyala, Beleil and Kass) were visited in autumn or winter. RESULTS: Out of 478 screened goats, 82.4% were infected with gastrointestinal helminths and 82% were shedding eggs of strongyle nematodes with 90% of the strongyle larvae representing Haemonchus spp. A FECRT using naturally infected goats (n = 225: 71 untreated, 104 and 50 treated with 5 and 10 mg ABZ/kg bw, respectively) detected reduced ABZ efficacy in Nyala and Kass. Paired and unpaired FECRT calculations detected reductions of 72-92% with samples taken at 8 days post treatment with 5 mg ABZ/kg bw and of 85-94% with 10 mg ABZ/kg bw. The FECRT based on day 14 post treatment samples showed reductions of 69-77% with 5 mg/kg and of 75-87% with 10 mg ABZ/kg bw. In Beleil, ABZ efficacy was 95%. In the egg hatch test EC50 values for Nyala and Kass ranged from 0.12-0.24 µg thiabendazole/ml, corresponding to benzimidazole resistant phenotypes. Only Haemonchus spp. larvae were present after treatments in coprocultures. When the efficacy was evaluated experimentally using isolates of H. contortus from Nyala and Kass, the 5 mg ABZ/kg dose revealed reductions of 76-78% on day 8 and of 62-70% on day 14 with the unpaired method. Using 10 mg ABZ/kg, the FECR was still only 77-82%. CONCLUSIONS: Both, in vivo and in vitro methods detected resistant H. contortus populations in goats from South Darfur State. The time point 14 days post treatment was more sensitive for detection of ABZ resistance than 8 days post treatment. This is the first report on the occurrence of anthelmintic resistance in Sudan confirming that anthelmintic resistance selection is occurring in African subsistence farming systems.


Assuntos
Albendazol/uso terapêutico , Antinematódeos/uso terapêutico , Doenças das Cabras/parasitologia , Hemoncose/epidemiologia , Haemonchus/efeitos dos fármacos , Enteropatias Parasitárias/veterinária , Animais , Resistência a Medicamentos , Feminino , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/epidemiologia , Cabras , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Enteropatias Parasitárias/epidemiologia , Masculino , Contagem de Ovos de Parasitas/veterinária , Prevalência , Sudão/epidemiologia
5.
Parasit Vectors ; 12(1): 105, 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30871600

RESUMO

BACKGROUND: Hepatocellular carcinoma-associated antigen 59 (HCA59), which is one of the most important excretory/secretory products of Haemonchus contortus (HcESPs), is known to have antigenic functions. However, its immunomodulatory effects on host cells are poorly understood. METHODS: Here, we cloned the HCA59 gene and expressed the recombinant protein of HCA59 (rHCA59). Binding activities of rHCA59 to goat peripheral blood mononuclear cells (PBMCs) and dendritic cells (DCs) were checked by immunofluorescence assay (IFA) and the immunoregulatory effects of rHCA59 on cytokine secretions, cell migration, cell proliferation, nitric oxide production, and changes in expression of genes in related pathways were observed by co-incubation of rHCA59 with goat PBMCs and DCs. Monocyte phagocytosis and characterization of goat blood DC subsets were detected by flow cytometry. RESULTS: The IFA results revealed that rHCA59 could bind to PBMCs and DCs. Treatment of PBMCs with rHCA59 significantly increased cellular proliferation and NO production in a dose-dependent manner, while cell migration was vigorously blocked. Treatment with rHCA59 significantly suppressed monocytes phagocytosis. The quantity of surface marker CD80 on DCs increased significantly after rHCA59 treatment. In addition, the expression of genes included in the WNT pathway was related to the differentiation and maturation of DCs, and the production of IL-10 and IL-17 produced by PBMCs was altered. CONCLUSIONS: Our findings illustrated that rHCA59 could enhance host immune responses by regulating the functions of goat PBMCs and DCs, which would benefit our understanding of HCA59 from parasitic nematodes contributing to the mechanism of parasitic immune evasion.


Assuntos
Antígenos Glicosídicos Associados a Tumores/imunologia , Carcinoma Hepatocelular/veterinária , Hemoncose/veterinária , Haemonchus/imunologia , Proteínas de Helminto/imunologia , Neoplasias Hepáticas/imunologia , Animais , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/parasitologia , Diferenciação Celular , Movimento Celular , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/parasitologia , Feminino , Cabras , Hemoncose/parasitologia , Proteínas de Helminto/genética , Imunomodulação , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/parasitologia , Neoplasias Hepáticas/parasitologia , Masculino , Monócitos/imunologia , Monócitos/parasitologia , Óxido Nítrico/metabolismo , Ratos , Proteínas Recombinantes
6.
Parasitol Res ; 118(4): 1239-1248, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30788574

RESUMO

Haemonchus contortus is a highly pathogenic gastrointestinal nematode of small ruminant animals. In modern intensive farming, livestock often suffer from different types of stress. However, whether host stress hormones influence H. contortus infection is largely unknown. Therefore, we treated H. contortus with norepinephrine (NE) and analyzed the changes in its excretory/secretory products (ESPs). Label-free quantitative proteomic analysis was used to identify differences in body proteins and ESPs between the control and NE-treated groups. We also investigated the changes in ESP action by analyzing cytokine secretion and goat peripheral blood mononuclear cell (PBMC) proliferation after incubation with ESPs secreted by NE-treated H. contortus. Thirty-two proteins in the body samples and 137 in the ESPs were differentially expressed between the groups. Gene ontology (GO) annotation showed that the functions of these different proteins might be involved in energy metabolism, protein metabolism, lipid metabolism, redox homeostasis, ion channel, and cell structure. NE treatment caused oxidative stress in H. contortus and changed the expression levels of some immunogenic proteins, such as the 15-kDa ESP. Meanwhile, the ESPs secreted by NE-treated H. contortus significantly decreased PBMC proliferation and the interleukin (IL)-2, IL-4, and interferon-gamma contents. Thus, NE treatment significantly affected the H. contortus body and ESP expression, and changes in the ESPs influenced PBMC function. The results reveal a relationship between host hormones and parasites and provide new clues to explain some of the variation in individual responses to infection.


Assuntos
Gastroenteropatias/veterinária , Cabras/parasitologia , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Haemonchus/metabolismo , Leucócitos Mononucleares/fisiologia , Norepinefrina/farmacologia , Proteínas de Protozoários/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Gastroenteropatias/parasitologia , Cabras/sangue , Hemoncose/parasitologia , Interferon gama/sangue , Interleucina-2/sangue , Interleucina-4/sangue , Estresse Oxidativo/efeitos dos fármacos , Ligação Proteica , Proteômica
7.
Vet Res ; 50(1): 7, 2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30678719

RESUMO

Haemonchus contortus is one of the most pathogenic gastrointestinal nematodes in small ruminants. To understand molecular mechanisms underlying host resistance to this parasite, we used RNA-sequencing technology to compare the transcriptomic response of the abomasal tissue, the site of the host-parasite interaction, of Merino sheep bred to be either genetically resistant or susceptible to H. contortus infection. Two different selection flocks, the Haemonchus selection flock (HSF) and the Trichostrongylus selection flock (TSF), and each contains a resistant and susceptible line, were studied. The TSF flock was seemingly more responsive to both primary and repeated infections than HSF. A total of 127 and 726 genes displayed a significant difference in abundance between resistant and susceptible animals in response to a primary infection in HSF and TSF, respectively. Among them, 38 genes were significantly affected by infection in both flocks. Gene ontology (GO) enrichment of the differentially expressed genes identified in this study predicted the likely involvement of extracellular exosomes in the immune response to H. contortus infection. While the resistant lines in HSF and TSF relied on different mechanisms for the development of host resistance, adhesion and diapedesis of both agranulocytes and granulocytes, coagulation and complement cascades, and multiple pathways related to tissue repair likely played critical roles in the process. Our results offered a quantitative snapshot of changes in the host transcriptome induced by H. contortus infection and provided novel insights into molecular mechanisms of host resistance.


Assuntos
Abomaso/parasitologia , Resistência à Doença/genética , Hemoncose/veterinária , Haemonchus/fisiologia , Transcriptoma , Animais , Cruzamento , Perfilação da Expressão Gênica/veterinária , Hemoncose/genética , Hemoncose/parasitologia , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Interações Hospedeiro-Parasita , Análise de Sequência de RNA/veterinária , Ovinos , Doenças dos Ovinos/genética , Doenças dos Ovinos/parasitologia
8.
Exp Parasitol ; 197: 20-28, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30633914

RESUMO

The indiscriminate use of chemical drugs to deworm livestock tends to trigger an anthelmintic resistance problem. In this context, the use of plant extracts rich in secondary metabolites could be an alternative method for the control of gastrointestinal nematodes. Baccharis conferta Kunth is a native plant species from Mexico that is widely used by several ethnic groups as forage for farm animals and medicinally to treat gastrointestinal diseases such as acute stomach ache, dysentery, diarrhoea, vomiting, indigestion, colic, intestinal spasms, urinary problems, and cramps. The aim of the present study was to isolate and characterise the ovicidal constituents of B. conferta and to determine a possible mode of action against Haemonchus contortus. The ovicidal activity was determined using the egg hatching inhibition test (EHI) to assess the methanol extract obtained from B. conferta foliage. The dry extract was partitioned (water/ethyl acetate) to obtain an ethyl acetate (BcEtOAc-F) and aqueous fraction. BcEtOAc-F showed an ovicidal activity of 72.32% EHI at 1 mg/mL. The chromatographic fractionation of BcEtOAc-F resulted in three active sub-fractions with higher ovicidal activity: BcC1R4 (99.15% EHI at 1.0 mg/mL); BcC1R5 (92.51% EHI at 0.75 mg/mL); and BcC1R8 (96.8% EHI at 3.0 mg/mL). Chemical analysis of the BcC1R4 fraction allowed the identification of the major active compound, isokaempferide (1, 98.06% EHI at 1 mg/mL). While, 4,5-di-O-acid caffeoylquinic (3; 96.8% EHI at 3 mg/mL) and an inactive flavone (vicenin-2, 2) were identified as the main compounds in BcC1R8. Chemical characterisation of the isolated compounds was performed via spectroscopic (NMR) and spectrometric (UPLC-MS) analyses. Additionally, the environmental and confocal scanning microscopy analyses revealed that isokaempferide was able to cross the eggshell layer without breaking it and attach itself to the embryo, causing its death. The flavonol, isokaempferide, and the hydroxycinamic acid, 4,5-di-O-caffeoylquinic, displayed powerful ovicidal effects, proving to be a potential alternative for the development of a phytodrug for the control of haemonchosis.


Assuntos
Anti-Helmínticos/farmacologia , Baccharis/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Anti-Helmínticos/química , Baccharis/ultraestrutura , Bioensaio , Cromatografia Líquida de Alta Pressão , Resistência a Medicamentos , Fezes/parasitologia , Flavonoides/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Hemoncose/parasitologia , Hemoncose/veterinária , Haemonchus/ultraestrutura , México , Microscopia Confocal , Microscopia Eletrônica de Varredura , Óvulo/efeitos dos fármacos , Extratos Vegetais/química , Ovinos , Doenças dos Ovinos/parasitologia
9.
Exp Parasitol ; 197: 36-42, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30633915

RESUMO

Molecules from natural sources, such as essential oils, have shown activity against parasites in vitro, but have not yet been explored extensively in vivo. Anethole and carvone (10% each), encapsulated with 80% of a solid matrix, referred to as EO (encapsulated oils), were tested in vivo in 2 experiments. In Experiment 1: Lambs were artificially infected with multidrug resistant Haemonchus contortus, or left uninfected, and treated (or not) with 50 mg/kg bw (body weight) of EO in a controlled environment. Thirty-two male lambs were kept in individual cages for a period of 45 days, after which animals were evaluated for parasitological, hematological, toxicological, and nutritional parameters. After 45 days of treatment, EO at 50 mg/kg bw provided a significant (P ≤ 0.05) reduction in fecal egg count (FEC). Although FEC was reduced, animals from both treatments had similar counts of total adult worms. The low FEC was caused probably by a significant reduction (P ≤ 0.05) in both male worm size and female fecundity. Dry matter intake of uninfected controls was significantly (P ≤ 0.05) reduced, although no toxicity was observed in treated animals. Thus, in Experiment 2, conducted for five months we used an EO dose of 20 mg/kg bw. Thirty-four weaned lambs, free of parasites, were divided in two groups and kept in collective pens. One group received EO at 20 mg/kg bw mixed with concentrate for 5 months and the other was kept as a control group (CTL). Parasitological and hematological parameters as well as body weight were evaluated. In the first 2.5 months, CTL and EO groups were confined, and both presented similar clinical parameters. Then, animals were allotted to graze on contaminated pastures to acquire natural infection for the next 2.5 months. The infection was patent after 25 days and both groups had similar decreases in weight gain, increases in FEC, and decreases in blood parameters. Coprocultures from CTL and EO groups established that parasite population was 90% Haemonchus sp. We concluded that the technology of encapsulation is safe and practical to deliver to lambs at the farm level and anethole and carvone at 50 mg/kg bw caused a significant decrease in FEC and, consequently, in pasture contamination by free living stages of H. contortus. However, EO at 20 mg/kg bw was not effective to prevent or treat sheep naturally-infected with gastrointestinal nematodes.


Assuntos
Anisóis/uso terapêutico , Hemoncose/veterinária , Monoterpenos/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Abomaso/parasitologia , Animais , Anisóis/administração & dosagem , Anisóis/química , Aspartato Aminotransferases/sangue , Cápsulas , Creatinina/sangue , Resistência a Múltiplos Medicamentos , Sinergismo Farmacológico , Ingestão de Alimentos , Contagem de Eritrócitos/veterinária , Fezes/parasitologia , Feminino , Fertilidade , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/efeitos dos fármacos , Haemonchus/crescimento & desenvolvimento , Haemonchus/fisiologia , Masculino , Monoterpenos/administração & dosagem , Monoterpenos/química , Contagem de Ovos de Parasitas/veterinária , Distribuição Aleatória , Ovinos , Ureia/sangue , Ganho de Peso , gama-Glutamiltransferase/sangue
10.
Vet Parasitol ; 265: 48-54, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30638520

RESUMO

Benzimidazoles have been intensively (for over 40 years) used in the livestock sector, particularly in small ruminants. This has been led to the widespread emergence of resistance in a number of small ruminant parasite species, especially Haemonchus contortus. In many countries benzimidazole resistance has severely compromised the control of H. contortus in small ruminants; but there is a little information on benzimidazole resistance in H. contortus infecting buffalo and cattle. Resistance to benzimidazoles have also been reported in the large ruminant parasite, Haemonchus placei, but again there is relatively little information on its prevalence. Hence it is very important to understand how resistance-conferring mutations emerge and spread in both parasites in buffalo and cattle hosts in order to develop approaches for the recognition of the problem at an early stage of its development. The present study suggests that the F200Y (TAC) mutation is common in H. contortus, being detected in 5/7 populations at frequencies between 7 and 57%. Furthermore, 6/10 H. placei populations contained the F200Y (TAC) mutation, albeit at low frequencies of between 0.4 and 5%. The phylogenetic analysis suggests that the F200Y (TAC) mutation in H. contortus has emerged on multiple occasions in the region, with at least three independent emergences across the populations. In contrast, the F200Y (TAC) resistance-conferring mutation in H. placei is only seen on a single haplotype. A high level frequency of the resistance haplotypes in the region, suggests that the unique resistance conferring-mutation has spread from a single emergence; likely by anthropogenic animal movement. Overall, these results provide the first clear genetic evidence for the spread of benzimidazole resistance-conferring mutations to multiple different locations from a single emergence in H. placei; while being consistent with previous small ruminant-based observations of multiple emergence of resistance mutations in H. contortus.


Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Búfalos/parasitologia , Doenças dos Bovinos/parasitologia , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Animais , Anti-Helmínticos/uso terapêutico , Benzimidazóis/uso terapêutico , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Resistência a Medicamentos/genética , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/genética , Mutação , Filogenia
11.
Parasitol Res ; 118(1): 245-253, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30542822

RESUMO

Benzimidazole (BZ) resistance of Haemonchus contortus has been associated with single nucleotide polymorphisms (SNPs) in codons 200 (F200Y) and 167 (F167Y) and, to a lesser extent, in codon E198A, of the ß-tubulin isotype 1 gene. The present study was undertaken to survey the status of BZ resistance in naturally infected goats in smallholder farms in southern Mozambique by real-time PCR (qPCR) using TaqMan® assays. H. contortus-infective larvae (L3; n = 432) from 12 populations were individually genotyped for F200Y and F167Y SNPs to detect BZ resistance. For the F200Y SNP, the results revealed an overall mean percentages of 18.8% homozygous resistant (RR), 47.8% homozygous susceptible (SS) and 33.4% heterozygous (RS) H. contortus. For the F167Y SNP, the overall mean percentages were 1.6% RR, 94.9% SS and 3.5% RS. The percentage of resistant alleles (%R) for the F200Y and F167Y SNPs was 35.7 and 3.4%, respectively. Genotype combinations of the two mutations indicate resistant percentages ranging from 0.0 to 52.9%. From the four herds with high RR individuals, three farms dewormed the animals monthly, while the fourth farm dewormed the animals every 3 months. In farms where animals were dewormed every 6 months, low percentages of RR individuals were found, whereas no RR individuals were discovered in herds where animals were dewormed annually. These results suggest that the F200Y SNP is more significant in BZ resistance development of the surveyed population compared with the F167Y SNP.


Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Resistência a Medicamentos , Doenças das Cabras/parasitologia , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Haemonchus/genética , Polimorfismo de Nucleotídeo Único , Alelos , Animais , Genótipo , Cabras , Hemoncose/parasitologia , Haemonchus/classificação , Haemonchus/isolamento & purificação , Moçambique
12.
Vet Parasitol ; 262: 11-15, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30389005

RESUMO

In a survey involving 34 sheep flocks spread over the Netherlands anthelmintic resistance (AR), based on a fecal egg count reduction (FECR) test, was determined for six different products. The study was conducted in ewes shortly after lambing during spring 2015. A FECR of less than 90%, indicating presence of AR against one or more nematode genera producing strongylid eggs, was found in 22 of 30 (73.3%) flocks against oxfendazole, 18 of 23 (78.3%) flocks against ivermectin, 15 of 32 (46.9%) flocks against moxidectin, and 2 of 26 (7.7%) flocks against monepantel. No AR was observed against levamisole. If oxfendazole resistance was observed, Haemonchus contortus was involved in 90.5% of the cases. If resistance against ivermectin, moxidectin or monepantel was observed, it invariably involved H. contortus. In the majority of cases resistance was also observed for Teladorsagia circumcincta and/or Trichostrongylus spp, between which no distinction was made in this study. Based on FECR 9 of 15 (60.0%) flocks showed resistance against closantel, which was mainly due to closantel not being effective against most other nematode species than H. contortus. However, in 44.4% of flocks showing reduced FECR it did involve H. contortus as well. Multi-drug resistance (excluding closantel) was found in 16 flocks, of which 8 showed resistance against 2 products, 7 against 3 products and 1 flock showed resistance against 4 products. If resistance against 3 or 4 products was present, there invariably was resistance against both ivermectin and moxidectin. Overall, of the 22 flocks in which both macrocyclic lactones (ML) were tested, 4 (18.2%) showed no resistance against both products, 9 (40.9%) showed resistance against ivermectin only, and 9 (40.9%) showed resistance against both MLs. It is concluded that AR is widespread in sheep in the Netherlands and involves products from all major anthelmintic classes, with possibly the exception of levamisole. It appears that the macrocyclic lactones have lost much of their efficacy against sheep nematodes over the last decade.


Assuntos
Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Enteropatias Parasitárias/veterinária , Doenças dos Ovinos/epidemiologia , Aminoacetonitrila/análogos & derivados , Aminoacetonitrila/farmacologia , Animais , Benzimidazóis/farmacologia , Fezes/parasitologia , Hemoncose/tratamento farmacológico , Hemoncose/epidemiologia , Hemoncose/parasitologia , Enteropatias Parasitárias/tratamento farmacológico , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Ivermectina/farmacologia , Levamisol/farmacologia , Macrolídeos/farmacologia , Contagem de Ovos de Parasitas/veterinária , Salicilanilidas/farmacologia , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia
13.
Vet Parasitol ; 262: 6-10, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30389014

RESUMO

The present investigation was carried out with the objective to identify putative candidate genes / Quantitative trait loci for resistance / susceptibility towards Haemonchus infestation in tropical goat breed (Rohilkhandi goat) of India. The mean faecal egg count (FEC) and packed cell volume (PCV) of the population were 142.78 ± 22.54 epg (eggs per gram) and 31.73% ± 0.49, respectively. Grouping of animals as per dot ELISA test showed 41.33% (n = 124) positive and 58.66% (n = 176) negative for Haemonchus infestation. The microsatellite loci DYA and ODRB1.2 were significantly associated (P ≤ 0.05) to parasite resistance. The locus DYA showed significant association with log FEC and dot ELISA and the locus ODRB1.2 showed significant association with log FEC, PCV and dot ELISA at P ≤ 0.05. Real time expression profiling revealed that the susceptible group (high FEC group) had 11.1-fold more expression of IFNγ mRNA (Th1 cytokine) and 0.11-fold lower expression of IL-10 mRNA (Th2 cytokine), which was found to be statistically significant (P ≤ 0.05).


Assuntos
Doenças das Cabras/epidemiologia , Hemoncose/veterinária , Haemonchus/genética , Repetições de Microssatélites/genética , Animais , Coinfecção/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Fezes/parasitologia , Feminino , Marcadores Genéticos/genética , Genótipo , Doenças das Cabras/parasitologia , Cabras , Hemoncose/epidemiologia , Hemoncose/parasitologia , Haemonchus/imunologia , Hematócrito/veterinária , Índia/epidemiologia , Interferons/genética , Interleucina-10/genética , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Especificidade da Espécie
14.
Exp Parasitol ; 195: 38-43, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30393118

RESUMO

Helminthiasis is a common disease in which parasite resistance is frequently caused by inadequate administration of anthelmintics in small ruminant production. Since phytotherapy may be an adjuvant for parasite control, we assessed whether the ingestion of cashew apple fiber (Anacardium occidentale) would reduce Haemonchus contortus infection in Santa Inês sheep. Twenty-one male sheep with mean age of 240 ±â€¯9.7 days were dewormed, infected with 4000 L3 of H. contortus Embrapa2010 (day 0 - D0) and on D28 were divided into three equally sized experimental groups: 1) control (no treatment), 2) treated with anthelmintic (monepantel, 2.5 mg/kg PV) and 3) cashew apple fiber (0.3% BW) for 7 days of adaptation plus 28 days (D63). The animals were weighed weekly for diet adjustment and individual EPGs were performed twice a week. Corn silage was given ad libitum after each animal had eaten all the cashew apple fiber, which always occurred due to its palatable flavor. The silage, cashew apple fiber and leftovers were weighed daily and the samples were analyzed for dry matter. In cashew apple fiber, the total polyphenol contents were determined spectrophotometrically and the phenol compounds were identified by LC-MS. Cashew apple fiber contained 93.6% DM, 13.0% CP, 68.7% NDF, 47.6% FDA, 1.3% MM, 1.9% EE and 22.3% LIG. Twenty phenolic compounds were detected, among them phenolic acids and flavonoids, including glycosylated ones. The general EPG averages were statistically different among control, anthelmintic and cashew groups (3449, 14 and 2070, respectively), while the mean total weight gain did not differ (3.21, 3.20 and 1.94 kg, respectively) (p < 0.05). In relation to the control group, the anthelmintic showed efficacy of 99.6% and the cashew apple fiber 40.8%. Phenolic compounds appear to play an important role in the anthelmintic activity of cashew apple fiber. Thus, its use as an adjuvant in the control of H. contortus can be encouraged in regions where it is available at low cost, mitigating the use of veterinary drugs, reducing environmental contamination by agroindustrial residues and promoting the more sustainable production of small ruminants.


Assuntos
Anacardium , Fibras na Dieta/administração & dosagem , Hemoncose/veterinária , Doenças dos Ovinos/parasitologia , Aminoacetonitrila/análogos & derivados , Aminoacetonitrila/uso terapêutico , Anacardium/química , Animais , Anti-Helmínticos/uso terapêutico , Fibras na Dieta/análise , Resistência a Medicamentos , Fezes/parasitologia , Flavonoides/administração & dosagem , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/efeitos dos fármacos , Masculino , Contagem de Ovos de Parasitas/veterinária , Fitoterapia/veterinária , Polifenóis/administração & dosagem , Polifenóis/análise , Ovinos , Doenças dos Ovinos/prevenção & controle , Silagem/análise , Ganho de Peso , Zea mays
15.
Vet Parasitol ; 261: 1-8, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30253846

RESUMO

In this paper, we present for the first time a new tool, based on Droplet Digital™ Polymerase Chain Reaction (ddPCR), for absolute quantification of key genera of gastrointestinal (GI) nematode parasites of grazing livestock. Four combinations of primers/probe sets targeting the internal transcribed spacer region 2 (ITS2) of the ribosomal RNA gene array were designed using the Primer3 software, following in silico analysis of nucleotide sequences from nematodes of interest downloaded from common databases. The amplified regions include both a universal region for detection of any strongylid gastrointestinal parasite and three different genus specific regions, making it possible to differentiate between the most important GI nematodes of sheep in Sweden: Haemonchus, Teladorsagia and Trichostrongylus. Analysis of samples containing serial dilutions and different mixtures of genomic DNA extracted from different species of adult worms proved useful in assessment of different threshold settings with the QuantaSoft software. Analysis of template DNA from these worms indicated that ddPCR is a viable choice for detection and absolute quantification of the different genera and also in samples with multiple species. Interpretation of the ddPCR results was straightforward and choice of analytical approach had little influence on the final results. Thus, the results obtained in the different analytical approaches seemed to be robust and the concentrations determined were uniform. Furthermore, the linear range of the Haemonchus ddPCR assay was similar to that of real-time PCR (qPCR). Taken together, our data confirm the suitability of ddPCR for detection and absolute quantification of three major sheep pathogens when tested on larval cultures from pooled ovine faeces. The results also indicate that ddPCR can be a useful complement to applications based on conventional egg counting methods such as the faecal egg reduction test (FECRT).


Assuntos
Hemoncose/veterinária , Ostertagíase/veterinária , Reação em Cadeia da Polimerase/veterinária , Doenças dos Ovinos/diagnóstico , Tricostrongilose/veterinária , Animais , Fezes/parasitologia , Hemoncose/diagnóstico , Hemoncose/parasitologia , Haemonchus/isolamento & purificação , Ostertagia/isolamento & purificação , Ostertagíase/diagnóstico , Ostertagíase/parasitologia , Reação em Cadeia da Polimerase/métodos , Ovinos , Doenças dos Ovinos/parasitologia , Suécia , Tricostrongilose/diagnóstico , Tricostrongilose/parasitologia , Trichostrongylus/isolamento & purificação
16.
Acta Parasitol ; 63(3): 504-514, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-29975652

RESUMO

The mechanisms responsible for the imbalance between oxidants and antioxidants in sheep infected with Haemonchus contortus are not well established. This study aimed to prove the hypothesis that oxidative stress occurring during infection by H. contortus varies according to breed, and that the parasite burden correlates with hypoalbuminaemia and anaemia. Thus, after deworming and confirming the absence of infection, two different sheep breeds, Suffolk (n = 15) and Santa Ines (n = 22), were orally inoculated with a single dose of 5,000 L3 of H. contortus. The egg counts per gram of faeces (EPG), packed cell volume (PCV) and concentrations of several plasma markers of oxidative stress (lipid peroxidation, albumin, uric acid, total bilirubin, total antioxidant capacity [TAC], total oxidant concentration [TOC] and the oxidative stress index [OSI]) were quantified before (control group) and during the experimental infection (28, 34 and 42 days post-inoculation). In both breeds, TOC increased at 28 days and TAC increased at 42 days. In Suffolk sheep, there was a positive correlation of EPG with oxidant components (28 days) and a negative correlation of EPG with PCV (42 days). In Santa Ines sheep, there was a positive correlation of EPG with bilirubin (r = 0.492; p = 0.020). H. contortus infection caused oxidative stress, which varied according to the breed. Parasite burden was not associated with hypoalbuminaemia, whereas there was a negative correlation with PCV. This research provides the first evidence that the antioxidant status contributes more to the resilience to H. contortus in Santa Ines sheep compared to Suffolk sheep.


Assuntos
Anemia/veterinária , Hemoncose/veterinária , Haemonchus/fisiologia , Hipoalbuminemia/veterinária , Estresse Oxidativo , Doenças dos Ovinos/parasitologia , Anemia/parasitologia , Animais , Fezes/parasitologia , Feminino , Gastroenteropatias/parasitologia , Hemoncose/parasitologia , Hematócrito/veterinária , Hipoalbuminemia/parasitologia , Larva , Peroxidação de Lipídeos , Masculino , Contagem de Ovos de Parasitas/veterinária , Ovinos
17.
Acta Parasitol ; 63(3): 563-571, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-29975659

RESUMO

Drug resistance in helminth parasites has incurred several difficulties to livestock industry and ranked among the top public health concerns. Therefore, seeking for new agents to control parasites is an urgent strategy. In the recent years, metallic nanoparticles have been considerably evaluated for anthelmintic effects. The current research was conducted to assess possible anthelmintic impacts of zinc oxide nanoparticles (ZnO-NPs) on a prevalent gastrointestinal nematode, H. contortus. Moreover, several biomarkers of oxidative/nitrosative stress and DNA damage were measured. Various concentrations of the nanoparticle were prepared and incubated with the worms for 24 hours. The parasite mobility, mortality rate, antioxidant enzymes activities (SOD, Catalase and GSH-Px), lipid peroxidation, total antioxidant status as well as nitric oxide (NO) contents and DNA damage were determined. ZnO-NPs exerted significant wormicidal effects via induction of oxidative/nitrosative stress and DNA damage. Conclusively, ZnO-NPs can be utilized as a novel and potential agent to control and treatment of helminth parasitic infections.


Assuntos
Anti-Helmínticos/farmacologia , Biomarcadores/análise , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Nanopartículas Metálicas/química , Óxido de Zinco/farmacologia , Animais , Antioxidantes/metabolismo , Dano ao DNA/efeitos dos fármacos , Feminino , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/genética , Haemonchus/fisiologia , Peroxidação de Lipídeos/efeitos dos fármacos , Gado , Óxido Nítrico/análise , Estresse Nitrosativo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
18.
Vet Parasitol ; 254: 105-113, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29656994

RESUMO

We have set up an ex vivo ovine abomasal model, which can mimic the multicellular process to explore the early steps in haemonchine nematode infection using RNA-seq technology. Ovine abomasal explants were collected for histological and transcriptional analysis and supernatants collected to quantitate lactate dehydrogenase (LDH) enzymes. Atotal of 233 were substantially induced genes between L4-inoculated and uninoculated-control tissues, respectively. However, a total of 14 were considerably down-regulated genes between the 51 aforementioned tissues. Fifteen pathways were annotated by Kyoto Encyclopedia of Genes, and Genomes pathway analysis accounted for the significant percentage in immediate response to larval-stage of H. contortus. Key genes upregulated in response to the addition of L4-inoculum of H. contortus were IL-6, IL-8, C1q, Atypical chemokine receptor-3, chemokine ligand-2, manganese superoxide dismutase, integrin alpha-7, -8, -9, integrin subunit beta-1, integrin subunit beta 6, intercellular adhesion molecule-1 and actin alpha-1. This study shows for the first time that galectin-1 is up-regulated in an ex vivo abomasal segment model exposed to L4-inoculum of H. contortus following 6 h of incubation. The abomasal segment model has been shown to be a suitable tool to study the haemonchine larval-stage effects on the ovine abomasal tissues prior to in vivo assessment.


Assuntos
Abomaso/imunologia , Hemoncose/veterinária , Imunidade Inata , Doenças dos Ovinos/imunologia , Transcriptoma/imunologia , Animais , Modelos Animais de Doenças , Regulação para Baixo , Hemoncose/imunologia , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Haemonchus/fisiologia , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ovinos , Doenças dos Ovinos/parasitologia , Regulação para Cima
19.
Vet Parasitol ; 254: 43-48, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29657010

RESUMO

Sheep production in tropical and temperate regions is hampered by the presence of Haemonchus contortus, the blood-sucking nematode that is the major cause of economic losses in small ruminant enterprises. The most limiting factor in the control of this parasitic disease is the steady progress of anthelmintic resistance worldwide. The search for control strategies that minimise the use of anthelmintics is therefore central to various efforts worldwide. One strategy is the introduction of susceptible parasites in refugia when these refugia are at low levels. This strategy could lead to a renewed possibility anthelmintics being effective. At farm level, this management practice could recover the use of anthelmintics in flocks with high levels of resistance. This review explores the possibility of replacing resistant H. contortus populations with susceptible ones through refugia management and. highlights the experiences of on-farm research attempts carried out in different geographical areas, reaching various degrees of success.


Assuntos
Anti-Helmínticos/farmacologia , Resistência a Medicamentos/genética , Hemoncose/veterinária , Haemonchus/fisiologia , Doenças dos Ovinos/prevenção & controle , Animais , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/genética , Parasitos/genética , Parasitos/fisiologia , Refúgio , Ovinos , Doenças dos Ovinos/parasitologia
20.
Vet Parasitol ; 254: 6-9, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29657013

RESUMO

Haemonchus contortus is the most prevalent nematode in tropical and subtropical regions and is responsible for significant losses in small ruminant production systems. Control of this parasite is based on the use of synthetic anthelmintics; although effective, prolonged and indiscriminate use can select for populations of resistant nematodes. Hydrolyzed yeast can help prevent populations of nematodes and is low in cost. The present study aimed to evaluate the preventive effect of hydrolyzed yeast on H. contortus through in vitro and in vivo assays. In in vitro experiments, the yeast preparation was tested at different stages of the H. contortus life cycle via tests of egg hatchability, larval development, larval exsheathment and larval migration. Both eggs and L3 larvae were obtained from sheep artificially infected with a monospecific strain of H. contortus. In in vivo experiments, animals were treated with hydrolyzed yeast (53.4 mg/kg/BW), and fecal egg counts (FECs), feces culture and Famacha were performed. The yeast preparation inhibited larval exsheathment in a dose-dependent manner (IC95 of 0.46 mg/mL), though no activity at the other stages of the H. contortus life cycle was observed. The hydrolyzed yeast preparation was able to reduce FECs in treated animals from D40 to D54 (p < 0.05), showing an average efficiency of 60%. The yeast exhibited preventive properties, and the IC95 value suggests that H. contortus is highly susceptible. Our results indicate that administration of hydrolyzed yeast, which is already used commercially in ruminant nutrition, is an alternative method for the control of nematodes, mainly H. contortus.


Assuntos
Antinematódeos/farmacologia , Doenças das Cabras/tratamento farmacológico , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Fermento Seco/farmacologia , Animais , Antinematódeos/administração & dosagem , Fezes/parasitologia , Doenças das Cabras/parasitologia , Cabras , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Técnicas In Vitro , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Contagem de Ovos de Parasitas/veterinária , Fermento Seco/administração & dosagem
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