Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.928
Filtrar
1.
Rev Bras Parasitol Vet ; 28(3): 522-527, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31483036

RESUMO

The anthelmintic resistance stimulated the search for strategies for controlling gastrointestinal nematodes, including the use of free essential oils or its nanoemulsion. This study evaluated the anthelmintic efficacy of Cymbopogon citratus essential oil (CcEO) and C. citratus essential oil nanoemulsion (CcEOn). Pysicochemical analyses were performed. The in vitro effect was determined using the egg hatch test (EHT) on Haemonchus contortus and in vivo effect was evaluated in sheep infected with gastrointestinal nematodes. The animals were treated with CcEO (500 mg/kg) or CcEOn (450 mg/kg) for the fecal egg count (FEC) and the determination of worm burden. The main component of CcEO was citral. The CcEO content in the nanoemulsion was 20% (v/v), and the mean particle size was 248 nm. In EHT, CcEO and CcEOn (1.25 mg/mL) inhibited larval hatching by 98.4 and 97.1%, respectively. Three animals treated with CcEO died whereas in the group treated with CcEOn one animal died. The FEC and total worm burden of the treated groups did not differ from the negative control (p>0.05). The CcEOn showed efficacy only on H. contortus (p<0.05). In conclusion, nanoencapsulation reduced toxicity and increased efficacy on H. contortus.


Assuntos
Anti-Helmínticos/farmacologia , Cymbopogon/química , Nematoides/efeitos dos fármacos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Doenças dos Ovinos/parasitologia , Animais , Fezes/parasitologia , Feminino , Masculino , Nematoides/classificação , Nematoides/isolamento & purificação , Ovinos
2.
Vet Parasitol ; 272: 17-22, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31395200

RESUMO

In this study we aimed to evaluate the effect of Trichostrongylus colubriformis infection on digesta passage rate, rumen fermentation and lamb performance. Eighteen three-month-old Santa Ines castrated male lambs (16.9 ±â€¯1.43 kg of body weight) were randomly distributed in two experimental treatments: Infected with T. colubriformis (I, n = 9) and Uninfected (U, n = 9). The I lambs received a total of 45,000 L3 larvae of T. colubriformis (5,000 infective larvae, three times per week for three weeks). Daily feed intake was assessed using the I lambs as a reference for their respective pairs on the U group (pair-fed). Weight, body condition score and faeces (stool) samples were obtained every 15 days for 75 days. In both treatments, faecal egg count (FEC), digesta passage rate, rumen fermentation parameters, protozoa count and short chain fatty acids (SCFA) were evaluated. The lambs presented moderate infection (FEC = 620). The retention time of the digesta in the rumen-reticulum segment was lower (P < 0.05) in I lambs. The I lambs presented no inappetence, however, lower concentrations of total SCFA and butyrate, while higher acetate concentration were observed in these lambs (P < 0.05). The present findings highlight that T. colubriformis infection decreased the retention time (solid and liquid content) of the digesta in the rumen-reticulum, as well as negatively affected lamb growth.


Assuntos
Digestão , Doenças dos Ovinos/parasitologia , Tricostrongilose/veterinária , Animais , Apetite , Peso Corporal , Ingestão de Alimentos , Fezes/parasitologia , Masculino , Contagem de Ovos de Parasitas , Distribuição Aleatória , Ovinos/crescimento & desenvolvimento , Ovinos/parasitologia , Doenças dos Ovinos/patologia , Tricostrongilose/parasitologia , Tricostrongilose/patologia , Trichostrongylus
3.
Exp Parasitol ; 205: 107735, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31381870

RESUMO

Two experiments were performed to determine whether oral administration of copper oxide capsules controlled helminthic infections in Lacaune sheep without acute collateral effects on animal health. In experiment 1, 48 multiparous lactating sheep (60.1 ±â€¯8.5 kg) were stratified according to initial number of eggs (Haemonchus contortus) per gram of feces (EPG) and were assigned randomly to 1 of two treatments (24 sheep/treatment): no oral administration (control) or oral administration of two copper capsules (treated; approximately 58 mg copper/kg body weight). Blood and fecal samples were collected on days 0, 15 and 45. Animals treated with copper capsules showed lower of EPG, eosinophils, acetylcholinesterase (AChE) in whole blood, and lower butyrylcholinesterase (BChE) activity in serum. Treated sheep had higher erythrocyte numbers, hemoglobin concentrations, hematocrit, and lymphocyte numbers. In experiment 2, 12 male lambs negative for helminths and coccidia were assigned randomly to one of two treatments (six lambs/treatment): control or treated (one copper capsule; approximately 58 mg copper/kg body weight); the experiment was designed to determine whether the results of experiment 1 were due to treatment or parasitism. Blood samples were collected on days 0, 5, 10 and 15 and fecal samples were collected on days 0, 7 and 15. Treated animals showed greater concentrations of lymphocytes; however, treatment had no effect on other hemogram variables, AChE and BChE activities, or levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, creatinine, urea, albumin, total protein, and reactive oxygen species. These data suggest that copper capsules in dairy sheep efficiently controlled H. contortus infections. Treatment was not harmful to lambs during the first 15 days, i.e. there were no signs of acute toxicity.


Assuntos
Cobre/administração & dosagem , Hemoncose/veterinária , Helmintíase Animal/tratamento farmacológico , Lactação , Doenças dos Ovinos/tratamento farmacológico , Acetilcolinesterase/sangue , Administração Oral , Animais , Butirilcolinesterase/sangue , Cápsulas , Cobre/uso terapêutico , Indústria de Laticínios , Resíduos de Drogas , Eosinófilos/efeitos dos fármacos , Contagem de Eritrócitos/veterinária , Fezes/parasitologia , Feminino , Hemoncose/tratamento farmacológico , Hemoncose/prevenção & controle , Helmintíase Animal/sangue , Helmintíase Animal/prevenção & controle , Hematócrito/veterinária , Hemoglobinas/análise , Contagem de Linfócitos/veterinária , Masculino , Leite/química , Contagem de Ovos de Parasitas/veterinária , Paridade , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/sangue , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/prevenção & controle
4.
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
5.
Prev Vet Med ; 169: 104697, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311638

RESUMO

Malignant theileriosis of sheep and goats caused by Theileria lestoquardi is considered to be among the most important tick borne diseases in the Sudan. Information on the prevalence of the disease in different parts of the Sudan is limited. The purpose of this study was to estimate the prevalence of the disease in five states of the Sudan using molecular and serological assays. A total of 393 blood and serum samples from clinically asymptomatic sheep were analysed using nested reverse line blot (nRLB) and loop mediated isothermal amplification (LAMP), as well as an enzyme-linked immunosorbent assay (ELISA). The results indicated a sero-prevalence of 33.8% while RLB and LAMP assays revealed molecular prevalences of 29.5 and 22.6% respectively. The prevalence of Theileria lestoquardi varied significantly according to the geographical origin of the infected animals, whereas age and gender did not have a significant effect. RLB data indicated that T. lestoquardi usually occurred as a co-infection with the non-pathogenic Theileria ovis. Using RLB as a gold standard, a sensitivity of 68.1% and a specificity of 96.4% were recorded for LAMP and a sensitivity of 75.9% and a specificity of 83.8% for ELISA. The Kappa coefficient between nRLB and LAMP indicated a significant level of agreement (0.692), but only moderate concordance (0.572) between nRLB and ELISA. The results of the present study confirm and extend earlier findings regarding the widespread of T. lestoquardi infections in sheep in the Sudan. The data provide evidence that should enable the veterinary authorities to deploy appropriate control measures.


Assuntos
Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia , Theileria/isolamento & purificação , Theileriose/epidemiologia , Animais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Geografia , Masculino , Reação em Cadeia da Polimerase/veterinária , Prevalência , Ovinos , Doenças dos Ovinos/sangue , Sudão/epidemiologia , Theileriose/sangue
6.
Parasit Vectors ; 12(1): 339, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292008

RESUMO

BACKGROUND: The primary cause of parasitic gastroenteritis in small ruminants in temperate regions is the brown stomach worm, Teladorsagia circumcincta. Host immunity to this parasite is slow to develop, consistent with the ability of T. circumcincta to suppress the host immune response. Previous studies have shown that infective fourth-stage T. circumcincta larvae produce excretory-secretory products that are able to modulate the host immune response. The objective of this study was to identify immune modulatory excretory-secretory proteins from populations of fourth-stage T. circumcincta larvae present in two different host-niches: those associated with the gastric glands (mucosal-dwelling larvae) and those either loosely associated with the mucosa or free-living in the lumen (lumen-dwelling larvae). RESULTS: In this study excretory-secretory proteins from mucosal-dwelling and lumen-dwelling T. circumcincta fourth stage larvae were analysed using comparative 2-dimensional gel electrophoresis. A total of 17 proteins were identified as differentially expressed, with 14 proteins unique to, or enriched in, the excretory-secretory proteins of mucosal-dwelling larvae. One of the identified proteins, unique to mucosal-dwelling larvae, was a putative peroxiredoxin (T. circumcincta peroxiredoxin 1, Tci-Prx1). Peroxiredoxin orthologs from the trematode parasites Schistosoma mansoni and Fasciola hepatica have previously been shown to alternatively activate macrophages and play a key role in promoting parasite induced Th2 type immunity. Here we demonstrate that Tci-Prx1 is expressed in all infective T. circumcincta life-stages and, when produced as a recombinant protein, has peroxidase activity, whereby hydrogen peroxide (H2O2) is reduced and detoxified. Furthermore, we use an in vitro macrophage stimulation assay to demonstrate that, unlike peroxiredoxins from trematode parasites Schistosoma mansoni and Fasciola hepatica, Tci-Prx1 is unable to alternatively activate murine macrophage cells. CONCLUSIONS: In this study, we identified differences in the excretory-secretory proteome of mucosal-dwelling and lumen-dwelling infective fourth-stage T. circumcincta larvae, and demonstrated the utility of this comparative proteomic approach to identify excretory-secretory proteins of potential importance for parasite survival and/or host immune modulation.


Assuntos
Proteínas de Helminto/metabolismo , Peroxirredoxinas/metabolismo , Trichostrongyloidea/metabolismo , Animais , Eletroforese em Gel Bidimensional , Proteínas de Helminto/genética , Interações Hospedeiro-Parasita , Peróxido de Hidrogênio/metabolismo , Enteropatias Parasitárias , Larva/imunologia , Larva/metabolismo , Camundongos , Membrana Mucosa/parasitologia , Peroxirredoxinas/genética , Proteoma/análise , Proteômica , Ovinos/parasitologia , Doenças dos Ovinos/parasitologia , Trichostrongyloidea/imunologia
7.
Parasit Vectors ; 12(1): 342, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300008

RESUMO

BACKGROUND: This study investigated the epidemiological and molecular aspects of dicrocoeliosis in extensive sheep farms. METHODS: From 2013 to 2014, copromicroscopical analyses in 190 dairy sheep farms and anatomo-pathological inspections in six slaughterhouses were carried in Sardinia, Italy. Rectal faecal samples were analyzed using the FLOTAC® method, and anatomo-pathological examinations were based on detecting thickened terminal bile ducts (TTBDs). In addition, genetic analyses were conducted on representative DNA samples of adult Dicrocoelium spp. RESULTS: Ninety-seven (51.1%) out of 190 sheep farms were coprologically positive for Dicrocoelium spp. In the liver, on the surface and cut surface, TTBDs were reported in 40.1% (309/770) and 15.3% (118/770) of the animals examined, respectively, with an overall prevalence of 25.5% (196/770). No intraspecific genetic variation was observed among the Dicrocoelium dendriticum isolates. CONCLUSIONS: Our survey reveals the widespread presence of D. dendriticum in Sardinia, although seasonal, geographical and climatic conditions might be key factors in modulating the infection prevalence. Examining typical lesions due to D. dendriticum in the liver in abattoirs can be used as a marker for tracking chronic dicrocoeliosis infection.


Assuntos
Dicrocelíase/veterinária , Fazendas/estatística & dados numéricos , Doenças dos Ovinos/epidemiologia , Ovinos/parasitologia , Matadouros , Animais , DNA de Helmintos/genética , Dicrocelíase/epidemiologia , Dicrocoelium/genética , Dicrocoelium/isolamento & purificação , Fezes/parasitologia , Itália/epidemiologia , Fígado , Doenças dos Ovinos/parasitologia , Inquéritos e Questionários
8.
Parasit Vectors ; 12(1): 346, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300017

RESUMO

BACKGROUND: Oestrosis, caused by the larvae of Oestrus ovis, commonly known as sheep nose bot, is an obligatory cavitary myiasis of sheep and goats. Oestrus ovis is a widespread parasite, but little is known about the prevalence of oestrosis at the global and broad geographical levels. The present study aimed to explore the epidemiology of oestrosis at the global and regional level to estimate prevalences and their associated factors using a systematic approach. This is, to the author's knowledge, the first meta-analysis of oestrosis in sheep and goats. METHODS: Published articles were obtained from nine electronic databases (PubMed, CAB Abstracts, Web of Science, Scopus, UCB library, Medline, Biosis Citation Index, Indian journals and Google Scholar) reporting the prevalence of O. ovis in sheep and goats from 1970 to 2018. Pooled prevalences were estimated using a random effect meta-analysis model. RESULTS: Sixty-six studies were eligible, and data from 40,870 sheep and 18,216 goats were used for quantitative analysis. The random effect estimated prevalence of oestrosis at the global level in sheep was 51.15% (95% CI: 42.80-59.51%) and in goats was 42.19% (95% CI: 33.43-50.95%). The pooled prevalence estimates for Africa, Asia, Europe and the Americas were 47.85% (95% CI: 36.04-59.66%), 44.48% (95% CI: 33.09-55.87%), 56.83% (95% CI: 48.92-64.74%) and 34.46% (95% CI: 19.90-49.01%), respectively. Heterogeneity (I2 > 80%) was detected in most pooled estimates. CONCLUSIONS: Oestrosis is highly prevalent in many geographical regions of the world, especially in Europe and Africa. Factors that contribute to the pooled prevalence estimate of oestrosis need to be emphasised in any survey to estimate the true prevalence of oestrosis. Furthermore, there is a need for immunisation or implementation of other preventive measures to reduce the burden of oestrosis in sheep and goats and to improve the health and welfare status.


Assuntos
Dípteros , Ectoparasitoses/veterinária , Doenças das Cabras/epidemiologia , Miíase/veterinária , Doenças dos Ovinos/epidemiologia , Animais , Bases de Dados Factuais , Ectoparasitoses/epidemiologia , Feminino , Doenças das Cabras/parasitologia , Cabras/parasitologia , Larva , Masculino , Miíase/epidemiologia , Nariz/parasitologia , Prevalência , Estações do Ano , Ovinos/parasitologia , Doenças dos Ovinos/parasitologia
9.
Exp Parasitol ; 205: 107714, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31279927

RESUMO

The objective of the present study was to evaluate the clinical signs, electrocardiographic signs and evolution of histopathological lesions in the heart of sheep experimentally infected by Trypanosoma vivax during the acute and chronic phases of infection as well as to investigate the presence of parasitic DNA in the heart using polymerase chain reaction (PCR). Twenty-two male sheep were divided into the following four groups: G1, which consisted of six sheep infected by T. vivax that were evaluated until 20 days post-infection (dpi; acute phase); G2, which consisted of six sheep infected by T. vivax that were evaluated until 90 dpi (chronic phase); and G3 and G4 groups, which each consisted of five uninfected sheep. At the end of the experimental period, electrocardiographic evaluations and necroscopic examinations were performed. Fragments of the heart were collected and stained by Hematoxylin-Eosin and Masson's trichrome, and the fragments were also evaluated by PCR for T. vivax. G2 animals presented clinical signs suggestive of heart failure and electrocardiogram alterations characterized by prolonged P, T and QRS complex durations as well as by a cardiac electrical axis shift to the left and increased heart rate. In these animals, mononuclear multifocal myocarditis and interstitial fibrosis were also observed. PCR revealed positivity for T. vivax in two G1 animals and in all G2 animals. Thus, these findings suggested that T. vivax is responsible for the occurrence of cardiac lesions, which are related to heart failure, electrocardiographic alterations and mortality of the infected animals.


Assuntos
DNA de Protozoário/isolamento & purificação , Insuficiência Cardíaca/veterinária , Coração/parasitologia , Doenças dos Ovinos/parasitologia , Trypanosoma vivax/patogenicidade , Tripanossomíase Africana/veterinária , Doença Aguda , Animais , Anticorpos Antiprotozoários/sangue , Doença Crônica/veterinária , Eletrocardiografia/veterinária , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/parasitologia , Imunoglobulina G/sangue , Masculino , Miocárdio/patologia , Parasitemia/veterinária , Pericardite/parasitologia , Pericardite/patologia , Pericardite/veterinária , Reação em Cadeia da Polimerase/veterinária , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/mortalidade , Doenças dos Ovinos/patologia , Trypanosoma vivax/genética , Trypanosoma vivax/imunologia , Trypanosoma vivax/isolamento & purificação , Tripanossomíase Africana/complicações , Tripanossomíase Africana/mortalidade , Tripanossomíase Africana/patologia
10.
Rev Bras Parasitol Vet ; 28(2): 258-265, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271641

RESUMO

Cysticercus ovis or sheep measles is the larval stage of Taenia ovis, which is the intestinal tapeworm of dogs. It is found in the cardiac and skeletal muscles of sheep and can be the cause of partial or total condemnation of carcasses at abattoirs. The aim of the current work was to determine the prevalence of C. ovis among sheep in Upper Egypt and to present the molecular and phylogenetic analysis of this using the amplified Mitochondrial Cytochrome Oxidase subunit 1 (MT-CO1) gene. A total of 1885 sheep slaughtered at local abattoirs of 4 different governorates of Upper Egypt (Asuit, Sohag, Qena and Aswan) were carefully examined for C. ovis. The overall prevalence of infection was 2.02%. The highest rate of infection was observed in adult animals over 4 years of age (44.73%). There was no significant effect of animal sex on infection rates. The phylogenic analysis of C. ovis Egyptian isolates showed very close similarity to the New Zealand isolate (AB731675). This is the first report showing the genetic analysis of C. ovis in Egypt, which provides a very powerful tool for taxonomy and definitive diagnosis of C. ovis, which could be helpful for preventive and control programs.


Assuntos
Cisticercose/veterinária , Cysticercus/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Doenças dos Ovinos/parasitologia , Ovinos/parasitologia , Matadouros , Animais , Cisticercose/epidemiologia , Cysticercus/isolamento & purificação , Egito/epidemiologia , Perfilação da Expressão Gênica , Filogenia , Prevalência , Fatores de Risco , Doenças dos Ovinos/epidemiologia
11.
Genet Sel Evol ; 51(1): 37, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31269896

RESUMO

BACKGROUND: This study aimed at identifying genomic regions that underlie genetic variation of worm egg count, as an indicator trait for parasite resistance in a large population of Australian sheep, which was genotyped with the high-density 600 K Ovine single nucleotide polymorphism array. This study included 7539 sheep from different locations across Australia that underwent a field challenge with mixed gastrointestinal parasite species. Faecal samples were collected and worm egg counts for three strongyle species, i.e. Teladorsagia circumcincta, Haemonchus contortus and Trichostrongylus colubriformis were determined. Data were analysed using genome-wide association studies (GWAS) and regional heritability mapping (RHM). RESULTS: Both RHM and GWAS detected a region on Ovis aries (OAR) chromosome 2 that was highly significantly associated with parasite resistance at a genome-wise false discovery rate of 5%. RHM revealed additional significant regions on OAR6, 18, and 24. Pathway analysis revealed 13 genes within these significant regions (SH3RF1, HERC2, MAP3K, CYFIP1, PTPN1, BIN1, HERC3, HERC5, HERC6, IBSP, SPP1, ISG20, and DET1), which have various roles in innate and acquired immune response mechanisms, as well as cytokine signalling. Other genes involved in haemostasis regulation and mucosal defence were also detected, which are important for protection of sheep against invading parasites. CONCLUSIONS: This study identified significant genomic regions on OAR2, 6, 18, and 24 that are associated with parasite resistance in sheep. RHM was more powerful in detecting regions that affect parasite resistance than GWAS. Our results support the hypothesis that parasite resistance is a complex trait and is determined by a large number of genes with small effects, rather than by a few major genes with large effects.


Assuntos
Enteropatias Parasitárias/veterinária , Doenças dos Ovinos/genética , Doenças dos Ovinos/parasitologia , Animais , Austrália , Mapeamento Cromossômico/veterinária , Resistência à Doença/genética , Fezes/parasitologia , Estudo de Associação Genômica Ampla/veterinária , Hereditariedade , Enteropatias Parasitárias/genética , Ovinos/genética
12.
Vet Parasitol ; 271: 14-21, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31303198

RESUMO

Foraging behavior by parasitized herbivores can be interpreted as a decision-making process where individuals are faced with trading-off the ingestion of nutrients with the ingestion of potentially medicinal -and toxic- plant secondary compounds. We determined how parasitized sheep prioritize selection of crude protein, energy and a medicinal plant secondary compound (quebracho tannins-QT). Foraging preferences were tested in 40 lambs before experiencing a parasitic infection (Phase 1), during an infection (Phase 2; 10,000 L3Haemonchus contortus per lamb) and after chemotherapy (Phase 3). Lambs were assigned to four groups (10 lambs/group) such that animals in Group 1 (Control) could choose between foods of high (HEP) or low (LEP) energy to protein ratios. The other groups received the same choice, but QT were added (4%) to HEP (Group 2), to LEP (Group 3) or to both foods (Group 4). All groups under a parasitic infection (Phase 2) increased their preference for HEP (from 0.44 to 0.66 ±â€¯0.042; P < 0.05) and intake of digestible energy (from 0.106 to 0.126 ±â€¯0.007 Mcal/kg BW; P < 0.05) relative to Phase 1, a pattern that remained during Phase 3. Only lambs receiving QT in HEP increased their intake of QT from Phase 1 to Phase 2 (P < 0.05). Fecal egg counts and blood parameters revealed a parasitic infection (P < 0.05) in Phase 2 that subsided in Phase 3, although no differences were detected among groups (P > 0.05). The importance of protein nutrition on parasitized animals has been highlighted before, but these results suggest that lambs prioritized the ingestion of energy-dense over protein-dense foods or medicinal condensed tannins when challenged by gastrointestinal parasitism. Consumption of medicinal tannins represented a side-effect of the preference manifested for energy-dense foods during testing.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Dieta/veterinária , Ovinos/fisiologia , Ovinos/parasitologia , Animais , Comportamento Alimentar/fisiologia , Preferências Alimentares/fisiologia , Nutrientes/metabolismo , Doenças dos Ovinos/parasitologia , Taninos/metabolismo
13.
Exp Appl Acarol ; 78(2): 223-229, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31172458

RESUMO

Protozoan parasites of the genus Babesia and Theileria are significant tick-borne pathogens of domestic animals and cause economic losses to the livestock industry in tropical and subtropical regions worldwide. In this study, 274 blood samples and 32 tick samples were collected from four counties of Wuwei City in northwestern China in June and July in 2018. The DNA from the field samples was analyzed for Babesia or Theileria infection using specific PCR and sequencing based on 18S rRNA gene fragments. The total infection rates were 0.4% for B. motasi and T. separata (both 1/274) in sheep, 3.1% for T. annulata (1/32), 6.2% for B. occultans (2/32) and 9.4% for B. bigemina (3/32) in ticks, respectively. In particular, T. separata has been for the first time detected in sheep in China and B. occultans in Hyalomma asiaticum from Gansu Province of China.


Assuntos
Babesia/isolamento & purificação , Babesiose/epidemiologia , Doenças dos Ovinos/epidemiologia , Theileria/isolamento & purificação , Theileriose/epidemiologia , Animais , Babesia/genética , Babesiose/microbiologia , China/epidemiologia , Filogenia , RNA Bacteriano/análise , RNA Ribossômico 18S/análise , Análise de Sequência de RNA/veterinária , Ovinos , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/parasitologia , Theileria/genética , Theileriose/parasitologia
14.
Vet Parasitol ; 270: 31-39, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213239

RESUMO

Breeding for resistance to gastrointestinal nematodes (GIN) in sheep relies largely on the use of worm egg counts (WEC) to identify animals that are able to resist infection. As an alternative to such measures of parasite load we aimed to develop a method to identify animals showing resistance to GIN infection based on the impact of the infection on blood parameters. We hypothesized that blood parameters may provide a measure of infection level with a blood-feeding parasite through perturbation of red blood cell parameters due to feeding behaviour of the parasite, and white blood cell parameters through the mounting of an immune response in the host animal. We measured a set of blood parameters in 390 sheep that had been exposed to an artificial regime of repeated challenges with Trichostrongylus colubriformis followed by Haemonchus contortus. A simple analysis revealed strong relationships between single blood parameters and WECs with correlation coefficients -0.54 to -0.60. We then used more complex multi-variate methods based on supervised classifier models (including Bayesian Network) as well as regression models (Lasso and Elastic Net) to study the relationships between WECs and blood parameters, and derived algorithms describing the relationships. The ability of these algorithms to classify sheep GIN resistance status was tested using the WEC and blood parameters collected from a different group of 418 sheep that had acquired natural infections of H. contortus from pasture. We identified the most resistant and most susceptible animals (10% percentiles) of this group based on WECs, and then compared the identities of these animals to the identities of animals that were predicted to be most resistant and most susceptible by our algorithms. The models showed varying abilities to predict susceptible and resistant sheep, with up to 65% of the most susceptible animals and 30% of the most resistant animals identified by the Elastic Net model algorithms. The prediction algorithms derived from female sheep data performed better than those for male sheep in some cases, with the predicted animals accounting for up to 50-60% of the actual resistant and susceptible female animals. Heritability values were calculated for blood parameters and the aggregate trait descriptions defined by the novel prediction algorithms. The aggregate trait descriptions were moderately heritable and may therefore be suitable for use in genetic selection strategies. The present study indicates that multivariate models based on blood parameter data showed some ability to predict the resistance status of sheep to infection with H. contortus.


Assuntos
Resistência à Doença , Modelos Biológicos , Infecções por Nematoides/veterinária , Doenças dos Ovinos/sangue , Doenças dos Ovinos/parasitologia , Algoritmos , Animais , Análise Química do Sangue , Cruzamento , Feminino , Masculino , Nematoides , Infecções por Nematoides/sangue , Infecções por Nematoides/imunologia , Ovinos , Doenças dos Ovinos/imunologia
15.
Parasit Vectors ; 12(1): 312, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31234937

RESUMO

BACKGROUND: Babesiosis is an economically important disease caused by tick-borne apicomplexan protists of the genus Babesia. Most apicomplexan parasites, including Babesia, have a plastid-derived organelle termed an apicoplast, which is involved in critical metabolic pathways such as fatty acid, iron-sulphur, haem and isoprenoid biosynthesis. Apicoplast genomic data can provide significant information for understanding and exploring the biological features, taxonomic and evolutionary relationships of apicomplexan parasites, and identify targets for anti-parasitic drugs. However, there are limited data on the apicoplast genomes of Babesia species infective to small ruminants. METHODS: PCR primers were designed based on the previously reported apicoplast genome sequences of Babesia motasi Lintan and Babesia sp. Xinjiang using Illumina technology. The overlapped apicoplast genomic fragments of six ovine Babesia isolates were amplified and sequenced using the Sanger dideoxy chain-termination method. The full-length sequences of the apicoplast genomes were assembled and annotated using bioinformatics software. The gene contents and order of apicoplast genomes obtained in this study were defined and compared with those of other apicomplexan parasites. Phylogenetic trees were constructed on the concatenated amino acid sequences of 13 gene products using MEGA v.6.06. RESULTS: The results showed that the six ovine Babesia apicoplast genomes consisted of circular DNA. The genome sizes were 29,916-30,846 bp with 78.7-81.0% A + T content, 29-31 open reading frames (ORF) and 23-24 transport RNAs. The ORFs encoded four DNA-directed RNA polymerase subunits (rpoB, rpoCl, rpoC2a and rpoC2b), 13 ribosomal proteins, one elongation factor TU (tufA), two ATP-dependent Clp proteases (ClpC) and 7-11 hypothetical proteins. Babesia sp. has three more genes than Babesia motasi (rpl5, rps8 and rpoB). Phylogenetic analysis showed that Babesia sp. is located in a separate clade. Babesia motasi Lintan/Tianzhu and B. motasi Ningxian/Hebei were divided into two subclades. CONCLUSIONS: To our knowledge, this study is the first to elucidate the whole apicoplast genomic structural features of six Babesia isolates infective to small ruminants in China using Sanger sequencing. The data provide useful information confirming the taxonomic relationships of these parasites and identifying targets for anti-apicomplexan parasite drugs.


Assuntos
Apicoplastos/genética , Babesia/genética , Genoma de Protozoário , Ruminantes/parasitologia , Animais , Babesiose/epidemiologia , China , Biologia Computacional , Primers do DNA/genética , Anotação de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia
16.
Genet Sel Evol ; 51(1): 32, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31242855

RESUMO

BACKGROUND: This study aimed at (1) comparing the accuracies of genomic prediction for parasite resistance in sheep based on whole-genome sequence (WGS) data to those based on 50k and high-density (HD) single nucleotide polymorphism (SNP) panels; (2) investigating whether the use of variants within quantitative trait loci (QTL) regions that were selected from regional heritability mapping (RHM) in an independent dataset improved the accuracy more than variants selected from genome-wide association studies (GWAS); and (3) comparing the prediction accuracies between variants selected from WGS data to variants selected from the HD SNP panel. RESULTS: The accuracy of genomic prediction improved marginally from 0.16 ± 0.02 and 0.18 ± 0.01 when using all the variants from 50k and HD genotypes, respectively, to 0.19 ± 0.01 when using all the variants from WGS data. Fitting a GRM from the selected variants alongside a GRM from the 50k SNP genotypes improved the prediction accuracy substantially compared to fitting the 50k SNP genotypes alone. The gain in prediction accuracy was slightly more pronounced when variants were selected from WGS data compared to when variants were selected from the HD panel. When sequence variants that passed the GWAS [Formula: see text] threshold of 3 across the entire genome were selected, the prediction accuracy improved by 5% (up to 0.21 ± 0.01), whereas when selection was limited to sequence variants that passed the same GWAS [Formula: see text] threshold of 3 in regions identified by RHM, the accuracy improved by 9% (up to 0.25 ± 0.01). CONCLUSIONS: Our results show that through careful selection of sequence variants from the QTL regions, the accuracy of genomic prediction for parasite resistance in sheep can be improved. These findings have important implications for genomic prediction in sheep.


Assuntos
Doenças dos Ovinos/genética , Doenças dos Ovinos/parasitologia , Sequenciamento Completo do Genoma/veterinária , Animais , Austrália , Resistência à Doença/genética , Feminino , Marcadores Genéticos , Testes Genéticos/veterinária , Variação Genética , Estudo de Associação Genômica Ampla/veterinária , Masculino , Contagem de Ovos de Parasitas/veterinária , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Ovinos
17.
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
18.
Turkiye Parazitol Derg ; 43(2): 92-95, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31204464

RESUMO

During the routine postmortem inspection from carcasses and offal of slaughtered ewes in an abattoir in Isfahan (Iran), an ovine heart was discovered with a firm nodule in the myocard on palpation. In closer examination, a liquid containing cyst (1x1 cm) was recognized on left part of the heart. The cyst had thick fibrotic capsule in outer surface and a thin inner layer containing few white clusters of scolices. White clusters contained scolices that adhered to the inner transparent layer, like white beads. Based on the gross and microscopical characteristics, the cyst was diagnosed as non-cerebral coenurus cyst. This is a rare report of heart coenurosis in a sheep.


Assuntos
Cestoides/isolamento & purificação , Infecções por Cestoides/veterinária , Coração/parasitologia , Doenças dos Ovinos/diagnóstico , Matadouros , Animais , Autopsia/veterinária , Cestoides/anatomia & histologia , Cestoides/classificação , Infecções por Cestoides/diagnóstico , Infecções por Cestoides/patologia , Feminino , Miocárdio/patologia , Ovinos , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/patologia
19.
Parasitol Int ; 72: 101930, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31121267

RESUMO

Recently, phosphoenol pyruvate carboxykinase (pepck) and DNA polymerase delta (pold) were established as reliable nuclear markers for species identification of Fasciola spp. in multiplex polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism-based assays, respectively. Currently, little is known about Fasciola species distribution in Central Asia. Therefore, the objective of the present study was to perform precise molecular species identification of liver flukes from Afghanistan and to reveal their dispersal route(s) via phylogenetic analysis based on mitochondrial nad1 haplotypes. Ninety-two Fasciolaflukes collected from sheep in Kabul, Afghanistan, were identified as F. hepatica based on pepck and pold screening. Although the pepck fragment pattern obtained via multiplex PCR analysis could not distinguish the species of the seven Fasciola flukes, the pepck nucleotide sequence data confirmed that they were F. hepatica.The 20 nad1 haplotypes detected among the Afghani liver flukes were closely related to those from China and Egypt, with the FSTvalue (-0.003, P = .41) between the F. hepatica populations from Afghanistan and China confirming a very close relationship. Nucleotide diversity was greater in the population from Afghanistan compared with that from China, indicating that the Afghani population was older, and that the dispersal direction of F. hepatica was from Afghanistan to China. The results of the present study contribute to our understanding of the dispersal of F. hepatica from its predicted origin, the Fertile Crescent.


Assuntos
DNA de Helmintos/genética , Fasciola/genética , Fasciolíase/veterinária , Doenças dos Ovinos/epidemiologia , Afeganistão/epidemiologia , Animais , China/epidemiologia , DNA Polimerase III/genética , Fasciola/isolamento & purificação , Fasciolíase/epidemiologia , Variação Genética , Haplótipos , NADH Desidrogenase/genética , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Ovinos/parasitologia , Doenças dos Ovinos/parasitologia
20.
Korean J Parasitol ; 57(2): 153-159, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31104407

RESUMO

Echinococcus granulosus is an important zoonotic parasite globally causing cystic echinococcosis (CE) in humans and animals. In this study, prevalence of CE and variation of cox1 gene sequence were analyzed with isolates E. granulosus collected from different areas in northern Xinjiang, China. The survey showed that 3.5% of sheep and 4.1% of cattle were infected with CE. Fragment of cox1 was amplified from all the positive sheep and cattle samples by PCR. In addition, 26 positive samples across the 4 areas were included. The isolates were all E. granulosus sensu stricto (s.s.) containing 15 haplotypes (Hap1-15), and clustered into 2 genotypes, G1 (90.1%, 91/101) and G3 (9.9%, 10/101). Hap1 was the most common haplotype (48.5%, 49/101). Hap9 were found in humans samples, indicating that sheep and cattle reservoir human CE. It is indicate that E. granulosus may impact on control of CE in livestock and humans in the region.


Assuntos
Doenças dos Bovinos/epidemiologia , Equinococose/epidemiologia , Equinococose/veterinária , Echinococcus granulosus/genética , Echinococcus granulosus/isolamento & purificação , Doenças dos Ovinos/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , China/epidemiologia , Análise por Conglomerados , Equinococose/parasitologia , Echinococcus granulosus/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genótipo , Humanos , Epidemiologia Molecular , Prevalência , Ovinos , Doenças dos Ovinos/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA