RESUMO
In dairy sheep flocks from Mediterranean countries, replacement and adult ewes are the animals most affected by gastrointestinal nematode (GIN) infections. In this study, we have exploited the information derived from an RNA-Seq experiment with the aim of identifying potential causal mutations related to GIN resistance in sheep. Considering the RNA-Seq samples from 12 ewes previously classified as six resistant and six susceptible animals to experimental infection by Teladorsagia circumcincta, we performed a variant calling analysis pipeline using two different types of software, gatk version 3.7 and Samtools version 1.4. The variants commonly identified by the two packages (high-quality variants) within two types of target regions - (i) QTL regions previously reported in sheep for parasite resistance based on SNP-chip or sequencing technology studies and (ii) functional candidate genes selected from gene expression studies related to GIN resistance in sheep - were further characterised to identify mutations with a potential functional impact. Among the genes harbouring these potential functional variants (930 and 553 respectively for the two types of regions), we identified 111 immune-related genes in the QTL regions and 132 immune-related genes from the initially selected candidate genes. For these immune-related genes harbouring potential functional variants, the enrichment analyses performed highlighted significant GO terms related to apoptosis, adhesion and inflammatory response, in relation to the QTL related variants, and significant disease-related terms such as inflammation, adhesion and necrosis, in relation to the initial candidate gene list. Overall, the study provides a valuable list of potential causal mutations that could be considered as candidate causal mutations in relation to GIN resistance in sheep. Future studies should assess the role of these suggested mutations with the aim of identifying genetic markers that could be directly implemented in sheep breeding programmes considering not only production traits, but also functional traits such as resistance to GIN infections.
Assuntos
Resistência à Doença/genética , Gastroenteropatias/veterinária , Doenças dos Ovinos/genética , Trichostrongyloidea/fisiologia , Tricostrongiloidíase/veterinária , Animais , Gastroenteropatias/genética , Gastroenteropatias/parasitologia , RNA-Seq/veterinária , Ovinos , Doenças dos Ovinos/parasitologia , Tricostrongiloidíase/genética , Tricostrongiloidíase/parasitologiaRESUMO
BACKGROUND: In this study, two traits related with resistance to gastrointestinal nematodes (GIN) were measured in 529 adult sheep: faecal egg count (FEC) and activity of immunoglobulin A in plasma (IgA). In dry years, FEC can be very low in semi-extensive systems, such as the one studied here, which makes identifying animals that are resistant or susceptible to infection a difficult task. A zero inflated negative binomial model (ZINB) model was used to calculate the extent of zero inflation for FEC; the model was extended to include information from the IgA responses. RESULTS: In this dataset, 64% of animals had zero FEC while the ZINB model suggested that 38% of sheep had not been recently infected with GIN. Therefore 26% of sheep were predicted to be infected animals with egg counts that were zero or below the detection limit and likely to be relatively resistant to nematode infection. IgA activities of all animals were then used to decide which of the sheep with zero egg counts had been exposed and which sheep had not been recently exposed. Animals with zero FEC and high IgA activity were considered resistant while animals with zero FEC and low IgA activity were considered as not recently infected. For the animals considered as exposed to the infection, the correlations among the studied traits were estimated, and the influence of these traits on the discrimination between unexposed and infected animals was assessed. CONCLUSIONS: The model presented here improved the detection of infected animals with zero FEC. The correlations calculated here will be useful in the development of a reliable index of GIN resistance that could be of assistance for the study of host resistance in studies based on natural infection, especially in adult sheep, and also the design of breeding programs aimed at increasing resistance to parasites.
Assuntos
Enteropatias Parasitárias/veterinária , Modelos Estatísticos , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Animais , Feminino , Imunoglobulina A/sangue , Contagem de Ovos de Parasitas/veterinária , Fenótipo , OvinosRESUMO
Inter-simple sequence repeats markers were used to determinate the genetic variability of Fasciola hepatica populations recovered from sheep and cattle from Spain (Sp1, Sp2, Sp3 and Sp4), UK (Eng), Ireland (Ir) and Mexico (Mex). Twenty five primers were tested but only five produced 39 reproducible bands, being 71.79% polymorphic bands. This percentage ranged from 10.26% in Sp4 to 48.72% in Sp1, and per host between 28.21 and 48.72% in sheep and between 10.26 and 38.46% in cattle. This relatively low range of genetic diversity within populations, with a mean of 34.40%, implies that a large proportion of variation resided among populations. The population differentiation (Gst = 0.547) indicated that 54.7% of variation is due to differences between populations and 45.3% due to differences within population. The Nei's distance ranged between 0.091 and 0.230 in sheep and between 0.150 and 0.337 in cattle. The genetic relationships between populations and individuals were shown by a UPGMA dendrogram and a principal coordinate analysis; both grouped all populations separately from Sp4, a population of from the Midwest of Spain with the lowest level of diversity. Small genetic distances were observed between Eng and Ir, on the one hand, and Sp1, Sp2, Sp3, from the Northwest of Spain, together with Mex, on the other.
Assuntos
Doenças dos Bovinos/parasitologia , Fasciola hepatica/genética , Fasciolíase/veterinária , Variação Genética , Doenças dos Ovinos/parasitologia , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Primers do DNA/genética , Fasciola hepatica/classificação , Fasciolíase/epidemiologia , Fasciolíase/parasitologia , Marcadores Genéticos , Irlanda/epidemiologia , Fígado/parasitologia , México/epidemiologia , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Ovinos , Doenças dos Ovinos/epidemiologia , Espanha/epidemiologia , Reino Unido/epidemiologiaRESUMO
In the current study, we identified five sheep flocks with fasciolosis in the province of León (northwestern Spain) in order to determine the anthelmintic resistance status to three commonly used anthelmintics, namely albendazole (ABZ), triclabendazole (TCBZ) and clorsulon (CLOR). The identification of one flock resistant to ABZ and CLOR was shown after the faecal egg count reduction test (FECRT). The reductions in eggs per gram values were -17.6% and -68% against immature and adult flukes, respectively, after ABZ treatment; 85.15% and 44.91% against immature and adult flukes, respectively, after CLOR treatment; and 97.06% against both stages, after the administration of TCBZ. As an alternative to control the infection, two combinations of ABZ and CLOR were tested. In the first, both drugs were administered at the recommended dose of each; in this case, the efficiency reached values above 95% against both immature and adult flukes. However, when the combined drugs were administered at half the recommended dose of each, the efficiency of the combination was very low, i.e. 16.67% and -11.11% against mature and immature flukes, respectively. In conclusion, this preliminary report suggests a possible interaction between ABZ and CLOR after their joint administration. However, these results should be confirmed in other flocks.
Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Doenças dos Ovinos/tratamento farmacológico , Sulfanilamidas/uso terapêutico , Administração Oral , Albendazol/administração & dosagem , Albendazol/farmacologia , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/farmacologia , Benzimidazóis/administração & dosagem , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Resistência a Múltiplos Medicamentos , Quimioterapia Combinada , Fasciolíase/tratamento farmacológico , Fezes/parasitologia , Feminino , Injeções Subcutâneas/veterinária , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/parasitologia , Sulfanilamidas/administração & dosagem , Sulfanilamidas/farmacologia , TriclabendazolRESUMO
The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium was evaluated in sheep experimentally infected with Fasciola hepatica. Animals were divided into four groups: two treated with the LPS (T1/T2) and two controls (C1/C2). T1/C1 were slaughtered at 30 days postinfection (dpi) and T2/C2 at 85 dpi. Body weight and body condition were found higher in T1 and T2 than in controls, although differences were not significant. Treated sheep showed lower cumulative fecal egg count than controls (p < 0.01). Levels of red blood cells (RBC), white blood cells, hemoglobin, and hematocrit (HCT) were higher in T1 and T2. Significant differences (p < 0.05) in RBC and HCT were found between groups at 84 dpi. More severe macrocytic and hypochromic anemia was observed in C1 and C2 than in treated groups. Total protein and albumin values were higher in T1 and T2 (p < 0.01) until 29 dpi. At the end of the trial, no significant differences were observed in hepatic enzymes, although gamma-glutamyl transferase and aspartate aminotransferase values were higher in C2, and alanine aminotransferase was higher in T2. At necropsy, the mean weight of liver, fibrosis in portal triads, and ganglion size were similar in all groups. The number and size of flukes was greater in C2 than in T2 (p < 0.05). The histological examinations revealed a higher degree of parenchymatous fibrosis in T2 compared to C2 (p < 0.05). The administration of LPS from O. intermedium increased the nonspecific resistance against F. hepatica in experimentally infected sheep.
Assuntos
Fasciola hepatica/imunologia , Fasciolíase/veterinária , Fatores Imunológicos/farmacologia , Lipopolissacarídeos/farmacologia , Ochrobactrum , Doenças dos Ovinos/parasitologia , Animais , Fasciolíase/tratamento farmacológico , Fasciolíase/parasitologia , Imunomodulação/imunologia , Ovinos , Doenças dos Ovinos/tratamento farmacológicoRESUMO
The aim of this work was to know the anthelmintic resistance (AR) status of a Spanish sheep flock infected by gastrointestinal nematodes (GIN) and the possible cross resistance among anthelmintics of the macrocyclic lactones (ML) family. The Faecal Egg Count Reduction Test (FECRT) was carried out to check the efficacy of albendazole (Zodalben®), levamisole (LEV) (Endex®) and an oral formulation of ivermectin (IVM) (Oramec®), at the recommended dose rates. Then, the study was extended to check the cross resistance between drugs of the ML family: injectable IVM (Ivomec®), oral moxidectin (Cydectin®), injectable moxidectin (Biodectin®) and doramectin (Dectomax®), at the recommended dose rates. The GIN species were identified after faecal cultures in all groups. The FECRT showed the resistance of a Teladorsagia circumcincta isolate against LEV (39-58%), IVM (88-92%) and doramectin (85%). This study is the first report to confirm the side resistance between these MLs, which belong to the avermectin chemical group, in a Spanish sheep flock. The in vitro efficacy of LEV and IVM was measured by the Larval Feeding Inhibition Assay (LFIA) using the IC(50) measurement (concentration needed to inhibit the ingestion of 50% L1). The values of the multidrug resistant isolate were 0.25 µg/ml for LEV and 3 ng/ml for IVM. Both results were higher than the values obtained with a susceptible isolate, which could be indicative of AR. However, further research examining the response of a greater range of susceptible and resistant nematodes isolates should be carried out to establish a discrimination threshold.
Assuntos
Anti-Helmínticos/farmacologia , Resistência a Múltiplos Medicamentos , Ovinos/parasitologia , Trichostrongyloidea/efeitos dos fármacos , Trichostrongyloidea/isolamento & purificação , Administração Oral , Animais , Anti-Helmínticos/administração & dosagem , Fezes/microbiologia , Concentração Inibidora 50 , Injeções Intravenosas , Contagem de Ovos de Parasitas , EspanhaRESUMO
Anthelmintic resistance (AR) is a growing concern for effective parasite control in farmed ruminants globally. Combatting AR will require intensified and integrated research efforts in the development of innovative diagnostic tests to detect helminth infections and AR, sustainable anthelmintic treatment strategies and the development of complementary control approaches such as vaccination and plant-based control. It will also require a better understanding of socio-economic drivers of anthelmintic treatment decisions, in order to support a behavioural shift and develop targeted communication strategies that promote the uptake of evidence-based sustainable solutions. Here, we review the state-of-the-art in these different fields of research activity related to AR in helminths of livestock ruminants in Europe and beyond. We conclude that in the advent of new challenges and solutions emerging from continuing spread of AR and intensified research efforts, respectively, there is a strong need for transnational multi-actor initiatives. These should involve all key stakeholders to develop indicators of infection and sustainable control, set targets and promote good practices to achieve them.
Assuntos
Anti-Helmínticos , Helmintíase Animal , Helmintos , Nematoides , Infecções por Nematoides , Doenças dos Ovinos , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos , Helmintíase Animal/tratamento farmacológico , Gado , Infecções por Nematoides/parasitologia , Ruminantes/parasitologia , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/prevenção & controleRESUMO
Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.
Assuntos
Nematoides , Parasitos , Animais , Inteligência Artificial , Gado , Animais de Estimação , ProteômicaRESUMO
To determine whether purified Ascaris suum haemoglobin (AsHb) is a suitable vaccine candidate for the control of Ascaris infections, pigs were vaccinated with AsHb in combination with QuilA adjuvant and challenged with A. suum eggs. The number of liver lesions and worms in the intestine was assessed on day 14, 28 and 56 post-infection (p.i.). No significant differences were found in the number of worms recovered between vaccinated and control pigs on any of these days. However, significantly more white spots were counted on the livers of vaccinated pigs on day 14 (+86%) and day 28 (+118%) p.i. compared with nonvaccinated controls. To investigate whether the increased immunoreactivity against the liver stage L3s in vaccinated pigs was triggered by and directed against AsHb, the transcription and expression of AsHb in this larval life stage was analysed by RT-PCR and immunoblotting. The results showed that neither the AsHb transcript nor protein was detectable in freshly hatched L3. However, the immunoblot analysis showed that vaccination with AsHb resulted in the production of antibodies binding to several other antigens of the L3, suggesting that these might be involved in the increased white spot development.
Assuntos
Ascaris suum/imunologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Hemoglobinas/imunologia , Fígado/patologia , Vacinas/efeitos adversos , Adjuvantes Imunológicos/administração & dosagem , Animais , Ascaris suum/patogenicidade , Hemoglobinas/toxicidade , Saponinas de Quilaia , Saponinas/administração & dosagem , Suínos , Vacinas/imunologiaRESUMO
The aim of this study was to develop, perfect and validate the PCR (polymerase chain reaction) technique using mitochondrial (mt) and ribosomal (ITS-2) DNA for the accurate identification of Dicrocoelium dendriticum in molluscs and ants, the first and second intermediate hosts, and their early detection. The first primers that were designed amplified a 169 pb mtDNA fragment of D. dendriticum permitted the detection of a single D. dendriticum metacercaria from the Formica rufibarbis and Formica pratensis abdomen, as well as the detection of the brainworm in the head of the ants collected in tetania. Although these primers did not amplify Dicrocoelium chinensis DNA and permitted detected D. dendriticum in the molluscs, they did not discriminate Brachylaimidae metacercariae found in the same mollusc. The PCR that was designed to amplify a 93 bp fragment of the ITS-2 is D. dendriticum specific as it did not amplify D. chinensis, Brachylaimidae and other trematodes. This technique is very sensitive since it permitted the detection of D. dendriticum in the molluscs from the first day post-infection, the brainworm in the head of the ants and only 1 D. dendriticum metacercaria from the abdomen of the ants. Both techniques are important, mainly the latter.
Assuntos
Formigas/parasitologia , Dicrocoelium/isolamento & purificação , Moluscos/parasitologia , Animais , Sequência de Bases , Primers do DNA/genética , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Dicrocoelium/genética , Mitocôndrias/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/veterinária , Sensibilidade e Especificidade , Análise de Sequência de DNA/veterinária , Especificidade da EspécieRESUMO
We report a European wide assessment of the economic burden of gastrointestinal nematodes, Fasciola hepatica (common liver fluke) and Dictyocaulus viviparus (bovine lungworm) infections to the ruminant livestock industry. The economic impact of these parasitic helminth infections was estimated by a deterministic spreadsheet model as a function of the proportion of the ruminant population exposed to grazing, the infection frequency and intensity, the effect of the infection on animal productivity and mortality and anthelmintic treatment costs. In addition, we estimated the costs of anthelmintic resistant nematode infections and collected information on public research budgets addressing helminth infections in ruminant livestock. The epidemiologic and economic input data were collected from international databases and via expert opinion of the Working Group members of the European Co-operation in Science and Technology (COST) action COMbatting Anthelmintic Resistance in ruminants (COMBAR). In order to reflect the effects of uncertainty in the input data, low and high cost estimates were obtained by varying uncertain input data arbitrarily in both directions by 20 %. The combined annual cost [low estimate-high estimate] of the three helminth infections in 18 participating countries was estimated at 1.8 billion [ 1.0-2.7 billion]. Eighty-one percent of this cost was due to lost production and 19 % was attributed to treatment costs. The cost of gastrointestinal nematode infections with resistance against macrocyclic lactones was estimated to be 38 million [ 11-87 million] annually. The annual estimated costs of helminth infections per sector were 941 million [ 488 - 1442 million] in dairy cattle, 423 million [ 205-663 million] in beef cattle, 151million [ 90-213 million] in dairy sheep, 206 million [ 132-248 million] in meat sheep and 86 million [ 67-107 million] in dairy goats. Important data gaps were present in all phases of the calculations which lead to large uncertainties around the estimates. Accessibility of more granular animal population datasets at EU level, deeper knowledge of the effects of infection on production, levels of infection and livestock grazing exposure across Europe would make the largest contribution to improved burden assessments. The known current public investment in research on helminth control was 0.15 % of the estimated annual costs for the considered parasitic diseases. Our data suggest that the costs of enzootic helminth infections which usually occur at high prevalence annually in ruminants, are similar or higher than reported costs of epizootic diseases. Our data can support decision making in research and policy to mitigate the negative impacts of helminth infections and anthelmintic resistance in Europe, and provide a baseline against which to measure future changes.
Assuntos
Doenças dos Bovinos/economia , Efeitos Psicossociais da Doença , Infecções por Dictyocaulus/economia , Fasciolíase/veterinária , Doenças das Cabras/economia , Doenças dos Ovinos/economia , Animais , Bovinos , Dictyocaulus/fisiologia , Europa (Continente) , Fasciola hepatica/fisiologia , Fasciolíase/economia , Cabras , Ovinos , Carneiro DomésticoRESUMO
Fasciola hepatica is a trematode parasite with a global distribution, which is responsible for considerable disease and production losses in a range of food producing species. It is also identified by WHO as a re-emerging neglected tropical disease associated with endemic and epidemic outbreaks of disease in human populations. In Europe, F. hepatica is mostly associated with disease in sheep, cattle and goats. This study reviews the most recent advances in our understanding of the transmission, diagnosis, epidemiology and the economic impact of fasciolosis. We also focus on the impact of the spread of resistance to anthelmintics used to control F. hepatica and consider how vaccines might be developed and applied in the context of the immune-modulation driven by the parasite. Several major research gaps are identified which, when addressed, will contribute to providing focussed and where possible, bespoke, advice for farmers on how to integrate stock management and diagnosis with vaccination and/or targeted treatment to more effectively control the parasite in the face of increasing the prevalence of infection and spread of anthelmintic resistance that are likely to be exacerbated by climate change.
Assuntos
Doenças dos Bovinos/epidemiologia , Doenças Transmissíveis Emergentes/veterinária , Fasciola hepatica/patogenicidade , Fasciolíase/veterinária , Doenças das Cabras/epidemiologia , Doenças dos Ovinos/epidemiologia , Animais , Anti-Helmínticos/uso terapêutico , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/prevenção & controle , Doenças dos Bovinos/transmissão , Doenças Transmissíveis Emergentes/diagnóstico , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/transmissão , Europa (Continente)/epidemiologia , Fasciolíase/diagnóstico , Fasciolíase/epidemiologia , Fasciolíase/transmissão , Doenças das Cabras/diagnóstico , Doenças das Cabras/prevenção & controle , Doenças das Cabras/transmissão , Cabras , Humanos , Prevalência , Ruminantes , Ovinos , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/prevenção & controle , Doenças dos Ovinos/transmissão , Vacinação/veterináriaRESUMO
Bacteria firmly attached to the gastrointestinal epithelium during the pre-weaning phase may show a significant impact on nutrient processing, immunity parameters, health and feed efficiency of lambs during post-weaning phases. Thus, the aim of this study was to describe the differences in the ileal epimural microbiota (e.g. total bacteria, Prevotella spp., Bifidobacterium spp. and Lactobacillus spp.) of fattening lambs promoted by early feed restriction during the suckling phase trying to elucidate some of the underlying mechanisms behind changes in feed efficiency during the fattening period. A total of 24 Merino lambs (average BW 4.81±0.256 kg) were used, 12 of them (ad libitum, ADL) kept permanently in individual pens with their mothers, whereas the other 12 lambs were separated from their dams for 9 h each day to be exposed to milk restriction (RES). After weaning (BW=15 kg) all the animals were penned individually, offered the same complete pelleted diet (35 g/kg BW per day) and slaughtered at a BW of 27 kg. During the fattening period, reduced gain : feed ratio (0.320 v. 0.261, P<0.001) was observed for the RES group. Moreover, increments of Prevotella spp. were detected in the ileal epimural microbiota of RES lambs (P<0.05). There were also higher numbers of infiltrated lymphocytes (T and B cells) in the ileal lamina propria (P<0.05), a higher M-cell labelling intensity in ileal Peyer's patches domes (P<0.05) and a trend towards a thickening of the submucosa layer when compared with the ADL group (P=0.057). Some other immunological parameters, such as an increased immunoglobulin A (IgA) production (pg IgA/µg total protein) and increments in CD45+ cells were also observed in the ileum of RES group (P<0.05), whereas transforming growth factor ß and toll-like receptor gene expression was reduced (P<0.05). In conclusion, early feed restriction during the suckling phase promoted changes in ileal epimural microbiota and several immunity parameters that could be related to differences in feed efficiency traits during the fattening period of Merino lambs.
Assuntos
Ração Animal , Microbioma Gastrointestinal , Carneiro Doméstico , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta , Microbiota , Ovinos , Carneiro Doméstico/fisiologiaRESUMO
The aim of the present study was to determine the association between the presence of Ascaris suum at fattening pig farms, using different serological methods and the percentage of affected livers at slaughter, with performance and management indices. In total, 21 fattening pig farms from the North of Spain were included in the study. Serum samples were collected from pigs at slaughter and analysed for the presence of anti-Ascaris antibodies. For this, two different ELISAs were used. The first was based on the antibody recognition of the A. suum haemoglobin (As-Hb) molecule whereas the second test used the total extract of A. suum lung stage L3. The serological results were subsequently correlated with the percentage of condemned livers at slaughter, management practices and technical performance parameters including average daily gain (ADG) and feed conversion ratio (FCR). According to the data from the slaughterhouse, 12 out of the 21 farms had livers condemned due to liver white spots. A total of 10 farms (48%) had an average optical density ratio (ODr) exceeding the test cutoff when the As-Hb ELISA was used. This number increased to 18 farms (81%) when using the As-Lung-L3 ELISA. The average ODr of the farms on both ELISAs correlated positively with the percentage of affected livers (P<0.01). Only the average ODr values obtained with the As-Lung-L3 ELISA were positively correlated with the FCR (P<0.01). No correlation was found between percentage of affected livers or serology and the ADG. In relation to management practices, farms with greater than or equal to 50% slatted flooring and that applied the 'all-in/all-out' flow system showed a lower percentage of liver condemnations (P<0.01), lower average ODr results on the As-Lung-L3 ELISA (P<0.05) and lower FCR (P<0.01) compared with those with less than 50% slatted flooring. This study emphasizes that serology is a promising diagnostic tool for diagnosing ascariasis at fattening pig farms. It also supports earlier findings that the presence of A. suum can have a significant negative impact on farm productivity and that stable infrastructure or management practices can have a considerable impact on the control of this parasite.
Assuntos
Ascaríase/veterinária , Ascaris suum/isolamento & purificação , Hepatopatias/veterinária , Doenças dos Suínos/epidemiologia , Matadouros , Animais , Ascaríase/epidemiologia , Ascaríase/parasitologia , Ensaio de Imunoadsorção Enzimática/veterinária , Fígado/parasitologia , Hepatopatias/epidemiologia , Hepatopatias/parasitologia , Prevalência , Espanha/epidemiologia , Suínos , Doenças dos Suínos/parasitologiaRESUMO
The objective of this study was to evaluate the status of anthelmintic resistance (AR) in ruminants and horses in Spain. The efficacy of commonly used macrocyclic lactones (MLs) - ivermectin (IVM) and moxidectin (MOX) - was measured in sheep, cattle and horses. In addition, albendazole (ABZ) and levamisole (LEV) were evaluated in sheep and oxibendazole (OXI) and pyrantel (PYR) in horses. Efficacy was evaluated based on the difference between the arithmetic mean pre- and post-treatment faecal egg count (in cattle and horses), or compared to an untreated control group (in sheep). AR was present when the percentage reduction in egg count was <95% and the lower 95% confidence interval (CI) was <90%; if only one of these two criteria was met, the finding was recorded as suspected AR (SAR). In horses, AR-PYR and OXI was considered when the percentage reduction in egg count was ≤ 90% and the lower 95% CI was ≤ 80%. For each animal species, at least 10 study sites were selected. AR to at least one of the drugs was detected in all 10 sheep flocks; the main parasite identified after treatment was Teladorsagia circumcincta. Moreover, in 5 flocks multidrug resistance was identified, on 4 farms to drugs from different families, on one farm to both MOX and IVM and on another farm to all drugs tested. In cattle, the efficacy of both MOX and IVM was 100% on 4 and 3 farms, respectively, and therefore 60% of these farms were considered to have AR or SAR to both MLs. The most frequent parasite identified after treatment was Trichostrongylus spp., although Ostertagia ostertagi was also identified after treatment on one farm. In contrast to ruminants, the 4 drugs evaluated in horses were highly efficacious against strongyles, with efficacies for the MLs and OXI between 95 and 100% and between 94 and 100% for PYR, although 3 herds were SAR against PYR. In conclusion, AR to at least one of the commonly used drugs was identified on all sheep flocks investigated in the northwest of Spain. The occurrence of AR to MLs in cattle was higher than expected but consistent with what was observed in sheep. In horses, all currently used drugs were confirmed as effective against strongyles.
Assuntos
Anti-Helmínticos/farmacologia , Doenças dos Bovinos/parasitologia , Doenças dos Cavalos/parasitologia , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Animais , Bovinos , Resistência a Medicamentos , Doenças dos Cavalos/epidemiologia , Cavalos , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Ovinos , Doenças dos Ovinos/epidemiologia , Espanha/epidemiologiaRESUMO
The effects of the lipopolysaccharide (LPS) from Ochrobactrum intermedium in sheep with fasciolosis was reported previously, resulting in lower fecal egg counts and fluke burden. In the current study, we analyzed its immunological effects in two groups of sheep, treated (T) and controls (C). Fasciolosis induces a T helper (Th) type-2 response, characterized by IL-4 and IL-10 production; however, at the beginning of the infection, the IFN-γ production predominates (Th type-1 response). Although we did not find differences in IL-4 production or in the expression level of this gene in the hepatic lymph nodes, the expression level of IL-10 was higher (P < 0.05) in the T group at 4 wpi. The IFN-γ production was higher (P < 0.01) at 12 wpi as well as its level of expression at 4 wpi (P < 0.05) in the T group. We found a higher expression level of TGF-ß at 4 wpi in the T group (P < 0.05), associated with the previous report of thicker fibrous tracks in a treated group. Immunoglobulin G1, related with a Th type-2 response, was higher (P < 0.01) in the T group at 4 and 12 wpi. In conclusion, the effects of LPS from O. intermedium could have resulted from a predominant Th type-2 immune response.
Assuntos
Fasciola hepatica/imunologia , Fasciolíase/veterinária , Lipopolissacarídeos/farmacologia , Ochrobactrum/metabolismo , Doenças dos Ovinos/imunologia , Ovinos/imunologia , Ovinos/parasitologia , Animais , Fasciolíase/imunologia , Fasciolíase/metabolismo , Fezes/parasitologia , Imunoglobulina G/metabolismo , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Lipopolissacarídeos/metabolismo , Doenças dos Ovinos/metabolismo , Doenças dos Ovinos/patologia , Células Th2/efeitos dos fármacos , Células Th2/patologia , Fator de Crescimento Transformador beta/metabolismoRESUMO
The aim of this study was to develop an egg hatch assay (EHA) to detect the resistance of Fasciola hepatica to albendazole (ABZ). With this purpose, two different F. hepatica isolates were tested: (i) susceptible (Shrewsbury/South Gloucester strain) to ABZ (SA); (ii) resistant to ABZ (RA). A commercial formulation of ABZ (Sinvermin) diluted in dimethyl sulfoxide (DMSO) was used at concentrations of 0.0002, 0.002, 0.02, 0.2, and 2 µg/ml. In the SA isolates, eggs from feces exposed to ABZ at the three highest concentrations showed significantly lower hatching percentages than the control well (P<0.01); also for the two highest concentrations, the percentage of development was significantly lower than the control (P<0.01). However, in the RA isolate, no differences among treatments and control were found in the percentage of hatched or developed eggs. On the other hand, the EHA was conducted over a 15 day period following treatment with ABZ for sheep infected by the RA isolate. On day 7 post-treatment (pt), no differences among treatments and controls were observed. On day 15 pt, the development and hatching rates exposed to the highest ABZ concentration were lower than at lower concentrations, suggesting susceptibility. The ovicidal effect of ABZ and the potential use of EHA to differentiate between ABZ susceptible and resistant isolates are confirmed in the current study. However, the use of this technique should be confirmed with a higher number of isolates.
Assuntos
Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Parasitologia/métodos , Doenças dos Ovinos/parasitologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Fasciolíase/tratamento farmacológico , Fasciolíase/parasitologia , Fezes/parasitologia , Óvulo/efeitos dos fármacos , Ovinos , Doenças dos Ovinos/tratamento farmacológicoRESUMO
The effects of two diets supplemented with flaxseed oil (FO) or vitamin E (VE) were studied in sheep infected with Fasciola hepatica. The control group (CO), not supplemented, had higher weight gain and faecal egg count (P < 0.05) at the end of the study. At necropsy, the number (71.2 ± 26.5) and size of flukes were lower in the FO group (P < 0.01), probably due to the higher levels of white blood cells and lymphocytes (P < 0.01). This group also had higher red blood cell and haematocrit values (P < 0.01). The CO group had more severe hypoproteinaemia and hypoalbuminaemia, due to having the highest fluke burden (123.0 ± 35.2), and also the highest IgG1 titre (P < 0.01). The diet did not affect production or gene expression levels of IFN-γ and IL-4. On the other hand, the supplementation with VE led to a reduction in adult fluke burden (97.7 ± 39.9) and lower lipid oxidation in the liver (P < 0.001).
Assuntos
Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Óleo de Semente do Linho/administração & dosagem , Doenças dos Ovinos/dietoterapia , Doenças dos Ovinos/parasitologia , Vitamina E/administração & dosagem , Análise de Variância , Animais , Constituição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Primers do DNA/genética , Suplementos Nutricionais , Fasciolíase/sangue , Fasciolíase/dietoterapia , Fezes/parasitologia , Imunoglobulina G/sangue , Interferon gama/metabolismo , Interleucina-4/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Contagem de Ovos de Parasitas/veterinária , Reação em Cadeia da Polimerase em Tempo Real , Ovinos , Doenças dos Ovinos/sangue , Carneiro Doméstico , Substâncias Reativas com Ácido TiobarbitúricoRESUMO
The aim of this study was to develop a PCR for the diagnosis of Fasciola hepatica infection in feces of sheep based on the ribosomal internal transcribed spacer. Detection of infection was possible from the second week post-infection in experimentally infected sheep by amplification of a 292bp fragment. This PCR was employed for the detection of anthelmintic resistance (AR) in naturally infected sheep flocks, and results were compared with techniques such as the fecal egg count reduction test (FECRT) and the copro-antigen reduction test (CRT). The FECRT was carried out in two flocks, Santillan de la Vega (SV) and Corullón (CR), with sheep treated with albendazole (ABZ), clorsulon (CL), or triclabendazole (TCBZ). Feces were collected from individuals on days 0, 7, 15, and 30 post-treatment (pt). The FECRT showed adult F. hepatica to be resistant to ABZ and CL in both flocks. All parasite stages in the SV flock were susceptible to TCBZ, while in the CR flock, adult flukes showed resistance and immature forms were susceptible to the treatment. To compare FECRT and the PCR results, we calculated the percent of positive sheep on day 1 pt. In both flocks, the percent positive sheep was consistently higher by PCR than by sedimentation, confirming that the PCR is a more sensitive method of diagnosing infection and therefore to detect the resistance in infected animals. The CRT was carried out in the SV flock using a sandwich ELISA kit. The percent of sheep found positive by PCR was higher than with ELISA. Comparison of FECRT, CRT, and PCR for the detection of AR showed PCR to be the most sensitive.