Resistência anti-helmíntica em nematoides gastrintestinais de pequenos ruminantes: avanços e limitações para seu diagnóstico

Fortes, Filomeno; Molento, Marcelo Beltrão

doi:10.1590/s0100-736x2013001200001

Cited by 40 publications

(26 citation statements)

References 77 publications

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“…Molecular tests based on the analysis of polymorphisms in the target gene associated with resistance, using PCR, are highly sensitive (SILVESTRE & HUMBERT, 2000), do not require fecal cultures, and can supplement traditional diagnostic methods (NUNES et al, 2013). However, due to the extremely polygenic nature of populations, researchers have yet to discover the mechanism of drug resistance and pinpoint one or more candidates for specific markers (FORTES & MOLENTO, 2013). Knowledge about the molecular mechanisms of AHR is still limited mainly to benzimidazoles (COLES et al, 2006;TAYLOR et al, 2002), involving a mutation of tyrosine to phenylalanine in the beta-tubulin gene (SILVESTRE & HUMBERT, 2000).…”

Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

“…The controlled reduced parasitic load test, which is performed after the autopsy of the animal, evaluates the real situation of parasite elimination in the host (WOOD et al, 1995). However, it requires killing the animals and its cost is high, so it is not widely used (FORTES & MOLENTO, 2013). The standard method is the fecal egg count reduction test (FECRT) and is the method most widely employed to evaluate the effectiveness of drugs in animals in the field (COLES et al, 2006;TAYLOR et al, 2002).…”

Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

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Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

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Frequent and inappropriate use of all classes of antiparasitic drugs in small ruminants has led to failures in their effectiveness, culminating in a global problem of anthelmintic resistance. Brazil stands out as one of the world's leaders in publications about anthelmintic resistance, and for having the most numerous reports of this resistance in small ruminants in the Americas. These studies have involved mainly the fecal egg count reduction test (FECRT) and its correlation with field management practices. In vivo effectiveness testing is conducted in areas where livestock is of greater economic significance, e.g., in the South (sheep) and Northeast (goats), or is important for research and economic centers, such as the Southeast (sheep). The most widely studied species is sheep, for which the widest range of drugs is also evaluated. Despite significant advances achieved in molecular research, laboratory analyses should include knowledge about the reality in the field so that they can become feasible for the producer. Moreover, molecular studies can be underpinned by the analysis of field studies, such as the maintenance of antiparasitic effectiveness over time and the mechanisms involved in this process.Keywords: Small ruminants, anthelmintic resistance, sheep, goat, gastrointestinal nematodes. ResumoO uso frequente e inapropriado de todas as classes de antiparasitários em pequenos ruminantes levou a falhas de eficácia, culminando na problemática global de resistência anti-helmíntica. O Brasil destaca-se como sendo um dos pioneiros nas publicações com resistência anti-helmíntica no mundo e por ter o maior número de relatos em pequenos ruminantes na América. Essas pesquisas envolvem principalmente o teste da redução da contagem de ovos nas fezes (TRCOF) e sua correlação com as práticas de manejo utilizadas no campo. Os estudos de testes de eficácia in vivo localizam-se em áreas onde há maior importância dos rebanhos como nas Regiões Sul (ovinos) e Nordeste (caprinos), ou com importância em polos de pesquisa e econômicos, como a região Sudeste (ovinos). Ovina é a espécie mais estudada e com maior gama de drogas avaliadas. Mesmo com grande avanço em pesquisas moleculares, as análises laboratoriais devem envolver o conhecimento da realidade do campo para que possam se tornar viáveis ao produtor. Além disso, a análise dos estudos de campo pode nortear estudos moleculares como, por exemplo, a manutenção da eficácia das drogas ao longo dos anos e os mecanismos envolvidos em tal processo.

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Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

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“…The primary factors that interfere in sheep farming are the high prevalence of parasitic infections and the difficulty of effective control of gastrointestinal nematodes in small ruminants, and these factors jeopardize animal performance and well-being and increase mortality (FORTES;MOLENTO, 2013).…”

Section: Introductionmentioning

confidence: 99%

Resistance to monepantel in multiresistant gastrointestinal nematodes in sheep flocks in Rio Grande do Sul

Júnior¹,

Raimondo²,

Rivero³

et al. 2018

SCA

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The excessive, indiscriminate, and continued use of anthelmintic drugs as control methods favors parasite resistance, and this phenomenon has been reported in Brazil and worldwide. The current status of parasite resistance to anthelmintic drugs in sheep flocks in Rio Grande do Sul was assessed by calculating the EPG count in the stool to estimate the prevalence of resistance to the anthelmintic drugs closantel, levamisole, fenbendazole, monepantel, and moxidectin in seven properties. The animals from each flock were randomly distributed in six groups according to the anthelminthic drug used, as follows: T1, levamisole; T2, fenbendazole; T3, monepantel; T4, moxidectin; T5, closantel; and T6, control. On day zero, fecal samples were collected, and each animal was treated with one anthelminthic drug. Fecal samples were collected again after 14 days to calculate the efficacy of each active principle. Coproculture was performed using a pool of fecal samples from each group on day 0 and 14 to identify the predominant genera and prevalence of helminths. The genera identified in the coprocultures were Haemonchus, Trichostrongylus, Oesophagostomum, and Teladorsagia. All flocks developed resistance to levamisole, fenbendazole, moxidectin, and closantel. Moreover, resistance to monepantel was found in four of the seven farms. These results demonstrate the critical situation of anthelmintic resistance in sheep flocks in Rio Grande do Sul and the need to adopt other integrated control measures in addition to anthelmintic treatment.

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“…Among this programs, we can highlight the use of anthelmintic compounds with the aimed of reduction of infective larvae on pasture by decreasing the population of adult parasites in animals. However, despite the use of antiparasitic compounds as main tools, its use have negative effects, such as: drug residues in animal products (Padilha, 1996), toxic effects in the environment and in non-target organisms (Lumaret and Errouissi, 2002) and the develop of anthelmintic resistance (Kaplan, 2004;Fortes and Molento, 2013).…”

Section: Introductionmentioning

confidence: 99%

Antiparasitic drugs: in vitro tests against nematophagous fungi

et al. 2016

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The use of biological agents has been intensified in recent years against eggs and larvae of gastrointestinal nematodes as an alternative control method in pasture plant health management, with the concomitant use with antiparasitic drugs still occurring. The aim of this study was to test the in vitro activity of the following antiparasitic drugs: Ivermectin and albendazole against the following nematophagous fungi: Paecilomyces fumosoroseus, Paecilomyces lilacinus and Paecilomyces variotii. The agar diffusion test was performed using an initial concentration of 0.0016g/mL of each drug, after solidification of the culture medium containing the drug concentration each nematophagous fungi was inoculated. The results showed that in a concentration of 80μg/mL, the fungal growth decreased, however, with the concentration of 160μg/mL, there was no fungal growth in both drugs, compared to the control, which indicates an inhibition in the development of the nematophagous fungi studied when they come in contact with ivermectin and albendazole.Keywords: ivermectin, albendazole, biological control. Antiparasitários: teste in vitro contra fungos nematófagosResumo O uso de agentes biológicos que atuam em ovos e larvas de nematódeos gastrintestinais como uma alternativa para o manejo de pastagens de saúde tem se intensificado nos últimos anos, bem como o uso concomitante com outros medicamentos antiparasitários. O objetivo deste estudo foi testar o efeito in vitro dos fármacos Ivermectina e Albendazol em fungos nematófagos Paecilomyces fumosoroseus, Paecilomyces lilacinus e Paecilomyces variotii. Foi utilizada a técnica de difusão em agar, sendo preparado a partir de uma concentração inicial de 0,0016g/mL de cada uma das drogas e diluídas em meio de cultura, com posterior semeadura dos fungos nematófagos. Os resultados mostraram que na concentração de 80μg/mL, o crescimento diminuiu, no entanto, com a concentração de 160μg/mL de ambas as drogas, não houve crescimento de fungos durante o período de estudo, em comparação com o controle, indicando a inibição do desenvolvimento dos fungos nematófagos estudados quando em contato com a Ivermectina e Albendazol.Palavras-chave: ivermectina, albendazol, controle biológico.

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Resistência anti-helmíntica em nematoides gastrintestinais de pequenos ruminantes: avanços e limitações para seu diagnóstico

Cited by 40 publications

References 77 publications

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Resistance to monepantel in multiresistant gastrointestinal nematodes in sheep flocks in Rio Grande do Sul

Antiparasitic drugs: in vitro tests against nematophagous fungi

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