Anthelmintic resistance in cattle nematode in the western Pampeana Region of Argentina

Suárez, Víctor Humberto; Cristel, S. L.

doi:10.1016/j.vetpar.2006.09.016

Cited by 79 publications

(31 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Em uma primeira análi-se, estes resultados não confirmariam as evidências de que a pressão de seleção, exercida pelas LMs, seria capaz de aumentar a freqüência de alelos envolvidos na resistência aos benzimidazóis na população parasitária, como comprovado, in vitro, na espécie Haemonchus contortus (Mottier & Prichard 2008 (Rangel et al 2005, Soutello et al 2007, Suarez & Cristel 2007, Borges et al 2008. Em relação ao gênero Cooperia spp., isto pode estar relacionado à sua característica de ser dose-limitante para as LMs (Shoop et al 1995), ou seja, de ser naturalmente mais tolerante a esses fármacos se comparado a maioria dos demais gê-neros de nematódeos.…”

Section: Resultsunclassified

Ação anti-helmíntica de diferentes formulações de lactonas macrocíclicas em cepas resistentes de nematódeos de bovinos

et al. 2010

View full text Add to dashboard Cite

523Pesq. Vet. Bras. 30(7):523-528, julho 2010 RESUMO.-As lactonas macrocíclicas (LMs) (avermectinas e milbemicinas) são endectocidas amplamente utilizados em animais e em algumas parasitoses humanas. Em bovinos, a resistência parasitária às LMs é emergente, e o surgimento de formulações que diferem nas suas propriedades farmacológicas tornou complexa a escolha da droga mais indicada a cada caso. Com o objetivo de avaliar possí-veis alternativas para recuperar a eficácia de LMs sobre cepas resistentes de nematódeos gastrintestinais, testaram-se, neste estudo, dez diferentes tratamentos a base de LMs sobre uma população de nematódeos gastrintestinais de bovinos a qual, sabidamente, sofrera pressão de seleção por avermectinas a 1%. Adicionalmente, testou-se um benzimidazol. A eficácia das drogas foi calculada com base na redução de ovos por grama de fezes (OPG) dos bovinos. A resistência de cada gênero foi avaliada por meio de identificação de larvas, obtidas de cultivos nas fezes, pré-e pós-tratamentos. Não se obteve a eficácia desejada com o emprego de avermectinas The macrocyclic lactones (MLs) (avermectins and milbemycins) are endectocides broadly used in livestock and in some parasitic diseases of humans. In cattle, parasite resistance to MLs is emerging, and the appearance of formulations that differ in their pharmacological properties become complex the choice of the most appropriate drug to each case. In order to evaluate possible alternatives to restore the effectiveness of MLs on resistant strains of gastrointestinal nematodes, were tested, in this study, ten different treatments based on the MLs on a population of gastrointestinal nematodes of cattle which, known, was under pressure of selection by 1% avermectins. Additionally, was tested a benzimidazole. The efficacy of the drugs was calculated with basis on the reduction of eggs per gram of feces (EPG) of cattle. The resistance of each genus was evaluated by identification of the larvae, obtained from culture in the feces, pre-and post-treatments. The desired efficacy was not obtained using long action avermectins -with high concentration and in association -even with the application of high doses. The genera Cooperia spp., Haemonchus spp. and Trichostrongylus spp. were resistant to avermectins, and Ostertagia spp. to ivermectin. It was observed that, once established parasite resistance to the 1% MLs, the application of drugs, of this same chemical group, even in formulations of high concentration, association or in high doses, may not result in the expected efficacy.

show abstract

Section: Resultsunclassified

Ação anti-helmíntica de diferentes formulações de lactonas macrocíclicas em cepas resistentes de nematódeos de bovinos

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Data of 23 FECRTs were obtained from Suarez and Cristel (2007) and data of 27 FECRTs were kindly provided by the following colleague parasitologists: O. Anziani, C. Descarga, C. Rossanigo, M. Buffarini, R. Sanabria, J. Romero, F. Olaechea, C. Entrocasso, C. Fiel. In all cases, FECRTs and resistance were confirmed by a mean egg count reduction percentage of less than 95% (100(1-[T2/C2])) and the 95% confidence level of less than 90%, according to the protocol of the WAAVP (COLES et al, 1992).…”

Section: Farm Selectionmentioning

confidence: 99%

“…Cases of multiple anthelmintic and nematode species resistance were detected later (MEJÍA et al, 2003;ANZIANI et al, 2004). Some recent surveys made in Argentina have attempted to quantify regional AR occurrence in cattle ranches (CARACOSTANTOGOLO et al, 2005;CRISTEL, 2007).…”

Section: Introductionmentioning

confidence: 99%

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

Suárez

Cristel²

2014

Rev. Bras. Parasitol. Vet.

View full text Add to dashboard Cite

Risk factors for anthelmintic resistance (AR) on bovine ranches were studied. Data were derived from a survey made to 50 ranch owners, who had conducted a faecal egg-count-reduction test. The questionnaire contained descriptors of bovine ranch management and nematode control. A case-control design study was undertaken and AR cases were present in 26 herds. Associations between the binary outcome variable (AR versus not AR) and risk factors recorded in the questionnaire were evaluated. Variables associated with the presence of AR at P< 0.15 and/or odds ratio (OR) > 2 were subjected to a multivariable logistic regression model. The main effects contributing to general AR (avermectin AVM and/or benzimidazole) in the final model were total number of annual treatments (OR 7.68; 95% CI 2.4 to 28.3) and use of more than 75% of AVM in the past (OR= 18.6; 95% CI 1.3 to 97.3), whereas for AVM resistance alone were total number of AVM annual treatments (OR= 11.5; 95% CI 2.9 to 45.5) and number of AVM Nov-Jan treatments (OR= 5.8; 95% CI 1.71 to 47.9). The results showed that treatment frequency, date of treatment and frequency of treatment in the past with a single drug were the main risk factors involved in AR development.Keywords: Nematode, cattle, anthelmintic resistance, risk factor. ResumoFatores de risco para resistência anti-helmíntica (AR) em fazendas de criação de bovinos foram estudados de dados obtidos de um levantamento em 50 propriedades. Em todas foram conduzidos testes de redução de contagem de ovos (opg) e um questionário preenchido pelos proprietários sobre o manejo e o controle de verminose nessas fazendas. Um estudo com desenho de caso controlado foi realizado e casos de AR estavam presentes em 26 rebanhos. Associações foram avaliadas entre a variável binária produzida (AR versus sem AR) e fatores de risco registrados nos questionários. Variáveis associadas com o resultado de interesse a P<0.15 e/ou razão de prevalência (OR) > 2 foram usados num modelo de regressão logística multivariável. Os principais efeitos contribuintes para AR geral (avermectina AVM e/ou benzimidazole), no modelo final, foram número total de tratamentos anuais (OR 7,68; 95% IC 2,4 a 28,3) e uso no passado mais que 75% de AVM (OR= 18,6; 95% IC 1,3 a 97,3), e para resistência à AVM foram número total de tratamentos anuais (OR=11,5; 95% IC 2,9 a 45,5), número de tratamentos com AVM de novembro a janeiro (OR= 5,8; 95% IC 1,71 a 47,9). Estes resultados mostraram que a frequência dos tratamentos, a época do ano em que foram feitos os tratamentos e a frequência dos tratamentos no passado com uma única droga foram os principais fatores de risco implicado no desenvolvimento de AR.Palavras-chave: Nematóide, gado, resistência anti-helmíntica, fator de risco.

show abstract

“…Although it appears to be less of a problem in cattle, there have been reports of resistance from England (Stafford and Coles, 1999), New Zealand (Pomroy, 2006) and South America (Soutello et al, 2007;Suarez and Cristel, 2007) in cattle herds, and thus it is likely to become Anthelmintic resistance is recognised as a major problem affecting small ruminant production worldwide and now threatens the sustainability of many of these systems. One method that has been proposed to prolong the efficacy of our current anthelmintics is the maintenance of a parasite population in refugia (unexposed to a drug) which will maintain the genes for susceptibility within the parasite population.…”

Section: Introductionmentioning

confidence: 99%

The role of targeted selective treatments in the development of refugia-based approaches to the control of gastrointestinal nematodes of small ruminants

Kenyon

Greer

Coles

et al. 2009

Veterinary Parasitology

236

138

View full text Add to dashboard Cite

Anthelmintic resistance in cattle nematode in the western Pampeana Region of Argentina

Cited by 79 publications

References 24 publications

Ação anti-helmíntica de diferentes formulações de lactonas macrocíclicas em cepas resistentes de nematódeos de bovinos

Ação anti-helmíntica de diferentes formulações de lactonas macrocíclicas em cepas resistentes de nematódeos de bovinos

Risk factors for anthelmintic resistance development in cattle gastrointestinal nematodes in Argentina

The role of targeted selective treatments in the development of refugia-based approaches to the control of gastrointestinal nematodes of small ruminants

Contact Info

Product

Resources

About