Prevalence of anthelmintic resistance on 62 beef cattle farms in the North Island of New Zealand

Waghorn, T.S.; Leathwick, Dave M.; Rhodes, A.P.; Jackson, Rodney; Pomroy, W.E.; West, D.M.; Moffat, JR

doi:10.1080/00480169.2006.36711

Cited by 122 publications

(50 citation statements)

References 22 publications

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“…has become increasingly common in Brazil (Echevarria and Pinheiro, 1999), Argentina Fiel et al, 2001;Mejia et al, 2003), New Zealand (Familton et al, 2001;Loveridge et al, 2003;Vermunt et al, 1996), the US (Gasbarre et al, 2004) and the UK (Coles et al, 1998. To date, the first cases of suspected emerging IVM resistance in O. ostertagi are reported in New Zealand (Mason and McKay, 2006;Waghorn et al, 2006) and Argentina (Suarez and Cristel, 2007 not yet been confirmed with controlled field studies. In the light of these recent findings ML resistance in O. ostertagi might be more common than currently recognized.…”

Section: Introductionmentioning

confidence: 99%

Experimental selection for ivermectin resistance in Ostertagia ostertagi in cattle

Zeveren

Casaert

Alvinerie³

et al. 2007

Veterinary Parasitology

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Recent reports of suspected ivermectin (IVM) resistance in Ostertagia ostertagi have highlighted the need for research into the mechanisms of IVM resistance. However, there are no reports of resistant field isolates of O. ostertagi, which have been characterized for molecular research. Therefore, an anthelmintic susceptible O. ostertagi population was selected for IVM resistance by repeatedly exposing the population to subtherapeutic and therapeutic levels of IVM over 10 generations. In each selection round, a group of calves was infected with the progeny of the previous IVM-selected O. ostertagi population. In the last selection round a therapeutic IVM dose (0.2 mg/kg BW) only reduced the faecal egg counts by 57% and 65% on days 7 and 14 after treatment, respectively. In contrast, the therapeutic IVM dose was 100% effective at eliminating the parental IVM-susceptible isolate. #

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Section: Introductionmentioning

confidence: 99%

Experimental selection for ivermectin resistance in Ostertagia ostertagi in cattle

Zeveren

Casaert

Alvinerie³

et al. 2007

Veterinary Parasitology

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“…Numerous studies about bovine nematode AR have been reported worldwide, mostly in regions where production systems are based on grazing management, such as New Zealand, Brazil, Colombia, UK and the United States. AR has been reported for all the broad-spectrum anthelmintics *Corresponding author: Víctor Humberto Suarez Laboratório de Parasitología, Unidad de Salud Animal Estación Experimental Agropecuaria Salta, INTA, RN68 Km 172, 4403, Cerrillos, Salta, Argentina e-mail: suarez.victor@inta.gob.ar; suarez@correo.inta.gov.ar (levamisole, benzimidazoles and macrocyclic lactones) used for cattle (PAIVA et al, 2001;FAMILTON et al, 2001;COLES, 2002;WAGHORN et al, 2006;MÁRQUEZ et al, 2008;GASBARRE et al, 2009). In Argentina, the first cases of macrocyclic lactone and benzimidazoles resistance in cattle were reported by Anziani et al (2001) and Fiel et al (2001).…”

Section: Introductionmentioning

confidence: 99%

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

Suárez

Cristel²

2014

Rev. Bras. Parasitol. Vet.

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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.

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“…Adult worms can be readily identified, but collecting them requires euthanasia of the host. Morphological features cannot be used to distinguish eggs of all species parasitising sheep (Wilson et al 2008;Bailey et al 2009) and cattle (Waghorn et al 2006); therefore, eggs are hatched in culture and the larvae are examined. Routine identification of third-stage infective larvae (L3) is based on either morphological features or size (Lancaster and Hong 1987;McMurtry et al 2000;van Wyk et al 2004): Haemonchus contortus can be identified by a long, whiplike tail, whereas Teladorsagia circumcincta and Trichostrongylus colubriformis are distinguished by length, the ranges of which can overlap for the two species (Lancaster and Hong 1987).…”

Section: Introductionmentioning

confidence: 99%

Use of fluorescent lectin binding to distinguish Teladorsagia circumcincta and Haemonchus contortus eggs, third-stage larvae and adult worms

et al. 2011

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Lectin binding to carbohydrates on parasite surfaces has been investigated as a method of distinguishing adult worms, eggs and sheathed and exsheathed L3 of Teladorsagia circumcincta and Haemonchus contortus, economically important abomasal parasites in temperate climates. Both species were maintained as pure laboratory cultures of field isolates from New Zealand. Each of the four life cycle stages could be distinguished by the binding of at least one lectin: adult worms by Sambucus nigra agglutinin (SNA); eggs by peanut agglutinin (PNA), ConcavalinA and Lens culinaris agglutinin (LCA); exsheathed L3 by Griffonia simplicifolia-I lectin (GSL-I) and Lotus tetragonolobus lectin (LTL) and sheathed L3 by Aleuria aurantia lectin (AAL). The whole surface of both adult T. circumcincta and H. contortus strongly bound lectins specific for N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GalNAc), mannose and fucose, but the two species could be distinguished by SNA binding only to T. circumcincta. Eggs could be distinguished by the binding of mannose-specific PNA to H. contortus and GalNAc-specific LCA and PSA to T. circumcincta eggs. GalNAc, GlcNAc and mannose lectins bound to the cuticle and over the excretory pores of a large proportion of sheathed L3 of both species, but only the H. contortus surface had exposed fucose or sialic acid complexes. The distinguishing lectin for sheathed L3 was AAL, which did not bind to T. circumcincta, but bound weakly to the head region of all fresh H. contortus and to 50-90% after 3 months storage. The cuticle of exsheathed L3 was unresponsive to all 19 lectins, and any binding was restricted to the head and tail regions. L3 exsheathed after 2-4 months storage could be distinguished by the binding of GSL-I and LTL to H. contortus but not to T. circumcincta. Lectin binding could be a useful adjunct in identifying L3, but lacked the consistency to be definitive, whereas it could be further developed as a practical method of distinguishing parasitic nematodes at other stages in the life cycle, particularly the eggs.

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Prevalence of anthelmintic resistance on 62 beef cattle farms in the North Island of New Zealand

Cited by 122 publications

References 22 publications

Experimental selection for ivermectin resistance in Ostertagia ostertagi in cattle

Experimental selection for ivermectin resistance in Ostertagia ostertagi in cattle

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

Use of fluorescent lectin binding to distinguish Teladorsagia circumcincta and Haemonchus contortus eggs, third-stage larvae and adult worms

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