Resistance of selected lines of Haemonchus contortus to thiabendazole, morantel tartrate and levamisole

Jambre, L.F. Le; Southcott, W. H.; Dash, K.M.

doi:10.1016/0020-7519(76)90037-0

Cited by 67 publications

(11 citation statements)

References 8 publications

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“…The nematode strains resistant to benzimidazole were highly susceptible to imidazothiazoles, but in Australia, Le Jambre et al (1976) reported the potential resistance of nematode strains selected in vitro to these drugs, and their report was soon followed by other reports about resistance around the world, including field strains (KELLY & HALL, 1979). In Brazil, a previous report by Santiago et al (1977) identified a strain of Trichostrongylus colubriformis resistant to levamisole.…”

Section: History Of Ahr In Small Ruminants In Brazil and Around The Wmentioning

confidence: 99%

“…Levamisole, albeit a long-standing drug with reports of resistance around the world and in Brazil dating back to the 70s (LE JAMBRE et al, 1976;SANTIAGO et al, 1977), is reportedly the anthelmintic that has shown the highest effectiveness over the years in Brazil, including in recent surveys. In Brazil, its reported effectiveness rate was higher than that of other drugs tested in eight studies involving sheep (AMARANTE et al, 1992;THOMAZ-SOCCOL et al, 1996;MELO et al, 2003;ROSALINSKI-MORAES et al, 2007;CRUZ et al, 2010;VERÍSSIMO et al, 2012;SPRENGER et al, 2013) and in three studies involving goats (MATTOS et al, 2000;RODRIGUES et al, 2007;LIMA et al, 2010a).…”

Section: Developments In Research and The Effectiveness Of Anthelmintmentioning

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: History Of Ahr In Small Ruminants In Brazil and Around The Wmentioning

confidence: 99%

Section: Developments In Research and The Effectiveness Of Anthelmintmentioning

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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“…Effects tested in analyses of variance included selection line, year of birth (1978-91 for FEC;1976-79, 1982,1984 for PCVD), birth type (twin or single), dam age (2-year-old dams or older dams), sex (males or females), age (as a covariable) and all first-order interactions. The inbreeding coefficient of each animal was also fitted as a covariable.…”

Section: Preliminary Analysesmentioning

confidence: 99%

Selection of Merino sheep for resistance to Haemonchus contortus: genetic variation

1996

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An animal model was used to estimate heritabilities of faecal egg count (FEC) and packed cell volume decline (PCVD) in lines of Merinos selected for divergent levels of resistance to Haemonchus contortus. The estimated heritability of FEC was 0-23 (s.e. 0-03) and of PCVD was 0-21 (s.e. 0-03). A cube root transformation was found to be effective in normalizing FEC data and reducing the range of within selection line-birth year variances from 118fold to 10-fold. Transforming FEC data increased the heritability estimate to 0-29 (s.e. 0-03) and reduced selection bias due to heterogeneity of variance, but the further step of pre-adjusting the transformed data to a common variance had only a trivial effect. Heritability estimates for FEC in years with high means and variances were similar, as were estimates for transformed FEC. The estimated genetic correlations between measurements in years with high and low means and variabilities were 0-77 to 0-91.PCVD and pre-adjusted transformed FEC had a phenotypic correlation of 0-48. Estimates for the genetic correlation ranged from 0-76 in the decreased resistance line to 1-00 in the increased resistance line and 0-87 with pooled data. Other effects on resistance included birth type and dam age, with twins and progeny of maiden dams being more resistant than their cohorts. Sex effects were unimportant for FEC but males had higher PCVD than females in most, but not all, years. Younger animals had higher FEC and PCVD than older animals. Maternal genetic effects were found to be unimportant, as were the effects of low levels of inbreeding.

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“…(Le Jambre et al 1976, 1979Webb et al 1979 ;Edwards and Chaneet, 1980 ;Green et al 1981 ;Rolfe, 1990 ;Sangster and Bjorn, 1995 ;Dobson et al 2001 ;Kotze et al 2002 ;Besier and Love, 2003). In Australia, the main nematodes causing production loss are Teladorsagia circumcincta, Trichostrongylus spp.…”

Section: Introductionmentioning

confidence: 99%

The use of DNA markers to map anthelmintic resistance loci in an intraspecific cross ofHaemonchus contortus

et al. 2009

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The use of DNA markers to track the development of anthelmintic resistance in parasites of livestock would allow informed choices for the management of this important problem. We describe a genetic mapping approach for the discovery of DNA markers for anthelmintic resistance in Haemonchus contortus. We crossed a multi-drug resistant field isolate of H. contortus with a well-characterized laboratory strain susceptible to 4 drug classes. The F2 were separately selected with 5 anthelmintics from 4 drug classes, producing drug-resistant populations carrying gene variants derived from both the field isolate and the laboratory strain. Individual F2 worms were analysed using amplicon length polymorphisms (ALPs). We looked for field isolate alleles over- or under-represented in F2 populations compared to the unselected F2 and/or the laboratory strain. The data we obtained suggest that marker association can be used to link neutral markers with resistance, but also that more markers and perhaps more inbred laboratory strains would make the procedure more likely to succeed.

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Resistance of selected lines of Haemonchus contortus to thiabendazole, morantel tartrate and levamisole

Cited by 67 publications

References 8 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

Selection of Merino sheep for resistance to Haemonchus contortus: genetic variation

The use of DNA markers to map anthelmintic resistance loci in an intraspecific cross ofHaemonchus contortus

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