In vitro evaluation of fitness parameters for isolates of Teladorsagia circumcincta resistant and susceptible to multiple anthelmintic classes

Hamilton, Kyra; Waghorn, T.S.; Waal, Theo de; Keane, Orla M.; Green, Peter; Leathwick, Dave M.

doi:10.1016/j.vetpar.2022.109791

Cited by 4 publications

(5 citation statements)

References 45 publications

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“…For example, some laboratory studies showed migration declined over time (days) stored at a constant high temperature of 30°C (Hamilton et al . 2022) and an optimum temperature for L3 larvae migration out of faeces (Gyeltshen et al . 2022).…”

Section: Resultsmentioning

confidence: 99%

“…The effect of temperature on parasite behaviour and movement (out of faeces and in soil) is not conclusive (n p = 6, n r = 8, Table S10) (Saunders et al 2000a;Gyeltshen et al 2022). For example, some laboratory studies showed migration declined over time (days) stored at a constant high temperature of 30°C (Hamilton et al 2022) and an optimum temperature for L3 larvae migration out of faeces (Gyeltshen et al 2022). However, temperature did not affect migration out of faeces in a greenhouse setting (Wang et al 2018) and had no significant effect (but a positive trend) on vertical S11) (Stankiewicz 1996;Dulovic et al 2022; and for a more extensive review, see Bryant & Hallem 2018;Mendez et al 2022;Takeishi 2022).…”

Section: Labmentioning

confidence: 99%

See 1 more Smart Citation

Climate change effects on terrestrial parasitic nematodes: Where are the knowledge gaps?

Moerman,

Albon,

Coulson

et al. 2023

J. Helminthol.

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Climate change is expected to affect parasitic nematodes and hence possibly parasite–host dynamics and may have far-reaching consequences for animal health, livestock production, and ecosystem functioning. However, there has been no recent overview of current knowledge to identify how studies could contribute to a better understanding of terrestrial parasitic nematodes under changing climates. Here we screened almost 1,400 papers to review 57 experimental studies on the effects of temperature and moisture on hatching, development, survival, and behaviour of the free-living stages of terrestrial parasitic nematodes with a direct life cycle in birds and terrestrial mammals. Two major knowledge gaps are apparent. First, research should study the temperature dependency curves for hatching, development, and survival under various moisture treatments to test the interactive effect of temperature and moisture. Second, we specifically advocate for more studies that investigate how temperature, and its interaction with moisture, affect both vertical and horizontal movement of parasitic nematodes to understand infection risks. Overall, we advocate for more field experiments that test environmental effects on life-history traits and behaviour of parasitic nematodes in their free-living stages under natural and realistic circumstances. We also encourage studies to expand the range of used hosts and parasitic nematodes because 66% of results described in the available studies use sheep and cattle as hosts and 32% involve just three nematode species. This new comprehension brings attention to understudied abiotic impacts on terrestrial parasitic nematodes and will have broader implications for livestock management, wildlife conservation, and ecosystem functioning in a rapidly warming climate.

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Section: Resultsmentioning

confidence: 99%

Section: Labmentioning

confidence: 99%

Climate change effects on terrestrial parasitic nematodes: Where are the knowledge gaps?

Moerman,

Albon,

Coulson

et al. 2023

J. Helminthol.

View full text Add to dashboard Cite

show abstract

“…Once resistant strains have been selected, the absence of selection pressure (i.e. absence of the use of anthelmintics) do not guarantee the reversion of resistance (Hamilton et al, 2022; Leathwick et al, 2015). Consequently, ibex could probably maintain benzimidazole-resistant strains for several years even in the absence of selection pressure.…”

Section: Discussionmentioning

confidence: 99%

“…does not guarantee the reversion of resistance (Hamilton et al, 2022;Leathwick et al, 2015). Consequently, ibex may maintain benzimidazole-resistant strains for several years even in the absence of selection pressure.…”

Section: Discussionmentioning

confidence: 99%

Cross-transmission of resistant gastrointestinal nematodes between wildlife and transhumant sheep

Beaumelle,

Toïgo,

Papet

et al. 2023

Preprint

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Wild and domestic ungulates can be infected with the same species of gastrointestinal parasitic nematodes. These parasites have a free leaving stage in the environment that contributes to the ease of transmission among different host species. In addition, gastrointestinal nematodes have developed resistance to anthelmintics which is now considered a major problem for the livestock sector. In a context where wild and domestic ungulates share the same pastures, the maintenance and circulation of resistant gastrointestinal nematodes between species have rarely been explored. In the European Alps, domestic sheep are driven in the high-altitude summer pastures leaving in sympatry with wild ungulates for several months. In this study we investigated the nemabiome of domestic sheep and Alpine ibex, Capra ibex, in three different areas of the French Alps to evaluate the parasites circulation between the two host species. The Alpine ibex is a protected mountain ungulate that is phylogenetically related to sheep and hosts nematode species common to sheep. Using internal transcribed spacer 2 (ITS-2) nemabiome metabarcoding, we found sheep and ibex sharing similar gastrointestinal nematodes, except for a few species, such as Marshallagia marshalli and Trichostrongylus axei. This suggests that the long-term co-occurrence of sheep and ibex on mountain pastures has promoted the exchange of gastrointestinal nematodes between the two hosts. Based on the sequencing of the isotype 1 of the beta tubulin gene, associated with benzimidazole resistance, we found resistant nematodes in all sheep farms and in all Ibex populations. Our results demonstrated that Ibex can host and shed resistant strains before transhumant sheep arrive on pastures, and then can act as a reservoir or refugia for resistant gastrointestinal nematodes. The relative role of ibex to the nemabiome and in particular to the maintenance and circulation of resistant strains in sheep remain to be determined.

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“…Besides its broad-spectrum efficacy, ivermectin has a wide safety margin making it the drug of choice against parasitic nematodes and arthropods in domestic animals [8]. The widespread use of ivermectin in the last decades has led to the evolution of resistance, which has been initially reported from countries with intensive ruminant farming such as Australia, New Zealand and South Africa and is now also found widespread in South America, the United Kingdom and the European Union [9][10][11][12]. In Sub-Saharan Africa (excluding South Africa with its intensive farming system), resistance to ivermectin has been reported for subsistence farming systems in sheep, goats and cattle in many regions, including Ethiopia [13], Kenya [14], Nigeria [15] and Uganda [16].…”

Section: Introductionmentioning

confidence: 99%

First evaluation and detection of ivermectin resistance in gastrointestinal nematodes of sheep and goats in South Darfur, Sudan

Mohammedsalih,

Ibrahim,

Juma

et al. 2024

Preprint

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In Sudan, resistance to benzimidazoles has been reported recently in cattle and goats from South Darfur. Herein, ivermectin efficacy against gastrointestinal nematodes (GINs) was evaluated in sheep and goats in three study areas in South Darfur. The faecal egg count reduction test (FECRT) was used to evaluate the efficacy of ivermectin in sheep and goats naturally infected with GINs in the region of Bulbul (goats: n=106), Kass (goats: n=40) and Nyala (Domaia (sheep: n=47, goats: n=77) and the University farm (goats: n=52)), using different treatment plans, and the efficacy was evaluated 12 days after treatment. Ivermectin efficacy was also evaluated in goats experimentally infected using local Haemonchus contortus isolates from Kass and Nyala. Nematodes surviving ivermectin treatment in goats in Bulbul and Nyala were harvested and larvae used to infect worm-free male sheep (n=6, ≤ 6 months old). Infected sheep were dosed subcutaneously with ivermectin every eight days with increasing doses from 0.2 mg/kg to 1.6 mg/kg bodyweight (bw). Reduced ivermectin efficacy was identified in sheep and goats in the four study locations. Using a paired statistic, the efficacy of a therapeutic dose in sheep was 75.6% (90% upper credible limit (UCrL): 77.5%), while twice the recommended dose led to a reduction of 92.6% (90% UCrL: 93.3%). In goats, the FECRs of a therapeutic dose were 72.9 – 95.3% (90% UCrL range: 73.6 – 95.7%) in Bulbul, Nyala Domaia, Nyala University farm and Kass. Twice the dose recommended for goats in Bulbul revealed a 90% UCrL of 87.6%. All post-treatment faecal cultures contained only Haemonchus spp. larvae. The experimental infection trials in sheep and goats supported our findings from field trials and calculated upper 90% CrL of below 98.9%. For the first time highly ivermectin resistant H. contortus populations have been identified in sheep and goats in Sudan, and resistance was experimentally confirmed.

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In vitro evaluation of fitness parameters for isolates of Teladorsagia circumcincta resistant and susceptible to multiple anthelmintic classes

Cited by 4 publications

References 45 publications

Climate change effects on terrestrial parasitic nematodes: Where are the knowledge gaps?

Climate change effects on terrestrial parasitic nematodes: Where are the knowledge gaps?

Cross-transmission of resistant gastrointestinal nematodes between wildlife and transhumant sheep

First evaluation and detection of ivermectin resistance in gastrointestinal nematodes of sheep and goats in South Darfur, Sudan

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