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Khangembam R, Vass N, Morrison A, Melville LA, Antonopoulos A, Czeglédi L. Preliminary results of the recombinase polymerase amplification technique for the detection of Haemonchus contortus from Hungarian field samples. Vet Parasitol 2023; 320:109974. [PMID: 37354888 DOI: 10.1016/j.vetpar.2023.109974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/07/2023] [Accepted: 06/14/2023] [Indexed: 06/26/2023]
Abstract
Haemonchus contortus is a parasitic nematode of small ruminants responsible for significant economic losses and animal health concerns globally. Detection of gastrointestinal nematode (GIN) infection in veterinary practice typically relies on microscopy-based methods such as the faecal egg count and morphological identification of larval culture. However, mixed co-infections are common and species-specific identification is typically time-consuming and expertise-intensive. Compounded by increasing anthelmintic resistance, there is an urgent need to implement the molecular diagnosis of GIN in the livestock industry, preferably in field settings. Advances in isothermal amplification techniques including recombinase polymerase amplification (RPA) assays could improve this. Yet, constraints in RPA kit availability and amplicon detection systems limit the use of this technology in point of care settings. In this study, we present an early-stage, proof-of-concept demonstration of RPA targeting the internal transcribed spacer (ITS2) region of H. contortus. Having tested against eight closely related nematodes and also against five farm isolates in Eastern Hungary, preliminary results derived from a comparative analysis of 3 primer sets showed the assay detects H. contortus DNA and has a limit of detection of 10-5 ng/μl. We also tested an end-result naked eye detection system using various DNA binding dyes, of which EvaGreen® dye was successful for a qualitative RPA detection that could be adaptable at farm sites.
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Affiliation(s)
- Rojesh Khangembam
- Doctoral School of Animal Science, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary; Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary.
| | - Nóra Vass
- Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary
| | - Alison Morrison
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK
| | - Lynsey A Melville
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK
| | - Alistair Antonopoulos
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, Scotland, UK; Kreavet, Kruibeke, Belgium.
| | - Levente Czeglédi
- Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary
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Rajagopal A, Sabu L, Radhika R, Devada K, Jose KJ, Thomas N, Aravindakshan T. Development of PCR-RFLP for the detection of benzimidazole resistance polymorphisms in isotype 1 β-tubulin gene of Trichostrongylus colubriformis. Small Rumin Res 2023. [DOI: 10.1016/j.smallrumres.2023.106954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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3
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Carbohydrate larval antigen (CarLA IgA) responses to mixed species nematode infection in pasture grazed Angora goats. Vet Parasitol 2023; 315:109883. [PMID: 36701944 DOI: 10.1016/j.vetpar.2023.109883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/19/2022] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
The genetics of indicator traits for resistance of Angora goats to gastrointestinal nematode parasite infections, and their relationships with productivity traits, were investigated on a commercial mixed-enterprise farm in the eastern North Island of New Zealand. Faecal egg counts (FEC), specific Immunoglobulin A (IgA) and Immunoglobulin G (IgG) antibody titres against carbohydrate larval antigen (CarLA) in saliva, live weight and fleece weights were recorded from 278 goats of 19-20 months of age, run as four separate mobs (breeding bucks, castrated males (wethers), or 2 groups of breeding does). Summary statistics showed the mobs differed significantly in liveweight, loge (FEC+50), loge (IgA) and loge (IgG). Genetic parameters were estimated using an animal model with repeated records where appropriate, after adjusting for the different contemporary animal groups, using the restricted maximum likelihood (REML) package. Heritability estimates from repeated measures were 0.19 ± 0.16 for FEC, 0.28 ± 0.16 for CarLA specific IgA and 0.23 ± 0.15 for CarLA specific IgG. The CarLA specific IgA response was negatively genetically correlated with FEC (-0.99 ± 0.31) suggesting that it could be used as a selection tool for breeding resistant animals. Although the genetic and phenotypic correlations between CarLA IgA and IgG were high and significant, the analysis between loge (FEC+50) and loge CarLA IgG did not converge. Further, both FEC and CarLA IgA showed significant and favourable genetic correlations with live weight. In contrast, CarLA IgG showed an unfavourable phenotypic correlation with liveweight. While this is only a preliminary study, the results do suggest that the immunoassay measuring salivary CarLA IgA response may have utility as a selection tool for parasite resistance in some breeds of goats.
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Hamilton KM, Waghorn TS, de Waal T, Keane OM, Green P, Leathwick DM. In vitro evaluation of fitness parameters for isolates of Teladorsagia circumcincta resistant and susceptible to multiple anthelmintic classes. Vet Parasitol 2022; 310:109791. [PMID: 36049292 DOI: 10.1016/j.vetpar.2022.109791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022]
Abstract
Anthelmintic resistance (AR) is an ever increasing problem for the sheep industry. Several studies worldwide have investigated reversing the trend of increasing AR and documented evidence for reversion toward susceptibility has been found. The hypothesis that resistance mutations compromise parasite fitness was drawn from this evidence. The aim of this study was to assess whether there were measurable differences in the fitness of Teladorsagia circumcincta isolates depending on their AR status. Four isolates were selected for the trial based on their known resistance status; D and M were multi-drug resistant, and T and W were susceptible to the benzimidazole, levamisole, and macrocyclic lactone anthelmintic classes. A secondary aim was to develop a series of in vitro bioassays for assessing fitness characteristics of parasites. The in vitro assays included; the cold stress test measured the number of third stage larvae (L3) developing from eggs stored at 4 °C for different lengths of time. Larval aging measured the locomotory activity of L3 after storage at 30 °C for different lengths of time. The exsheathment assay measured the exsheathment percentage of L3. Larval Length used length as a proxy for fecundity. The egg hatch assay evaluated egg hatch rate in water at room temperature. All isolates exhibited a decrease in the number of L3 recovered after storage of eggs at 4 °C (p < 0.001). Storage of L3 at 30 °C significantly influenced the ability of L3 to migrate through a 20 µm sieve (p < 0.001), however, there were no differences between isolates (p > 0.05). Exsheathment rate was higher for isolate D in comparison to isolates M and W, and for isolate T compared to isolate W. Isolate W was significantly longer than all other isolates (p < 0.05), whilst isolate M was significantly longer than isolate D (p < 0.05). No significant differences were found between isolates in egg hatch (p > 0.05). Overall, the results do not support differences in fitness associated with anthelmintic resistance status, even though differences were seen between the isolates for some assays. This suggests there is considerable variation in fitness parameters between isolates, making it difficult to determine whether resistance genotypes come with lower fitness.
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Affiliation(s)
- Kyra M Hamilton
- Animal & Bioscience Department, Teagasc, Athenry, Co. Galway, Ireland; AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand; School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland.
| | - Tania S Waghorn
- AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - Theo de Waal
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Orla M Keane
- Animal & Bioscience Department, Teagasc, Grange, Dunsany, Co. Meath, Ireland
| | - Peter Green
- AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - Dave M Leathwick
- AgResearch, Grasslands Research Centre, Palmerston North 4442, New Zealand
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Waghorn TS, Miller CM, Candy P, Carvalho L, Meban J, Green P, Leathwick DM. The production costs of Haemonchus contortus and other nematode parasites in pre-weaned beef calves in New Zealand. Vet Parasitol Reg Stud Reports 2022; 30:100718. [PMID: 35431074 DOI: 10.1016/j.vprsr.2022.100718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 02/17/2022] [Accepted: 03/04/2022] [Indexed: 11/16/2022]
Abstract
Haemonchus contortus can frequently be found infecting pre-weaned beef calves on sheep and beef farms around the North Island of New Zealand. The purpose of this study was to consider whether the presence of this parasite alone, or as part of a mixed infection, could be impacting growth rates of young animals, on three commercial farms in the North Island of New Zealand. Trials were conducted on commercial sheep and beef farms in each of the Northland, King Country and Gisborne regions, in late summer/autumn (February to April) of 2016 to measure the effect of treatment with narrow and broad spectrum anthelmintics on liveweight gain of spring-born calves pre-weaning. Each farm was chosen based on the presence of Haemonchus and that it was a beef cow/calf system with the cows and calves grazing the same pastures as sheep at some stage. Three sampling visits were made to each farm with the animals being weighed, faecal sampled and treated with one of two anthelmintics (Closantel alone to remove only Haemonchus or a triple combination containing moxidectin, levamisole and oxfendazole to remove all nematodes) or left untreated, on each of the first two visits. There was no significant difference in liveweight gain between any of the treatment groups, hence there was no evidence for an impact of Haemonchus alone, or a mixed nematode infection, on pre-weaned calf growth rates on these farms. It remains unclear whether there may be a justification to consider treatment of calves should they constitute a significant source of pasture larval infestation with H. contortus, in an integrated cattle-sheep system.
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Affiliation(s)
- T S Waghorn
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand.
| | - C M Miller
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - P Candy
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - L Carvalho
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - J Meban
- Eastland Veterinary Services, 743 Gladstone Road, PO Box 829, Gisborne 4040, New Zealand
| | - P Green
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
| | - D M Leathwick
- AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North 4442, New Zealand
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Mickiewicz M, Czopowicz M, Moroz A, Potărniche AV, Szaluś-Jordanow O, Spinu M, Górski P, Markowska-Daniel I, Várady M, Kaba J. Prevalence of anthelmintic resistance of gastrointestinal nematodes in Polish goat herds assessed by the larval development test. BMC Vet Res 2021; 17:19. [PMID: 33413368 PMCID: PMC7791792 DOI: 10.1186/s12917-020-02721-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 12/09/2020] [Indexed: 12/27/2022] Open
Abstract
Background Helminthic infections, in particular those caused by gastrointestinal nematodes (GIN), are found worldwide and are among the most economically important diseases of goats. Anthelmintic resistance (AR) in GIN of goats is currently present worldwide, and single- or multidrug resistant species are widespread. The aim of this study was to determine the prevalence of AR to benzimidazoles (BZ), macrocyclic lactones (ML) and imidazothiazoles represented by levamisole (LEV) in the Polish goat herds by using an in vitro larval development test, which is useful especially in large-scale epidemiological surveys. Results This cross-sectional study was conducted from September 2018 to June 2019 and enrolled 42 dairy goat herds scattered over the entire country. The most commonly used anthelmintic class in goat herds in Poland were BZ (92%), followed by ML (85%) and LEV (13%). BZ-resistant GIN populations were found in 37 herds (88%, CI 95%: 75 to 95%), ML-resistant GIN populations in 40 herds (95%, CI 95, 84 to 99%), and LEV-resistant GIN populations in 5 herds (12%, CI 95%: 5 to 25%). Multidrug resistance involving all three anthelmintic classes was found in 5 herds (12%, CI 95, 5 to 25%). Based on the morphological features of stage 3 larvae the main resistant GIN turned out to be Haemonchus contortus and Trichostrongylus spp. The use of BZ and frequency of anthelmintic treatments were significantly related to the presence of AR to BZ in Polish goat herds. Conclusions This cross-sectional study demonstrates the existence of AR to BZ, ML and LEV on Polish goat farms. Resistance to BZ and ML is widespread, while AR to LEV is currently at a low level. A considerable proportion of herds harbours multidrug resistant GIN, which requires further consideration. An effective anthelmintic treatment strategy, reasonable preventive measures and better understanding of the resistance-related management practices by farmers and veterinarians may delay further development of AR. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-020-02721-9.
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Affiliation(s)
- Marcin Mickiewicz
- Division of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-786, Warsaw, Poland
| | - Michał Czopowicz
- Division of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-786, Warsaw, Poland.
| | - Agata Moroz
- Division of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-786, Warsaw, Poland
| | - Adrian-Valentin Potărniche
- Department of Infectious Diseases and Preventive Medicine, Law and Ethics, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăștur 3-5, 400372, Cluj-Napoca, Romania
| | - Olga Szaluś-Jordanow
- Department of Small Animal Diseases with Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159c, 02-786, Warsaw, Poland
| | - Marina Spinu
- Department of Infectious Diseases and Preventive Medicine, Law and Ethics, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăștur 3-5, 400372, Cluj-Napoca, Romania
| | - Paweł Górski
- Division of Parasitology and Invasiology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Ciszewskiego 8, 02-786, Warsaw, Poland
| | - Iwona Markowska-Daniel
- Division of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-786, Warsaw, Poland
| | - Marián Várady
- Institute of Parasitology, Slovak Academy of Sciences, Hlinkova 3, 04001, Košice, Slovakia
| | - Jarosław Kaba
- Division of Veterinary Epidemiology and Economics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-786, Warsaw, Poland
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Ghatee MA, Malek Hosseini SAA, Marashifard M, Karamian M, Taylor WR, Jamshidi A, Mobedi I, Azarmehr H. Phylogenetic analysis of Trichostrongylus vitrinus isolates from southwest Iran. Parasit Vectors 2020; 13:553. [PMID: 33160415 PMCID: PMC7648934 DOI: 10.1186/s13071-020-04438-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/30/2020] [Indexed: 11/11/2022] Open
Abstract
Background Trichostrongylus is one of the most important zoonotic trichostrongylid nematodes, infecting mostly livestock. Data on its genetic characteristics are lacking in Iran. Methods We determined the phylogenetic relationships of Trichostrongylus species in three counties of Kohgiloyeh and Boyerahmad (K-B) province, southwest Iran. Small intestine and abomasum of 70 sheep and goats were investigated. Results A total of 35 isolates of Trichostrongylus worms were detected and all were genetically identified as Trichostrongylus vitrinus. Analysis of 321 bp of the internal transcribed spacer 2 (ITS2) of ribosomal DNA revealed 16 genotypes. All genotypes were single nucleotide polymorphisms, including some hypervariable points. All sequences were trimmed to 170 bp, compared with sequences on GenBank including short sequences from other endemic foci of Iran and other countries and all isolates were used to generate a maximum likelihood phylogenetic tree, which consisted of two clades A and B. Clade A included isolates from Iran, Russia, New Zealand, Australia and the UK; clade B only contained South African isolates. Most clade A isolates (north, southwest and west Iran, Russia, New Zealand, Australia and UK) were in a similar phylogenetic position. One subclade was detected in clade A (isolates from Southwest Iran, New Zealand and UK). Conclusions We hypothesize that drug resistant T. vitrinus may account for its exclusive detection in our samples. The high similarity of genotypes from Iran, New Zealand and UK may be due to their close political relationships during the colonial era. More research is needed to understand better the phylogeny of T. vitrinus and its relationship with drug resistance and human transmission. ![]()
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Affiliation(s)
- Mohammad Amin Ghatee
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran. .,Department of Parasitology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran.
| | | | - Masoud Marashifard
- Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Mehdi Karamian
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Walter Robert Taylor
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand.,Oxford Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Ali Jamshidi
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Iraj Mobedi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Hasan Azarmehr
- Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
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Waghorn TS, Bouchet CLG, Bekelaar K, Leathwick DM. Nematode parasites in young cattle: what role for unexpected species? N Z Vet J 2018; 67:40-45. [DOI: 10.1080/00480169.2018.1532849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- TS Waghorn
- AgResearch Grasslands, Private Bag 11008, Palmerston North 4442, New Zealand
| | - CLG Bouchet
- AgResearch Grasslands, Private Bag 11008, Palmerston North 4442, New Zealand
| | - K Bekelaar
- AgResearch Grasslands, Private Bag 11008, Palmerston North 4442, New Zealand
| | - DM Leathwick
- AgResearch Grasslands, Private Bag 11008, Palmerston North 4442, New Zealand
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Hodgson B, Mulvaney CJ. Resistance to a triple-combination anthelmintic in Trichostrongylus spp. on a commercial sheep farm in New Zealand. N Z Vet J 2017; 65:277-281. [PMID: 28532295 DOI: 10.1080/00480169.2017.1333468] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AIM To evaluate resistance to anthelmintics containing abamectin, levamisole, and oxfendazole (AB-LEV-OX), derquantal and abamectin (DEQ-AB), moxidectin, and monepantel in naturally acquired gastrointestinal nematodes present on a sheep farm. METHODS Faecal nematode egg count reduction tests (FECRT) were carried out on lambs that were approximately 7 months-old and infected with naturally acquired nematodes. Lambs were randomly allocated to one of five groups (n=15 per group): treatment with 2 mg/kg derquantel and 0.2 mg/kg abamectin; 0.2 mg/kg abamectin, 8 mg/kg levamisole HCl and 4.5 mg/kg oxfendazole; 2.5 mg/kg monepantel; 0.2 mg/kg moxidectin, or no treatment. Post-treatment samples were collected 12 days later. Abomasa and small intestines were collected from two slaughtered lambs from each of the DEQ-AB, AB-LEV-OX, moxidectin and control groups 15 days after treatment, for nematode counting. RESULTS The FECRT demonstrated that efficacy was 90.3 (95% CI=84.2-94.1)% for AB-LEV-OX, 54.5 (95% CI=28.4-71.1)% for moxidectin, 99.2 (95% CI=97.4-99.8)% for DEQ-AB and 100% for monepantel, across all genera. For Trichostrongylus spp. efficacy was 85.5% for AB-LEV-OX and 46.7% for moxidectin. Haemonchus spp. were fully susceptible to all treatments. Post-treatment nematode counts indicated that the resistant Trichostrongylus spp. were from the small intestine. CONCLUSIONS Anthelmintic resistance to both AB-LEV-OX and moxidectin was present in the Trichostrongylus genus on a commercial sheep farm. Monepantel and DEQ-AB were both effective against Trichostrongylus spp. based on FECRT results. CLINICAL RELEVANCE This finding of resistance to an AB-LEV-OX triple-combination anthelmintic in the Trichostrongylus genus in sheep in New Zealand further limits anthelmintic treatment options available, and calls into question whether this combination is suitable for use as a quarantine treatment.
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Affiliation(s)
- Bas Hodgson
- a VetEnt , 6 Seddon St, Te Kuiti , 3800 , New Zealand
| | - C J Mulvaney
- b AgriNetworks Limited , PO Box 83, Te Awamutu , 3840 , New Zealand
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Oliver A, Pomroy WE, Leathwick DM. Benzimidazole resistance in Nematodirus spathiger and N. filicollis in New Zealand. N Z Vet J 2016; 64:201-6. [PMID: 26846152 DOI: 10.1080/00480169.2016.1149117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIM To determine the prevalence of benzimidazole resistance in Nematodirus spathiger and N. filicollis from a sample of New Zealand farms. METHODS The efficacy of albendazole (ABZ) against Nematodirus spp. was assessed by faecal nematode egg count reduction (FECR) tests undertaken in lambs aged 3-8 months old on 27 sheep farms throughout New Zealand. On each farm, groups of 10-16 lambs were either treated with ABZ (4.75 mg/kg) or remained as untreated controls. Faecal samples were collected from all animals at the time of treatment and 7-10 days later. Faecal nematode egg counts (FEC) were performed using a modified McMaster technique. Larvae were cultured from pooled faecal samples, collected 7-10 days after treatment from each group, by incubation at 20°C for 6 weeks, 4°C for 26 weeks then 13°C for 2 weeks. The resulting third stage larvae were identified to species using a multiplex PCR assay, that identified species-specific sequences in the second internal transcribed spacer region of ribosomal DNA. The efficacy of ABZ for N. spathiger and N. filicollis was calculated from the proportion of the two species in culture and the group mean FEC before and after treatment. Only farms with a mean of 10 epg for each species in untreated samples were included for analysis. Resistance was defined as an efficacy <95%. RESULTS On farms that met the threshold of 10 epg in faecal samples, benzimidazole resistance was found on 20/21 (95%) farms for N. spathiger compared with 4/10 (40%) farms for N. filicollis (p<0.05). In samples collected following treatment, a mean of 83 (min 46, max 100)% of Nematodirus spp. larvae recovered from the untreated groups were N. spathiger, compared with 94 (min 45, max 100)% in the ABZ treated groups (p=0.03). This change in percentage was not influenced by the overall efficacy of treatment based on the FECR test (p=0.324). CONCLUSION The results confirm the high level of resistance in N. spathiger in New Zealand and that benzimidazole resistance was more common in N. spathiger than N. filicollis. While resistance to benzimidazole anthelmintics has been reported previously in New Zealand, this is the first report of N. filicollis being resistant to benzimidazole anthelmintics.
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Affiliation(s)
- Amb Oliver
- a Animal Health, AgResearch Grasslands , Private Bag 11008, Palmerston North 4442 , New Zealand
| | - W E Pomroy
- b Institute for Veterinary, Animal and Biomedical Science , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand
| | - D M Leathwick
- a Animal Health, AgResearch Grasslands , Private Bag 11008, Palmerston North 4442 , New Zealand
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Sutherland IA. Recent developments in the management of anthelmintic resistance in small ruminants – an Australasian perspective. N Z Vet J 2015; 63:183-7. [DOI: 10.1080/00480169.2015.1019947] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Leathwick DM, Ganesh S, Waghorn TS. Evidence for reversion towards anthelmintic susceptibility in Teladorsagia circumcincta in response to resistance management programmes. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 5:9-15. [PMID: 25941625 PMCID: PMC4412914 DOI: 10.1016/j.ijpddr.2015.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/28/2015] [Accepted: 01/30/2015] [Indexed: 10/28/2022]
Abstract
Maintaining production and economic viability in the face of resistance to multiple anthelmintic actives is a challenge for farmers in many countries. In this situation, most farmers in New Zealand rely on the use of combination products, containing multiple actives with similar spectra of activity, in order to maintain control. However, there are concerns that use of combinations, once resistance has already developed to the individual actives, could rapidly lead to complete failure of all actives. This study followed seven farms, previously diagnosed with resistance to at least two classes of anthelmintic, which were implementing a tailored programme of 'best practice parasite management'. The aim was to ascertain whether the programmes, which included the almost exclusive use of combination anthelmintics, were able to prevent resistance from developing further. Strategies implemented on each farm varied, but had consistent underlying principles i.e. to avoid over-use of anthelmintics; to minimise parasite challenge to susceptible stock; to maintain refugia of susceptibility and to ensure that only effective anthelmintics were used. Annual faecal egg count reduction tests (FECRT) were undertaken in lambs on all farms to monitor anthelmintic efficacy over 5 years. The efficacy of albendazole, ivermectin and levamisole was calculated and the changes in efficacy against Teladorsagia circumcincta assessed. Overall, there was a significant improvement in the effectiveness of both levamisole and ivermectin against T. circumcincta, and a positive but non-significant trend in efficacy of albendazole, i.e. there was evidence for reversion towards susceptibility. Hence, the almost exclusive use of combination anthelmintics, integrated with other resistance management strategies, did not result in further resistance development despite all farms exhibiting resistance to multiple actives at the outset. What-is-more, the measured increases in anthelmintic efficacy suggests that adoption of best practice management strategies may extend the useful life of anthelmintics even after resistance has been diagnosed.
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Affiliation(s)
- Dave M Leathwick
- AgResearch Grasslands, private Bag 11008, Palmerston North, New Zealand
| | - Siva Ganesh
- AgResearch Grasslands, private Bag 11008, Palmerston North, New Zealand
| | - Tania S Waghorn
- AgResearch Grasslands, private Bag 11008, Palmerston North, New Zealand
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Roeber F, Kahn L. The specific diagnosis of gastrointestinal nematode infections in livestock: larval culture technique, its limitations and alternative DNA-based approaches. Vet Parasitol 2014; 205:619-28. [PMID: 25182210 DOI: 10.1016/j.vetpar.2014.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 08/01/2014] [Accepted: 08/09/2014] [Indexed: 11/29/2022]
Abstract
The specific diagnosis of gastrointestinal nematode infections in ruminants is routinely based on larval culture technique and on the morphological identification of developed third-stage larvae. However, research on the ecology and developmental requirements of different species suggests that environmental conditions (e.g., temperature and humidity) for optimal development to occur vary between the different species. Thus, employing a common culture protocol for all species will favour the development of certain species over others and can cause a biased result in particular when species proportions in a mixed infection are to be determined. Furthermore, the morphological identification of L3 larvae is complicated by a lack of distinctive, obvious features that would allow the identification of all key species. In the present paper we review in detail the potential limitations of larval culture technique and morphological identification and provide account to some modern molecular alternatives to the specific diagnosis of gastrointestinal nematode infection in ruminants.
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Affiliation(s)
- Florian Roeber
- AusDiagnostics Pty. Ltd., Beaconsfield 2015, NSW, Australia.
| | - Lewis Kahn
- Environmental and Rural Science, University of New England, Armidale 2351, NSW, Australia
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A multiplex PCR-based method to identify strongylid parasite larvae recovered from ovine faecal cultures and/or pasture samples. Vet Parasitol 2014; 200:117-27. [DOI: 10.1016/j.vetpar.2013.12.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 11/01/2013] [Accepted: 12/02/2013] [Indexed: 11/22/2022]
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