International Journal for Parasitology: Drugs and Drug Resistance最新文献

{"title":"Reflecting on the past and fast forwarding to present day anthelmintic resistant Ancylostoma caninum–A critical issue we neglected to forecast","authors":"Antoinette E. Marsh ,&nbsp;Jeffrey Lakritz","doi":"10.1016/j.ijpddr.2023.04.003","DOIUrl":"10.1016/j.ijpddr.2023.04.003","url":null,"abstract":"<div><p>Reports of anthelmintic resistance in <em>Ancylostoma caninum</em> are increasing in frequency in the United States of America (USA). In the last few years <em>in vitro</em> and <em>in vivo</em> studies characterized individual isolates, demonstrating multiple anthelmintic drug resistance (MADR). In 2021, the American Association of Veterinary Parasitologists initiated a hookworm task force to address this issue. The first report of drug resistant <em>A. caninum</em> occurred in 1987 in Australian racing Greyhounds. In the last five years multiple case reports and investigations show drug resistant <em>A. caninum</em> is becoming a much greater problem in the USA and now extends beyond racing Greyhounds into the general companion animal dog population. The literature, regarding drug resistance in livestock and equine nematodes, provides helpful guidance along with diagnostic methods to better understand the evolution and selection of canine MADR hookworms; however, there are limitations and caveats due to <em>A. caninum's</em> unique biology and zoonotic potential. Mass drug administration (MDA) of anthelminthic drugs to humans to reduce morbidity associated with human hookworms (<em>Necator americanus</em>) should consider the factors that contributed to the development of MADR <em>A. caninum</em>. Finally, as Greyhound racing undergoes termination in some regions and the retired dogs undergo subsequent rehoming, drug resistant parasites, if present, are carried with them. Drug resistant <em>A. caninum</em> requires greater recognition by the veterinary community, and small animal practitioners need to be aware of the spread into current pet dog populations. The current understanding of anthelmintic resistance, available treatments, and environmental mitigation for these drug resistant <em>A. caninum</em> isolates must be monitored for horizontal spread. A major goal in this emerging problem is to prevent continued dissemination.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"22 ","pages":"Pages 36-43"},"PeriodicalIF":4.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/12/46/main.PMC10229760.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9946081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ascaridia galli - An old problem that requires new solutions","authors":"Johan Höglund ,&nbsp;Gürbüz Daş ,&nbsp;Behdad Tarbiat ,&nbsp;Peter Geldhof ,&nbsp;Désirée S. Jansson ,&nbsp;Matthias Gauly","doi":"10.1016/j.ijpddr.2023.07.003","DOIUrl":"10.1016/j.ijpddr.2023.07.003","url":null,"abstract":"<div><p>Reports of <em>Ascaridia galli</em> in laying hens in Europe have increased since the ban on conventional battery cages in 2012. As this parasite is transmitted directly via the faecal-oral route by parasite eggs containing a larva, it is reasonable to assume that the escalating problem is related to the increased exposure now occurring in modern welfare-friendly cage-free housing systems. On many farms, <em>A. galli</em> reappears in subsequent flocks, even though the birds have no access to the outdoors, biosecurity is high and empty houses are cleaned and disinfected during downtime. Since the egg production cycle lasts only ≈80 weeks and recombinant antigen production for helminth vaccines has not yet been solved, the development of a vaccine seems to be an unrealistic option. Therefore, disrupting the life cycle of the parasite by other means, including the strategic use of dewormers, appears to be the key to controlling infection. Of concern is that only one class of anthelmintics is licenced for poultry in Europe and that are usually administered indiscriminately through the birds' drinking water and often too late when the parasite is already established. If current calendar-based parasite control strategies are not changed, there is a risk that resistance to anthelmintics may develop, as has already been demonstrated with nematodes in livestock. We insist that treatments can be more effective and the risk of developing drug resistance can be mitigated if we invest in a better understanding of <em>A. galli</em> responses to more prudent and judicious use of anthelmintics. This review identifies knowledge gaps and highlights aspects of sustainable parasite control that require further research to support commercial egg producers.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"23 ","pages":"Pages 1-9"},"PeriodicalIF":4.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10409999/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9972010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Droplet digital PCR as a tool to detect resistant isolates of Dirofilaria immitis","authors":"Sohini Kumar ,&nbsp;Roger K. Prichard ,&nbsp;Thavy Long","doi":"10.1016/j.ijpddr.2023.07.002","DOIUrl":"10.1016/j.ijpddr.2023.07.002","url":null,"abstract":"<div><p>Prevention of canine heartworm disease, caused by <em>Dirofilaria immitis</em>, relies on macrocyclic lactones for which drug resistance is now a concern. Although genetic polymorphisms have been associated with resistance in <em>D. immitis</em> populations, the mechanism is still not well understood. The lack of reliable <em>in vitro</em> assays to detect resistance is a limitation for confirming resistance. Ten single nucleotide polymorphisms (SNPs) were previously clinically validated in <em>D. immitis</em> resistant isolates, using the MiSeq platform. This technique although useful for research studies is expensive and does not facilitate rapid detection of these markers in small numbers of clinical samples. We developed a droplet digital PCR protocol for detecting SNPs correlating with ML resistance. Specific primers and hydrolysis probes encompassing the wildtype and mutant alleles were designed to amplify the SNP targets from genomic DNA of different <em>D. immitis</em> isolates. Allele frequencies were determined and the suitability of the ddPCR assay was assessed and compared with MiSeq data. The ddPCR assay accurately detected and quantified alternate nucleotides in two isolates of reference, the ML-susceptible Missouri (MO) and ML-resistant JYD-34, at the previously identified SNP positions. The presence of the SNPs was also determined in additional isolates with known or putative susceptible or resistant phenotypes. We observed SNP1 and SNP2 are more predictive markers and appear suitable for rapid detection and monitoring of drug resistance. Our results suggested that ddPCR could be employed to distinguish infection due to actual genetic resistance from infection with susceptible parasites and also for rapid detection of isolates not only with ML susceptible and resistant genotypes but also mixed genotypes that correspond to heterogeneous isolates containing a mixed population of ML susceptible and resistant parasites. DdPCR may be a useful tool for conducting surveys, or assessments of individual isolates, for genetic evidence of resistance or developing resistance.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"23 ","pages":"Pages 10-18"},"PeriodicalIF":4.0,"publicationDate":"2023-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e1/99/main.PMC10407818.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10336518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ring stage dormancy of Plasmodium falciparum tolerant to artemisinin and its analogues – A genetically regulated “Sleeping Beauty”","authors":"Saranya Auparakkitanon ,&nbsp;Prapon Wilairat","doi":"10.1016/j.ijpddr.2023.01.002","DOIUrl":"10.1016/j.ijpddr.2023.01.002","url":null,"abstract":"<div><p>The appearance in 2008 in western Cambodia of <em>Plasmodium falciparum</em> tolerant to artemisinin, defined by longer parasite clearance time following drug administration and <em>in vitro</em> by a slightly higher survival rate of the ring stage after a 3-h treatment with 700 nM artemisinin (or analogues, collectively termed ART), has raised concerns of the possible loss of this frontline antimalarial [used in the form of an artemisinin combination therapy (ACT)], with its low IC₅₀ value against the ring stage and pleiotropic pro-drug/poison property. The key genetic marker of ART tolerance phenotype is a number of non-synonymous mutations in <em>Pfkelch13</em> propeller domain. This results in defective assembly at the ring stage of a cytostome structure located at cytoplasmic side of the parasite membrane required for invagination of a double-membrane endosome carrying host cytosol haemoglobin to the digestive vacuole. The consequential deprivation of amino acids initiates ring stage parasites bearing the causal mutations in <em>Pf</em>K13 (or other key cytostome components) entry into a dormant state (“Sleeping Beauty”), which, after a duration longer than that the short-lived ART, “Sleeping Beauty” ring parasite resumes its normal, but accelerated, development to maintain the 48-h intra-erythrocytic life-cycle. We posit that when ART-tolerant <em>P</em>. <em>falciparum</em> has acquired under ART stress the causative <em>Pf</em>K13 mutation (not obligatory if mutations occur in other critical cytostome components), together with other necessary mutations to adjust to the new normalcy and to provide survival competitiveness, ART-tolerant parasite has now evolved into a genetically programmed “Sleeping Beauty”. The onus of preventing the spread of ART-tolerant <em>P</em>. <em>falciparum</em> lies with the efficacy of ACT partner drug, hence the recommendation of a triple ACT (TACT). Nevertheless, attention should also be focussed on understanding the mechanisms of dormancy, such as induction, maintenance and recovery, to enable discovery and development of novel antimalarials targeting this unique parasite stage.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 61-64"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/40/5c/main.PMC9883618.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9810589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thiophene derivatives activity against the protozoan parasite Leishmania infantum","authors":"Sophia Bigot ,&nbsp;Philippe Leprohon ,&nbsp;Abimael Vasquez ,&nbsp;Rohit Bhadoria ,&nbsp;Rachid Skouta ,&nbsp;Marc Ouellette","doi":"10.1016/j.ijpddr.2022.11.004","DOIUrl":"10.1016/j.ijpddr.2022.11.004","url":null,"abstract":"<div><p>Treatments against leishmaniasis are limited and the development of new molecules is crucial. One class of developmental drug that has shown activity against the parasite <em>Leishmania</em> are thiophene derivatives. Here we synthetized thirty-eight novel thiophene compounds and characterized their activity and potential for resistance against <em>L. infantum</em>. Half of the molecules had an EC₅₀ in the low micromolar range, the piperidine derivatives being more potent than the tetramethylpyran derivatives. Resistance was challenging to select for, and resistant cells could only be raised against one (GC1-19) of the four most active compounds. Using chemogenomic screens we show that a gene conversion event at the <em>ABCG2</em> locus as well as the overexpression of a tryparedoxin peroxidase are responsible for a weak but significant resistance to the GC1-19 drug candidate. Together, our results suggest that thiophene is a scaffold of interest for further drug development against leishmaniasis.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 13-20"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/fb/1f/main.PMC9772499.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9439988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic diversity in the metronidazole metabolism genes nitroreductases and pyruvate ferredoxin oxidoreductases in susceptible and refractory clinical samples of Giardia lamblia","authors":"Christina S. Saghaug ,&nbsp;Astrid L. Gamlem ,&nbsp;Kirsti B. Hauge ,&nbsp;Juha Vahokoski ,&nbsp;Christian Klotz ,&nbsp;Toni Aebischer ,&nbsp;Nina Langeland ,&nbsp;Kurt Hanevik","doi":"10.1016/j.ijpddr.2022.12.003","DOIUrl":"10.1016/j.ijpddr.2022.12.003","url":null,"abstract":"<div><p>The effectiveness of metronidazole against the tetraploid intestinal parasite <em>Giardia lamblia</em> is dependent on its activation/inactivation within the cytoplasm. There are several activating enzymes, including pyruvate ferredoxin reductase (PFOR) and nitroreductase (NR) 1 which metabolize metronidazole into toxic forms, while NR2 on the other hand inactivates it. Metronidazole treatment failures have been increasing rapidly over the last decade, indicating genetic resistance mechanisms. Analyzing genetic variation in the PFOR and NR genes in susceptible and refractory <em>Giardia</em> isolates may help identify potential markers of resistance.</p><p>Full length <em>PFOR1</em>, <em>PFOR2</em>, <em>NR1</em> and <em>NR2</em> genes from clinical culturable isolates and non-cultured clinical <em>Giardia</em> assemblage B samples were cloned, sequenced and single nucleotide variants (SNVs) were analyzed to assess genetic diversity and alleles.</p><p>A similar ratio of amino acid changing SNVs per gene length was found for the NRs; 4.2% for <em>NR1</em> and 6.4% for <em>NR2</em>, while the <em>PFOR1</em> and <em>PFOR2</em> genes had less variability with a ratio of 1.1% and 1.6%, respectively. One of the samples from a refractory case had a nonsense mutation which caused a truncated <em>NR1</em> gene in one out of six alleles. Further, we found three <em>NR2</em> alleles with frameshift mutations, possibly causing a truncated protein in two susceptible isolates. One of these isolates was homozygous for the affected <em>NR2</em> allele. Three nsSNVs with potential for affecting protein function were found in the ferredoxin domain of the <em>PFOR2</em> gene. The considerable variation and discovery of mutations possibly causing dysfunctional NR proteins in clinical <em>Giardia</em> assemblage B isolates, reveal a potential for genetic link to metronidazole susceptibility and resistance.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 51-60"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9871439/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9433400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmacokinetic and pharmacodynamic considerations for treating sarcoptic mange with cross-relevance to Australian wildlife","authors":"Kotaro Takano ,&nbsp;Lachlan de Hayr ,&nbsp;Scott Carver ,&nbsp;Robert J. Harvey ,&nbsp;Kate E. Mounsey","doi":"10.1016/j.ijpddr.2023.02.004","DOIUrl":"10.1016/j.ijpddr.2023.02.004","url":null,"abstract":"<div><p><em>Sarcoptes scabiei</em> is the microscopic burrowing mite responsible for sarcoptic mange, which is reported in approximately 150 mammalian species. In Australia, sarcoptic mange affects a number of native and introduced wildlife species, is particularly severe in bare-nosed wombats (<em>Vombatus ursinus</em>) and an emerging issue in koala and quenda. There are a variety of acaricides available for the treatment of sarcoptic mange which are generally effective in eliminating mites from humans and animals in captivity. In wild populations, effective treatment is challenging, and concerns exist regarding safety, efficacy and the potential emergence of acaricide resistance. There are risks where acaricides are used intensively or inadequately, which could adversely affect treatment success rates as well as animal welfare. While reviews on epidemiology, treatment strategies, and pathogenesis of sarcoptic mange in wildlife are available, there is currently no review evaluating the use of specific acaricides in the context of their pharmacokinetic and pharmacodynamic properties, and subsequent likelihood of emerging drug resistance, particularly for Australian wildlife. This review critically evaluates acaricides that have been utilised to treat sarcoptic mange in wildlife, including dosage forms and routes, pharmacokinetics, mode of action and efficacy. We also highlight the reports of resistance of <em>S. scabiei</em> to acaricides, including clinical and <em>in vitro</em> observations.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 97-113"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/ea/68/main.PMC10023865.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9440544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of geranylated dihydrochalcone from Artocarpus altilis leaves extract on Plasmodium falciparum ultrastructural changes and mitochondrial malate: Quinone oxidoreductase","authors":"Agriana Rosmalina Hidayati ,&nbsp;Melinda ,&nbsp;Hilkatul Ilmi ,&nbsp;Takaya Sakura ,&nbsp;Miako Sakaguchi ,&nbsp;Junko Ohmori ,&nbsp;Endah Dwi Hartuti ,&nbsp;Lidya Tumewu ,&nbsp;Daniel Ken Inaoka ,&nbsp;Mulyadi Tanjung ,&nbsp;Eri Yoshida ,&nbsp;Fuyuki Tokumasu ,&nbsp;Kiyoshi Kita ,&nbsp;Mihoko Mori ,&nbsp;Kazuyuki Dobashi ,&nbsp;Tomoyoshi Nozaki ,&nbsp;Din Syafruddin ,&nbsp;Achmad Fuad Hafid ,&nbsp;Danang Waluyo ,&nbsp;Aty Widyawaruyanti","doi":"10.1016/j.ijpddr.2022.12.001","DOIUrl":"10.1016/j.ijpddr.2022.12.001","url":null,"abstract":"<div><p>Nearly half of the world's population is at risk of being infected by <em>Plasmodium falciparum,</em> the pathogen of malaria. Increasing resistance to common antimalarial drugs has encouraged investigations to find compounds with different scaffolds. Extracts of <em>Artocarpus altilis</em> leaves have previously been reported to exhibit <em>in vitro</em> antimalarial activity against <em>P. falciparum</em> and <em>in vivo</em> activity against <em>P. berghei</em>. Despite these initial promising results, the active compound from <em>A. altilis</em> is yet to be identified. Here, we have identified 2-geranyl-2′, 4′, 3, 4-tetrahydroxy-dihydrochalcone (<strong>1</strong>) from <em>A. altilis</em> leaves as the active constituent of its antimalarial activity. Since natural chalcones have been reported to inhibit food vacuole and mitochondrial electron transport chain (ETC), the morphological changes in food vacuole and biochemical inhibition of ETC enzymes of (<strong>1</strong>) were investigated. In the presence of (<strong>1</strong>), intraerythrocytic asexual development was impaired, and according to the TEM analysis, this clearly affected the ultrastructure of food vacuoles. Amongst the ETC enzymes, (<strong>1</strong>) inhibited the mitochondrial malate: quinone oxidoreductase (<em>Pf</em>MQO), and no inhibition could be observed on dihydroorotate dehydrogenase (DHODH) as well as <em>bc</em>₁ complex activities. Our study suggests that (<strong>1</strong>) has a dual mechanism of action affecting the food vacuole and inhibition of <em>Pf</em>MQO-related pathways in mitochondria.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 40-50"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e4/56/main.PMC9798170.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9495054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OBITUARY- Ian Fairweather","authors":"Mark W. Robinson ,&nbsp;Bob Hanna ,&nbsp;Philip Skuce ,&nbsp;Gerry Brennan","doi":"10.1016/j.ijpddr.2023.02.003","DOIUrl":"10.1016/j.ijpddr.2023.02.003","url":null,"abstract":"","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Page 96"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42453788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of Ancylostoma caninum parasites with the benzimidazole resistance F167Y polymorphism in the US dog population","authors":"Christian M. Leutenegger ,&nbsp;Cecilia E. Lozoya ,&nbsp;Jeffrey Tereski ,&nbsp;Christian Savard ,&nbsp;Jennifer Ogeer ,&nbsp;Rene Lallier","doi":"10.1016/j.ijpddr.2023.01.001","DOIUrl":"10.1016/j.ijpddr.2023.01.001","url":null,"abstract":"<div><h3>Background</h3><p>Anthelmintic resistance to benzimidazole has been detected in the canine hookworm, <em>Ancylostoma caninum</em>. Benzimidazole resistance is believed to have developed originally in greyhounds, but has also been detected in non-greyhound pet dogs. The aim of this study was to validate a probe-based allele-specific real-time PCR tests for the F167Y polymorphism on the β-tubulin isotype-1 gene and to determine the geographic distribution.</p></div><div><h3>Methods</h3><p>Allele-specific real-time PCR tests were established and validated to detect the codon 167 polymorphism in the <em>Ancylostoma caninum</em> β-tubulin isotype-1gene. Additionally, real-time PCR tests were validated for <em>Ancylostoma</em> spp. and <em>Uncinaria stenocephala</em>. Two nucleic acid extraction protocols were validated including mechanical disruption of parasite structures in stool. The frequency of the F167Y single nucleotide polymorphism (SNP) was determined in hookworm confirmed stool samples. Samples with the resistant 167Y genotype were confirmed by β-tubulin gene sequencing and allele frequencies were determined.</p></div><div><h3>Results</h3><p>The <em>Ancylostoma</em> spp. and <em>A. caninum</em> F167Y allele-specific real-time PCR tests were highly sensitive and specific when tested against synthetic DNA, spiked samples, and characterized parasites. Using an optimized total nucleic acid extraction protocol, 54 of 511 (10.6%) were found to contain the benzimidazole resistance allele. All 55 samples containing hookworms with the resistance mutation were confirmed by β-tubulin gene sequencing. The majority of resistant hookworms (44 resistant, 183 tested; 24.4%) originated from Florida, five from California (103 tested, 4.9%), three from Idaho (40 tested, 7.5%), two from Nevada (22 tested, 9.1%), and one sample from Hawaii (13 tested, 7.7%). Resistant genotypes were found in 14 different dog breeds including eight in Greyhounds. Allele-frequency determination revealed resistance allele frequencies between 1 and 100% with 58% above 50%.</p></div><div><h3>Conclusions</h3><p>This data strongly supports recent findings of benzimidazole resistant canine hookworms present throughout the general US pet dog population.</p></div>","PeriodicalId":13775,"journal":{"name":"International Journal for Parasitology: Drugs and Drug Resistance","volume":"21 ","pages":"Pages 131-140"},"PeriodicalIF":4.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10068012/pdf/main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9794171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}