Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat?
Abstract Background The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-12-01
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| Series: | Parasites & Vectors |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13071-019-3828-6 |
| _version_ | 1830089791658524672 |
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| author | Pablo D. Jimenez Castro Sue B. Howell John J. Schaefer Russell W. Avramenko John S. Gilleard Ray M. Kaplan |
| author_facet | Pablo D. Jimenez Castro Sue B. Howell John J. Schaefer Russell W. Avramenko John S. Gilleard Ray M. Kaplan |
| author_sort | Pablo D. Jimenez Castro |
| collection | DOAJ |
| description | Abstract Background The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum. Methods Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 β-tubulin gene. Results Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 β-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases. Conclusions These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this. |
| first_indexed | 2024-12-16T16:51:49Z |
| format | Article |
| id | doaj.art-eb40e204f2834826beb50673cc7e8844 |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-12-16T16:51:49Z |
| publishDate | 2019-12-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-eb40e204f2834826beb50673cc7e88442022-12-21T22:24:00ZengBMCParasites & Vectors1756-33052019-12-0112111510.1186/s13071-019-3828-6Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat?Pablo D. Jimenez Castro0Sue B. Howell1John J. Schaefer2Russell W. Avramenko3John S. Gilleard4Ray M. Kaplan5Department of Infectious Diseases, College of Veterinary Medicine, University of GeorgiaDepartment of Infectious Diseases, College of Veterinary Medicine, University of GeorgiaSchool of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, University of TennesseeDepartment of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of CalgaryDepartment of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of CalgaryDepartment of Infectious Diseases, College of Veterinary Medicine, University of GeorgiaAbstract Background The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum. Methods Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 β-tubulin gene. Results Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 β-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases. Conclusions These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this.https://doi.org/10.1186/s13071-019-3828-6Ancylostoma caninumHookwormsResistanceAnthelminticsCanine health |
| spellingShingle | Pablo D. Jimenez Castro Sue B. Howell John J. Schaefer Russell W. Avramenko John S. Gilleard Ray M. Kaplan Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? Parasites & Vectors Ancylostoma caninum Hookworms Resistance Anthelmintics Canine health |
| title | Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? |
| title_full | Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? |
| title_fullStr | Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? |
| title_full_unstemmed | Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? |
| title_short | Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? |
| title_sort | multiple drug resistance in the canine hookworm ancylostoma caninum an emerging threat |
| topic | Ancylostoma caninum Hookworms Resistance Anthelmintics Canine health |
| url | https://doi.org/10.1186/s13071-019-3828-6 |
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