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Leutenegger CM, Evason MD, Willcox JL, Rochani H, Richmond HL, Meeks C, Lozoya CE, Tereski J, Loo S, Mitchell K, Andrews J, Savard C. Benzimidazole F167Y polymorphism in the canine hookworm, Ancylostoma caninum: Widespread geographic, seasonal, age, and breed distribution in United States and Canada dogs. Int J Parasitol Drugs Drug Resist 2024; 24:100520. [PMID: 38237210 PMCID: PMC10825515 DOI: 10.1016/j.ijpddr.2024.100520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 02/02/2024]
Abstract
Surveillance data for Ancylostoma spp. and the A. caninum benzimidazole treatment resistance associated F167Y polymorphism using molecular diagnostics was obtained in a large population of dogs from the United States and Canada. Real-time PCR (qPCR) for Ancylostoma spp. and allele-specific qPCR detecting a single nucleotide polymorphism (SNP) F167Y was used in 262,872 canine stool samples collected between March and December of 2022. Ancylostoma spp. was found at an overall prevalence of 2.5% (6538/262,872), with the highest prevalence in the Southern US, 4.4% (4490/103,095), and the lowest prevalence in Canada 0.6% (101/15,829). The A. caninum F167Y polymorphism was found with the highest prevalence (13.4%, n = 46/343) in the Western US and the lowest in Canada at 4.1% (4/97). The F167Y polymorphism was detected every month over the 10-month collection period. Seasonal distribution showed a peak in June for both Ancylostoma spp. (3.08%, 547/17,775) and A. caninum F167Y (12.25%, 67/547). However, the A. caninum F167Y polymorphism prevalence was highest in September (13.9%, 119/856). Age analysis indicates a higher prevalence of both hookworm infections and occurrence of resistant isolates in puppies. The breeds with the highest F167Y polymorphism prevalence in Ancylostoma spp. detected samples were poodles (28.9%), followed by Bernese Mountain dogs (25%), Cocker spaniels (23.1%), and greyhounds (22.4%). Our data set describes widespread geographic distribution of the A. caninum benzimidazole resistance associated F167Y polymorphism in the United States and Canada, with no clear seasonality compared to the Ancylostoma spp. prevalence patterns. The F167 polymorphism was present in all geographic areas with detected hookworms, including Canada. Our study highlights that the F167Y polymorphism is represented in many dog breeds, including greyhounds.
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Affiliation(s)
| | | | | | | | | | - Cathy Meeks
- Antech Diagnostics, Fountain Valley, CA, USA
| | | | | | | | | | - Jan Andrews
- Antech Diagnostics, Fountain Valley, CA, USA
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2
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Ranasinghe S, Armson A, Lymbery AJ, Zahedi A, Ash A. Medicinal plants as a source of antiparasitics: an overview of experimental studies. Pathog Glob Health 2023; 117:535-553. [PMID: 36805662 PMCID: PMC10392325 DOI: 10.1080/20477724.2023.2179454] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
Despite advances in modern human and veterinary medicine, gastrointestinal (GI) parasitic infections remain a significant health issue worldwide, mainly in developing countries. Increasing evidence of the multi-drug resistance of these parasites and the side effects of currently available synthetic drugs have led to increased research on alternative medicines to treat parasitic infections. The exploration of potential botanical antiparasitics, which are inexpensive and abundant, may be a promising alternative in this context. This study summarizes the in vitro/in vivo antiparasitic efficacy of different medicinal plants and their components against GI parasites. Published literature from 1990-2020 was retrieved from Google Scholar, Web of Science, PubMed and Scopus. A total of 68 plant species belonging to 32 families have been evaluated as antiparasitic agents against GI parasites worldwide. The majority of studies (70%) were conducted in vitro. Most plants were from the Fabaceae family (53%, n = 18). Methanol (37%, n = 35) was the most used solvent. Leaf (22%, n = 16) was the most used plant part, followed by seed and rhizome (each 12%, n = 9). These studies suggest that herbal medicines hold a great scope for new drug discoveries against parasitic diseases and that the derivatives of these plants are useful structures for drug synthesis and bioactivity optimization.
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Affiliation(s)
- Sandamalie Ranasinghe
- Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia
| | - Anthony Armson
- Exercise Science and Chiropractic, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Alan J. Lymbery
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia
| | - Alireza Zahedi
- Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia
| | - Amanda Ash
- Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, Australia
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3
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Zhang X, Sicalo Gianechini L, Li K, Kaplan RM, Witola WH. Broad-Spectrum Inhibitors for Conserved Unique Phosphoethanolamine Methyltransferases in Parasitic Nematodes Possess Anthelmintic Efficacy. Antimicrob Agents Chemother 2023; 67:e0000823. [PMID: 37212658 PMCID: PMC10269165 DOI: 10.1128/aac.00008-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/20/2023] [Indexed: 05/23/2023] Open
Abstract
In humans, nematode infections are prevalent in developing countries, causing long-term ill health, particularly in children. Worldwide, nematode infections are prevalent in livestock and pets, affecting productivity and health. Anthelmintic drugs are the primary means of controlling nematodes, but there is now high prevalence of anthelmintic resistance, requiring urgent identification of new molecular targets for anthelmintics with novel mechanisms of action. Here, we identified orthologous genes for phosphoethanolamine methyltransferases (PMTs) in nematodes within the families Trichostrongylidae, Dictyocaulidae, Chabertiidae, Ancylostomatoidea, and Ascarididae. We characterized these putative PMTs and found that they possess bona fide PMT catalytic activities. By complementing a mutant yeast strain lacking the ability to synthesize phosphatidylcholine, the PMTs were validated to catalyze the biosynthesis of phosphatidylcholine. Using an in vitro phosphoethanolamine methyltransferase assay with PMTs as enzymes, we identified compounds with cross-inhibitory effects against the PMTs. Corroboratively, treatment of PMT-complemented yeast with the PMT inhibitors blocked growth of the yeast, underscoring the essential role of the PMTs in phosphatidylcholine synthesis. Fifteen of the inhibitors with the highest activity against complemented yeast were tested against Haemonchus contortus using larval development and motility assays. Among them, four were found to possess potent anthelmintic activity against both multiple drug-resistant and susceptible isolates of H. contortus, with IC50 values (95% confidence interval) of 4.30 μM (2.15-8.28), 4.46 μM (3.22-6.16), 28.7 μM (17.3-49.5), and 0.65 μM (0.21-1.88). Taken together, we have validated a molecular target conserved in a broad range of nematodes and identified its inhibitors that possess potent in vitro anthelmintic activity.
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Affiliation(s)
- Xuejin Zhang
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | | | - Kun Li
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
- Institute of Traditional Chinese Veterinary Medicine, MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Ray M. Kaplan
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
- Pathobiology Department, School of Veterinary Medicine, St. George’s University, Grenada, West Indies
| | - William H. Witola
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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4
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Schmidt H, Mauer K, Glaser M, Dezfuli BS, Hellmann SL, Silva Gomes AL, Butter F, Wade RC, Hankeln T, Herlyn H. Identification of antiparasitic drug targets using a multi-omics workflow in the acanthocephalan model. BMC Genomics 2022; 23:677. [PMID: 36180835 PMCID: PMC9523657 DOI: 10.1186/s12864-022-08882-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/12/2022] [Indexed: 08/30/2023] Open
Abstract
Background With the expansion of animal production, parasitic helminths are gaining increasing economic importance. However, application of several established deworming agents can harm treated hosts and environment due to their low specificity. Furthermore, the number of parasite strains showing resistance is growing, while hardly any new anthelminthics are being developed. Here, we present a bioinformatics workflow designed to reduce the time and cost in the development of new strategies against parasites. The workflow includes quantitative transcriptomics and proteomics, 3D structure modeling, binding site prediction, and virtual ligand screening. Its use is demonstrated for Acanthocephala (thorny-headed worms) which are an emerging pest in fish aquaculture. We included three acanthocephalans (Pomphorhynchus laevis, Neoechinorhynchus agilis, Neoechinorhynchus buttnerae) from four fish species (common barbel, European eel, thinlip mullet, tambaqui). Results The workflow led to eleven highly specific candidate targets in acanthocephalans. The candidate targets showed constant and elevated transcript abundances across definitive and accidental hosts, suggestive of constitutive expression and functional importance. Hence, the impairment of the corresponding proteins should enable specific and effective killing of acanthocephalans. Candidate targets were also highly abundant in the acanthocephalan body wall, through which these gutless parasites take up nutrients. Thus, the candidate targets are likely to be accessible to compounds that are orally administered to fish. Virtual ligand screening led to ten compounds, of which five appeared to be especially promising according to ADMET, GHS, and RO5 criteria: tadalafil, pranazepide, piketoprofen, heliomycin, and the nematicide derquantel. Conclusions The combination of genomics, transcriptomics, and proteomics led to a broadly applicable procedure for the cost- and time-saving identification of candidate target proteins in parasites. The ligands predicted to bind can now be further evaluated for their suitability in the control of acanthocephalans. The workflow has been deposited at the Galaxy workflow server under the URL tinyurl.com/yx72rda7. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08882-1.
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Affiliation(s)
- Hanno Schmidt
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany. .,Present address: Institute for Virology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Katharina Mauer
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Manuel Glaser
- Molecular and Cellular Modeling, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | | | - Sören Lukas Hellmann
- Institute of Organismic and Molecular Evolution (iomE), Molecular Genetics and Genomic Analysis, Johannes Gutenberg University Mainz, Mainz, Germany.,Present address: Nucleic Acids Core Facility, Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology (IMB), Mainz, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany.,Center for Molecular Biology (ZMBH) and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Thomas Hankeln
- Institute of Organismic and Molecular Evolution (iomE), Molecular Genetics and Genomic Analysis, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Holger Herlyn
- Institute of Organismic and Molecular Evolution (iomE), Anthropology, Johannes Gutenberg University Mainz, Mainz, Germany.
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Kim SY, Barnes MA, Sureshchandra S, Menicucci AR, Patel JJ, Messaoudi I, Nair MG. CX3CR1-Expressing Myeloid Cells Regulate Host-Helminth Interaction and Lung Inflammation. Adv Biol (Weinh) 2022; 6:e2101078. [PMID: 35119218 PMCID: PMC8934291 DOI: 10.1002/adbi.202101078] [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: 07/12/2021] [Revised: 12/31/2021] [Indexed: 11/06/2022]
Abstract
Many helminth life cycles, including hookworm, involve a mandatory lung phase, where myeloid and granulocyte subsets interact with the helminth and respond to infection-induced lung injury. To evaluate these innate subsets in Nippostrongylus brasiliensis infection, reporter mice for myeloid cells (CX3CR1GFP ) and granulocytes (PGRPdsRED ) are employed. Nippostrongylus infection induces lung infiltration of reporter cells, including CX3CR1+ myeloid cells and PGRP+ eosinophils. Strikingly, CX3CR1GFP/GFP mice, which are deficient in CX3CR1, are protected from Nippostrongylus infection with reduced weight loss, lung leukocyte infiltration, and worm burden compared to CX3CR1+/+ mice. This protective effect is specific for CX3CR1 as CCR2-deficient mice do not exhibit reduced worm burdens. Nippostrongylus co-culture with lung Ly6C+ monocytes or CD11c+ cells demonstrates that CX3CR1GFP/GFP monocytes secrete more pro-inflammatory cytokines and actively bind the parasites causing reduced motility. RNA sequencing of Ly6C+ or CD11c+ cells shows Nippostrongylus-induced gene expression changes, particularly in monocytes, associated with inflammation, chemotaxis, and extracellular matrix remodeling pathways. Analysis reveals cytotoxic and adhesion molecules as potential effectors against the parasite, such as Gzma and Gzmb, which are elevated in CX3CR1GFP/GFP monocytes. These studies validate a dual innate cell reporter for lung helminth infection and demonstrate that CX3CR1 impairs monocyte-helminth interaction.
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Affiliation(s)
| | | | | | - Andrea R. Menicucci
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, California 92697-3900, United States
| | - Jay J. Patel
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, California 92521, United States
| | - Ilhem Messaoudi
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, California 92697-3900, United States
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6
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Bungiro RD, Harrison LM, Dondji B, Cappello M. Comparison of percutaneous vs oral infection of hamsters with the hookworm Ancylostoma ceylanicum: Parasite development, pathology and primary immune response. PLoS Negl Trop Dis 2022; 16:e0010098. [PMID: 34986139 PMCID: PMC8765627 DOI: 10.1371/journal.pntd.0010098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/18/2022] [Accepted: 12/15/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Hundreds of millions of people in poor countries continue to suffer from disease caused by bloodfeeding hookworms. While mice and rats are not reliably permissive hosts for any human hookworm species, adult Golden Syrian hamsters are fully permissive for the human and animal pathogen Ancylostoma ceylanicum. Similar to humans, hamsters may be infected with A. ceylanicum third-stage larvae orally or percutaneously. Oral infection typically leads to consistent worm yields in hamsters but may not accurately reflect the clinical and immunological manifestations of human infection resulting from skin penetration. METHODOLOGY/PRINCIPAL FINDINGS In this study we compared host responses following percutaneous infection to those utilizing an established oral infection protocol. Infected hamsters exhibited a dose-dependent pathology, with 1000 percutaneous larvae (L3) causing anemia and adult worm recovery comparable to that of 50 orally administered L3. A delayed arrival and maturity of worms in the intestine was observed, as was variation in measured cellular immune responses. A long-term study found that the decline in blood hemoglobin was more gradual and did not reach levels as low, with the nadir of disease coming later in percutaneously infected hamsters. Both groups exhibited moderate growth delay, an effect that was more persistent in the percutaneously infected group. Fecal egg output also peaked later and at lower levels in the percutaneously infected animals. In contrast to orally infected hamsters, antibody titers to larval antigens continued to increase throughout the course of the experiment in the percutaneous group. CONCLUSIONS/SIGNIFICANCE These results demonstrate that the route of infection with A. ceylanicum impacts disease pathogenesis, as well as humoral and cellular immune responses in an experimental setting. These data further validate the utility of the Golden Syrian hamster as a model of both oral and percutaneous infection with human hookworms.
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Affiliation(s)
- Richard D. Bungiro
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Lisa M. Harrison
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Blaise Dondji
- Laboratory of Cellular Immunology and Parasitology, Department of Biological Sciences, Central Washington University, Ellensburg, Washington, United States of America
| | - Michael Cappello
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, United States of America
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7
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Jayawardene KLTD, Palombo EA, Boag PR. Natural Products Are a Promising Source for Anthelmintic Drug Discovery. Biomolecules 2021; 11:1457. [PMID: 34680090 PMCID: PMC8533416 DOI: 10.3390/biom11101457] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/23/2021] [Accepted: 09/28/2021] [Indexed: 12/23/2022] Open
Abstract
Parasitic nematodes infect almost all forms of life. In the human context, parasites are one of the major causative factors for physical and intellectual growth retardation in the developing world. In the agricultural setting, parasites have a great economic impact through a reduction in livestock performance or control cost. The main method of controlling these devastating conditions is the use of anthelmintic drugs. Unfortunately, there are only a few anthelmintic drug classes available in the market and significant resistance has developed in most of the parasitic species of livestock. Therefore, development of new anthelmintics with different modes of action is critical for sustainable parasitic control in the future. The drug development pipeline is broadly limited to two types of molecules, namely synthetic compounds and natural plant products. Compared to synthetic compounds, natural products are highly diverse, and many have historically proven valuable in folk medicine to treat various gastrointestinal ailments. This review focus on the use of traditional knowledge-based plant extracts in the development of new therapeutic leads, the approaches used as screening techniques, and common bottlenecks and opportunities in plant-based anthelmintic drug discovery.
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Affiliation(s)
- K. L. T. Dilrukshi Jayawardene
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia;
- Development and Stem Cells Program, Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Enzo A. Palombo
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Melbourne, VIC 3122, Australia
| | - Peter R. Boag
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia;
- Development and Stem Cells Program, Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
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8
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von Samson-Himmelstjerna G, Thompson RA, Krücken J, Grant W, Bowman DD, Schnyder M, Deplazes P. Spread of anthelmintic resistance in intestinal helminths of dogs and cats is currently less pronounced than in ruminants and horses - Yet it is of major concern. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 17:36-45. [PMID: 34343829 PMCID: PMC8347694 DOI: 10.1016/j.ijpddr.2021.07.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 11/17/2022]
Abstract
Anthelmintic resistance (AR) has thus far only rarely been reported for intestinal helminths of dogs and cats, in contrast to parasites of livestock and horses. We highlight possible reasons for this striking and important discrepancy, including ecological, biological and genetic factors and/or intervention regimens of key intestinal helminths concerning both host groups. In view of the current knowledge related to the genetics, mechanisms and principles of AR development, we point at issues which in our view contribute to a comparatively lower risk of AR development in intestinal helminths of dogs and cats. Finally, we specify research needs and provide recommendations by which, based on the available information about AR in ruminant and equine helminths, the development of AR in dog and cat helminths may best be documented, prevented or at least postponed.
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Affiliation(s)
| | | | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Germany
| | - Warwick Grant
- Department of Physiology, Anatomy & Microbiology, La Trobe University, Australia
| | - Dwight D Bowman
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, USA
| | | | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Switzerland
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9
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Umbrello G, Pinzani R, Bandera A, Formenti F, Zavarise G, Arghittu M, Girelli D, Maraschini A, Muscatello A, Marchisio P, Bosis S. Hookworm infection in infants: a case report and review of literature. Ital J Pediatr 2021; 47:26. [PMID: 33563313 PMCID: PMC7871578 DOI: 10.1186/s13052-021-00981-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/02/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hookworm infections (Necator americanus, Ancylostoma duodenale) are common in rural areas of tropical and subtropical countries. Human acquisition results from direct percutaneous invasion of infective larvae from contaminated soil. Overall, almost 472 million people in developing rural countries are infected. According to simulation models, hookworm disease has a global financial impact of over US$100 billion a year. Hookworm infection in newborn or infancy is rare, and most of the cases reported in literature are from endemic countries. Here, we describe the case of an infant with an Ancylostoma duodenale infection and review the literature currently available on this topic. CASE PRESENTATION An Italian 2-month-old infant presented with vomit and weight loss. Her blood exams showed anemia and eosinophilia and stool analysis resulted positive for hookworms' eggs, identified as Ancylostoma duodenale with real time-PCR. Parasite research on parents' stools resulted negative, and since the mother travelled to Vietnam and Thailand during pregnancy, we assumed a transplacental transmission of the infection. The patient was treated successfully with oral Mebendazole and discharged in good conditions. DISCUSSION Hookworm helminthiasis is a major cause of morbidity in children in the tropics and subtropics, but rare in developed countries. Despite most of the patients is usually asymptomatic, children are highly exposed to negative sequelae such as malnutrition, retarded growth and impaired cognitive development. In infants and newborns, the mechanism of infection remains unclear. Although infrequent, vertical transmission of larvae can occur through breastfeeding and transplacentally. Hookworm infection should be taken into account in children with abdominal symptoms and unexplained persistent eosinophilia. The treatment of infants infected by hookworm has potential benefit, but further studies are needed to define the best clinical management of these cases.
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Affiliation(s)
- G Umbrello
- Università degli Studi di Milano, Milan, Italy.
| | - R Pinzani
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - A Bandera
- Università degli Studi di Milano, Milan, Italy.,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - F Formenti
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona, Negrar, Italy.,Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - G Zavarise
- Tropical Pediatric Unit, IRCCS Ospedale Sacro Cuore Don Calabria, Verona, Negrar, Italy
| | - M Arghittu
- Laboratory of Clinical Chemistry and Microbiology, ASST Melegnano and Martesana, Milan, Italy
| | - D Girelli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - A Maraschini
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - A Muscatello
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - P Marchisio
- Università degli Studi di Milano, Milan, Italy.,Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - S Bosis
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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10
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Gordon CA, Shield JM, Bradbury RS, Muhi S, Page W, Judd JA, Lee R, Biggs BA, Ross K, Kurscheid J, Gray DJ, McManus DP. HTLV-I and Strongyloides in Australia: The worm lurking beneath. ADVANCES IN PARASITOLOGY 2021; 111:119-201. [PMID: 33482974 DOI: 10.1016/bs.apar.2020.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Strongyloidiasis and HTLV-I (human T-lymphotropic virus-1) are important infections that are endemic in many countries around the world with an estimated 370 million infected with Strongyloides stercoralis alone, and 5-10 million with HTVL-I. Co-infections with these pathogens are associated with significant morbidity and can be fatal. HTLV-I infects T-cells thus causing dysregulation of the immune system which has been linked to dissemination and hyperinfection of S. stercoralis leading to bacterial sepsis which can result in death. Both of these pathogens are endemic in Australia primarily in remote communities in Queensland, the Northern Territory, and Western Australia. Other cases in Australia have occurred in immigrants and refugees, returned travellers, and Australian Defence Force personnel. HTLV-I infection is lifelong with no known cure. Strongyloidiasis is a long-term chronic disease that can remain latent for decades, as shown by infections diagnosed in prisoners of war from World War II and the Vietnam War testing positive decades after they returned from these conflicts. This review aims to shed light on concomitant infections of HTLV-I with S. stercoralis primarily in Australia but in the global context as well.
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Affiliation(s)
- Catherine A Gordon
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| | - Jennifer M Shield
- Department of Pharmacy and Biomedical Sciences, La Trobe University, Bendigo, VIC, Australia; Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Richard S Bradbury
- School of Health and Life Sciences, Federation University, Berwick, VIC, Australia
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Wendy Page
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Jenni A Judd
- School of Health Medical and Applied Sciences, Central Queensland University, Bundaberg, QLD, Australia; Centre for Indigenous Health Equity Research, Central Queensland University, Bundaberg, QLD, Australia
| | - Rogan Lee
- Westmead Clinical School, The University of Sydney, Westmead, NSW, Australia
| | - Beverley-Ann Biggs
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia; Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Kirstin Ross
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Johanna Kurscheid
- Department of Global Health, Research School of Population Health, Australian National University, Acton, ACT, Australia
| | - Darren J Gray
- Department of Global Health, Research School of Population Health, Australian National University, Acton, ACT, Australia
| | - Donald P McManus
- Infectious Diseases Program, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
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11
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Kaji MD, Geary TG, Beech RN. A Functional Comparison of Homopentameric Nicotinic Acetylcholine Receptors (ACR-16) Receptors From Necator americanus and Ancylostoma ceylanicum. Front Mol Neurosci 2020; 13:601102. [PMID: 33324163 PMCID: PMC7725692 DOI: 10.3389/fnmol.2020.601102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022] Open
Abstract
Effective control of hookworm infections in humans and animals relies on using a small group of anthelmintics. Many of these drugs target cholinergic ligand-gated ion channels, yet the direct activity of anthelmintics has only been studied in a subset of these receptors, primarily in the non-parasitic nematode, Caenorhabditis elegans. Here we report the characterization of a homopentameric ionotropic acetylcholine receptor (AChR), ACR-16, from Necator americanus and Ancylostoma ceylanicum, the first known characterization of human hookworm ion channels. We used two-electrode voltage clamp electrophysiology in Xenopus laevis oocytes to determine the pharmacodynamics of cholinergics and anthelmintics on ACR-16 from both species of hookworm. The A. ceylanicum receptor (Ace-ACR-16) was more sensitive to acetylcholine (EC50 = 20.64 ± 0.32 μM) and nicotine (EC50 = 24.37 ± 2.89 μM) than the N. americanus receptor (Nam-ACR-16) (acetylcholine EC50 = 170.1 ± 19.23 μM; nicotine EC50 = 597.9 ± 59.12 μM), at which nicotine was a weak partial agonist (% maximal acetylcholine response = 30.4 ± 7.4%). Both receptors were inhibited by 500 μM levamisole (Ace-ACR-16 = 65.1 ± 14.3% inhibition, Nam-ACR-16 = 79.5 ± 7.7% inhibition), and responded to pyrantel, but only Ace-ACR-16 responded to oxantel. We used in silico homology modeling to investigate potential structural differences that account for the differences in agonist binding and identified a loop E isoleucine 130 of Nam-ACR-16 as possibly playing a role in oxantel insensitivity. These data indicate that key functional differences exist among ACR-16 receptors from closely related species and suggest mechanisms for differential drug sensitivity.
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Affiliation(s)
- Mark D. Kaji
- Institute of Parasitology, McGill University, Montreal, QC, Canada
| | - Timothy G. Geary
- Institute of Parasitology, McGill University, Montreal, QC, Canada
- School of Biological Sciences, Queen’s University-Belfast, Belfast, United Kingdom
| | - Robin N. Beech
- Institute of Parasitology, McGill University, Montreal, QC, Canada
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12
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The Neglected Cestode Infection: Epidemiology of Hymenolepis Nana Infection Among Children in Rural Yemen. Helminthologia 2020; 57:293-305. [PMID: 33364898 PMCID: PMC7734673 DOI: 10.2478/helm-2020-0038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022] Open
Abstract
Hymenolepis nana is the most common cestode reported in humans worldwide. It is prevalent among children in the tropics and subtropics, particularly in rural poor communities where sanitation is inadequate or lacking. This cross-sectional study aims to determine the prevalence and significant risk factors of H. nana infection among children in rural Yemen. Faecal samples were collected from 498 children and screened for intestinal parasites by using wet mount, formalin-ether concentration and Kato–Katz techniques. A pretested questionnaire was used to collect demographic, socioeconomic, housing condition, and personal hygiene information. Overall, 77.5 % (386/498) of the children were found to be infected by at least one intestinal parasite species. The overall prevalence of H. nana was 17.5 % (87/498). Multivariate analysis confirmed that an age of < 6 years (adjusted odds ratio [AOR] = 4.28; 95 % (confidence interval [CI] = 2.04, 8.98), presence of other family members infected with H. nana (AOR = 2.48; 95 % CI = 1.45, 4.24), living in the highlands (AOR = 2.87; 95 % CI = 1.56, 5.26), living in a house without improved toilet facilities (AOR = 2.19; 95 % CI = 1.23, 3.88), not washing vegetables before consumption (AOR = 2.11; 95 % CI = 1.06, 4.19), and not washing hands after defecation (AOR = 1.88; 95 % CI = 1.08, 3.27) were the key factors significantly associated with H. nana infection among the studied children. In conclusion, H. nana is prevalent among children in rural Yemen, particularly among preschool-aged children. Thus, an integrated and effective programme to control intestinal parasitic infections should include preschool-aged children. Such a programme should focus on providing health education on hygienic practices, providing adequate sanitation and improved sources of drinking water, and screening and treating other infected family members.
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13
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Nag R, Whyte P, Markey BK, O'Flaherty V, Bolton D, Fenton O, Richards KG, Cummins E. Ranking hazards pertaining to human health concerns from land application of anaerobic digestate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 710:136297. [PMID: 32050363 PMCID: PMC7126561 DOI: 10.1016/j.scitotenv.2019.136297] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/20/2019] [Accepted: 12/21/2019] [Indexed: 04/14/2023]
Abstract
Anaerobic digestion (AD) has been identified as one of the cleanest producers of green energy. AD typically uses organic materials as feedstock and, through a series of biological processes, produces methane. Farmyard manure and slurry (FYM&S) are important AD feedstock and are typically mixed with agricultural waste, grass and/or food wastes. The feedstock may contain many different pathogens which can survive the AD process and hence also possibly be present in the final digestate. In this study, a semi-quantitative screening tool was developed to rank pathogens of potential health concern emerging from AD digestate. A scoring system was used to categorise likely inactivation during AD, hazard pathways and finally, severity as determined from reported human mortality rates, number of global human-deaths and infections per 100,000 populations. Five different conditions including mesophilic and thermophilic AD and three different pasteurisation conditions were assessed in terms of specific pathogen inactivation. In addition, a number of scenarios were assessed to consider foodborne incidence data from Ireland and Europe and to investigate the impact of raw FYM&S application (without AD and pasteurisation). A sensitivity analysis revealed that the score for the mortality rate (S3) was the most sensitive parameter (rank coefficient 0.49) to influence the final score S; followed by thermal inactivation score (S1, 0.25) and potential contamination pathways (S2, 0.16). Across all the scenarios considered, the screening tool prioritised Cryptosporidium parvum, Salmonella spp., norovirus, Streptococcus pyogenes, enteropathogenic E. coli (EPEC), Mycobacterium spp., Salmonella typhi (followed by S. paratyphi), Clostridium spp., Listeria monocytogenes and Campylobacter coli as the highest-ranking pathogens of human health concern resulting from AD digestate in Ireland. This tool prioritises potentially harmful pathogens which can emerge from AD digestate and highlights where regulation and intervention may be required.
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Affiliation(s)
- Rajat Nag
- University College Dublin School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
| | - Paul Whyte
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Bryan K Markey
- University College Dublin School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Vincent O'Flaherty
- National University of Ireland Galway, School of Natural Sciences, Galway, Ireland.
| | - Declan Bolton
- TEAGASC, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
| | - Owen Fenton
- TEAGASC, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Karl G Richards
- TEAGASC, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Enda Cummins
- University College Dublin School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
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14
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Tinkler SH. Preventive chemotherapy and anthelmintic resistance of soil-transmitted helminths - Can we learn nothing from veterinary medicine? One Health 2019; 9:100106. [PMID: 31956691 PMCID: PMC6957790 DOI: 10.1016/j.onehlt.2019.100106] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/21/2022] Open
Abstract
Current parasite control programs in veterinary species have moved away from mass anthelmintic treatment approaches due to the emergence of significant anthelmintic resistance (AR), and the availability of few classes of anthelmintics. A number of parallels between livestock and human helminths exist that warn of the risk of AR in human soil-transmitted helminthiases, yet current public health interventions continue to prioritize mass treatment strategies, a known risk factor for AR. This review discusses the existing parallels between human and animal helminth biology and management, along with current public health recommendations and strategies for helminth control in humans. The effectiveness of current recommendations and alternative management strategies are considered.
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15
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Hii SF, Senevirathna D, Llewellyn S, Inpankaew T, Odermatt P, Khieu V, Muth S, McCarthy J, Traub RJ. Development and Evaluation of a Multiplex Quantitative Real-Time Polymerase Chain Reaction for Hookworm Species in Human Stool. Am J Trop Med Hyg 2019; 99:1186-1193. [PMID: 30226132 PMCID: PMC6221243 DOI: 10.4269/ajtmh.18-0276] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Hookworm disease caused by Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum affects half a billion people worldwide. The prevalence and intensity of infection of individual hookworm species are vital for assessing morbidity and generating targeted intervention programs for their control. The present study aims to evaluate a multiplex real-time quantitative PCR (qPCR) assay to determine the prevalence and egg intensity of all three hookworm species and compare this with standard microscopy and published genus-based conventional and real-time multiplex qPCRs. Performance of the diagnostic assays was evaluated using DNA extracted from 192 fecal samples collected as part of a soil-transmitted helminth (STH) survey in northern Cambodia. The prevalence of hookworms as detected by the multiplex hookworm qPCR of 84/192 (43.8%) was significantly higher than that using microscopy of 49/192 (25.5%). The hookworm multiplex qPCR showed very good agreement for the detection of both N. americanus (Kappa 0.943) and Ancylostoma spp. (Kappa 0.936) with a multiplex STH qPCR. A strong and moderate quantitative correlation between cycle threshold and eggs per gram (EPG) feces was obtained for the hookworm qPCR for seeded DNA egg extracts (R 2 ≥ 0.9004) and naturally egg-infected individuals (R 2 = 0.6848), respectively. The newly developed hookworm quantitative multiplex qPCR has the potential for application in anthelmintic efficacy trials and for monitoring the success of mass deworming programs targeting individual species of anthroponotic and zoonotic hookworms.
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Affiliation(s)
- Sze Fui Hii
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Dammika Senevirathna
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
| | - Stacey Llewellyn
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Tawin Inpankaew
- Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Peter Odermatt
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Virak Khieu
- National Centre for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - Sinoun Muth
- National Centre for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
| | - James McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Herston, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Australia
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16
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Choudhary S, Tipton JG, Abongwa M, Brewer MT, Chelladurai JJ, Musselman N, Martin RJ, Robertson AP. Pharmacological characterization of a homomeric nicotinic acetylcholine receptor formed by Ancylostoma caninum ACR-16. INVERTEBRATE NEUROSCIENCE : IN 2019; 19:11. [PMID: 31486912 PMCID: PMC7869652 DOI: 10.1007/s10158-019-0231-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/17/2019] [Indexed: 01/07/2023]
Abstract
Parasitic nematode infections are treated using anthelmintic drugs, some of which target nicotinic acetylcholine receptors (nAChRs) located in different parasite tissues. The limited arsenal of anthelmintic agents and the prevalence of drug resistance imply that future defense against parasitic infections will depend on the discovery of novel targets and therapeutics. Previous studies have suggested that Ascaris suum ACR-16 nAChRs are a suitable target for the development of antinematodal drugs. In this study, we characterized the pharmacology of the Ancylostoma caninum ACR-16 receptor using two-electrode voltage-clamp electrophysiology. This technique allowed us to study the effects of cholinergic agonists and antagonists on the nematode nAChRs expressed in Xenopus laevis oocytes. Aca-ACR-16 was not sensitive to many of the existing cholinomimetic anthelmintics (levamisole, oxantel, pyrantel, and tribendimidine). 3-Bromocytisine was the most potent agonist (> 130% of the control acetylcholine current) on the Aca-ACR-16 nAChR but, unlike Asu-ACR-16, oxantel did not activate the receptor. The mean time constants of desensitization for agonists on Aca-ACR-16 were longer than the rates observed in Asu-ACR-16. In contrast to Asu-ACR-16, the A. caninum receptor was completely inhibited by DHβE and moderately inhibited by α-BTX. In conclusion, we have successfully reconstituted a fully functional homomeric nAChR, ACR-16, from A. caninum, a model for human hookworm infections. The pharmacology of the receptor is distinct from levamisole-sensitive nematode receptors. The ACR-16 homologue also displayed some pharmacological differences from Asu-ACR-16. Hence, A. caninum ACR-16 may be a valid target site for the development of anthelmintics against hookworm infections.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - James G Tipton
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Melanie Abongwa
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Matthew T Brewer
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Jeba Jesudoss Chelladurai
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Nicole Musselman
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.
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17
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Hess LB, Millward LM, Rudinsky A, Vincent E, Marsh A. Combination Anthelmintic Treatment for Persistent Ancylostoma caninum Ova Shedding in Greyhounds. J Am Anim Hosp Assoc 2019; 55:160-166. [PMID: 30870603 DOI: 10.5326/jaaha-ms-6904] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ancylostoma caninum is a nematode of the canine gastrointestinal tract commonly referred to as hookworm. This study involved eight privately owned adult greyhounds presenting with persistent A. caninum ova shedding despite previous deworming treatments. The dogs received a combination treatment protocol comprising topical moxidectin, followed by pyrantel/febantel/praziquantel within 24 hr. At 7-10 days posttreatment, a fecal examination monitored for parasite ova. Dogs remained on the monthly combination treatment protocol until they ceased shedding detectable ova. The dogs then received only the monthly topical moxidectin maintenance treatment. The dogs remained in the study for 5-14 mo with periodical fecal examinations performed. During the study, three dogs reverted to positive fecal ova status, with two being associated with client noncompliance. Reinstitution of the combination treatment protocol resulted in no detectable ova. Use of monthly doses of combination pyrantel, febantel and moxidectin appears to be an effective treatment for nonresponsive or persistent A. caninum ova shedding. Follow-up fecal examinations were important for verifying the presence or absence of ova shedding despite the use of anthelmintic treatment. Limitations of the current study include small sample size, inclusion of only privately owned greyhounds, and client compliance with fecal collection and animal care.
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Affiliation(s)
- Lindie B Hess
- From the Department of Veterinary Preventive Medicine (L.B.H., A.M.), and Department of Veterinary Clinical Sciences (L.M.M., A.R., E.V.), College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Laurie M Millward
- From the Department of Veterinary Preventive Medicine (L.B.H., A.M.), and Department of Veterinary Clinical Sciences (L.M.M., A.R., E.V.), College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Adam Rudinsky
- From the Department of Veterinary Preventive Medicine (L.B.H., A.M.), and Department of Veterinary Clinical Sciences (L.M.M., A.R., E.V.), College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Emily Vincent
- From the Department of Veterinary Preventive Medicine (L.B.H., A.M.), and Department of Veterinary Clinical Sciences (L.M.M., A.R., E.V.), College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Antoinette Marsh
- From the Department of Veterinary Preventive Medicine (L.B.H., A.M.), and Department of Veterinary Clinical Sciences (L.M.M., A.R., E.V.), College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
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18
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Mutombo PN, Man NWY, Nejsum P, Ricketson R, Gordon CA, Robertson G, Clements ACA, Chacón-Fonseca N, Nissapatorn V, Webster JP, McLaws ML. Diagnosis and drug resistance of human soil-transmitted helminth infections: A public health perspective. ADVANCES IN PARASITOLOGY 2019; 104:247-326. [PMID: 31030770 DOI: 10.1016/bs.apar.2019.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Soil-transmitted helminth (STH) infections represent a major public health problem globally, particularly among socio-economically disadvantaged populations. Detection of STH infections is often challenging, requiring a combination of diagnostic techniques to achieve acceptable sensitivity and specificity, particularly in low infection-intensity situations. The microscopy-based Kato-Katz remains the most widely used method but has low sensitivity in the detection of, for instance, Strongyloides spp. infections, among others. Antigen/antibody assays can be more sensitive but are parasite species-specific. Highly sensitive PCR methods have been developed to be multiplexed to allow multi-species detection. Novel diagnostic tests for all STH species are needed for effective monitoring, evaluation of chemotherapy programmes, and to assess the potential emergence of parasite resistance. This review discusses available diagnostic methods for the different stages of STH control programmes, which vary in sensitivity and spectrum of detection requirements, and tools to evaluate drug efficacy and resistance.
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Affiliation(s)
- Polydor Ngoy Mutombo
- School of Public Health and Community Medicine, UNSW Medicine, UNSW, Sydney, NSW, Australia; Centre for Biomedical Research, Burnet Institute, Melbourne, VIC, Australia.
| | - Nicola W Y Man
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
| | - Peter Nejsum
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus, Denmark
| | - Robert Ricketson
- Hale O'mana'o Biomedical Research, Division of Emerging Pathogens, Edmond, OK, United States
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Gemma Robertson
- Public and Environmental Health, Forensic and Scientific Services, Department of Health, Brisbane, QLD, Australia
| | | | - Nathalie Chacón-Fonseca
- Soil-Transmitted Helminths Section, Tropical Medicine Institute, Tropical Medicine Department, Faculty of Medicine, Central University of Venezuela, Caracas, Venezuela
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand; Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat, Thailand
| | - Joanne P Webster
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - Mary-Louise McLaws
- School of Public Health and Community Medicine, UNSW Medicine, UNSW, Sydney, NSW, Australia.
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19
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Rusdi B, Laird T, Abraham R, Ash A, Robertson ID, Mukerji S, Coombs GW, Abraham S, O'Dea MA. Carriage of critically important antimicrobial resistant bacteria and zoonotic parasites amongst camp dogs in remote Western Australian indigenous communities. Sci Rep 2018; 8:8725. [PMID: 29880792 PMCID: PMC5992169 DOI: 10.1038/s41598-018-26920-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/22/2018] [Indexed: 12/18/2022] Open
Abstract
Camp dogs in indigenous communities in the Western Australian Kimberley Region, share the domestic environment with humans and have the potential to act as carriers of, and sentinels for, a wide range of zoonotic agents, including intestinal parasites and antimicrobial resistant bacteria. In this study, we investigated the carriage of extended-spectrum-cephalosporin-resistant (ESC-resistant) Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and species of hookworm and Giardia among camp dogs in remote Western Australian Aboriginal communities. A total of 141 canine faecal samples and 156 nasal swabs were collected from dogs in four communities of the Western Australian Kimberley region. Overall, ESC-resistant E. coli was detected in 16.7% of faecal samples and MRSA was isolated from 2.6% of nasal swabs. Of most significance was the presence of the community-associated Panton-Valentine leucocidin (PVL)-positive MRSA ST93 and ST5 clones and ESC-resistant E. coli ST38 and ST131. The most prevalent zoonotic intestinal parasite infection was Ancylostoma caninum (66%). The prevalence of Giardia was 12.1%, with the main genotypes of Giardia detected being dog specific assemblages C and D, which are unlikely to cause disease in humans.
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Affiliation(s)
- Bertha Rusdi
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Tanya Laird
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Rebecca Abraham
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Amanda Ash
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Ian D Robertson
- College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Shewli Mukerji
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.,Australian Centre for Antimicrobial Resistance Ecology, University of Adelaide, Adelaide, Australia
| | - Geoffrey W Coombs
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.,PathWest laboratory Medicine - WA, Fiona Stanley Hospital, Murdoch, Australia
| | - Sam Abraham
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.
| | - Mark A O'Dea
- Antimicrobial Resistance and Infectious Diseases Laboratory, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.
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20
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Bacillus thuringiensis Cry5B protein as a new pan-hookworm cure. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:287-294. [PMID: 29772478 PMCID: PMC6039361 DOI: 10.1016/j.ijpddr.2018.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/27/2018] [Accepted: 05/03/2018] [Indexed: 11/20/2022]
Abstract
Hookworms are intestinal nematode parasites that infect nearly half a billion people and are globally one of the most important contributors to iron-deficiency anemia. These parasites have significant impacts in developing children, pregnant women and working adults. Of all the soil-transmitted helminths or nematodes (STNs), hookworms are by far the most important, with disease burdens conservatively estimated at four million DALYs (Disability-Adjusted Life Years) and with productivity losses of up to US$139 billion annually. To date, mainly one drug, albendazole is used for hookworm therapy in mass drug administration, which has on average ∼80% cure rate that is lower (<40%) in some places. Given the massive numbers of people needing treatment, the threat of parasite resistance, and the inadequacy of current treatments, new and better cures against hookworms are urgently needed. Cry5B, a pore-forming protein produced by the soil bacterium Bacillus thuringiensis (Bt) has demonstrated good efficacy against Ancylostoma ceylanicum hookworm infections in hamsters. Here we broaden studies of Cry5B to include tests against infections of Ancylostoma caninum hookworms in dogs and against infections of the dominant human hookworm, Necator americanus, in hamsters. We show that Cry5B is highly effective against all hookworm parasites tested in all models. Neutralization of stomach acid improves Cry5B efficacy, which will aid in practical application of Cry5B significantly. Importantly, we also demonstrate that the anti-nematode therapeutic efficacy of Cry5B is independent of the host immune system and is not itself negated by repeated dosing. This study indicates that Bt Cry5B is a pan-hookworm anthelmintic with excellent properties for use in humans and other animals.
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21
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Blanchard A, Guégnard F, Charvet CL, Crisford A, Courtot E, Sauvé C, Harmache A, Duguet T, O’Connor V, Castagnone-Sereno P, Reaves B, Wolstenholme AJ, Beech RN, Holden-Dye L, Neveu C. Deciphering the molecular determinants of cholinergic anthelmintic sensitivity in nematodes: When novel functional validation approaches highlight major differences between the model Caenorhabditis elegans and parasitic species. PLoS Pathog 2018; 14:e1006996. [PMID: 29719008 PMCID: PMC5931475 DOI: 10.1371/journal.ppat.1006996] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/28/2018] [Indexed: 01/14/2023] Open
Abstract
Cholinergic agonists such as levamisole and pyrantel are widely used as anthelmintics to treat parasitic nematode infestations. These drugs elicit spastic paralysis by activating acetylcholine receptors (AChRs) expressed in nematode body wall muscles. In the model nematode Caenorhabditis elegans, genetic screens led to the identification of five genes encoding levamisole-sensitive-AChR (L-AChR) subunits: unc-38, unc-63, unc-29, lev-1 and lev-8. These subunits form a functional L-AChR when heterologously expressed in Xenopus laevis oocytes. Here we show that the majority of parasitic species that are sensitive to levamisole lack a gene orthologous to C. elegans lev-8. This raises important questions concerning the properties of the native receptor that constitutes the target for cholinergic anthelmintics. We demonstrate that the closely related ACR-8 subunit from phylogenetically distant animal and plant parasitic nematode species functionally substitutes for LEV-8 in the C. elegans L-AChR when expressed in Xenopus oocytes. The importance of ACR-8 in parasitic nematode sensitivity to cholinergic anthelmintics is reinforced by a ‘model hopping’ approach in which we demonstrate the ability of ACR-8 from the hematophagous parasitic nematode Haemonchus contortus to fully restore levamisole sensitivity, and to confer high sensitivity to pyrantel, when expressed in the body wall muscle of C. elegans lev-8 null mutants. The critical role of acr-8 to in vivo drug sensitivity is substantiated by the successful demonstration of RNAi gene silencing for Hco-acr-8 which reduced the sensitivity of H. contortus larvae to levamisole. Intriguingly, the pyrantel sensitivity remained unchanged thus providing new evidence for distinct modes of action of these important anthelmintics in parasitic species versus C. elegans. More broadly, this highlights the limits of C. elegans as a predictive model to decipher cholinergic agonist targets from parasitic nematode species and provides key molecular insight to inform the discovery of next generation anthelmintic compounds. Parasitic nematodes have global health and economic impacts. They infect animals, including livestock, humans, and plants including all major food crops. Their control in human and veterinary medicine is reliant on anthelmintic drugs but this is now challenged by resistant worms especially in livestock. Importantly, for anthelmintics such as levamisole and other cholinergic agonists, resistance appears to be less frequent stressing the need to investigate their molecular target in parasitic nematodes. The levamisole receptor was first identified in the free-living model nematode C. elegans but it is now becoming apparent that this is not a good predictor for many parasitic species. In particular we have found that the LEV-8 subunit which is involved in levamisole sensitivity in C. elegans, is not present in many levamisole-sensitive parasitic species. Here we used heterologous expression systems and gene silencing to provide the functional in vivo demonstration that the ACR-8 subunit, which is not an essential component of the levamisole receptor in C. elegans, has a critical role in the levamisole sensitivity of parasitic nematodes. This has important significance for understanding the molecular targets of cholinergic anthelmintics and addresses the increasing challenge of drug resistance.
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Affiliation(s)
| | | | | | - Anna Crisford
- Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Elise Courtot
- ISP, INRA, Université Tours, UMR1282, Nouzilly, France
| | | | | | - Thomas Duguet
- Institute of Parasitology, McGill University, Macdonald Campus, Ste. Anne de Bellevue, Québec, Canada
| | - Vincent O’Connor
- Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | | | - Barbara Reaves
- Department of Infectious Disease & Center for Tropical and Emerging Global Disease, University of Georgia, Athens, GA, United States of America
| | - Adrian J. Wolstenholme
- Department of Infectious Disease & Center for Tropical and Emerging Global Disease, University of Georgia, Athens, GA, United States of America
| | - Robin N. Beech
- Institute of Parasitology, McGill University, Macdonald Campus, Ste. Anne de Bellevue, Québec, Canada
| | - Lindy Holden-Dye
- Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Cedric Neveu
- ISP, INRA, Université Tours, UMR1282, Nouzilly, France
- * E-mail:
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Shepherd C, Wangchuk P, Loukas A. Of dogs and hookworms: man's best friend and his parasites as a model for translational biomedical research. Parasit Vectors 2018; 11:59. [PMID: 29370855 PMCID: PMC5785905 DOI: 10.1186/s13071-018-2621-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/03/2018] [Indexed: 02/06/2023] Open
Abstract
We present evidence that the dog hookworm (Ancylostoma caninum) is underutilised in the study of host-parasite interactions, particularly as a proxy for the human-hookworm relationship. The inability to passage hookworms through all life stages in vitro means that adult stage hookworms have to be harvested from the gut of their definitive hosts for ex vivo research. This makes study of the human-hookworm interface difficult for technical and ethical reasons. The historical association of humans, dogs and hookworms presents a unique triad of positive evolutionary pressure to drive the A. caninum-canine interaction to reflect that of the human-hookworm relationship. Here we discuss A. caninum as a proxy for human hookworm infection and situate this hookworm model within the current research agenda, including the various 'omics' applications and the search for next generation biologics to treat a plethora of human diseases. Historically, the dog hookworm has been well described on a physiological and biochemical level, with an increasing understanding of its role as a human zoonosis. With its similarity to human hookworm, the recent publications of hookworm genomes and other omics databases, as well as the ready availability of these parasites for ex vivo culture, the dog hookworm presents itself as a valuable tool for discovery and translational research.
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Affiliation(s)
- Catherine Shepherd
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia.
| | - Phurpa Wangchuk
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia.
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Buntschuh I, Raps DA, Joseph I, Reid C, Chait A, Totanes R, Sawh M, Li C. FLP-1 neuropeptides modulate sensory and motor circuits in the nematode Caenorhabditis elegans. PLoS One 2018; 13:e0189320. [PMID: 29293515 PMCID: PMC5749679 DOI: 10.1371/journal.pone.0189320] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/23/2017] [Indexed: 11/19/2022] Open
Abstract
Parasitic nematodes infect over one quarter of the population worldwide, causing morbidity in over one billion people. Current anthelmintic drugs are beginning to lose effectiveness due to the presence of resistant strains. We are interested in the role of neuropeptides, which regulate behaviors in all organisms, as another possible target for anthelmintic drugs. FMRFamide-related peptides (FaRPs) are a family of neuropeptides that are conserved throughout the animal kingdom. In particular, nematodes contain the largest family of FaRPs identified thus far and many of these FaRPs are identical among different nematode species; FaRPs in nematodes are collectively referred to as FLPs (FMRFamide-like peptides). However, little is known about the function of these FLPs. We are using the non-parasitic nematode Caenorhabditis elegans as a model for examining FLPs in nematodes. C. elegans contains at least 31 flp genes that encode 72 potential FLPs. Among the flp genes, flp-1 is one of the few that is universally found in nematodes. FLP-1 neuropeptides were previously reported to be involved in sensory and motor functions. However, previous alleles of flp-1 also disrupted a neighboring gene, daf-10. To understand the phenotypes of flp-1, new alleles that specifically disrupt flp-1 were characterized. The previously reported locomotory and egg-laying defects were found to be due to loss of flp-1, while the osmolarity defect is due to loss of daf-10. In addition, loss of flp-1 and daf-10 both cause several phenotypes that increase in severity in the double mutants by disrupting different neurons in the neural circuits.
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Affiliation(s)
- Ingrid Buntschuh
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Daniel A. Raps
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Ivor Joseph
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Christopher Reid
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
| | - Alexander Chait
- Department of Psychology, City College of New York, City University of New York, New York, NY, United States of America
| | - Raubern Totanes
- Department of Physics, City College of New York, City University of New York, New York, NY, United States of America
| | - Michelle Sawh
- Department of Chemistry & Biochemistry, City College of New York, City University of New York, New York, NY, United States of America
| | - Chris Li
- Department of Biology, City College of New York, City University of New York, New York, NY, United States of America
- The Graduate Center, City University of New York, New York, NY, United States of America
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Application of PCR-Based Tools to Explore Strongyloides Infection in People in Parts of Northern Australia. Trop Med Infect Dis 2017; 2:tropicalmed2040062. [PMID: 30270919 PMCID: PMC6082066 DOI: 10.3390/tropicalmed2040062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/01/2017] [Accepted: 12/01/2017] [Indexed: 12/24/2022] Open
Abstract
Strongyloidiasis, which is caused by infection with the nematode Strongyloides stercoralis, is endemic to areas of northern Australia. Diagnosis in this region remains difficult due to the distances between endemic communities and diagnostic laboratories, leading to lengthy delays in stool processing for microscopy and culture. PCR represents a viable solution to this difficulty, having potential for high sensitivity detection of S. stercoralis, even in older, unpreserved faecal samples. We prospectively collected 695 faecal specimens that were submitted to The Townsville Hospital Microbiology Laboratory from the North Queensland region for routine parasitological examination, and subjected them to a Strongyloides sp. real-time (q)PCR. Results were confirmed with a novel nested conventional PCR assay targeting the 18S rRNA gene, followed by single-strand conformation polymorphism analysis (SSCP). Of the 695 specimens tested, S. stercoralis was detected in three specimens (0.4%) by classical parasitological methods (direct microscopy and formyl-ether acetate concentration), whereas 42 positives were detected by qPCR (6.0%). Conventional PCR confirmed the real-time PCR results in 24 of the samples (3.5%). Several apparent false-positive results occurred at higher cycle times (Ct) in the qPCR. Use of real-time PCR in these populations is promising for the enhanced detection of disease and to support eradication efforts.
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Moser W, Schindler C, Keiser J. Efficacy of recommended drugs against soil transmitted helminths: systematic review and network meta-analysis. BMJ 2017; 358:j4307. [PMID: 28947636 PMCID: PMC5611648 DOI: 10.1136/bmj.j4307] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Objective To evaluate efficacies of anthelmintic drugs against soil transmitted helminths in terms of cure rates and egg reduction rates.Design Systematic review and network meta-analysis.Data Sources PubMed, ISI Web of Science, Embase, ScienceDirect, the Cochrane Central Register of Clinical Trials, and the World Health Organization library database from 1960 until 31 December 2016.Study selection Randomised controlled trials evaluating the efficacy of a single dose regimen of albendazole, mebendazole, levamisole, and pyrantel pamoate against Ascaris lumbricoides, hookworm (Necator americanus and Ancylostoma duodenale) and Trichuris trichiura. The primary outcomes included cure rates analysed by network meta-analysis with mixed logistic regression models and egg reduction rates with mixed linear models.Results 55 and 46 randomised controlled trials were included in the analysis of cure rates and egg reduction rates, respectively. All drugs were highly efficacious against A lumbricoides Albendazole showed the highest efficacy against hookworm infections with a cure rate of 79.5% (95% confidence interval 71.5% to 85.6%) and an egg reduction rate of 89.6% (81.9% to 97.3%). All drugs had low efficacy against T trichiura, with mebendazole showing the highest cure rate of 42.1% (25.9% to 60.2%) and egg reduction rate of 66.0% (54.6% to 77.3%). Estimates for the years 1995 and 2015 showed significant reductions in efficacy of albendazole against T trichiura: by 2015 the egg reduction rates fell from 72.6% (53.7% to 91.5%) to 43.4% (23.5% to 63.3%; P=0.049) and the cure rates fell from 38.6% (26.2% to 52.7%) to 16.4 (7.7% to 31.3%; P=0.027).Conclusions All four currently recommended drugs show limitations in their efficacy profile. While only albendazole showed good efficacy against hookworm infection, all drugs had low efficacy against T trichiura The decrease in efficacy of albendazole against T trichiura over the past two decades is of concern. The findings indicate the need for strengthening efforts to develop new drug treatments, with a particular focus on drugs against T trichiura.
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Affiliation(s)
- Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Christian Schindler
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
- University of Basel, Basel, Switzerland
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26
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Papaiakovou M, Pilotte N, Grant JR, Traub RJ, Llewellyn S, McCarthy JS, Krolewiecki AJ, Cimino R, Mejia R, Williams SA. A novel, species-specific, real-time PCR assay for the detection of the emerging zoonotic parasite Ancylostoma ceylanicum in human stool. PLoS Negl Trop Dis 2017; 11:e0005734. [PMID: 28692668 PMCID: PMC5519186 DOI: 10.1371/journal.pntd.0005734] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/20/2017] [Accepted: 06/21/2017] [Indexed: 11/18/2022] Open
Abstract
Background Molecular-based surveys have indicated that Ancylostoma ceylanicum, a zoonotic hookworm, is likely the second most prevalent hookworm species infecting humans in Asia. Most current PCR-based diagnostic options for the detection of Ancylostoma species target the Internal Transcribed Spacer (ITS) regions of the ribosomal gene cluster. These regions possess a considerable degree of conservation among the species of this genus and this conservation can lead to the misidentification of infecting species or require additional labor for accurate species-level determination. We have developed a novel, real-time PCR-based assay for the sensitive and species-specific detection of A. ceylanicum that targets a non-coding, highly repetitive genomic DNA element. Comparative testing of this PCR assay with an assay that targets ITS sequences was conducted on field-collected samples from Argentina and Timor-Leste to provide further evidence of the sensitivity and species-specificity of this assay. Methods/Principal findings A previously described platform for the design of primers/probe targeting non-coding highly repetitive regions was used for the development of this novel assay. The assay’s limits of detection (sensitivity) and cross-reactivity with other soil-transmitted helminth species (specificity) were assessed with real-time PCR experiments. The assay was successfully used to identify infections caused by A. ceylanicum that were previously only identified to the genus level as Ancylostoma spp. when analyzed using other published primer-probe pairings. Further proof of sensitive, species-specific detection was provided using a published, semi-nested restriction fragment length polymorphism-PCR assay that differentiates between Ancylostoma species. Conclusions/Significance Due to the close proximity of people and domestic/wild animals in many regions of the world, the potential for zoonotic infections is substantial. Sensitive tools enabling the screening for different soil-transmitted helminth infections are essential to the success of mass deworming efforts and facilitate the appropriate interpretation of data. This study describes a novel, species-specific, real-time PCR-based assay for the detection of A. ceylanicum that will help to address the need for such tools in integrated STH deworming programs. Trial registration ANZCTR.org.au ACTRN12614000680662 Historically, Ancylostoma ceylanicum has been viewed as an uncommon cause of human hookworm infection, with minimal public health importance. However, recent reports have indicated that this zoonotic hookworm causes a much greater incidence of infection within certain human populations than was previously believed. Current methods for the species-level detection of A. ceylanicum rely on techniques that involve conventional PCR accompanied by restriction enzyme digestions. These PCR-based assays are not only laborious but they lack sensitivity as they target suboptimal regions on the DNA. As efforts aimed at the eradication of hookworm disease have grown substantially over the last decade, the need for sensitive and specific tools to monitor and evaluate programmatic successes has correspondingly escalated. Since a growing body of evidence suggests that patient responses to drug treatment can vary based upon the species of hookworm that is causing infection, accurate species-level diagnostics are advantageous. Accordingly, the novel real-time PCR-based assay described here provides a sensitive, species-specific diagnostic tool that will facilitate the accurate mapping of disease endemicity and will aid in the evaluation of progress of programmatic deworming efforts.
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Affiliation(s)
- Marina Papaiakovou
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- * E-mail:
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Jessica R. Grant
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Science, University of Melbourne, Parkville, Australia
| | - Stacey Llewellyn
- Clinical Medical Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - James S. McCarthy
- Clinical Medical Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Alejandro J. Krolewiecki
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta/CONICET, Orán, Argentina
- Instituto de Patología Experimental (IPE-CONICET), Facultad de Ciencias de la Salud, Universidad Nacional de Salta, Salta, Argentina
| | - Rubén Cimino
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta/CONICET, Orán, Argentina
| | - Rojelio Mejia
- National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
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Smout FA, Skerratt LF, Butler JRA, Johnson CN, Congdon BC, Thompson RCA. The hookworm Ancylostoma ceylanicum: An emerging public health risk in Australian tropical rainforests and Indigenous communities. One Health 2017; 3:66-69. [PMID: 28616506 PMCID: PMC5454165 DOI: 10.1016/j.onehlt.2017.04.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 04/12/2017] [Accepted: 04/25/2017] [Indexed: 12/02/2022] Open
Abstract
Ancylostoma ceylanicum is the common hookworm of domestic dogs and cats throughout Asia, and is an emerging but little understood public health risk in tropical northern Australia. We investigated the prevalence of A. ceylanicum in soil and free-ranging domestic dogs at six rainforest locations in Far North Queensland that are Indigenous Australian communities and popular tourist attractions within the Wet Tropics World Heritage Area. By combining PCR-based techniques with traditional methods of hookworm species identification, we found the prevalence of hookworm in Indigenous community dogs was high (96.3% and 91.9% from necropsy and faecal samples, respectively). The majority of these infections were A. caninum. We also observed, for the first time, the presence of A. ceylanicum infection in domestic dogs (21.7%) and soil (55.6%) in an Indigenous community. A. ceylanicum was present in soil samples from two out of the three popular tourist locations sampled. Our results contribute to the understanding of dogs as a public health risk to Indigenous communities and tourists in the Wet Tropics. Dog health needs to be more fully addressed as part of the Australian Government's commitments to “closing the gap” in chronic disease between Indigenous and other Australians, and encouraging tourism in similar locations. Ancylostoma ceylanicum is the common hookworm of domestic dogs and cats throughout Asia. A. ceylanicum is an emerging public health risk in tropical northern Australia. A first time account of A. ceylanicum infection in domestic dogs in an Indigenous community. A. ceylanicum was present in soil samples from two out of three popular tourist locations sampled. Dogs may be a public health risk to Indigenous communities and tourists in the Wet Tropics.
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Affiliation(s)
- Felicity A Smout
- One Health Research Group, College of Public Health, Medical and Vet Sciences, James Cook University, Townsville, Queensland 4811, Australia.,College of Science & Engineering, James Cook University, Cairns, Queensland 4870, Australia
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medical and Vet Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - James R A Butler
- CSIRO Land and Water, EcoSciences Precinct, GPO Box 2583, Brisbane, Queensland 4001, Australia
| | - Christopher N Johnson
- School of Biological Sciences and Australian Research Council Centre of Excellence for Biodiversity and Heritage, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - Bradley C Congdon
- College of Science & Engineering, James Cook University, Cairns, Queensland 4870, Australia
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
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28
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Henriquez‐Camacho C, Gotuzzo E, Echevarria J, White Jr AC, Terashima A, Samalvides F, Pérez‐Molina JA, Plana MN. Ivermectin versus albendazole or thiabendazole for Strongyloides stercoralis infection. Cochrane Database Syst Rev 2016; 2016:CD007745. [PMID: 26778150 PMCID: PMC4916931 DOI: 10.1002/14651858.cd007745.pub3] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Strongyloidiasis is a gut infection with Strongyloides stercoralis which is common world wide. Chronic infection usually causes a skin rash, vomiting, diarrhoea or constipation, and respiratory problems, and it can be fatal in people with immune deficiency. It may be treated with ivermectin or albendazole or thiabendazole. OBJECTIVES To assess the effects of ivermectin versus benzimidazoles (albendazole and thiabendazole) for treating chronic strongyloides infection. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register (24 August 2015); the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE (January 1966 to August 2015); EMBASE (January 1980 to August 2015); LILACS (August 2015); and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) using 'strongyloid*' as a search term, reference lists, and conference abstracts. SELECTION CRITERIA Randomized controlled trials of ivermectin versus albendazole or thiabendazole for treating chronic strongyloides infection. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data and assessed risk of bias in the included trials. We used risk ratios (RRs) with 95% confidence intervals (CIs) and fixed- or random-effects models. We pooled adverse event data if the trials were sufficiently similar in their adverse event definitions. MAIN RESULTS We included seven trials, enrolling 1147 participants, conducted between 1994 and 2011 in different locations (Africa, Southeast Asia, America and Europe).In trials comparing ivermectin with albendazole, parasitological cure was higher with ivermectin (RR 1.79, 95% CI 1.55 to 2.08; 478 participants, four trials, moderate quality evidence). There were no statistically significant differences in adverse events (RR 0.80, 95% CI 0.59 to 1.09; 518 participants, four trials, low quality evidence).In trials comparing ivermectin with thiabendazole, there was little or no difference in parasitological cure (RR 1.07, 95% CI 0.96 to 1.20; 467 participants, three trials, low quality evidence). However, adverse events were less common with ivermectin (RR 0.31, 95% CI 0.20 to 0.50; 507 participants; three trials, moderate quality evidence).In trials comparing different dosages of ivermectin, taking a second dose of 200 μg/kg of ivermectin was not associated with higher cure in a small subgroup of participants (RR 1.02, 95% CI 0.94 to 1.11; 94 participants, two trials).Dizziness, nausea, and disorientation were commonly reported in all drug groups. There were no reports of serious adverse events or death. AUTHORS' CONCLUSIONS Ivermectin results in more people cured than albendazole, and is at least as well tolerated. In trials of ivermectin with thiabendazole, parasitological cure is similar but there are more adverse events with thiabendazole.
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Affiliation(s)
- Cesar Henriquez‐Camacho
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
- Hospital Universitario Fundación AlcorcónInternal MedicineCalle Budapest 1MadridSpain28922
| | - Eduardo Gotuzzo
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
- Hospital Nacional Cayetano HerediaAv Honorio Delgado 350. SMPLimaPeru
| | - Juan Echevarria
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
| | - A Clinton White Jr
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
- University of Texas Medical BranchDepartment of Internal Medicine301 University BoulevardGalvestonUSATX 77555‐0435
| | - Angelica Terashima
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
- Hospital Nacional Cayetano HerediaAv Honorio Delgado 350. SMPLimaPeru
| | - Frine Samalvides
- Universidad Peruana Cayetano HerediaInstituto de Medicina Tropical Alexander von HumboldtAv. Honorio Delgado 430Urb. Ingeniería S.M.P.LimaPeru31
| | - José A Pérez‐Molina
- Hospital Ramón y CajalTropical Medicine and Parasitology Unit, Infectious Disease ServiceCarretera de Colmenar Km 9,100MadridSpain28034
| | - Maria N Plana
- Clinical Biostatistics Unit. Ramón y Cajal Hospital (IRYCIS). Francisco de Vitoria University (UFV Madrid). CIBER Epidemiology and Public Health (CIBERESP)Cochrane Collaborating CentreCarretera de Colmenar Km 9.100MadridSpain28034
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Campbell SJ, Nery SV, McCarthy JS, Gray DJ, Soares Magalhães RJ, Clements ACA. A Critical Appraisal of Control Strategies for Soil-Transmitted Helminths. Trends Parasitol 2016; 32:97-107. [PMID: 26795294 DOI: 10.1016/j.pt.2015.10.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/10/2015] [Accepted: 10/13/2015] [Indexed: 12/29/2022]
Abstract
Interventions that lead to reductions in soil-transmitted helminths (STHs) include chemotherapy with anthelmintic drugs and improvements in water, sanitation, and hygiene (WASH). In this opinion article we aim to determine the evidence for optimal approaches for STH control. First we explore the evidence for the above interventions. We then appraise two integration strategies: current chemotherapy-oriented integrated neglected tropical disease (NTD) control and expanded 'multicomponent integration', which includes integrated chemotherapy, WASH, and other intervention strategies. While multicomponent integrated control may be an effective approach to sustainably reduce STH transmission, there is a need for evidence to prove the feasibility of this approach.
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Affiliation(s)
- Suzy J Campbell
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia.
| | - Susana V Nery
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia
| | - Darren J Gray
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia; QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Ricardo J Soares Magalhães
- Children's Health and Environment Program, Queensland Children's Medical Research Institute, University of Queensland, Brisbane, Australia; School of Veterinary Science, University of Queensland, Gatton, Australia
| | - Archie C A Clements
- Research School of Population Health, College of Medicine, Biology, and Environment, The Australian National University, Canberra, Australia
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Courtot E, Charvet CL, Beech RN, Harmache A, Wolstenholme AJ, Holden-Dye L, O’Connor V, Peineau N, Woods DJ, Neveu C. Functional Characterization of a Novel Class of Morantel-Sensitive Acetylcholine Receptors in Nematodes. PLoS Pathog 2015; 11:e1005267. [PMID: 26625142 PMCID: PMC4666645 DOI: 10.1371/journal.ppat.1005267] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 10/20/2015] [Indexed: 01/06/2023] Open
Abstract
Acetylcholine receptors are pentameric ligand-gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. In nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. Despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. Interestingly, parasitic nematodes affecting human or animal health possess two closely related members of this gene family, acr-26 and acr-27 that are essentially absent in free-living or plant parasitic species. Using the pathogenic parasitic nematode of ruminants, Haemonchus contortus, as a model, we found that Hco-ACR-26 and Hco-ACR-27 are co-expressed in body muscle cells. We demonstrated that co-expression of Hco-ACR-26 and Hco-ACR-27 in Xenopus laevis oocytes led to the functional expression of an acetylcholine-receptor highly sensitive to the anthelmintics morantel and pyrantel. Importantly we also reported that ACR-26 and ACR-27, from the distantly related parasitic nematode of horses, Parascaris equorum, also formed a functional acetylcholine-receptor highly sensitive to these two drugs. In Caenorhabditis elegans, a free-living model nematode, we demonstrated that heterologous expression of the H. contortus and P. equorum receptors drastically increased its sensitivity to morantel and pyrantel, mirroring the pharmacological properties observed in Xenopus oocytes. Our results are the first to describe significant molecular determinants of a novel class of nematode body wall muscle AChR.
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Affiliation(s)
- Elise Courtot
- INRA, UMR1282 Infectiologie et Santé Publique, Nouzilly, France
- Université de François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, Tours, France
| | - Claude L. Charvet
- INRA, UMR1282 Infectiologie et Santé Publique, Nouzilly, France
- Université de François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, Tours, France
| | - Robin N. Beech
- INRA, UMR1282 Infectiologie et Santé Publique, Nouzilly, France
- Institute of Parasitology, McGill University, Macdonald Campus, Sainte Anne de Bellevue, Québec, Canada
| | - Abdallah Harmache
- INRA, UMR1282 Infectiologie et Santé Publique, Nouzilly, France
- Université de François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, Tours, France
| | - Adrian J. Wolstenholme
- Department of Infectious Disease and Center for Tropical and Emerging Global Disease, University of Georgia, Athens, Georgia, United States of America
| | - Lindy Holden-Dye
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Vincent O’Connor
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Nicolas Peineau
- Université François Rabelais de Tours, Département de physiologie animale, Tours, France
| | - Debra J. Woods
- Veterinary Medicine Research and Development, Zoetis LLC, Kalamazoo, Michigan, United States of America
| | - Cedric Neveu
- INRA, UMR1282 Infectiologie et Santé Publique, Nouzilly, France
- Université de François Rabelais de Tours, UMR1282 Infectiologie et Santé Publique, Tours, France
- * E-mail:
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Srivastava M, Misra-Bhattacharya S. Overcoming drug resistance for macro parasites. Future Microbiol 2015; 10:1783-9. [PMID: 26517758 DOI: 10.2217/fmb.15.73] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Helminth infections impose burden on human and livestock populations, and their control predominantly relies on periodic mass administration of anthelmintic drugs. However, recent emergence of drug resistance among parasites to currently available drugs raises serious problems for continuation of control strategies and achievement of elimination of parasitic diseases. This review discusses the problem of anthelmintic resistance in humans and livestock, and suggests steps that can be taken to overcome this problem. To achieve the goals of morbidity reduction or elimination of infection we need to develop novel tools, including more efficacious drugs, vaccines and/or antivectorial agents; new diagnostics for infection and assessment of drug efficacy; and markers for possible anthelmintic resistance. Harnessing the knowledge generated from sequencing of parasite genome sequences is the key to identify genes responsible for drug resistance, which can be used as a starting point for discovery of target-specific pharmacological or genetic modulation to test the functional importance of individual genes and pathways. Involvement of chemical genetic screens and Caenorhabditis elegans as a model system for drug discovery needs to be explored in greater detail. Collective effort from several quarters is needed to think of a world that is free of parasitic infections.
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Affiliation(s)
- Mrigank Srivastava
- Division of Parasitology, CSIR-Central Drug Research Institute, Sitapur Road, Lucknow 226031, UP, India.,Academy of Scientific & Innovative Research (AcSIR), New Delhi 110025, India
| | - Shailja Misra-Bhattacharya
- Division of Parasitology, CSIR-Central Drug Research Institute, Sitapur Road, Lucknow 226031, UP, India.,Academy of Scientific & Innovative Research (AcSIR), New Delhi 110025, India
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Law W, Wuescher LM, Ortega A, Hapiak VM, Komuniecki PR, Komuniecki R. Heterologous Expression in Remodeled C. elegans: A Platform for Monoaminergic Agonist Identification and Anthelmintic Screening. PLoS Pathog 2015; 11:e1004794. [PMID: 25928899 PMCID: PMC4415803 DOI: 10.1371/journal.ppat.1004794] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 03/09/2015] [Indexed: 11/30/2022] Open
Abstract
Monoamines, such as 5-HT and tyramine (TA), paralyze both free-living and parasitic nematodes when applied exogenously and serotonergic agonists have been used to clear Haemonchus contortus infections in vivo. Since nematode cell lines are not available and animal screening options are limited, we have developed a screening platform to identify monoamine receptor agonists. Key receptors were expressed heterologously in chimeric, genetically-engineered Caenorhabditis elegans, at sites likely to yield robust phenotypes upon agonist stimulation. This approach potentially preserves the unique pharmacologies of the receptors, while including nematode-specific accessory proteins and the nematode cuticle. Importantly, the sensitivity of monoamine-dependent paralysis could be increased dramatically by hypotonic incubation or the use of bus mutants with increased cuticular permeabilities. We have demonstrated that the monoamine-dependent inhibition of key interneurons, cholinergic motor neurons or body wall muscle inhibited locomotion and caused paralysis. Specifically, 5-HT paralyzed C. elegans 5-HT receptor null animals expressing either nematode, insect or human orthologues of a key Gαo-coupled 5-HT1-like receptor in the cholinergic motor neurons. Importantly, 8-OH-DPAT and PAPP, 5-HT receptor agonists, differentially paralyzed the transgenic animals, with 8-OH-DPAT paralyzing mutant animals expressing the human receptor at concentrations well below those affecting its C. elegans or insect orthologues. Similarly, 5-HT and TA paralyzed C. elegans 5-HT or TA receptor null animals, respectively, expressing either C. elegans or H. contortus 5-HT or TA-gated Cl- channels in either C. elegans cholinergic motor neurons or body wall muscles. Together, these data suggest that this heterologous, ectopic expression screening approach will be useful for the identification of agonists for key monoamine receptors from parasites and could have broad application for the identification of ligands for a host of potential anthelmintic targets.
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Affiliation(s)
- Wenjing Law
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
| | - Leah M. Wuescher
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
| | - Amanda Ortega
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
| | - Vera M. Hapiak
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
| | - Patricia R. Komuniecki
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
| | - Richard Komuniecki
- Department of Biological Sciences, The University of Toledo, Toledo, Ohio, United States of America
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Cantacessi C, Hofmann A, Campbell BE, Gasser RB. Impact of next-generation technologies on exploring socioeconomically important parasites and developing new interventions. Methods Mol Biol 2015; 1247:437-474. [PMID: 25399114 DOI: 10.1007/978-1-4939-2004-4_31] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
High-throughput molecular and computer technologies have become instrumental for systems biological explorations of pathogens, including parasites. For instance, investigations of the transcriptomes of different developmental stages of parasitic nematodes give insights into gene expression, regulation and function in a parasite, which is a significant step to understanding their biology, as well as interactions with their host(s) and disease. This chapter (1) gives a background on some key parasitic nematodes of socioeconomic importance, (2) describes sequencing and bioinformatic technologies for large-scale studies of the transcriptomes and genomes of these parasites, (3) provides some recent examples of applications and (4) emphasizes the prospects of fundamental biological explorations of parasites using these technologies for the development of new interventions to combat parasitic diseases.
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Affiliation(s)
- Cinzia Cantacessi
- Department of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
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Satyendra RV, Vishnumurthy KA, Vagdevi HM, Dhananjaya BL, Shruthi A. Synthesis, in vitro anthelmintic, and molecular docking studies of novel 5-nitro benzoxazole derivatives. Med Chem Res 2014. [DOI: 10.1007/s00044-014-1207-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Anderson RC, Newton CL, Millar RP, Katz AA. The Brugia malayi neuropeptide receptor-4 is activated by FMRFamide-like peptides and signals via Gαi. Mol Biochem Parasitol 2014; 195:54-8. [DOI: 10.1016/j.molbiopara.2014.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/04/2014] [Accepted: 07/07/2014] [Indexed: 01/25/2023]
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Hawdon JM. Controlling Soil-Transmitted Helminths: Time to Think Inside the Box? J Parasitol 2014; 100:166-88. [DOI: 10.1645/13-412.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Brooker S, Bethony JM, Rodrigues LC, Alexander N, Geiger SM, Hotez PJ. Epidemiologic, immunologic and practical considerations in developing and evaluating a human hookworm vaccine. Expert Rev Vaccines 2014. [DOI: 10.1586/14760584.4.1.35] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Humphries D, Simms BT, Davey D, Otchere J, Quagraine J, Terryah S, Newton S, Berg E, Harrison LM, Boakye D, Wilson M, Cappello M. Hookworm infection among school age children in Kintampo north municipality, Ghana: nutritional risk factors and response to albendazole treatment. Am J Trop Med Hyg 2013; 89:540-8. [PMID: 23836564 DOI: 10.4269/ajtmh.12-0605] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Children (n = 812) 6-11 years of age attending 16 schools in the Kintampo North Municipality of Ghana were screened for participation in a study on hookworm infection, nutrition, and response to albendazole. The prevalence of Necator americanus hookworm infection (n = 286) was 39.1%, and significant predictors of infection included age, malaria parasitemia, lack of health care, school area, levels of antibodies against hookworm, and low consumption of animal foods. The cure rate after a single dose (400 mg) albendazole was 43%, and the mean fecal egg count reduction rate was 87.3%. Data for an in vitro egg hatch assay showed a trend toward reduced albendazole susceptibility in post-treatment hookworm isolates (P = 0.06). In summary, hookworm infection is prevalent among school age children in the Kintampo North Municipality and animal food intake inversely correlates with infection status. Modest cure rates and fecal egg count reduction rates reinforce the need for further investigation of potential benzimidazole resistance in Ghana.
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Affiliation(s)
- Debbie Humphries
- Program in International Child Health, Department of Pediatrics and School of Public Health, Yale School of Medicine, New Haven, CT 06520, USA.
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Cantacessi C, Hofmann A, Pickering D, Navarro S, Mitreva M, Loukas A. TIMPs of parasitic helminths - a large-scale analysis of high-throughput sequence datasets. Parasit Vectors 2013; 6:156. [PMID: 23721526 PMCID: PMC3679795 DOI: 10.1186/1756-3305-6-156] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/28/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Tissue inhibitors of metalloproteases (TIMPs) are a multifunctional family of proteins that orchestrate extracellular matrix turnover, tissue remodelling and other cellular processes. In parasitic helminths, such as hookworms, TIMPs have been proposed to play key roles in the host-parasite interplay, including invasion of and establishment in the vertebrate animal hosts. Currently, knowledge of helminth TIMPs is limited to a small number of studies on canine hookworms, whereas no information is available on the occurrence of TIMPs in other parasitic helminths causing neglected diseases. METHODS In the present study, we conducted a large-scale investigation of TIMP proteins of a range of neglected human parasites including the hookworm Necator americanus, the roundworm Ascaris suum, the liver flukes Clonorchis sinensis and Opisthorchis viverrini, as well as the schistosome blood flukes. This entailed mining available transcriptomic and/or genomic sequence datasets for the presence of homologues of known TIMPs, predicting secondary structures of defined protein sequences, systematic phylogenetic analyses and assessment of differential expression of genes encoding putative TIMPs in the developmental stages of A. suum, N. americanus and Schistosoma haematobium which infect the mammalian hosts. RESULTS A total of 15 protein sequences with high homology to known eukaryotic TIMPs were predicted from the complement of sequence data available for parasitic helminths and subjected to in-depth bioinformatic analyses. CONCLUSIONS Supported by the availability of gene manipulation technologies such as RNA interference and/or transgenesis, this work provides a basis for future functional explorations of helminth TIMPs and, in particular, of their role/s in fundamental biological pathways linked to long-term establishment in the vertebrate hosts, with a view towards the development of novel approaches for the control of neglected helminthiases.
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Affiliation(s)
- Cinzia Cantacessi
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Queensland, Australia
| | - Darren Pickering
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Severine Navarro
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, MO, USA
| | - Alex Loukas
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
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Puttachary S, Trailovic SM, Robertson AP, Thompson DP, Woods DJ, Martin RJ. Derquantel and abamectin: effects and interactions on isolated tissues of Ascaris suum. Mol Biochem Parasitol 2013; 188:79-86. [PMID: 23523993 DOI: 10.1016/j.molbiopara.2013.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 02/05/2013] [Accepted: 02/15/2013] [Indexed: 10/27/2022]
Abstract
Startect(®) is a novel anthelmintic combination of derquantel and abamectin. It is hypothesized that derquantel and abamectin interact pharmacologically. We investigated the effects of derquantel, abamectin and their combination on somatic muscle nicotinic acetylcholine receptors and pharyngeal muscle glutamate gated chloride receptor channels of Ascaris suum. We used muscle-strips to test the effects of abamectin, derquantel, and abamectin+derquantel together on the contraction responses to different concentrations of acetylcholine. We found that abamectin reduced the response to acetylcholine, as did derquantel. In combination (abamectin+derquantel), inhibition of the higher acetylcholine concentration response was greater than the predicted additive effect. A two-micropipette current-clamp technique was used to study electrophysiological effects of the anthelmintics on: (1) acetylcholine responses in somatic muscle and; (2) on l-glutamate responses in pharyngeal preparations. On somatic muscle, derquantel (0.1-30μM) produced a potent (IC50 0.22, CI 0.18-0.28μM) reversible antagonism of acetylcholine depolarizations. Abamectin (0.3μM) produced a slow onset inhibition of acetylcholine depolarizations. We compared effects of abamectin and derquantel on muscle preparations pretreated for 30min with these drugs. The effect of the combination was significantly greater than the predicted additive effect of both drugs at higher acetylcholine concentrations. On the pharynx, application of derquantel produced no significant effect by itself or on responses to abamectin and l-glutamate. Abamectin increased the input conductance of the pharynx (EC50 0.42, CI 0.13-1.36μM). Our study demonstrates that abamectin and derquantel interact at nicotinic acetylcholine receptors on the somatic muscle and suggested synergism can occur.
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Kline K, McCarthy JS, Pearson M, Loukas A, Hotez PJ. Neglected tropical diseases of Oceania: review of their prevalence, distribution, and opportunities for control. PLoS Negl Trop Dis 2013; 7:e1755. [PMID: 23383349 PMCID: PMC3561157 DOI: 10.1371/journal.pntd.0001755] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Among Oceania's population of 35 million people, the greatest number living in poverty currently live in Papua New Guinea (PNG), Fiji, Vanuatu, and the Solomon Islands. These impoverished populations are at high risk for selected NTDs, including Necator americanus hookworm infection, strongyloidiasis, lymphatic filariasis (LF), balantidiasis, yaws, trachoma, leprosy, and scabies, in addition to outbreaks of dengue and other arboviral infections including Japanese encephalitis virus infection. PNG stands out for having the largest number of cases and highest prevalence for most of these NTDs. However, Australia's Aboriginal population also suffers from a range of significant NTDs. Through the Pacific Programme to Eliminate Lymphatic Filariasis, enormous strides have been made in eliminating LF in Oceania through programs of mass drug administration (MDA), although LF remains widespread in PNG. There are opportunities to scale up MDA for PNG's major NTDs, which could be accomplished through an integrated package that combines albendazole, ivermectin, diethylcarbamazine, and azithromycin, in a program of national control. Australia's Aboriginal population may benefit from appropriately integrated MDA into primary health care systems. Several emerging viral NTDs remain important threats to the region.
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Affiliation(s)
- Kevin Kline
- Departments of Pediatrics and Molecular Virology & Microbiology, and National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Sabin Vaccine Institute and Texas Children's Hospital-Baylor College of Medicine Center for Vaccine Development, Houston, Texas, United States of America
| | - James S. McCarthy
- Clinical Tropical Medicine Laboratory, Queensland Institute of Medical Research, University of Queensland, Brisbane, Australia
| | - Mark Pearson
- Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Cairns, Queensland, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Cairns, Queensland, Australia
| | - Peter J. Hotez
- Departments of Pediatrics and Molecular Virology & Microbiology, and National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Sabin Vaccine Institute and Texas Children's Hospital-Baylor College of Medicine Center for Vaccine Development, Houston, Texas, United States of America
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The promise and pitfalls of mass drug administration to control intestinal helminth infections. Curr Opin Infect Dis 2012; 25:584-9. [DOI: 10.1097/qco.0b013e328357e4cf] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Cantacessi C, Campbell BE, Gasser RB. Key strongylid nematodes of animals — Impact of next-generation transcriptomics on systems biology and biotechnology. Biotechnol Adv 2012; 30:469-88. [DOI: 10.1016/j.biotechadv.2011.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 08/09/2011] [Accepted: 08/19/2011] [Indexed: 10/17/2022]
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In vitro and in vivo efficacy of tribendimidine and its metabolites alone and in combination against the hookworms Heligmosomoides bakeri and Ancylostoma ceylanicum. Acta Trop 2012; 122:101-7. [PMID: 22210439 DOI: 10.1016/j.actatropica.2011.12.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 12/12/2011] [Accepted: 12/18/2011] [Indexed: 01/23/2023]
Abstract
Worldwide, 3 billion people are at risk of hookworm infection, particularly in resource-poor countries. While control of soil-transmitted helminthiases relies mostly on chemotherapy, only few drugs are available and concern about potential emergence of drug resistance is rising. In the present study, tribendimidine, a derivative of amidantel, and its metabolites deacylated amidantel (dADT) and acetylated deacylated amidantel (AdADT) were tested in vitro and in vivo against Heligmosomoides bakeri and Ancylostoma ceylanicum, two hookworm rodent models, alone or in combination with standard drugs. Tribendimidine achieved IC(50)s ≤ 5 μg/ml against both H. bakeri third-stage larvae and adults in vitro and a single 2 mg/kg oral dose resulted in complete worm elimination in vivo. Comparable results were obtained with dADT, whereas AdADT displayed no effect in vitro and gave a moderate worm burden reduction of 42.9% in H. bakeri-infected mice. Tribendimidine combined with albendazole, levamisole or ivermectin revealed antagonistic interactions against H. bakeri in vitro and no significant killing effect in vivo. Tribendimidine and dADT exerted high efficacies against A. ceylanicum third-stage larvae (IC(50)s < 0.5 μg/ml) whereas adults were moderately affected in vitro (IC(50)s > 88 μg/ml). In vivo at single oral doses of 10 mg/kg, dADT showed a slightly higher efficacy than tribendimidine, achieving worm burden reductions of 87.4% and 74.8%, respectively. At the same dose, AdADT reduced the worm burden by 57.9%. Synergistic interactions were observed with tribendimidine-levamisole combinations against A. ceylanicum in vitro (combination index at IC(50)=0.5), and in vivo (combination index at ED(90)=0.19). In conclusion, tribendimidine and dADT show potent anti-hookworm properties. The potential of the promising tribendimidine-levamisole combination should be investigated in greater detail.
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Mohd Zain SN, Behnke JM, Lewis JW. Helminth communities from two urban rat populations in Kuala Lumpur, Malaysia. Parasit Vectors 2012; 5:47. [PMID: 22397763 PMCID: PMC3364890 DOI: 10.1186/1756-3305-5-47] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 03/07/2012] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The prevalence of parasitic infections among commensal animals such as black and brown rats in many tropical countries is high and in comparison with studies on rodents in temperate climates, little is known about the community structure of their parasites. Rodent borne parasites pose threats to human health since people living in close proximity to rodent populations can be exposed to infection. METHODS The helminth community structures of two urban rat populations in Kuala Lumpur, Malaysia were investigated. The rats were from two contrasting sites in the city caught over a period of 21 months in 2000-2002. RESULTS Eleven species of helminth parasites comprising seven nematodes (Heterakis spumosum, Mastophorus muris, Nippostrongylus brasiliensis, Syphacia muris, Pterygodermatites tani/whartoni, Gongylonema neoplasticum, Angiostrongylus malaysiensis), three cestodes (Hymenolepis (Rodentolepis) nana, H. diminuta and Taenia taeniaeformis) and one acanthocephalan (Moniliformis moniliformis) were recovered from 346 Rattus rattus and 104 R. norvegicus from two urban sites, Bangsar and Chow Kit, during 2000-2002. Rattus rattus harboured over 60% of all helminths compared with R. norvegicus, although both host species played a dominant role in the different sites with, for example R. norvegicus at Bangsar and R. rattus at Chow Kit accounting for most of the nematodes. Overall 80% of rats carried at least one species of helminth, with the highest prevalences being shown by H. diminuta (35%), H. spumosum (29.8%) and H. nana (28.4%). Nevertheless, there were marked differences in prevalence rates between sites and hosts. The influence of extrinsic (year, season and site) and intrinsic (species, sex and age) factors affecting infracommunity structure (abundance and prevalence of infection) and measures of component community structure were analyzed. CONCLUSIONS Since at least two species of rat borne helminths in Kuala Lumpur have the potential to infect humans, and these showed high prevalences in the rats, the assessment and regular monitoring of infections carried by wild rodents have important roles to play in public health.
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Affiliation(s)
- Siti N Mohd Zain
- School of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Jerzy M Behnke
- School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - John W Lewis
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
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Vercruysse J, Albonico M, Behnke JM, Kotze AC, Prichard RK, McCarthy JS, Montresor A, Levecke B. Is anthelmintic resistance a concern for the control of human soil-transmitted helminths? INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2011; 1:14-27. [PMID: 24533260 DOI: 10.1016/j.ijpddr.2011.09.002] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 09/13/2011] [Accepted: 09/16/2011] [Indexed: 11/16/2022]
Abstract
The major human soil-transmitted helminths (STH), Ascaris lumbricoides, hookworms (Necator americanus and Ancylostoma duodenale) and Trichuris trichiura have a marked impact on human health in many parts of the world. Current efforts to control these parasites rely predominantly on periodic mass administration of anthelmintic drugs to school age children and other at-risk groups. After many years of use of these same drugs for controlling roundworms in livestock, high levels of resistance have developed, threatening the sustainability of these livestock industries in some locations. Hence, the question arises as to whether this is likely to also occur in the human STH, thereby threatening our ability to control these parasites. This is particularly important because of the recent increase in mass control programmes, relying almost exclusively on benzimidazole anthelmintics. It will be important to ensure that resistance is detected as it emerges in order to allow the implementation of mitigation strategies, such as use of drug combinations, to ensure that the effectiveness of the few existing anthelmintic drugs is preserved. In this review we address these issues by firstly examining the efficacy of anthelmintics against the human STH, and assessing whether there are any indications to date that resistance has emerged. We then consider the factors that influence the effect of current drug-use patterns in selecting for resistant parasite populations. We describe the tools currently available for resistance monitoring (field-based coprological methods), and those under development (in vitro bioassays and molecular tests), and highlight confounding factors that need to be taken into account when interpreting such resistance-monitoring data. We then highlight means to ensure that the currently available tools are used correctly, particularly with regard to study design, and we set appropriate drug-efficacy thresholds. Finally, we make recommendations for monitoring drug efficacy in the field, as components of control programmes, in order to maximise the ability to detect drug resistance, and if it arises to change control strategy and prevent the spread of resistance.
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Affiliation(s)
- Jozef Vercruysse
- Ghent University, Faculty of Veterinary Medicine, Department of Virology, Parasitology and Immunology, Laboratory of Parasitology, Merelbeke, Belgium
| | | | - Jerzy M Behnke
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Andrew C Kotze
- Division of Livestock Industries, Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia
| | | | - James S McCarthy
- Queensland Institute for Medical Research, University of Queensland, Herston, Australia
| | - Antonio Montresor
- Department of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Bruno Levecke
- Ghent University, Faculty of Veterinary Medicine, Department of Virology, Parasitology and Immunology, Laboratory of Parasitology, Merelbeke, Belgium
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SLO-1-channels of parasitic nematodes reconstitute locomotor behaviour and emodepside sensitivity in Caenorhabditis elegans slo-1 loss of function mutants. PLoS Pathog 2011; 7:e1001330. [PMID: 21490955 PMCID: PMC3072372 DOI: 10.1371/journal.ppat.1001330] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 03/04/2011] [Indexed: 11/24/2022] Open
Abstract
The calcium-gated potassium channel SLO-1 in Caenorhabditis elegans was recently identified as key component for action of emodepside, a new anthelmintic drug with broad spectrum activity. In this study we identified orthologues of slo-1 in Ancylostoma caninum, Cooperia oncophora, and Haemonchus contortus, all important parasitic nematodes in veterinary medicine. Furthermore, functional analyses of these slo-1 orthologues were performed using heterologous expression in C. elegans. We expressed A. caninum and C. oncophora slo-1 in the emodepside-resistant genetic background of the slo-1 loss-of-function mutant NM1968 slo-1(js379). Transformants expressing A. caninum slo-1 from C. elegans slo-1 promoter were highly susceptible (compared to the fully emodepside-resistant slo-1(js379)) and showed no significant difference in their emodepside susceptibility compared to wild-type C. elegans (p = 0.831). Therefore, the SLO-1 channels of A. caninum and C. elegans appear to be completely functionally interchangeable in terms of emodepside sensitivity. Furthermore, we tested the ability of the 5′ flanking regions of A. caninum and C. oncophora slo-1 to drive expression of SLO-1 in C. elegans and confirmed functionality of the putative promoters in this heterologous system. For all transgenic lines tested, expression of either native C. elegans slo-1 or the parasite-derived orthologue rescued emodepside sensitivity in slo-1(js379) and the locomotor phenotype of increased reversal frequency confirming the reconstitution of SLO-1 function in the locomotor circuits. A potent mammalian SLO-1 channel inhibitor, penitrem A, showed emodepside antagonising effects in A. caninum and C. elegans. The study combined the investigation of new anthelmintic targets from parasitic nematodes and experimental use of the respective target genes in C. elegans, therefore closing the gap between research approaches using model nematodes and those using target organisms. Considering the still scarcely advanced techniques for genetic engineering of parasitic nematodes, the presented method provides an excellent opportunity for examining the pharmacofunction of anthelmintic targets derived from parasitic nematodes. In parasitic nematodes, experiments at the molecular level are currently not feasible, since in vitro culture and genetic engineering are still in their infancy. In the present study we chose the model organism Caenorhabditis elegans not only as a mere expression system for genes from parasitic nematodes, but used the transformants to examine the functionality of the expressed proteins for mediating anthelmintic effects in vivo. The results of our experiments confirmed that SLO-1 channels mediate the activity of the new anthelmintic drug emodepside and showed that the mode of action is conserved through several nematode species. The chosen method allowed us to examine the functionality of proteins from parasitic nematodes in a defined genetic background. Notably, expression of the parasitic nematode gene in anthelmintic-resistant C. elegans completely restored drug susceptibility. As C. elegans is highly tractable to molecular genetic and pharmacological approaches, the generation of lines expressing the parasite drug target will greatly facilitate structure-function analysis of the interaction between emodepside and ion channels with direct relevance to its anthelmintic properties. In a broader context, the demonstration of C. elegans as a heterologous expression system for functional analysis of parasite proteins further strengthens this as a model for anthelmintic studies.
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Krepp J, Gelmedin V, Hawdon JM. Characterisation of hookworm heat shock factor binding protein (HSB-1) during heat shock and larval activation. Int J Parasitol 2010; 41:533-43. [PMID: 21172351 DOI: 10.1016/j.ijpara.2010.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/07/2010] [Accepted: 12/09/2010] [Indexed: 11/30/2022]
Abstract
When hookworm infective L3s infect their mammalian host, they undergo a temperature shift from that of the ambient environment to that of their endothermic host. Additionally, L3s living in the environment can be exposed to temperature extremes associated with weather fluctuations. The heat shock response (HSR) is a conserved response to heat shock and other stress that involves the expression of protective heat shock proteins (HSPs). The HSR is controlled by heat shock factor-1 (HSF-1), a conserved transcription factor that binds to a heat shock element in the promoter of HSPs, causing their expression. HSF-1 is negatively regulated in part by a HSF binding protein (HSB-1) that binds to and removes HSF-1 trimers bound to HSP gene promoters, resulting in attenuation of the HSR. Herein we describe an HSB-1 orthologue, Ac-HSB-1, from the hookworm Ancylostoma caninum. The Ac-hsb-1 cDNA encodes a 79 amino acid protein that is 71% identical to the Caenorhabditis elegans HSB-1, and is predicted to share the characteristic coiled-coil structural motif comprised of two interacting alpha helices. Recombinant Ac-HSB-1 immunoprecipitated Ce-HSF-1 expressed in mammalian cells that had been heat shocked for 1h at 42°C, but not from cells incubated at 37°C, indicating that HSB-1 only bound to the active DNA binding form of HSF-1. Expression of Ac-hsb-1 transcripts decreased following 1h of heat shock, but increased when L3s were incubated at 37°C for 1h. Activation of hookworm L3s induces a five-sixfold increase in Ac-hsb-1 expression that peaks at 12h, coincident with L3 feeding, but that subsequently decreases to two-threefold above control at 24h. Recombinant Ac-HSB-1 immunoprecipitates greater amounts of 70 and 40kDa proteins from extracts of activated L3s than from non-activated L3s. We propose that an increase in Ac-hsb-1 levels early in activation allows feeding to resume, but that a subsequent decrease in expression permits a HSR that protects non-developing L3s at host-like temperatures. Further investigations of the HSR will clarify the role of HSB-1 and HSF-1 in hookworm infection.
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Affiliation(s)
- Joseph Krepp
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University Medical Center, 2300 Eye St. NW, Washington, DC 20037, USA
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50
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Parasitic diseases of remote Indigenous communities in Australia. Int J Parasitol 2010; 40:1119-26. [DOI: 10.1016/j.ijpara.2010.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Revised: 04/12/2010] [Accepted: 04/12/2010] [Indexed: 11/22/2022]
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