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Rivero J, Cutillas C, Callejón R. New Insights on Tools for Detecting β-Tubulin Polymorphisms in Trichuris trichiura Using rhAmp TM SNP Genotyping. Animals (Basel) 2024; 14:1545. [PMID: 38891592 PMCID: PMC11171370 DOI: 10.3390/ani14111545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/20/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
Soil-transmitted helminth (STH) infections, commonly treated with benzimidazoles, are linked to resistance through single nucleotide polymorphisms (SNPs) at position 167, 198, or 200 in the β-tubulin isotype 1 gene. The aim of this study was to establish a novel genotyping assay characterized by its rapidity and specificity. This assay was designed to detect the presence of SNPs within the partial β-tubulin gene of Trichuris trichiura. This was achieved through the biallelic discrimination at codons 167, 198, and 200 by employing the competitive binding of two allele-specific forward primers. The specificity and reliability of this assay were subsequently confirmed using Trichuris samples isolated from captive primates. Furthermore, a molecular study was conducted to substantiate the utility of the β-tubulin gene as a molecular marker. The assays showed high sensitivity and specificity when applied to field samples. Nevertheless, none of the SNPs within the β-tubulin gene were detected in any of the adult worms or eggs from the analyzed populations. All specimens consistently displayed an SS genotype. The examination of the β-tubulin gene further validated the established close relationships between the T. trichiura clade and Trichuris suis clade. This reaffirms its utility as a marker for phylogenetic analysis.
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Affiliation(s)
| | | | - Rocío Callejón
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain; (J.R.); (C.C.)
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Hon KL, Leung AKC. An update on the current and emerging pharmacotherapy for the treatment of human ascariasis. Expert Opin Pharmacother 2024. [PMID: 38372051 DOI: 10.1080/14656566.2024.2319686] [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: 07/29/2023] [Accepted: 02/13/2024] [Indexed: 02/20/2024]
Abstract
INTRODUCTION Globally, Ascaris lumbricoides is the commonest helminthic infection that affects people in underdeveloped countries and returning immigrants in industrialized nations. This article aims to provide latest updates on the epidemiology, clinical manifestations, and pharmacotherapy of ascariasis. AREAS COVERED A PubMed search was conducted using Clinical Queries and the key terms 'human ascariasis' OR 'Ascaris lumbricoides.' Ascaris lumbricoides is highly endemic in tropical and subtropic regions and among returning immigrants in industrialized nations. Predisposing factors include poor sanitation and poverty. The prevalence is greatest in young children. Most infected patients are asymptomatic. Patients with A. lumbricoides infection should be treated with anti-helminthic drugs to prevent complications from migration of the worm. Mebendazole and albendazole are indicated for children and nonpregnant women. Pregnant individuals should be treated with pyrantel pamoate. EXPERT OPINION Cure rates with anthelmintic treatment are high. No emerging pharmacotherapy can replace these existing drugs of good efficacy, safety profile and low cost for public health. It is opinioned that advances in the management of ascariasis include diagnostic accuracy at affordable costs, Emodepside is highly effective in single doses against ascarids in mammals and in human trials. The drug could be registered for human use in multiple neglected tropical diseases.
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Affiliation(s)
- Kam Lun Hon
- Department of Paediatrics, The Chinese University of Hong Kong, and Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Alexander K C Leung
- Department of Pediatrics, The University of Calgary and the Alberta Children's Hospital, Calgary, Alberta, Canada
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Farias MMB, Barreto NMPV, Araújo WAC, Oliveira CDEL, Gonçalves NLS, Campagnollo KSS, Teixeira MCA, Galvão-Castro B, Soares NM, Souza JNDE. Anthelmintic treatment follow up in a rural community in Camamu, Bahia, Brazil. AN ACAD BRAS CIENC 2023; 95:e20230323. [PMID: 37909545 DOI: 10.1590/0001-3765202320230323] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 07/17/2023] [Indexed: 11/03/2023] Open
Abstract
Enteroparasites are an important public health problem and the treatment seeks to cure and reduce transmission. The aim of this study was to evaluate the therapeutic efficacy of anthelmintic treatment in individuals living in a rural community area in Camamu, Bahia, Brazil. The parasitological diagnosis was performed by spontaneous sedimentation, Baermann-Moraes and Agar Plate Culture methods. A total of 212 individuals were evaluated. The most frequent helminth was Trichuris trichiura, 24.5% (52/212), followed by Ascaris lumbricoides, 21.2% (45/212), hookworms, 16.5% (35/212), and S. stercoralis, 4.7% (10/212). In the anthelmintic treatment follow up, T. trichiura infection presented the lowest parasitological cure rate, only 60.6% (20/33). Hookworm, Ascaris lumbricoides and Strongyloides stercoralis infections demonstrated cure rates of 70.5 (12/17), 78.1 (25/32) and 100% (5/5), respectively. Individuals who remained infected underwent a new drug therapy. The second parasitological cure rate for T. trichiura was 38.5% (5/13), and 66.7% (2/3) and 75% (3/4) for hookworms and Ascaris lumbricoides, respectively. Trichuris trichiura infection presented the lowest parasitological cure rate at this second evaluation. This reinforces the need to perform a follow-up of all treated individuals. The possibility of drug resistance denotes the necessity for studies to clarify the mechanisms and to evaluate new therapeutic approaches.
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Affiliation(s)
- Marina M B Farias
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Nilo Manoel P V Barreto
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Weslei A C Araújo
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Cíntia DE Lima Oliveira
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Noilson Lázaro S Gonçalves
- Centro de Pesquisas Gonçalo Moniz (Fiocruz), Laboratório de Saúde Pública/LASP, Rua Waldemar Falcão, 121, Candeal, 40296-710 Salvador, BA, Brazil
| | - Kamila S S Campagnollo
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Márcia Cristina A Teixeira
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Bernardo Galvão-Castro
- Centro Integrativo e Multidisciplinar de Atendimento ao Portador de HTLV, Escola Bahiana de Medicina e Saúde Pública (CHTLV/EBMSP), Av. Dom João VI, 275, Brotas, 40290-000 Salvador, BA, Brazil
| | - Neci M Soares
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
| | - Joelma N DE Souza
- Universidade Federal da Bahia/UFBA, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Rua Barão de Jeremoabo, 147, Ondina, 40170-115 Salvador, BA, Brazil
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Xu Y, Wang Y, Wang L, Kong X, Yan G, Li Y, Bu C, Zhang B. The prevalence of soil transmitted helminths and its influential factors in Shandong Province, China: an analysis of surveillance data from 2016 to 2020. Infect Dis Poverty 2023; 12:54. [PMID: 37217956 DOI: 10.1186/s40249-023-01100-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Soil-transmitted helminths (STHs) were previously endemic in Shandong Province, China. This study aimed to analyze the STHs prevalence trend and the natural, social, and human cognitive and behavioural factors influencing the discrepancies between high and low infection levels from 2016 to 2020 in Shandong Province in eastern China. METHODS STHs surveillance data of Shandong Province from 2016 to 2020 were obtained from China Information Management System for Prevention and Control of Parasitic Diseases. STHs infections were detected by modified Kato-Katz method. Comprehensive information on the natural and social factors, STHs-related knowledge and behaviours were collected through questionnaire surveys. Retrospective spatial scan analysis was performed using SaTScan v10.1 to evaluate any identified spatial clusters of STHs infection for statistical significance and Bayes discriminant analysis was used to discriminate the high or low infection groups of the villages. RESULTS In total, 72,160 participants were involved in our survey from 2016 to 2020. The overall STHs prevalence rate was 1.13%, with the eastern region of Shandong Province having the highest rate (2.02%). The predominant species was T. trichiura, with the prevalence rate of 0.99% and the ≥ 70-year age group possessed the highest rate of 2.21%. The STHs prevalence rate showed an annual linear downward trend from 2016 to 2020 ([Formula: see text] = 127.600, P < 0.001). Respondents aged ≥ 60 years had the lowest awareness level of STHs-related prevention knowledge (all P < 0.05), and were the most likely to adopt the practice of fertilizing with fresh stool (χ2 = 28.354, P < 0.001). Furthermore, the southern region demonstrated the highest temperature and rainfall level and the lowest GNP and annual net income per capita (all P < 0.05). CONCLUSIONS There is a remarkable declining in STHs prevalence in Shandong Province from 2016 to 2020. However, the prevalence rates of STHs especially T. trichiura in the southern and eastern regions were still high, and the elderly were more susceptible to be infected with STHs owning to their low awareness level of STHS-related prevention knowledge and high adoption rate of dangerous production and living behaviours. Integrated approaches of health education, environment improvement and behaviour change should be strengthened to obtain a further reduction of STHs prevalence in China.
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Affiliation(s)
- Yan Xu
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Yongbin Wang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Longjiang Wang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Xiangli Kong
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Ge Yan
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Yuejin Li
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Cancan Bu
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China
| | - Benguang Zhang
- Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, No.11 Taibai Middle Road, Rencheng District, Jining City, 272033, Shandong Province, People's Republic of China.
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Pfarr KM, Krome AK, Al-Obaidi I, Batchelor H, Vaillant M, Hoerauf A, Opoku NO, Kuesel AC. The pipeline for drugs for control and elimination of neglected tropical diseases: 1. Anti-infective drugs for regulatory registration. Parasit Vectors 2023; 16:82. [PMID: 36859332 PMCID: PMC9979492 DOI: 10.1186/s13071-022-05581-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/05/2022] [Indexed: 03/03/2023] Open
Abstract
The World Health Organization 'Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021-2030' outlines the targets for control and elimination of neglected tropical diseases (NTDs). New drugs are needed to achieve some of them. We are providing an overview of the pipeline for new anti-infective drugs for regulatory registration and steps to effective use for NTD control and elimination. Considering drugs approved for an NTD by at least one stringent regulatory authority: fexinidazole, included in WHO guidelines for Trypanosoma brucei gambiense African trypanosomiasis, is in development for Chagas disease. Moxidectin, registered in 2018 for treatment of individuals ≥ 12 years old with onchocerciasis, is undergoing studies to extend the indication to 4-11-year-old children and obtain additional data to inform WHO and endemic countries' decisions on moxidectin inclusion in guidelines and policies. Moxidectin is also being evaluated for other NTDs. Considering drugs in at least Phase 2 clinical development, a submission is being prepared for registration of acoziborole as an oral treatment for first and second stage T.b. gambiense African trypanosomiasis. Bedaquiline, registered for tuberculosis, is being evaluated for multibacillary leprosy. Phase 2 studies of emodepside and flubentylosin in O. volvulus-infected individuals are ongoing; studies for Trichuris trichuria and hookworm are planned. A trial of fosravuconazole in Madurella mycetomatis-infected patients is ongoing. JNJ-64281802 is undergoing Phase 2 trials for reducing dengue viral load. Studies are ongoing or planned to evaluate oxantel pamoate for onchocerciasis and soil-transmitted helminths, including Trichuris, and oxfendazole for onchocerciasis, Fasciola hepatica, Taenia solium cysticercosis, Echinococcus granulosus and soil-transmitted helminths, including Trichuris. Additional steps from first registration to effective use for NTD control and elimination include country registrations, possibly additional studies to inform WHO guidelines and country policies, and implementation research to address barriers to effective use of new drugs. Relative to the number of people suffering from NTDs, the pipeline is small. Close collaboration and exchange of experience among all stakeholders developing drugs for NTDs may increase the probability that the current pipeline will translate into new drugs effectively implemented in affected countries.
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Affiliation(s)
- Kenneth M. Pfarr
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Anna K. Krome
- grid.10388.320000 0001 2240 3300Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany
| | - Issraa Al-Obaidi
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Hannah Batchelor
- grid.11984.350000000121138138Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Michel Vaillant
- grid.451012.30000 0004 0621 531XCompetence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Grand Duchy of Luxembourg
| | - Achim Hoerauf
- grid.15090.3d0000 0000 8786 803XInstitute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany ,grid.452463.2German Center for Infection Research, Partner Site Bonn-Cologne, Bonn, Germany
| | - Nicholas O. Opoku
- grid.449729.50000 0004 7707 5975Department of Epidemiology and Biostatistics School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Annette C. Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (WHO/TDR), World Health Organization, Geneva, Switzerland
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Paulino ÉT, Ribeiro de Lima M, Viçosa AL, da Silva CH, Salomon CJ, Real DA, Leonardi D, Mello Silva CC, de Moraes Neto AHA. The Effect of Different Formulations of Praziquantel in Reducing Worms in the Prepatent Period of Schistosomiasis in Murine Models. Front Public Health 2022; 10:848633. [PMID: 35692307 PMCID: PMC9184718 DOI: 10.3389/fpubh.2022.848633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022] Open
Abstract
Schistosomiasis is a widely distributed parasitic disease and one of the most important neglected tropical diseases globally, for which Praziquantel® (PZQ) is the only available treatment. In this context, tests with new PZQ formulations become relevant for disease control. This study evaluated the effects of PZQ treatment in the prepatent phase of schistosomiasis using two formulations: nanoencapsulated (PZQ-NANO) and active pharmaceutical ingredient (PZQ-API). Five experimental groups were established, for which the following serological parameters were evaluated: ALT, AST, ALP, and TP. Animals treated with PZQ-API at 15 and 30 days post-infection showed decreased eggs per gram of feces (EPG) compared to untreated infected animals. The same animals showed reductions of 63.6 and 65.1%, respectively, at 60 days post-infection. Animals treated with PZQ-NANO experienced no significant changes in EPG at any time of observation. Animals treated with either PZQ-API or PZQ-NANO had higher ALT and AST levels in the patent period (60 and 90 days post-infection). Treatment with PZQ, either API or NANO, at 15 days post-infection reduced AST, ALT, and TP levels. It is concluded that prepatent treatment with PZQ-API can reduce the parasite load of infected animals and that treatment at 15 days post-infection can prevent increased serum levels of ALT, AST, and TP.
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Affiliation(s)
- Érica Tex Paulino
- Laboratory of Innovations in Therapies, Teaching and Bioproducts, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (LITEB/IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Laboratory of Environmental Health Evaluation and Promotion, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (LAPSA/IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Tropical Medicine Program, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Monique Ribeiro de Lima
- Animal Experimentation Center, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Alessandra Lifsitch Viçosa
- Laboratory of Experimental Pharmacotechnics, Farmanguinhos, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Cleber Hooper da Silva
- Institute of Science and Technology in Biomodels, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Claudio Javier Salomon
- Faculty of Biochemical and Pharmaceutical Sciences, University of Rosario, Rosario, Argentina
- Institute of Chemistry of Rosario—National Research Council Scientific and Techniques (IQUIR-CONICET), Rosario, Argentina
| | - Daniel Andrés Real
- Faculty of Biochemical and Pharmaceutical Sciences, University of Rosario, Rosario, Argentina
- Institute of Chemistry of Rosario—National Research Council Scientific and Techniques (IQUIR-CONICET), Rosario, Argentina
| | - Dario Leonardi
- Faculty of Biochemical and Pharmaceutical Sciences, University of Rosario, Rosario, Argentina
- Institute of Chemistry of Rosario—National Research Council Scientific and Techniques (IQUIR-CONICET), Rosario, Argentina
| | - Clélia Christina Mello Silva
- Laboratory of Environmental Health Evaluation and Promotion, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (LAPSA/IOC/FIOCRUZ), Rio de Janeiro, Brazil
- *Correspondence: Clélia Christina Mello Silva
| | - Antonio Henrique Almeida de Moraes Neto
- Laboratory of Innovations in Therapies, Teaching and Bioproducts, Oswaldo Cruz Institute, Oswaldo Cruz Foundation (LITEB/IOC/FIOCRUZ), Rio de Janeiro, Brazil
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Husin N, Pasaribu AP, Ali M, Suteno E, Suteno E, Wijaya W, Pasaribu S. Comparison of Albendazole and Mebendazole on Soil-Transmitted Helminth Infections among School-Aged Children. Open Access Maced J Med Sci 2022. [DOI: 10.3889/oamjms.2022.8588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND: Anthelmintics, such as albendazole and mebendazole, are widely used to treat soil-transmitted helminths (STHs). With its extensive usage and administration along with other medical prescriptions, different environmental conditions, etc., some studies have reported unsatisfactory efficacy from albendazole to treat STHs.
AIM: To observe the efficacy of albendazole and mebendazole as a single dose in treating STH infections in elementary school children.
METHODS: An open randomized clinical trial was conducted in Batubara, North Sumatra, comparing the efficacy of albendazole and mebendazole. Samples were 6−12-year-old children infected with STHs based on Kato-Katz examination. A Chi-square test was performed to compare the cure rate and a t-test was done to compare the number of eggs per gram (EPG) feces in both groups.
RESULT: A total of 199 children from 426 met the study criteria. There was a significant difference (p < 0.05) in the cure rate of Ascaris lumbricoides infections at 87.5% and 31% for albendazole and mebendazole groups, respectively. The cure rate of Trichuris trichiura infection at 61.5% and 65.6% with albendazole and mebendazole, respectively, and there was no significant difference (p > 0.05). There was a significant reduction in the number of eggs of all STHs after the treatment either with albendazole or mebendazole.
CONCLUSION: Single-dose albendazole has better efficacy against Ascaris lumbricoides infection than mebendazole. Meanwhile, both albendazole and mebendazole have high efficacy in reducing the number of eggs.
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Hübner MP, Townson S, Gokool S, Tagboto S, Maclean MJ, Verocai GG, Wolstenholme AJ, Frohberger SJ, Hoerauf A, Specht S, Scandale I, Harder A, Glenschek-Sieberth M, Hahnel SR, Kulke D. Evaluation of the in vitro susceptibility of various filarial nematodes to emodepside. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 17:27-35. [PMID: 34339934 PMCID: PMC8347670 DOI: 10.1016/j.ijpddr.2021.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 11/25/2022]
Abstract
Filariae are vector-borne nematodes responsible for an enormous burden of disease. Human lymphatic filariasis, caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori, and onchocerciasis (caused by Onchocerca volvulus) are neglected parasitic diseases of major public health significance in tropical regions. To date, therapeutic efforts to eliminate human filariasis have been hampered by the lack of a drug with sufficient macrofilaricidal and/or long-term sterilizing effects that is suitable for use in mass drug administration (MDA) programs, particularly in areas co-endemic with Loa loa, the causative agent of loiasis. Emodepside, a semi-synthetic cyclooctadepsipeptide, has been shown to have broad-spectrum efficacy against gastrointestinal nematodes in a variety of mammalian hosts, and has been approved as an active ingredient in dewormers for cats and dogs. This paper evaluates, compares (where appropriate) and summarizes the in vitro effects of emodepside against a range of filarial nematodes at various developmental stages. Emodepside inhibited the motility of all tested stages of filariae frequently used as surrogate species for preclinical investigations (Acanthocheilonema viteae, Brugia pahangi, Litomosoides sigmodontis, Onchocerca gutturosa, and Onchocerca lienalis), human-pathogenic filariae (B. malayi) and filariae of veterinary importance (Dirofilaria immitis) in a concentration-dependent manner. While motility of all filariae was inhibited, both stage- and species-specific differences were observed. However, whether these differences were detected because of stage- and/or species-specific factors or as a consequence of variations in protocol parameters among the participating laboratories (such as purification of the parasites, read-out units, composition of media, incubation conditions, duration of incubation etc.) remains unclear. This study, however, clearly shows that emodepside demonstrates broad-spectrum in vitro activity against filarial nematode species across different genera and can therefore be validated as a promising candidate for the treatment of human filariases, including onchocerciasis and lymphatic filariasis.
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Affiliation(s)
- Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.
| | - Simon Townson
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Suzanne Gokool
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Senyo Tagboto
- Griffin Institute (formerly Northwick Park Institute for Medical Research), London, HA1 3UJ, United Kingdom.
| | - Mary J Maclean
- National Institutes of Health, National Eye Institute, Clinical and Translational Immunology Section, Laboratory of Immunology, 10 Center Drive, Building 10, Room 10N113, Bethesda, MD, 20892, USA.
| | - Guilherme G Verocai
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, (current Address: INRAE Centre Val de Loire, 37380 Nouzilly, France), Athens, GA, 30602, USA; Department of Veterinary Pathobiology, College of Veterinary & Biomedical Sciences, Texas A&M University, 4467 TAMU College Station, TX, 77843, USA.
| | - Adrian J Wolstenholme
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, (current Address: INRAE Centre Val de Loire, 37380 Nouzilly, France), Athens, GA, 30602, USA.
| | - Stefan J Frohberger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany.
| | - Sabine Specht
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland.
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, Geneva, Switzerland.
| | - Achim Harder
- Independent Scholar, Europaring 54, 51109, Cologne, Germany.
| | | | - Steffen R Hahnel
- Elanco Animal Health, Alfred-Nobel-Str. 50, 40789, Monheim, Germany.
| | - Daniel Kulke
- Elanco Animal Health, Alfred-Nobel-Str. 50, 40789, Monheim, Germany; Iowa State University, Department of Biomedical Sciences, 2008 Vet Med, Ames, IA, 50011, United States.
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Krücken J, Holden-Dye L, Keiser J, Prichard RK, Townson S, Makepeace BL, Hübner MP, Hahnel SR, Scandale I, Harder A, Kulke D. Development of emodepside as a possible adulticidal treatment for human onchocerciasis-The fruit of a successful industrial-academic collaboration. PLoS Pathog 2021; 17:e1009682. [PMID: 34293063 PMCID: PMC8297762 DOI: 10.1371/journal.ppat.1009682] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Current mass drug administration (MDA) programs for the treatment of human river blindness (onchocerciasis) caused by the filarial worm Onchocerca volvulus rely on ivermectin, an anthelmintic originally developed for animal health. These treatments are primarily directed against migrating microfilariae and also suppress fecundity for several months, but fail to eliminate adult O. volvulus. Therefore, elimination programs need time frames of decades, well exceeding the life span of adult worms. The situation is worsened by decreased ivermectin efficacy after long-term therapy. To improve treatment options against onchocerciasis, a drug development candidate should ideally kill or irreversibly sterilize adult worms. Emodepside is a broad-spectrum anthelmintic used for the treatment of parasitic nematodes in cats and dogs (Profender and Procox). Our current knowledge of the pharmacology of emodepside is the result of more than 2 decades of intensive collaborative research between academia and the pharmaceutical industry. Emodepside has a novel mode of action with a broad spectrum of activity, including against extraintestinal nematode stages such as migrating larvae or macrofilariae. Therefore, emodepside is considered to be among the most promising candidates for evaluation as an adulticide treatment against onchocerciasis. Consequently, in 2014, Bayer and the Drugs for Neglected Diseases initiative (DNDi) started a collaboration to develop emodepside for the treatment of patients suffering from the disease. Macrofilaricidal activity has been demonstrated in various models, including Onchocerca ochengi in cattle, the parasite most closely related to O. volvulus. Emodepside has now successfully passed Phase I clinical trials, and a Phase II study is planned. This Bayer–DNDi partnership is an outstanding example of “One World Health,” in which experience gained in veterinary science and drug development is translated to human health and leads to improved tools to combat neglected tropical diseases (NTDs) and shorten development pathways and timelines in an otherwise neglected area. Onchocerca volvulus is the causative agent of human river blindness, and current elimination programs rely on the use of ivermectin to kill microfilariae. Since no adulticidal drug is available and adult worms have a life span of up to 15 years, elimination programs need to be sustained over several decades. Emodepside is an anthelmintic that is licensed as a dewormer for cats and dogs. Due to its ability to eliminate nematodes located in various extraintestinal host tissues, including migrating larvae and adult filarial worms, it is considered to be an excellent candidate for the treatment of onchocerciasis. Intense collaboration between academia and the pharmaceutical industry has led to a deep understanding of the novel mode of action of the drug and of its parasite target spectrum. Phase I clinical trials with emodepside have demonstrated its safety and adulticide activity against the closely related cattle parasite Onchocerca ochengi. Currently, Phase II clinical trials are planned to confirm that emodepside, developed initially to improve animal health, has also the potential to improve human health by tackling a very important neglected tropical disease (NTD).
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Affiliation(s)
- Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Roger K. Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada
| | - Simon Townson
- The Griffin Institute, Northwick Park and St. Mark’s Hospital, Harrow, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Steffen R. Hahnel
- Elanco Animal Health, Research & Exploratory Development, Monheim, Germany
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Geneva, Switzerland
| | | | - Daniel Kulke
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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10
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O'Sullivan JDB, Cruickshank SM, Withers PJ, Else KJ. Morphological variability in the mucosal attachment site of Trichuris muris revealed by X-ray microcomputed tomography. Int J Parasitol 2021; 51:797-807. [PMID: 34216623 DOI: 10.1016/j.ijpara.2021.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 11/27/2022]
Abstract
Parasitic infections can be challenging to study because two dimensional light and electron microscopy are often limited in visualising complex and inaccessible attachment sites. Exemplifying this, Trichuris spp. inhabit a tunnel of epithelial cells within the host caecum and colon. A significant global burden of this infection persists, partly because available anthelminthics lack efficacy, although the mechanisms underlying this remain unknown. Consequently, there is a need to pioneer new approaches to better characterize the parasite niche within the host and investigate how variation in its morphology and integrity may contribute to resistance to therapeutic intervention. To address these aims, we exploited three-dimensional X-ray micro-computed tomography (microCT) to image the mouse whipworm, Trichuris muris, in caeca of wild-type C57BL/6 and SCID mice ex vivo. Using osmium tetroxide staining to effectively enhance the contrast of worms, we found that a subset exhibited preferential positioning towards the bases of the intestinal crypts. Moreover, in one rare event, we demonstrated whipworm traversal of the lamina propria. This morphological variability contradicts widely accepted conclusions from conventional microscopy of the parasite niche, showing Trichuris in close contact with the host proliferative and immune compartments that may facilitate immunomodulation. Furthermore, by using a skeletonization-based approach we demonstrate considerable variation in tunnel length and integrity. The qualitative and quantitative observations provide a new morphological point of reference for future in vitro study of host-Trichuris interactions, and highlight the potential of microCT to characterise enigmatic host-parasite interactions more accurately.
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Affiliation(s)
- James D B O'Sullivan
- Henry Royce Institute, Department of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom
| | - Sheena M Cruickshank
- Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom
| | - Philip J Withers
- Henry Royce Institute, Department of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Kathryn J Else
- Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom.
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11
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Emodepside targets SLO-1 channels of Onchocerca ochengi and induces broad anthelmintic effects in a bovine model of onchocerciasis. PLoS Pathog 2021; 17:e1009601. [PMID: 34077488 PMCID: PMC8202924 DOI: 10.1371/journal.ppat.1009601] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/14/2021] [Accepted: 05/01/2021] [Indexed: 12/14/2022] Open
Abstract
Onchocerciasis (river blindness), caused by the filarial worm Onchocerca volvulus, is a neglected tropical disease mostly affecting sub-Saharan Africa and is responsible for >1.3 million years lived with disability. Current control relies almost entirely on ivermectin, which suppresses symptoms caused by the first-stage larvae (microfilariae) but does not kill the long-lived adults. Here, we evaluated emodepside, a semi-synthetic cyclooctadepsipeptide registered for deworming applications in companion animals, for activity against adult filariae (i.e., as a macrofilaricide). We demonstrate the equivalence of emodepside activity on SLO-1 potassium channels in Onchocerca volvulus and Onchocerca ochengi, its sister species from cattle. Evaluation of emodepside in cattle as single or 7-day treatments at two doses (0.15 and 0.75 mg/kg) revealed rapid activity against microfilariae, prolonged suppression of female worm fecundity, and macrofilaricidal effects by 18 months post treatment. The drug was well tolerated, causing only transiently increased blood glucose. Female adult worms were mostly paralyzed; however, some retained metabolic activity even in the multiple high-dose group. These data support ongoing clinical development of emodepside to treat river blindness.
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12
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Palmeirim MS, Specht S, Scandale I, Gander-Meisterernst I, Chabicovsky M, Keiser J. Preclinical and Clinical Characteristics of the Trichuricidal Drug Oxantel Pamoate and Clinical Development Plans: A Review. Drugs 2021; 81:907-921. [PMID: 33929716 PMCID: PMC8144136 DOI: 10.1007/s40265-021-01505-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2021] [Indexed: 12/31/2022]
Abstract
Soil-transmitted helminths (Ascaris lumbricoides, hookworm and Trichuris trichiura) infect about one-fifth of the world's population. The currently available drugs are all highly efficacious against A. lumbricoides. However, they are only moderately efficacious against hookworm and poorly efficacious against T. trichiura. Oxantel, a tetrahydropyrimidine derivative discovered in the 1970s, has recently been brought back to our attention given its high efficacy against T. trichiura infections (estimated 76% cure rate and 85% egg reduction rate at a 20 mg/kg dose). This review summarizes the current knowledge on oxantel pamoate and its use against T. trichiura infections in humans. Oxantel pamoate acts locally in the human gastrointestinal tract and binds to the parasite's nicotinic acetylcholine receptor (nAChR), leading to a spastic paralysis of the worm and subsequent expulsion. The drug is metabolically stable, shows low permeability and low systemic bioavailability after oral use. Oxantel pamoate was found to be safe in humans, with only a few mild adverse events reported. Several clinical trials have investigated the efficacy of this drug against T. trichiura and suggest that oxantel pamoate is more efficacious against T. trichiura than the currently recommended drugs, which makes it a strong asset to the depleted drug armamentarium and could help delay or even prevent the development of resistance to existing drugs. We highlight existing data to support the use of oxantel pamoate against T. trichiura infections.
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Affiliation(s)
- Marta S Palmeirim
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland
- University of Basel, P.O. Box, 4003, Basel, Switzerland
| | - Sabine Specht
- Drugs for Neglected Diseases Initiative, 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | | | - Monika Chabicovsky
- MC Toxicology Consulting GmbH, Siebensterngasse 31/8, 1070, Vienna, Austria
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland.
- University of Basel, P.O. Box, 4003, Basel, Switzerland.
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13
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Keiser J, Häberli C. Evaluation of Commercially Available Anthelminthics in Laboratory Models of Human Intestinal Nematode Infections. ACS Infect Dis 2021; 7:1177-1185. [PMID: 33410658 DOI: 10.1021/acsinfecdis.0c00719] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Drug repurposing from veterinary to human medicine has been the main strategy to develop the four recommended human anthelminthics, albendazole, mebendazole, levamisole, and pyrantel pamoate, for the treatment of soil-transmitted helminthiasis. A systematic, head-to-head comparison of the anthelminthic activity profile of derivatives of these drugs and other anthelminthics developed in succession has not been conducted to date. We studied eight benzimidazoles, five macrocyclic lactones, tribendimidine, levamisole, and pyrantel pamoate in laboratory models of human intestinal nematode infections. In vitro studies were performed on Trichuris muris L1 larval stage and adults, as well as Ancylostoma ceylanicum, Necator americanus, Heligmosomoides polygyrus, and Strongyloides ratti L3 larvae and adults. The benzimidazoles showed pronounced differences against larval and adult stages, with low activity against larvae and the highest activity observed against adult N. americanus (IC50 of flubendazole 1.1 μM). The macrocyclic lactones, on the other hand, revealed a higher activity on the larval stages, with the lowest IC50 values observed against N. americanus L3 (IC50 values of 0.03-3 μM). In vivo studies were performed in the T. muris and H. polygyrus mice models, with moxidectin and milbemycin oxime showing the highest activity against H. polygyrus (ED50 values of 0.009 and 0.006 mg/kg, respectively) and moxidectin and abamectin being the most effective drugs against T. muris (ED50 values of 0.2 and 0.5 mg/kg, respectively). Laboratory models for soil-transmitted helminthiasis can assist characterizing potential drug candidates. Drugs should be evaluated against different species, and both the adult and larval stages as activities could differ considerably.
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Affiliation(s)
- Jennifer Keiser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4051 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Cécile Häberli
- Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4051 Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
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14
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Population Pharmacokinetics and Exposure-Response Analysis of Tribendimidine To Improve Treatment for Children with Hookworm Infection. Antimicrob Agents Chemother 2021; 65:AAC.01778-20. [PMID: 33139293 DOI: 10.1128/aac.01778-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/26/2020] [Indexed: 12/28/2022] Open
Abstract
Tribendimidine has been successful in treating hookworm infections and may serve as an alternative to albendazole should resistance arise. Our aims were to (i) characterize the pharmacokinetics (PK) of tribendimidine's primary metabolite, deacetylated amidantel (dADT), and secondary metabolite, acetylated derivative of amidantel (adADT), in school-aged children and adolescents, (ii) link exposure to efficacy against hookworm, and (iii) evaluate whether tribendimidine pharmacotherapy in children could be further improved. First, a population PK model was developed based on dried-blood-spot samples collected from 155 school-aged children and adolescents with hookworm infections, following tribendimidine doses ranging from 100 to 400 mg. Second, an exposure-response analysis was conducted to link the active metabolite dADT to cure rates (CRs) and egg reduction rates (ERRs). Third, simulations were performed to identify a treatment strategy associated with >90% CRs. A two-compartmental model with transit compartments describing observed delay in absorption adequately described PK data of dADT and adADT. Allometric scaling was included to account for growth and development. The absorption rate was 56% lower with 200-mg tablets than with 50-mg tablets, while the extent of absorption remained unaffected. The identified E max models linking dADT exposure to ERRs and CRs showed shallow curves, as increasing exposure led to marginal efficacy increase. Combination therapy should be considered, as a 12-fold-higher dose would be needed to achieve 95% ERRs and CRs >90% with tribendimidine alone. Further studies are warranted to evaluate safety of higher tribendimidine doses and combination therapies with other anthelmintic agents to improve treatment strategy for children with hookworm infection.
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15
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Pharmacometric Analysis of Tribendimidine Monotherapy and Combination Therapies To Achieve High Cure Rates in Patients with Hookworm Infections. Antimicrob Agents Chemother 2021; 65:AAC.00714-20. [PMID: 33139276 DOI: 10.1128/aac.00714-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 09/27/2020] [Indexed: 02/06/2023] Open
Abstract
In the treatment of hookworm infections, pharmacotherapy has been only moderately successful and drug resistance is a threat. Therefore, novel treatment options including combination therapies should be considered, in which tribendimidine could play a role. Our aims were to (i) characterize the pharmacokinetics of tribendimidine's metabolites in adolescents receiving tribendimidine monotherapy or in combination with ivermectin or oxantel pamoate, (ii) evaluate possible drug-drug interactions (DDI), (iii) link exposure to response, and (iv) identify a treatment strategy associated with high efficacy, i.e., >90% cure rates (CRs), utilizing model-based simulations. A population pharmacokinetic model was developed for tribendimidine's primary and secondary metabolites, dADT and adADT, in 54 hookworm-positive adolescents, with combination therapy evaluated as a possible covariate. Subsequently, an exposure-response analysis was performed utilizing CRs as response markers. Simulations were performed to identify a treatment strategy to achieve >90% CRs. A two-compartmental model best described metabolite disposition. No pharmacokinetic DDI was identified with ivermectin or oxantel pamoate. All participants receiving tribendimidine plus ivermectin were cured. For the monotherapy arm and the arm including the combination with oxantel pamoate, E max models adequately described the correlation between dADT exposure and probability of being cured, with required exposures to achieve 50% of maximum effect of 39.6 and 15.6 nmol/ml·h, respectively. Based on our simulations, an unrealistically high monotherapy tribendimidine dose would be necessary to achieve CRs of >90%, while combination therapy with ivermectin would meet this desired target product profile. Further clinical studies should be launched to develop this combination for the treatment of hookworm and other helminth infections.
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16
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Else KJ, Keiser J, Holland CV, Grencis RK, Sattelle DB, Fujiwara RT, Bueno LL, Asaolu SO, Sowemimo OA, Cooper PJ. Whipworm and roundworm infections. Nat Rev Dis Primers 2020; 6:44. [PMID: 32467581 DOI: 10.1038/s41572-020-0171-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2020] [Indexed: 12/26/2022]
Abstract
Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. Both parasites are staggeringly prevalent, particularly in tropical and subtropical areas, and are associated with substantial morbidity. Infection is initiated by ingestion of infective eggs, which hatch in the intestine. Thereafter, T. trichiura larvae moult within intestinal epithelial cells, with adult worms embedded in a partially intracellular niche in the large intestine, whereas A. lumbricoides larvae penetrate the gut mucosa and migrate through the liver and lungs before returning to the lumen of the small intestine, where adult worms dwell. Both species elicit type 2 anti-parasite immunity. Diagnosis is typically based on clinical presentation (gastrointestinal symptoms and inflammation) and the detection of eggs or parasite DNA in the faeces. Prevention and treatment strategies rely on periodic mass drug administration (generally with albendazole or mebendazole) to at-risk populations and improvements in water, sanitation and hygiene. The effectiveness of drug treatment is very high for A. lumbricoides infections, whereas cure rates for T. trichiura infections are low. Novel anthelminthic drugs are needed, together with vaccine development and tools for diagnosis and assessment of parasite control in the field.
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Affiliation(s)
- Kathryn J Else
- Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Celia V Holland
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Richard K Grencis
- Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - David B Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Rayne Building, University College London, London, UK
| | - Ricardo T Fujiwara
- Department of Parasitology, Institute of Biological Sciences (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Lilian L Bueno
- Department of Parasitology, Institute of Biological Sciences (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Samuel O Asaolu
- Department of Zoology, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Oluyomi A Sowemimo
- Department of Zoology, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Philip J Cooper
- Institute of Infection and Immunity, St George's University of London, London, UK.,Facultad de Ciencias Medicas, de la Salud y la Vida, Universidad Internacional del Ecuador, Quito, Ecuador
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Vlaminck J, Cools P, Albonico M, Ame S, Chanthapaseuth T, Viengxay V, Do Trung D, Osei-Atweneboana MY, Asuming-Brempong E, Jahirul Karim M, Al Kawsar A, Keiser J, Khieu V, Faye B, Turate I, Mbonigaba JB, Ruijeni N, Shema E, Luciañez A, Santiago Nicholls R, Jamsheed M, Mikhailova A, Montresor A, Mupfasoni D, Yajima A, Ngina Mwinzi P, Gilleard J, Prichard RK, Verweij JJ, Vercruysse J, Levecke B. Piloting a surveillance system to monitor the global patterns of drug efficacy and the emergence of anthelmintic resistance in soil-transmitted helminth control programs: a Starworms study protocol. Gates Open Res 2020; 4:28. [PMID: 32266328 PMCID: PMC7120503 DOI: 10.12688/gatesopenres.13115.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2020] [Indexed: 11/20/2022] Open
Abstract
To eliminate soil-transmitted helminth (STH) infections as a public health problem, the administration of benzimidazole (BZ) drugs to children has recently intensified. But, as drug pressure increases, the development of anthelmintic drug resistance (AR) becomes a major concern. Currently, there is no global surveillance system to monitor drug efficacy and the emergence of AR. Consequently, it is unclear what the current efficacy of the used drugs is and whether AR is already present. The aim of this study is to pilot a global surveillance system to assess anthelmintic drug efficacy and the emergence of AR in STH control programs. For this, we will incorporate drug efficacy trials into national STH control programs of eight countries (Bangladesh, Cambodia, Lao PDR, Vietnam, Ghana, Rwanda, Senegal and a yet to be defined country in the Americas). In each country, one trial will be performed in one program implementation unit to assess the efficacy of BZ drugs against STHs in school-aged children by faecal egg count reduction test. Stool samples will be collected before and after treatment with BZs for Kato-Katz analysis and preserved to purify parasite DNA. The presence and frequency of known single nucleotide polymorphisms (SNPs) in the β-tubulin genes of the different STHs will subsequently be assessed. This study will provide a global pattern of drug efficacy and emergence of AR in STH control programs. The results will provide complementary insights on the validity of known SNPs in the ß-tubulin gene as a marker for AR in human STHs as well as information on the technical and financial resources required to set up a surveillance system. Finally, the collected stool samples will be an important resource to validate different molecular technologies for the detection of AR markers or to identify novel potential molecular markers associated with AR in STH.
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Affiliation(s)
- Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Piet Cools
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy.,Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Shaali Ame
- Laboratory of Parasitology, Public Health Laboratory Ivo de Carneri, Chake Chake, Tanzania
| | | | - Vanisaveth Viengxay
- National institute of Health, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Dung Do Trung
- National Institute of Malariology, Parasitology and Entomology, Ministry of Health, Hanoi, Vietnam
| | | | | | - Mohammad Jahirul Karim
- Filariasis Elimination, STH Control and Little Doctor Programme, CDC, Directorate General of Health Services, Dhaka, Bangladesh
| | - Abdullah Al Kawsar
- Filariasis Elimination, STH Control and Little Doctor Programme, CDC, Directorate General of Health Services, Dhaka, Bangladesh
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Babacar Faye
- Service of Parasitology and Mycology, University of Cheikh Anta DIOP, Dakar, Senegal
| | - Innocent Turate
- The institute of HIV/AIDS Disease Prevention and Control, Rwanda Biomedical Center, Kigali, Rwanda
| | - Jean Bosco Mbonigaba
- The institute of HIV/AIDS Disease Prevention and Control, Rwanda Biomedical Center, Kigali, Rwanda
| | - Nadine Ruijeni
- College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Eliah Shema
- College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Ana Luciañez
- Neglected Tropical Diseases, Communicable Diseases and Environmental Determinants of Health, Pan American Health Organization, Washington D.C., USA
| | - Ruben Santiago Nicholls
- Neglected Tropical Diseases, Communicable Diseases and Environmental Determinants of Health, Pan American Health Organization, Washington D.C., USA
| | - Mohamed Jamsheed
- Department of Communicable Diseases, World Health Organization, New Delhi, India
| | - Alexei Mikhailova
- Department of Control of Neglected Tropical Diseases, World Health organization, Geneva, Switzerland
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health organization, Geneva, Switzerland
| | - Denise Mupfasoni
- Department of Control of Neglected Tropical Diseases, World Health organization, Geneva, Switzerland
| | - Aya Yajima
- Western Pacific Regional Office, World Health Organization, Manilla, Philippines
| | - Pauline Ngina Mwinzi
- Expanded Special Project for Elimination of NTDs (ESPEN), World Health Organization, Brazzaville, Congo
| | - John Gilleard
- Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, Canada
| | | | - Jaco J Verweij
- Laboratory for Parasitology, Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
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18
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Clarke NE, Doi SAR, Wangdi K, Chen Y, Clements ACA, Nery SV. Efficacy of Anthelminthic Drugs and Drug Combinations Against Soil-transmitted Helminths: A Systematic Review and Network Meta-analysis. Clin Infect Dis 2020; 68:96-105. [PMID: 29788074 DOI: 10.1093/cid/ciy423] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/11/2018] [Indexed: 12/30/2022] Open
Abstract
Background Periodic mass distribution of benzimidazole anthelminthic drugs is the key strategy to control soil-transmitted helminths (STHs) globally. However, benzimidazoles have low efficacy against Trichuris trichiura, and there are concerns about benzimidazole resistance potentially emerging in humans. Therefore, identifying alternative drug regimens is a pressing priority. We present a systematic review and network meta-analysis comparing the efficacy of 21 different anthelminthic drug regimens, including standard, novel, and combination treatments. Methods We searched PubMed, Medline, Embase, Web of Science, and Cochrane databases and identified studies comparing anthelminthic treatments to each other or placebo. The outcomes calculated were relative risk (RR) of cure and difference in egg reduction rates (dERR). We used an automated generalized pairwise modeling framework to generate mixed treatment effects against a common comparator, the current standard treatment (single-dose albendazole). Results Our search identified 4876 studies, of which 114 were included in the meta-analysis. Results identified several drug combinations with higher efficacy than single-dose albendazole for T. trichiura, including albendazole-ivermectin (RR of cure, 3.22 [95% confidence interval {CI}, 1.84-5.63]; dERR, 0.97 [95% CI, .21-1.74]), albendazole-oxantel pamoate (RR, 5.07 [95% CI, 1.65-15.59]; dERR, 0.51 [95% CI, .50-.52]), mebendazole-ivermectin (RR, 3.37 [95% CI, 2.20-5.16]), and tribendimidine-oxantel pamoate (RR, 4.06 [95% CI, 1.30-12.64]). Conclusions There are several promising drug combinations that may enhance the impact of STH control programs on T. trichiura, without compromising efficacy against Ascaris lumbricoides and hookworm. We suggest further, large-scale trials of these drug combinations and consideration of their use in STH control programs where T. trichiura is present. International Prospective Register of Systematic Reviews Registration CRD42016050739.
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Affiliation(s)
- Naomi E Clarke
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Suhail A R Doi
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Department of Population Medicine, College of Medicine, Qatar University, Doha
| | - Kinley Wangdi
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Yingxi Chen
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Archie C A Clements
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Faculty of Health Sciences, Curtin University, Perth, Western Australia
| | - Susana V Nery
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Kirby Institute, University of New South Wales, Sydney, Australia
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Bibo-Verdugo B, Wang SC, Almaliti J, Ta AP, Jiang Z, Wong DA, Lietz CB, Suzuki BM, El-Sakkary N, Hook V, Salvesen GS, Gerwick WH, Caffrey CR, O’Donoghue AJ. The Proteasome as a Drug Target in the Metazoan Pathogen, Schistosoma mansoni. ACS Infect Dis 2019; 5:1802-1812. [PMID: 31355632 DOI: 10.1021/acsinfecdis.9b00237] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Proteases are fundamental to successful parasitism, including that of the schistosome flatworm parasite, which causes the disease schistosomiasis in 200 million people worldwide. The proteasome is receiving attention as a potential drug target for treatment of a variety of infectious parasitic diseases, but it has been understudied in the schistosome. Adult Schistosoma mansoni were incubated with 1 μM concentrations of the proteasome inhibitors bortezomib, carfilzomib, and MG132. After 24 h, bortezomib and carfilzomib decreased worm motility by more than 85% and endogenous proteasome activity by >75%, and after 72 h, they increased caspase activity by >4.5-fold. The association between the engagement of the proteasome target and the phenotypic and biochemical effects recorded encouraged the chromatographic enrichment of the S. mansoni proteasome (Sm20S). Activity assays with fluorogenic proteasome substrates revealed that Sm20S contains caspase-type (β1), trypsin-type (β2), and chymotrypsin-type (β5) activities. Sm20S was screened with 11 peptide epoxyketone inhibitors derived from the marine natural product carmaphycin B. Analogue 17 was 27.4-fold less cytotoxic to HepG2 cells than carmaphycin B and showed equal potency for the β5 subunits of Sm20S, human constitutive proteasome, and human immunoproteasome. However, this analogue was 13.2-fold more potent at targeting Sm20S β2 than it was at targeting the equivalent subunits of the human enzymes. Furthermore, 1 μM 17 decreased both worm motility and endogenous Sm20S activity by more than 90% after 24 h. We provide direct evidence of the proteasome's importance to schistosome viability and identify a lead for which future studies will aim to improve the potency, selectivity, and safety.
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Affiliation(s)
- Betsaida Bibo-Verdugo
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Steven C Wang
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Jehad Almaliti
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, Amman 11942, Jordan
| | - Anh P. Ta
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Zhenze Jiang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Derek A. Wong
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Christopher B. Lietz
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Brian M. Suzuki
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Nelly El-Sakkary
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Guy S. Salvesen
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, United States
| | - William H. Gerwick
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Anthony J. O’Donoghue
- Center for Discovery and Innovation in Parasitic Diseases, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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Vlaminck J, Cools P, Albonico M, Ame S, Ayana M, Cringoli G, Dana D, Keiser J, Maurelli MP, Matoso LF, Montresor A, Mekonnen Z, Mirams G, Corrêa-Oliveira R, Pinto SA, Rinaldi L, Sayasone S, Thomas E, Vercruysse J, Verweij JJ, Levecke B. Therapeutic efficacy of albendazole against soil-transmitted helminthiasis in children measured by five diagnostic methods. PLoS Negl Trop Dis 2019; 13:e0007471. [PMID: 31369562 PMCID: PMC6675043 DOI: 10.1371/journal.pntd.0007471] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/16/2019] [Indexed: 01/15/2023] Open
Abstract
Background Preventive chemotherapy (PC) with benzimidazole drugs is the backbone of soil-transmitted helminth (STH) control programs. Over the past decade, drug coverage has increased and with it, the possibility of developing anthelmintic resistance. It is therefore of utmost importance to monitor drug efficacy. Currently, a variety of novel diagnostic methods are available, but it remains unclear whether they can be used to monitor drug efficacy. In this study, we compared the efficacy of albendazole (ALB) measured by different diagnostic methods in a head-to-head comparison to the recommended single Kato-Katz. Methods An ALB efficacy trial was performed in 3 different STH-endemic countries (Ethiopia, Lao PDR and Tanzania), each with a different PC-history. During these trials, stool samples were evaluated with Kato-Katz (single and duplicate), Mini-FLOTAC, FECPAKG2, and qPCR. The reduction rate in mean eggs per gram of stool (ERR) and mean genome equivalents / ml of DNA extract (GERR) were calculated to estimate drug efficacy. Principal findings and conclusions The results of the efficacy trials showed that none of the evaluated diagnostic methods could provide reduction rates that were equivalent to a single Kato-Katz for all STH. However, despite differences in clinical sensitivity and egg counts, they agreed in classifying efficacy according to World Health Organization (WHO) guidelines. This demonstrates that diagnostic methods for assessing drug efficacy should be validated with their intended-use in mind and that other factors like user-friendliness and costs will likely be important factors in driving the choice of diagnostics. In addition, ALB efficacy against STH infections was lower in sites with a longer history of PC. Yet, further research is needed to identify factors that contribute to this finding and to verify whether reduced efficacy can be associated with mutations in the β-tubulin gene that have previously been linked to anthelmintic resistance. Trial registration ClinicalTrials.gov NCT03465488. During the last decade, the scale of deworming programs that aim to eliminate the morbidity caused by intestinal worms has increased to a level that is unprecedented in history. It is therefore of utmost importance to monitor any change in therapeutic efficacy that may arise from emerging drug resistance. Currently, a variety of novel methods have been described, but it remains unclear whether they can be used for monitoring drug efficacy. We applied different diagnostic methods to measure the efficacy of a commonly administered drug in deworming programs in 3 countries with different historical exposure to deworming programs. Compared to the standard diagnostic method, all diagnostic methods revealed good agreement in classifying the therapeutic efficacy according to World Health Organization guidelines, despite clear differences in diagnostic performance. We also noticed that the drug efficacy was lower in countries where drug pressure has been high. However, more research is necessary to identify factors that explain this variation in drug efficacy, including but not limited to the frequency in mutations in genes that are known to be linked with anthelmintic resistance.
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Affiliation(s)
- Johnny Vlaminck
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Piet Cools
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Marco Albonico
- Center for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Negrar, Italy
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Shaali Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Mio Ayana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Daniel Dana
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Maria P. Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Leonardo F. Matoso
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
- Nursing school, Federal University of Minas Gerais, Brazil
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Zeleke Mekonnen
- Jimma University Institute of Health, Jimma University, Jimma, Ethiopia
| | | | - Rodrigo Corrêa-Oliveira
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Simone A. Pinto
- Laboratory of Molecular and Cellular Immunology, Research Center René Rachou—FIOCRUZ, Belo Horizonte, Brazil
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Somphou Sayasone
- Lao Tropical and Public Health Institute, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | | | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
| | - Jaco J. Verweij
- Laboratory for Medical Microbiology and Immunology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- * E-mail:
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Anto EJ, Nugraha SE. Efficacy of Albendazole and Mebendazole With or Without Levamisole for Ascariasis and Trichuriasis. Open Access Maced J Med Sci 2019; 7:1299-1302. [PMID: 31110573 PMCID: PMC6514329 DOI: 10.3889/oamjms.2019.299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Helminthiasis in school-aged children potentially causing physical growth and intellectual development retardation. Trichuriasis was the most common type of helminthiasis in children. AIM To investigated the efficacy and side effects of albendazole, albendazole combined with levamisole and mebendazole combined with levamisole for trichuriasis and ascariasis. METHODS This study was conducted as a double-blind, randomised clinical trial by comparing the efficacy and side effects of albendazole, albendazole combined with levamisole and mebendazole combined with levamisole for trichuriasis. The sample of this study were 180 elementary school students at Deli Serdang Regency State Elementary School, Medan, Indonesia. The study was conducted from April to June 2015. RESULT The cure rate of helminthiasis on the 7th day was 81.7% after albendazole therapy, 88.3% after albendazole levamisole therapy, and 83.3% after mebendazole combined with levamisole therapy (p = 0.577). Cure rate on the 14th day was 88.3%, 95%, and 91.7% for albendazole, albendazole combined with levamisole, and mebendazole combined with levamisole therapy, respectively (p = 0.418). On the 21th day, the cure rate was 88.3%, 96.7%, and 91.7% (p = 0.230). Combination of albendazole and levamisole showed the highest cure rate, despite the statistically insignificant difference for all groups (p > 0.05). Combination of albendazole combined with levamisole showed better cure rate for mild trichuriasis (95.8%) than albendazole therapy (46.2%) and mebendazole combined with levamisole (83.3%), (p < 0.05). CONCLUSION Single-dose albendazole, a combination of albendazole and levamisole, and a combination of mebendazole and levamisole had similar efficacy in reducing egg count in helminthiasis. Combination of albendazole and levamisole showed better cure rate for mild trichuriasis and mixed infections. Side effects were similar in all treatment groups.
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Affiliation(s)
- Endy Juli Anto
- Department of Parasitology, Faculty of Medicine, University of Methodist Indonesia, Medan, Indonesia
| | - Sony Eka Nugraha
- Department of Pharmaceutical Biology, Faculty of Pharmacy, Universitas Sumatera Utara, Medan, Indonesia
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Abstract
The soil-transmitted helminths (STHs), Ascaris lumbricoides, hookworm and Trichuris trichiura are common in areas with warm and moist climates with little access to adequate water, sanitation, and hygiene affecting the poorest populations. The current control strategy of the World Health Organization is preventive chemotherapy (PC), i.e., the administration of the two benzimidazoles (albendazole and mebendazole) using single, oral doses to at risk populations without prior diagnosis. The recent success of PC is threatened by anthelmintic drug resistance and the low efficacy of the drugs against hookworm (mebendazole) and T. trichiura (albendazole and mebendazole). Only a handful of alternative drugs with anthelmintic properties are available, however, none of the drugs show high efficacy against all three STHs. The combination of two drugs with different activity profiles presents an attractive alternative, which could prevent the development of drug resistance and increase the efficacy compared to monotherapy. In this review, we summarize the efficacy of current and alternative anthelmintics, coadministrations and triple drug therapies assessed by means of network meta-analysis including only randomized controlled trials. Our results highlight that coadministrations have improved efficacy over monotherapy and the necessity of adapting current STH control strategies for the successful continuation of PC programs.
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Comprehensive evaluation of stool-based diagnostic methods and benzimidazole resistance markers to assess drug efficacy and detect the emergence of anthelmintic resistance: A Starworms study protocol. PLoS Negl Trop Dis 2018; 12:e0006912. [PMID: 30388108 PMCID: PMC6235403 DOI: 10.1371/journal.pntd.0006912] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 11/14/2018] [Accepted: 10/09/2018] [Indexed: 02/02/2023] Open
Abstract
Background To work towards reaching the WHO goal of eliminating soil-transmitted helminth (STH) infections as a public health problem, the total number of children receiving anthelmintic drugs has strongly increased over the past few years. However, as drug pressure levels rise, the development of anthelmintic drug resistance (AR) is more and more likely to appear. Currently, any global surveillance system to monitor drug efficacy and the emergence of possible AR is lacking. Consequently, it remains unclear to what extent the efficacy of drugs may have dropped and whether AR is already present. The overall aim of this study is to recommend the best diagnostic methods to monitor drug efficacy and molecular markers to assess the emergence of AR in STH control programs. Methods A series of drug efficacy trials will be performed in four STH endemic countries with varying drug pressure (Ethiopia and Brazil: low drug pressure, Lao PDR: moderate drug pressure and Tanzania: high drug pressure). These trials are designed to assess the efficacy of a single oral dose of 400 mg albendazole (ALB) against STH infections in school-aged children (SAC) by microscopic (duplicate Kato-Katz thick smear, Mini-FLOTAC and FECPAKG2) and molecular stool-based diagnostic methods (quantitative PCR (qPCR)). Data will be collected on the cost of the materials used, as well as the time required to prepare and examine stool samples for the different diagnostic methods. Following qPCR, DNA samples will also be submitted for pyrosequencing to assess the presence and prevalence of single nucleotide polymorphisms (SNPs) in the β-tubulin gene. These SNPs are known to be linked to AR in animal STHs. Discussion The results obtained by these trials will provide robust evidence regarding the cost-efficiency and diagnostic performance of the different stool-based diagnostic methods for the assessment of drug efficacy in control programs. The assessment of associations between the frequency of SNPs in the β-tubulin gene and the history of drug pressure and drug efficacy will allow the validation of these SNPs as a marker for AR in human STHs. Trial registration The trial was retrospectively registered the 7th of March 2018 on Clinicaltrials.gov (ID: NCT03465488). Soil-transmitted helminths (STHs) affect 1.4 billion people worldwide and cause significant morbidity when the intensity of infection is high. Currently, these infections are controlled in school-aged children by preventive chemotherapy with the benzimidazole drugs albendazole (ALB) or mebendazole (MEB). However, for the success of these control programs, it is essential to keep track of the efficacy of these drugs and to screen parasite populations for a possible rise of anthelmintic resistance (AR). In this light, a series of trials will be performed to assess the efficacy of ALB treatment against STH in four endemic countries with varying drug pressure. Both microscopic and molecular stool-based diagnostic methods will be used to evaluate drug efficacy. DNA samples will also be analysed for the presence and prevalence of mutations in a gene that was previously linked to AR in animal STHs. The results of these trials will provide evidence on the efficacy of ALB, help select the optimal diagnostic method to assess drug efficacy and provide information regarding the usefulness of genetic markers for AR detection in human STHs.
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Adnan M, Chy MNU, Rudra S, Tahamina A, Das R, Tanim MAH, Siddique TI, Hoque A, Tasnim SM, Paul A, Kamal ATMM. Evaluation of Bonamia semidigyna (Roxb.) for antioxidant, antibacterial, anthelmintic and cytotoxic properties with the involvement of polyphenols. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s13596-018-0334-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Moser W, Sayasone S, Xayavong S, Bounheuang B, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and tolerability of triple drug therapy with albendazole, pyrantel pamoate, and oxantel pamoate compared with albendazole plus oxantel pamoate, pyrantel pamoate plus oxantel pamoate, and mebendazole plus pyrantel pamoate and oxantel pamoate against hookworm infections in school-aged children in Laos: a randomised, single-blind trial. THE LANCET. INFECTIOUS DISEASES 2018; 18:729-737. [DOI: 10.1016/s1473-3099(18)30220-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/27/2018] [Accepted: 03/13/2018] [Indexed: 11/28/2022]
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Vijaya, Yadav AK, Gogoi S. In vitro and in vivo anthelmintic efficacy of two pentacyclic triterpenoids, ursolic acid and betulinic acid against mice pinworm, Syphacia obvelata. J Parasit Dis 2018; 42:144-149. [PMID: 29491574 PMCID: PMC5825362 DOI: 10.1007/s12639-017-0960-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/25/2017] [Indexed: 12/25/2022] Open
Abstract
Pinworm infections are one of the common problems in laboratory rodents and man. At present there are only few drugs against intestinal helminths, and new drugs are urgently needed to cope up any future risk of drug resistance. Interest in plant secondary metabolites (PSMs) has risen considerably in the recent years for the discovery and development of new drugs. In the present study, we explored the in vitro and in vivo anthelmintic potentials of two pentacyclic triterpenoids, ursolic acid (UA) and betulinic acid (BA), the important PSMs of many medicinal plants, against Syphacia obvelata (Nematoda: Oxyuridae), a common pinworm of mice. The results of this study indicated that in both, in vitro and in vivo assays, BA showed comparatively better anthelmintic effects than UA. In the in vitro assay, 1.00 mg/ml concentration of BA showed paralysis and mortality of worms in 1.20 ± 0.04 and 2.30 ± 0.03 h, respectively. In the in vivo assay, a single 10.00 mg/kg dose of BA, administered for 5 days, revealed 68.78% reduction in egg counts and 84.08% reduction in worm counts of infected mice. The present study suggests that BA holds a great promise to be pursued further for detailed testing against some other representative group of helminth parasites.
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Affiliation(s)
- Vijaya
- Department of Zoology, North-Eastern Hill University, Shillong, 793022 India
| | - Arun K. Yadav
- Department of Zoology, North-Eastern Hill University, Shillong, 793022 India
| | - S. Gogoi
- Department of Zoology, North-Eastern Hill University, Shillong, 793022 India
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Süssmuth RD, Mainz A. Nonribosomal Peptide Synthesis-Principles and Prospects. Angew Chem Int Ed Engl 2017; 56:3770-3821. [PMID: 28323366 DOI: 10.1002/anie.201609079] [Citation(s) in RCA: 536] [Impact Index Per Article: 76.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Indexed: 01/05/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) are large multienzyme machineries that assemble numerous peptides with large structural and functional diversity. These peptides include more than 20 marketed drugs, such as antibacterials (penicillin, vancomycin), antitumor compounds (bleomycin), and immunosuppressants (cyclosporine). Over the past few decades biochemical and structural biology studies have gained mechanistic insights into the highly complex assembly line of nonribosomal peptides. This Review provides state-of-the-art knowledge on the underlying mechanisms of NRPSs and the variety of their products along with detailed analysis of the challenges for future reprogrammed biosynthesis. Such a reprogramming of NRPSs would immediately spur chances to generate analogues of existing drugs or new compound libraries of otherwise nearly inaccessible compound structures.
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Affiliation(s)
- Roderich D Süssmuth
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623, Berlin, Germany
| | - Andi Mainz
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623, Berlin, Germany
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Süssmuth RD, Mainz A. Nicht-ribosomale Peptidsynthese - Prinzipien und Perspektiven. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201609079] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Roderich D. Süssmuth
- Technische Universität Berlin; Institut für Chemie; Straße des 17. Juni 124 10623 Berlin Deutschland
| | - Andi Mainz
- Technische Universität Berlin; Institut für Chemie; Straße des 17. Juni 124 10623 Berlin Deutschland
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In Vitro and In Vivo Drug Interaction Study of Two Lead Combinations, Oxantel Pamoate plus Albendazole and Albendazole plus Mebendazole, for the Treatment of Soil-Transmitted Helminthiasis. Antimicrob Agents Chemother 2016; 60:6127-33. [PMID: 27480864 DOI: 10.1128/aac.01217-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/25/2016] [Indexed: 11/20/2022] Open
Abstract
The current treatments against Trichuris trichiura, albendazole and mebendazole, are only poorly efficacious. Therefore, combination chemotherapy was recommended for treating soil-transmitted helminthiasis. Albendazole-mebendazole and albendazole-oxantel pamoate have shown promising results in clinical trials. However, in vitro and in vivo drug interaction studies should be performed before their simultaneous treatment can be recommended. Inhibition of human recombinant cytochromes P450 (CYPs) CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 was tested by exposure to albendazole, albendazole sulfoxide, mebendazole, and oxantel pamoate, as well as albendazole-mebendazole, albendazole sulfoxide-mebendazole, albendazole-oxantel pamoate, and albendazole sulfoxide-oxantel pamoate. A high-pressure liquid chromatography (HPLC)-UV/visible spectroscopy method was developed and validated for simultaneous quantification of albendazole sulfoxide, albendazole sulfone, mebendazole, and oxantel pamoate in plasma. Albendazole, mebendazole, oxantel pamoate, albendazole-mebendazole, and albendazole-oxantel pamoate were orally applied to rats (100 mg/kg) and pharmacokinetic parameters calculated. CYP1A2 showed a 2.6-fold increased inhibition by albendazole-oxantel pamoate (50% inhibitory concentration [IC50] = 3.1 μM) and a 3.9-fold increased inhibition by albendazole sulfoxide-mebendazole (IC50 = 3.8 μM) compared to the single drugs. In rats, mebendazole's area under the concentration-time curve (AUC) and maximal plasma concentration (Cmax) were augmented 3.5- and 2.8-fold, respectively (P = 0.02 for both) when coadministered with albendazole compared to mebendazole alone. Albendazole sulfone was slightly affected by albendazole-mebendazole, displaying a 1.3-fold-elevated AUC compared to albendazole alone. Oxantel pamoate could not be quantified, translating to a bioavailability below 0.025% in rats. Elevated plasma levels of albendazole sulfoxide, albendazole sulfone, and mebendazole in coadministrations are probably not mediated by CYP-based drug-drug interaction. Even though this study indicates that it is safe to coadminister albendazole-oxantel pamoate and albendazole-mebendazole, human pharmacokinetic studies are recommended.
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Diniz EMLP, Tomich de Paula da Silva CH, Gómez-Perez V, Federico LB, Campos Rosa JM. GRIND2-based 3D-QSAR and prediction of activity spectra for symmetrical bis-pyridinium salts with promastigote antileishmanial activity. J Biomol Struct Dyn 2016; 35:2430-2440. [DOI: 10.1080/07391102.2016.1221364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
| | | | - Verónica Gómez-Perez
- Facultad de Farmacia, Departamento de Química Farmacéutica y Orgánica, Universidad de Granada, c/ Campus de Cartuja s/n, Granada 18071, Spain
| | - Leonardo Bruno Federico
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Av. do Café S/N, CEP: 14040-903, Ribeirão Preto, SP, Brazil
- Facultad de Farmacia, Departamento de Química Farmacéutica y Orgánica, Universidad de Granada, c/ Campus de Cartuja s/n, Granada 18071, Spain
| | - Joaquín María Campos Rosa
- Facultad de Farmacia, Departamento de Química Farmacéutica y Orgánica, Universidad de Granada, c/ Campus de Cartuja s/n, Granada 18071, Spain
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Antiproliferative and Pro-Apoptotic Effect of Novel Nitro-Substituted Hydroxynaphthanilides on Human Cancer Cell Lines. Int J Mol Sci 2016; 17:ijms17081219. [PMID: 27483236 PMCID: PMC5000617 DOI: 10.3390/ijms17081219] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 12/14/2022] Open
Abstract
Ring-substituted hydroxynaphthanilides are considered as cyclic analogues of salicylanilides, compounds possessing a wide range of pharmacological activities, including promising anticancer properties. The aim of this study was to evaluate the potential anticancer effect of novel nitro-substituted hydroxynaphthanilides with a special focus on structure-activity relationships. The antiproliferative effect was assessed by Water Soluble Tetrazolium Salts-1 (WST-1) assay, and cytotoxicity was evaluated via dye exclusion test. Flow cytometry was used for cell cycle analysis and detection of apoptosis using Annexin V-FITC/PI assay. Protein expression was estimated by Western blotting. Our data indicate that the potential to cause the antiproliferative effect increases with the shift of the nitro substituent from the ortho- to the para-position. The most potent compounds, 3-hydroxy-N-(3-nitrophenyl)naphthalene-2-carboxamide (2), and 2-hydroxy-N-(4-nitrophenyl)-naphthalene-1-carboxamide (6) showed antiproliferative activity against THP-1 and MCF-7 cancer cells without affecting the proliferation of 3T3-L1 non-tumour cells. Compounds 2 and 6 induced the accumulation of THP-1 and MCF-7 cells in G1 phase associated with the downregulation of cyclin E1 protein levels, while the levels of cyclin B1 were not affected. Moreover, compound 2 was found to exert the pro-apoptotic effect on the THP-1 cells. These results suggest that hydroxynaphthanilides might represent a potential model structure for the development of novel anticancer agents.
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Vermeire JJ, Suzuki BM, Caffrey CR. Odanacatib, a Cathepsin K Cysteine Protease Inhibitor, Kills Hookworm In Vivo. Pharmaceuticals (Basel) 2016; 9:ph9030039. [PMID: 27384569 PMCID: PMC5039492 DOI: 10.3390/ph9030039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 11/30/2022] Open
Abstract
Hookworm infection is chief among soil-transmitted helminthiases (STHs) for the chronic morbidly inflicted. Deworming via mass drug administration (MDA) programs most often employs single doses of benzimidazole drugs to which resistance is a constant threat. To discover new drugs, we employ a hamster model of hookworm infection with Ancylostoma ceylanicum and use albendazole (ABZ; 10 mg/kg orally) as the gold standard therapy. We previously showed that a single oral 100 mg/kg dose of the cathepsin cysteine protease (CP) inhibitor, K11777, offers near cure of infection that is associated with a 95% reduction in the parasite’s resident CP activity. We confirm these findings here and demonstrate that odanacatib (ODN), Merck’s cathepsin K inhibitor and post-clinical Phase III drug candidate for treatment of osteoporosis, decreases worm burden by 73% at the same dose with a 51% reduction in the parasite’s CP activity. Unlike K11777, ODN is a modest inhibitor of both mammalian cathepsin B and the predominant cathepsin B-like activity measureable in hookworm extracts. ODN’s somewhat unexpected efficacy, therefore, may be due to its excellent pharmacokinetic (PK) profile which allows for sustained plasma exposure and, possibly, sufficient perturbation of hookworm cathepsin B activity to be detrimental to survival. Accordingly, identifying a CP inhibitor(s) that combines the inhibition potency of K11777 and the PK attributes of ODN could lead to a drug that is effective at a lower dose. Achieving this would potentially provide an alternative or back-up to the current anti-hookworm drug, albendazole.
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Affiliation(s)
- Jon J Vermeire
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, CA 94158, USA.
| | - Brian M Suzuki
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, CA 94158, USA.
| | - Conor R Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, CA 94158, USA.
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Analysis of the population-level impact of co-administering ivermectin with albendazole or mebendazole for the control and elimination of Trichuris trichiura. Parasite Epidemiol Control 2016; 1:177-187. [PMID: 27430028 PMCID: PMC4946157 DOI: 10.1016/j.parepi.2016.02.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 11/25/2022] Open
Abstract
Introduction Soil-transmitted helminth (STH) infections are predominately controlled by providing children with preventive chemotherapy with either albendazole or mebendazole. However, neither has a high efficacy against Trichuris trichiura. This low efficacy limits the overall effectiveness of the current STH control programmes against T. trichiura. It has been demonstrated that co-administering ivermectin with albendazole or mebendazole significantly increases the efficacy of current treatments, which may increase the overall effectiveness of control programmes. Methods Using a STH transmission mathematical model, we evaluated the potential impact of co-administering ivermectin with albendazole or mebendazole to treat T. trichiura within a preventive chemotherapy programme targeting children (2–15 year olds). We evaluated the impact in terms of reduction in prevalent infections, mean worm burden, and prevalence of heavy infections. Results Although the current treatment strategy reduced T. trichiura worm burden and prevalence of heavy infections, due to their poor efficacy the long term impact of preventive chemotherapy for children was smaller compared to the other STH. Co-administering ivermectin increased the projected impact of the preventive chemotherapy programme in terms of all three of the explored metrics, practically in high transmission settings. Furthermore, ivermectin co-administration greatly increased the feasibility of and timeframe for breaking transmission. Conclusions Co-administering ivermectin notably increased the projected impact of preventive chemotherapy in high transmission settings and increased the feasibility for breaking transmission. This has important implications for control programmes, some of which may be shifting focus from morbidity control to interruption of transmission, and some of which may be logistically unable to provide preventive chemotherapy twice a year as recommended. However, the benefit of co-administering ivermectin is limited by the fact that 2–5 year olds are often ineligible to receive treatment. The impact of chemotherapy against Trichuris is smaller compared to what can be seen for the other soil-transmitted helminths. Co-administering ivermectin increases the projected impact of preventive chemotherapy. It also has the potential to interrupt transmission in some settings.
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Key Words
- ALB, albendazole
- Control
- ERRs, egg reduction rates
- Elimination
- IVM, ivermectin
- Ivermectin co-administration
- MBZ, mebendazole
- Mass drug administration
- Pre-SAC, preschool-aged
- R0, basic reproductive number
- SAC, school-aged children
- STH, soil-transmitted helminth
- Soil-transmitted helminth
- Trichuris trichiura
- WASH, water, sanitation and hygiene
- WHO, World Health Organisation
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Kuesel AC. Research for new drugs for elimination of onchocerciasis in Africa. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2016; 6:272-286. [PMID: 27693536 PMCID: PMC5196484 DOI: 10.1016/j.ijpddr.2016.04.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 04/20/2016] [Indexed: 01/12/2023]
Abstract
Onchocerciasis is a parasitic, vector borne disease caused by the filarial nematode Onchocerca volvulus. More than 99% of the population at risk of infection live in Africa. Onchocerciasis control was initiated in West Africa in 1974 with vector control, later complemented by ivermectin mass drug administration and in the other African endemic countries in 1995 with annual community directed treatment with ivermectin (CDTI.) This has significantly reduced infection prevalence. Together with proof-of-concept for onchocerciasis elimination with annual CDTI from foci in Senegal and Mali, this has resulted in targeting onchocerciasis elimination in selected African countries by 2020 and in 80% of African countries by 2025. The challenges for meeting these targets include the number of endemic countries where conflict has delayed or interrupted control programmes, cross-border foci, potential emergence of parasite strains with low susceptibility to ivermectin and co-endemicity of loiasis, another parasitic vector borne disease, which slows down or prohibits CDTI implementation. Some of these challenges could be addressed with new drugs or drug combinations with a higher effect on Onchocerca volvulus than ivermectin. This paper reviews the path from discovery of new compounds to their qualification for large scale use and the support regulatory authorities provide for development of drugs for neglected tropical diseases. The status of research for new drugs or treatment regimens for onchocerciasis along the path to regulatory approval and qualification for large scale use is reviewed. This research includes new regimens and combinations of ivermectin and albendazole, antibiotics targeting the O. volvulus endosymbiont Wolbachia, flubendazole, moxidectin and emodepside and discovery of new compounds.
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Affiliation(s)
- Annette C Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, 20 Avenue Appia, 1211 Geneva, Switzerland.
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Ratnappan R, Vadnal J, Keaney M, Eleftherianos I, O'Halloran D, Hawdon JM. RNAi-mediated gene knockdown by microinjection in the model entomopathogenic nematode Heterorhabditis bacteriophora. Parasit Vectors 2016; 9:160. [PMID: 26993791 PMCID: PMC4797128 DOI: 10.1186/s13071-016-1442-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/10/2016] [Indexed: 12/21/2022] Open
Abstract
Background Parasitic nematodes threaten the health of humans and livestock and cause a major financial and socioeconomic burden to modern society. Given the widespread distribution of diseases caused by parasitic nematodes there is an urgent need to develop tools that will elucidate the genetic complexity of host-parasite interactions. Heterorhabditis bacteriophora is a parasitic nematode that allows simultaneous monitoring of nematode infection processes and host immune function, and offers potential as a tractable model for parasitic nematode infections. However, molecular tools to investigate these processes are required prior to its widespread acceptance as a robust model organism. In this paper we describe microinjection in adult H. bacteriophora as a suitable means of dsRNA delivery to knockdown gene transcripts. Methods RNA interference was used to knockdown four genes by injecting dsRNA directly into the gonad of adult hermaphrodite nematodes. RNAi phenotypes were scored in the F1 progeny on the fifth day post-injection, and knockdown of gene-specific transcripts was quantified with real-time quantitative RT-PCR (qRT-PCR). Results RNAi injection in adult hermaphrodites significantly decreased the level of target transcripts to varying degrees when compared with controls. The genes targeted by RNAi via injection included cct-2, nol-5, dpy-7, and dpy-13. In each case, RNAi knockdown was confirmed phenotypically by examining the progeny of injected animals, and also confirmed at the transcriptional level by real-time qRT-PCR. Conclusions Here we describe for the first time the successful use of microinjection to knockdown gene transcripts in H. bacteriophora. This technique can be used widely to study the molecular basis of parasitism.
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Affiliation(s)
- Ramesh Ratnappan
- Department of Microbiology Immunology and Tropical Medicine, George Washington University Medical Center, Washington, DC, 20037, USA
| | - Jonathan Vadnal
- Department of Microbiology Immunology and Tropical Medicine, George Washington University Medical Center, Washington, DC, 20037, USA
| | - Melissa Keaney
- Department of Microbiology Immunology and Tropical Medicine, George Washington University Medical Center, Washington, DC, 20037, USA
| | - Ioannis Eleftherianos
- Department of Biological Sciences, George Washington University, Science and Engineering Hall, suite 6000, 800 22nd Street NW, Washington, DC, 20052, USA
| | - Damien O'Halloran
- Department of Biological Sciences, George Washington University, Science and Engineering Hall, suite 6000, 800 22nd Street NW, Washington, DC, 20052, USA.,Institute for Neuroscience, George Washington University, 636 Ross Hall, 2300 I Street NW, Washington, DC, 20052, USA
| | - John M Hawdon
- Department of Microbiology Immunology and Tropical Medicine, George Washington University Medical Center, Washington, DC, 20037, USA.
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Hotez PJ, Pecoul B, Rijal S, Boehme C, Aksoy S, Malecela M, Tapia-Conyer R, Reeder JC. Eliminating the Neglected Tropical Diseases: Translational Science and New Technologies. PLoS Negl Trop Dis 2016; 10:e0003895. [PMID: 26934395 PMCID: PMC4774924 DOI: 10.1371/journal.pntd.0003895] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Today, the World Health Organization recognizes 17 major parasitic and related infections as the neglected tropical diseases (NTDs). Despite recent gains in the understanding of the nature and prevalence of NTDs, as well as successes in recent scaled-up preventive chemotherapy strategies and other health interventions, the NTDs continue to rank among the world’s greatest global health problems. For virtually all of the NTDs (including those slated for elimination under the auspices of a 2012 London Declaration for NTDs and a 2013 World Health Assembly resolution [WHA 66.12]), additional control mechanisms and tools are needed, including new NTD drugs, vaccines, diagnostics, and vector control agents and strategies. Elimination will not be possible without these new tools. Here we summarize some of the key challenges in translational science to develop and introduce these new technologies in order to ensure success in global NTD elimination efforts.
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Affiliation(s)
- Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Bernard Pecoul
- Drugs for Neglected Diseases Initiative (DNDi), Geneva, Switzerland
| | - Suman Rijal
- Drugs for Neglected Diseases Initiative (DNDi), Delhi, India
| | - Catharina Boehme
- Foundation for Innovative new Diagnostics (FIND), Geneva, Switzerland
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | | | | | - John C Reeder
- UNICEF/UNDP/ World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), Geneva, Switzerland
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Carreño A, Gacitúa M, Fuentes JA, Páez-Hernández D, Araneda C, Chávez I, Soto-Arriaza M, Manríquez JM, Polanco R, Mora GC, Otero C, Swords WB, Arratia-Pérez R. Theoretical and experimental characterization of a novel pyridine benzimidazole: suitability for fluorescence staining in cells and antimicrobial properties. NEW J CHEM 2016. [DOI: 10.1039/c5nj02772a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Imidazopyridine showed fluorescence properties suitable for imaging with both prokaryotic and eukaryotic cells.
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The Cyclooctadepsipeptide Anthelmintic Emodepside Differentially Modulates Nematode, Insect and Human Calcium-Activated Potassium (SLO) Channel Alpha Subunits. PLoS Negl Trop Dis 2015; 9:e0004062. [PMID: 26437177 PMCID: PMC4593646 DOI: 10.1371/journal.pntd.0004062] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/17/2015] [Indexed: 01/12/2023] Open
Abstract
The anthelmintic emodepside paralyses adult filarial worms, via a mode of action distinct from previous anthelmintics and has recently garnered interest as a new treatment for onchocerciasis. Whole organism data suggest its anthelmintic action is underpinned by a selective activation of the nematode isoform of an evolutionary conserved Ca2+-activated K+ channel, SLO-1. To test this at the molecular level we compared the actions of emodepside at heterologously expressed SLO-1 alpha subunit orthologues from nematode (Caenorhabditis elegans), Drosophila melanogaster and human using whole cell voltage clamp. Intriguingly we found that emodepside modulated nematode (Ce slo-1), insect (Drosophila, Dm slo) and human (hum kcnma1)SLO channels but that there are discrete differences in the features of the modulation that are consistent with its anthelmintic efficacy. Nematode SLO-1 currents required 100 μM intracellular Ca2+ and were strongly facilitated by emodepside (100 nM; +73.0 ± 17.4%; n = 9; p<0.001). Drosophila Slo currents on the other hand were activated by emodepside (10 μM) in the presence of 52 nM Ca2+ but were inhibited in the presence of 290 nM Ca2+ and exhibited a characteristic loss of rectification. Human Slo required 300nM Ca2+ and emodepside transiently facilitated currents (100nM; +33.5 ± 9%; n = 8; p<0.05) followed by a sustained inhibition (-52.6 ± 9.8%; n = 8; p<0.001). This first cross phyla comparison of the actions of emodepside at nematode, insect and human channels provides new mechanistic insight into the compound’s complex modulation of SLO channels. Consistent with whole organism behavioural studies on C. elegans, it indicates its anthelmintic action derives from a strong activation of SLO current, not observed in the human channel. These data provide an important benchmark for the wider deployment of emodepside as an anthelmintic treatment. Filarial diseases affect an estimated 200 million people and the Drugs for Neglected Diseases initiative (DNDi) has identified development of macrofilaricidal drugs as a priority. Emodepside, currently used in companion animals, paralyses adult filarial worms and may address this unmet need for human medicine. Its receptor is an evolutionary conserved Ca2+-activated K+ channel, SLO-1. In this paper we address an important knowledge gap in terms of understanding the interaction of emodepside with its target receptor SLO-1 in nematodes in comparison to the human orthologue KCNMA1 and provide the first cross phyla analysis of the interaction of emodepside with slo channels, in nematode, insect and human. Intriguingly, this shows that emodepside modulates slo/BK currents from heterologously expressed channels from all three organisms, however there are discrete differences in the feature of modulation; only the nematode channel exhibits a sustained facilitation by emodepside. This is consistent with the effects of emodepside on C. elegans behaviour and indicates that this differential action of emodepside on the nematode channel likely underlies its potent anthelmintic effects. These data provide an important benchmark for the wider deployment of emodepside as an anthelmintic treatment.
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Oxantel pamoate and deworming programmes. THE LANCET. INFECTIOUS DISEASES 2015; 16:5-6. [PMID: 26388170 DOI: 10.1016/s1473-3099(15)00305-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 08/25/2015] [Indexed: 11/22/2022]
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Jamkhande PG, Barde SR. Evaluation of anthelmintic activity and in silico PASS assisted prediction of Cordia dichotoma (Forst.) root extract. Anc Sci Life 2015; 34:39-43. [PMID: 25737609 PMCID: PMC4342648 DOI: 10.4103/0257-7941.150779] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Worm infection and associated complications are severe problems that afflict a large population worldwide. Failure of synthetic drugs in worm infections because of drug resistance has made alternative drug therapy desirable. Cordia dichotoma (Forst.) is an ethnomedicinal plant which is rich in several secondary metabolites. Traditionally, the plant has been claimed to have high medicinal properties including antimicrobial activity and cytotoxicity. Materials and Methods: The study begun with an aim to explore plant-based natural anthelmintic agents against Pheretima posthuma, an Indian earthworm. Methanol extract of the drug was obtained by successive soxhlet extraction. The extract was tested for different phytochemicals. Worms were exposed to 10 mg/ml, 25 mg/ml, 50 mg/ml, and 75 mg/ml concentrations of extract and standard drug, albendazole. A software-based tool, prediction of activity spectra for substances was used to estimate anthelmintic efficacy of plant metabolites. Result: The phytochemical analysis revealed presence of alkaloids, tannins, glycosides, saponins, flavonoids, and phenols. The extract showed dose-dependent effects, affecting worm motility, viability, and mortality. It was also found that the biological activity spectrum of the plant phytoconstituents such as octacosanol, lupeol, caffeic acid, and hentricontanol were >0.5 (probable activity > 0.5). Conclusion: The findings of the present work suggest that the extract of C. dichotoma significantly interferes with motility pattern of P. posthuma. The paralysis and mortality of P. posthuma might be due to the combined effects different phytoconstituents. The extract of C. dichotoma promises natural sources to control worm infection.
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Affiliation(s)
- Prasad G Jamkhande
- Department of Pharmacology, School of Pharmacy, Swami Ramanand Teerth Marathwada University, Nanded, Maharashtra, India
| | - Sonal R Barde
- Department of Pharmacology, School of Pharmacy, Swami Ramanand Teerth Marathwada University, Nanded, Maharashtra, India
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Levecke B, Montresor A, Albonico M, Ame SM, Behnke JM, Bethony JM, Noumedem CD, Engels D, Guillard B, Kotze AC, Krolewiecki AJ, McCarthy JS, Mekonnen Z, Periago MV, Sopheak H, Tchuem-Tchuenté LA, Duong TT, Huong NT, Zeynudin A, Vercruysse J. Assessment of anthelmintic efficacy of mebendazole in school children in six countries where soil-transmitted helminths are endemic. PLoS Negl Trop Dis 2014; 8:e3204. [PMID: 25299391 PMCID: PMC4191962 DOI: 10.1371/journal.pntd.0003204] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 08/20/2014] [Indexed: 12/26/2022] Open
Abstract
Background Robust reference values for fecal egg count reduction (FECR) rates of the most widely used anthelmintic drugs in preventive chemotherapy (PC) programs for controlling soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm) are still lacking. However, they are urgently needed to ensure detection of reduced efficacies that are predicted to occur due to growing drug pressure. Here, using a standardized methodology, we assessed the FECR rate of a single oral dose of mebendazole (MEB; 500 mg) against STHs in six trials in school children in different locations around the world. Our results are compared with those previously obtained for similarly conducted trials of a single oral dose of albendazole (ALB; 400 mg). Methodology The efficacy of MEB, as assessed by FECR, was determined in six trials involving 5,830 school children in Brazil, Cambodia, Cameroon, Ethiopia, United Republic of Tanzania, and Vietnam. The efficacy of MEB was compared to that of ALB as previously assessed in 8,841 school children in India and all the above-mentioned study sites, using identical methodologies. Principal Findings The estimated FECR rate [95% confidence interval] of MEB was highest for A. lumbricoides (97.6% [95.8; 99.5]), followed by hookworm (79.6% [71.0; 88.3]). For T. trichiura, the estimated FECR rate was 63.1% [51.6; 74.6]. Compared to MEB, ALB was significantly more efficacious against hookworm (96.2% [91.1; 100], p<0.001) and only marginally, although significantly, better against A. lumbricoides infections (99.9% [99.0; 100], p = 0.012), but equally efficacious for T. trichiura infections (64.5% [44.4; 84.7], p = 0.906). Conclusions/Significance A minimum FECR rate of 95% for A. lumbricoides, 70% for hookworm, and 50% for T. trichiura is expected in MEB-dependent PC programs. Lower FECR results may indicate the development of potential drug resistance. Soil-transmitted helminths (STHs; roundworms, whipworms, and hookworms) infect millions of children in sub-tropical and tropical countries, resulting in malnutrition, growth stunting, intellectual retardation, and cognitive deficits. To fight against STH, large-scale deworming programs are implemented in which anthelmintic drugs (either albendazole (ALB) or mebendazole (MEB)) are administered. Currently, these large-scale programs are intensifying, highlighting the need to closely monitor the efficacy of anthelmintic drugs to detect changes in drug efficacy that may arise through the evolution of anthelmintic drug resistance in the parasites. We have previously defined the minimum expected efficacy of ALB based on the fecal egg count reduction (FECR) rate, but these reference values are lacking for MEB. Therefore, we therefore evaluated the FECR rate of MEB against STHs in six STH endemic countries. In addition, we compared the results of the FECR rate for MEB with those we obtained previously for ALB. The results confirm that MEB treatment was highly efficacious against roundworms, and to a lesser extend against hookworms, but not against whipworms. Compared to ALB, MEB is less efficacious against hookworm, but equally efficacious against roundworms and whipworms. Based on this study we propose the minimum expected FECR rate for MEB-dependent large-scale deworming programs.
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Affiliation(s)
- Bruno Levecke
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
- * E-mail:
| | - Antonio Montresor
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | | | - Shaali M. Ame
- Public Health Laboratory-Ivo de Carneri, Chake Chake, United Republic of Tanzania
| | - Jerzy M. Behnke
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jeffrey M. Bethony
- Microbiology, Immunology, and Tropical Medicine, George Washington University Medical Center, Washington, D.C., United States of America
| | - Calvine D. Noumedem
- Centre for Schistosomiasis and Parasitology, University of Yaoundé I, Yaoundé, Cameroon
| | - Dirk Engels
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | | | - Andrew C. Kotze
- Division of Animal, Food and Health Sciences, Commonwealth Scientific and Industrial Research Organisation, St. Lucia, Australia
| | - Alejandro J. Krolewiecki
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta/CONICET, Oran, Argentina
| | - James S. McCarthy
- Queensland Institute for Medical Research, University of Queensland, Brisbane, Australia
| | - Zeleke Mekonnen
- Department of Medical Laboratory Sciences and Pathology, Jimma University, Jimma, Ethiopia
| | - Maria V. Periago
- Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Hem Sopheak
- Clinical Laboratory, Pasteur Institute, Phnom Penh, Cambodia
| | | | - Tran Thanh Duong
- Department of Parasitology, National Institute of Malariology, Parasitology and Entomology, Ha Noi, Vietnam
| | - Nguyen Thu Huong
- Department of Parasitology, National Institute of Malariology, Parasitology and Entomology, Ha Noi, Vietnam
| | - Ahmed Zeynudin
- Department of Medical Laboratory Sciences and Pathology, Jimma University, Jimma, Ethiopia
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Ghent University, Merelbeke, Belgium
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Abstract
Monepantel (MOP), a new anthelmintic drug from a group of amino-acetonitrile derivatives, has been intensively studied during last years. Many authors examined this new drug from different perspectives, e.g. efficacy against different species and stages of parasites, mode of action, metabolism, pharmacokinetics, toxicity, resistance, ecotoxicity, etc. MOP is an anthelmintic for livestock (currently only sheep and goats), with molecular mode of action which is different to all other anthelmintics. MOP has a broad-spectrum of activity against gastrointestinal nematodes of sheep, including adults and L4 larvae of the most important species. The key feature of MOP is its full effectiveness against strains of nematodes resistant to benzimidazoles, levamisole, macrocyclic lactones and closantel. After oral administration, MOP is quickly absorbed into the bloodstream and quickly metabolized to MOP sulfone that has a similar efficacy as the parent molecule. Several other MOP metabolites formed in ovine hepatocytes were described. MOP and its metabolites are considered to be non-toxic to environment and its components, such as soil microflora, aquatic organisms, dung organisms, vegetation, etc. The aim of the presented review was not to collect all reported data but to bring an overview of various approaches in the study of MOP and to evaluate their principal results.
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Panic G, Duthaler U, Speich B, Keiser J. Repurposing drugs for the treatment and control of helminth infections. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2014; 4:185-200. [PMID: 25516827 PMCID: PMC4266803 DOI: 10.1016/j.ijpddr.2014.07.002] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/04/2014] [Accepted: 07/13/2014] [Indexed: 01/01/2023]
Abstract
Drug repurposing continues to be the central drug discovery strategy for helminths. Most repurposed drugs come from veterinary medicine and known drug classes. Only a handful of drugs have advanced clinically. More collaborations and funding are needed to advance discoveries to the market.
Helminth infections are responsible for a considerable public health burden, yet the current drug armamentarium is small. Given the high cost of drug discovery and development, the high failure rates and the long duration to develop novel treatments, drug repurposing circumvents these obstacles by finding new uses for compounds other than those they were initially intended to treat. In the present review, we summarize in vivo and clinical trial findings testing clinical candidates and marketed drugs against schistosomes, food-borne trematodes, soil-transmitted helminths, Strongyloides stercoralis, the major human filariases lymphatic filariasis and onchocerciasis, taeniasis, neurocysticercosis and echinococcosis. While expanding the applications of broad-spectrum or veterinary anthelmintics continues to fuel alternative treatment options, antimalarials, antibiotics, antiprotozoals and anticancer agents appear to be producing fruitful results as well. The trematodes and nematodes continue to be most investigated, while cestodal drug discovery will need to be accelerated. The most clinically advanced drug candidates include the artemisinins and mefloquine against schistosomiasis, tribendimidine against liver flukes, oxantel pamoate against trichuriasis, and doxycycline against filariasis. Preclinical studies indicate a handful of promising future candidates, and are beginning to elucidate the broad-spectrum activity of some currently used anthelmintics. Challenges and opportunities are further discussed.
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Affiliation(s)
| | | | | | - Jennifer Keiser
- Corresponding author. Address: Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland. Tel.: +41 61 284 8218; fax: +41 61 284 8105.
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Levecke B, Buttle DJ, Behnke JM, Duce IR, Vercruysse J. Cysteine proteinases from papaya (Carica papaya) in the treatment of experimental Trichuris suis infection in pigs: two randomized controlled trials. Parasit Vectors 2014; 7:255. [PMID: 24886388 PMCID: PMC4049439 DOI: 10.1186/1756-3305-7-255] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/20/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cysteine proteinases (CPs) from papaya (Carica papaya) possess anthelmintic properties against human soil-transmitted helminths (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm), but there is a lack of supportive and up-to-date efficacy data. We therefore conducted two randomized controlled trials in pigs to assess the efficacy of papaya CPs against experimental infections with T. suis. METHODS First, we assessed efficacy by means of egg (ERR) and adult worm reduction rate (WRR) of a single-oral dose of 450 μmol active CPs (CP450) against low (inoculum of 300 eggs) and high (inoculum of 3,000 eggs) intensity T. suis infections and compared the efficacy with those obtained after a single-oral dose of 400 mg albendazole (ALB). In the second trial, we determined and compared the efficacy of a series of CP doses (45 [CP45], 115 [CP115], 225 [CP225], and 450 [CP450] μmol) against high intensity infections. RESULTS CP450 was highly efficacious against both levels of infection intensity, resulting in ERR and WRR of more than 97%. For both levels of infection intensity, CP450 was significantly more efficacious compared to ALB by means of WRR (low infection intensity: 99.0% vs. 39.0%; high infection intensity; 97.4% vs. 23.2%). When the efficacy was assessed by ERR, a significant difference was only observed for high intensity infections, CP450 being more efficacious than ALB (98.9% vs. 59.0%). For low infection intensities, there was no significant difference in ERR between CP450 (98.3%) and ALB (64.4%). The efficacy of CPs increased as a function of increasing dose. When determined by ERR, the efficacy ranged from 2.1% for CP45 to 99.2% for CP450. For WRR the results varied from -14.0% to 99.0%, respectively. Pairwise comparison revealed a significant difference in ERR and WRR only between CP45 and CP450, the latter being more efficacious. CONCLUSIONS A single dose of 450 μmol CPs provided greater efficacy against T. suis infections in pigs than a single-oral dose of 400 mg ALB. Although these results highlight the possibility of papaya CPs for controlling human STH, further development is needed in order to obtain and validate an oral formulation for human application.
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Affiliation(s)
- Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium.
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Kulke D, Krücken J, Harder A, von Samson-Himmelstjerna G. Efficacy of cyclooctadepsipeptides and aminophenylamidines against larval, immature and mature adult stages of a parasitologically characterized trichurosis model in mice. PLoS Negl Trop Dis 2014; 8:e2698. [PMID: 24587460 PMCID: PMC3930511 DOI: 10.1371/journal.pntd.0002698] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 01/02/2014] [Indexed: 01/17/2023] Open
Abstract
Background The genus Trichuris includes parasites of major relevance in veterinary and human medicine. Despite serious economic losses and enormous impact on public health, treatment options against whipworms are very limited. Additionally, there is an obvious lack of appropriately characterized experimental infection models. Therefore, a detailed parasitological characterization of a Trichuris muris isolate was performed in C57BL/10 mice. Subsequently, the in vivo efficacies of the aminophenylamidines amidantel, deacylated amidantel (dAMD) and tribendimidine as well as the cyclooctadepsipeptides emodepside and in particular PF1022A were analyzed. This was performed using various administration routes and treatment schemes targeting histotropic and further developed larval as well as immature and mature adult stages. Methodology/Principal Findings Duration of prepatent period, time-dependent localization of larvae during period of prepatency as well as the duration of patency of the infection were determined before drugs were tested in the characterized trichurosis model. Amidantel showed no effect against mature adult T. muris. Tribendimidine showed significantly higher potency than dAMD after oral treatments (ED50 values of 6.5 vs. 15.1 mg/kg). However, the opposite was found for intraperitoneal treatments (ED50 values of 15.3 vs. 8.3 mg/kg). When emodepside and PF1022A were compared, the latter was significantly less effective against mature adults following intraperitoneal (ED50 values of 6.1 vs. 55.7 mg/kg) or subcutaneous (ED50 values of 15.2 vs. 225.7 mg/kg) administration. Only minimal differences were observed following oral administration (ED50 values of 2.7 vs. 5.2 mg/kg). Triple and most single oral doses with moderate to high dosages of PF1022A showed complete efficacy against histotropic second stage larvae (3×100 mg/kg or 1×250 mg/kg), further developed larvae (3×10 mg/kg or 1×100 mg/kg) and immature adults (3×10 mg/kg or 1×100 mg/kg). Histotropic first stage larvae were only eliminated after three doses of PF1022A (3×100 mg/kg) but not after a single dose. Conclusions/Significance These results indicate that the cyclooctadepsipeptides are a drug class with promising candidates for further evaluation for the treatment of trichurosis of humans and livestock animals in single dose regimens. Treatment options against whipworm infections of humans and livestock are very limited and even anthelmintics recently introduced into the market do not significantly improve the situation. Here, we evaluated members of two relatively new drug classes, the aminophenylamidines (amidantel, deacylated amidantel, tribendimidine) and the cyclooctadepsipeptides (PF1022A, emodepside) in a murine trichurosis model. While tribendimidine is licensed for the treatment of human helminthosis caused by hookworms, pinworms and roundworms in China, emodepside is the nematocidal component of dewormers for cats and dogs. With the exception of amidantel, all drugs showed good efficacies against adult whipworms using three consecutive doses. Due to considerations regarding drug safety and price, PF1022A was further evaluated against histotropic first and second stage larvae, further developed larvae, immature and mature adults using a single or three consecutive doses. Three doses eliminated all stages while a single dose was inefficient against histotropic first stage larvae. In general, higher doses were required for early stages in comparison to stages protruding into the gut lumen. Since only a very basic formulation of drugs was tested, further improvement can be expected from optimized formulations. Cyclooctadepsipeptides should therefore be considered as candidates for evaluation to treat Trichuris spp. infections in livestock and humans.
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Affiliation(s)
- Daniel Kulke
- Institute of Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- Global Drug Discovery – Animal Health – Parasiticides, Bayer HealthCare, Leverkusen, Germany
| | - Jürgen Krücken
- Institute of Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
| | - Achim Harder
- WE Biology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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Rojo-Arreola L, Long T, Asarnow D, Suzuki BM, Singh R, Caffrey CR. Chemical and genetic validation of the statin drug target to treat the helminth disease, schistosomiasis. PLoS One 2014; 9:e87594. [PMID: 24489942 PMCID: PMC3906178 DOI: 10.1371/journal.pone.0087594] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 12/21/2013] [Indexed: 12/26/2022] Open
Abstract
The mevalonate pathway is essential in eukaryotes and responsible for a diversity of fundamental synthetic activities. 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the rate-limiting enzyme in the pathway and is targeted by the ubiquitous statin drugs to treat hypercholesterolemia. Independent reports have indicated the cidal effects of statins against the flatworm parasite, S. mansoni, and the possibility that SmHMGR is a useful drug target to develop new statin-based anti-schistosome therapies. For six commercially available statins, we demonstrate concentration- and time-dependent killing of immature (somule) and adult S. mansoni in vitro at sub-micromolar and micromolar concentrations, respectively. Cidal activity trends with statin lipophilicity whereby simvastatin and pravastatin are the most and least active, respectively. Worm death is preventable by excess mevalonate, the product of HMGR. Statin activity against somules was quantified both manually and automatically using a new, machine learning-based automated algorithm with congruent results. In addition, to chemical targeting, RNA interference (RNAi) of HMGR also kills somules in vitro and, again, lethality is blocked by excess mevalonate. Further, RNAi of HMGR of somules in vitro subsequently limits parasite survival in a mouse model of infection by up to 80%. Parasite death, either via statins or specific RNAi of HMGR, is associated with activation of apoptotic caspase activity. Together, our genetic and chemical data confirm that S. mansoni HMGR is an essential gene and the relevant target of statin drugs. We discuss our findings in context of a potential drug development program and the desired product profile for a new schistosomiasis drug.
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Affiliation(s)
- Liliana Rojo-Arreola
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Thavy Long
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Dan Asarnow
- Department of Computer Science, San Francisco State University, San Francisco, California, United States of America
| | - Brian M. Suzuki
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Rahul Singh
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
- Department of Computer Science, San Francisco State University, San Francisco, California, United States of America
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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Abstract
PURPOSE OF REVIEW To highlight the gastrointestinal helminths in the context of renewed global commitment to control or eliminate neglected tropical diseases in the coming decade. RECENT FINDINGS Two key documents, namely the 2012 London Declaration for Neglected Tropical Diseases and the 2013 World Health Assembly resolution, emphasize the importance of mass drug administration (MDA) for controlling several key neglected tropical diseases. These documents, together with the Global Burden of Disease Study 2010, establish the major gastrointestinal helminth infections, including the soil-transmitted helminthiases - ascariasis, trichuriasis, hookworm, and strongyloidiasis - in addition to the intestinal and liver fluke infections, as some of the most important gastrointestinal infections of humankind. Current MDA approaches using single-dose albendazole or mebendazole are effective for ascariasis, less so for other soil-transmitted helminth infections. Expanded use of albendazole in combination with ivermectin would ensure improved drug efficacies against trichuriasis and strongyloidiasis. There is no effective elimination strategy for targeting hookworm and liver and intestinal fluke infections through current MDA approaches. SUMMARY The global community must expand current MDA efforts, while simultaneously developing additional drugs, diagnostics, and vaccines alongside better utilizing transmission dynamics and modeling, if it is to successfully meet the goals and targets established by policymakers.
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In vivo efficacy of PF1022A and nicotinic acetylcholine receptor agonists alone and in combination against Nippostrongylus brasiliensis. Parasitology 2013; 140:1252-65. [PMID: 23742764 DOI: 10.1017/s0031182013000632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The cyclooctadepsipeptide PF1022A and the aminophenylamidines amidantel, deacylated amidantel (dAMD) and tribendimidine were tested as examples for drug classes potentially interesting for development as anthelmintics against human helminthiases. These compounds and levamisole were tested alone and in combination to determine their efficacy against the rat hookworm Nippostrongylus brasiliensis. After three oral treatments, intestinal worms were counted. Drug effects on parasite morphology were studied using scanning electron microscopy (SEM). Plasma pharmacokinetics were determined for tribendimidine and dAMD. All drugs reduced worm burden in a dose-dependent manner, however amidantel was significantly less active than the other aminophenylamidines. Combinations of tribendimidine and dAMD with levamisole or PF1022A at suboptimal doses revealed additive effects. While PF1022A caused virtually no changes in morphology, levamisole, dAMD and tribendimidine caused severe contraction, particularly in the hind body region. Worms exposed to combinations of PF1022A and aminophenylamidines were indistinguishable from worms exposed only to aminophenylamidines. After oral treatment with tribendimidine, only the active metabolite dAMD was detectable in plasma and concentrations were not significantly different for oral treatment with dAMD. The results support further evaluation of cyclooctadepsipeptides alone and in combination with cholinergic drugs to improve efficacy. Combining these with registered drugs may help to prevent development of resistance.
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Xiao SH, Utzinger J, Tanner M, Keiser J, Xue J. Advances with the Chinese anthelminthic drug tribendimidine in clinical trials and laboratory investigations. Acta Trop 2013; 126:115-26. [PMID: 23352956 DOI: 10.1016/j.actatropica.2013.01.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 01/08/2013] [Accepted: 01/11/2013] [Indexed: 12/16/2022]
Abstract
The anthelminthic drug tribendimidine has been approved by Chinese authorities for human use in 2004, and a first comprehensive review was published in Acta Tropica in 2005. Here, we summarise further advances made through additional clinical trials and laboratory investigations. Two phase IV trials have been conducted in the People's Republic of China, the first one enrolling 1292 adolescents and adults aged 15-70 years and the second one conducted with 899 children aged 4-14 years who were infected with one or multiple species of soil-transmitted helminths. Oral tribendimidine (single 400mg enteric-coated tablet given to adolescents/adults and 200mg to children) showed high cure rates against Ascaris lumbricoides (90.1-95.0%) and moderate-to-high cure rates against hookworm (82.0-88.4%). Another trial done in school-aged children using a rigorous diagnostic approach found a cure rate against hookworm of 76.5%. A single oral dose of tribendimidine showed only low cure rates against Trichuris trichiura (23.9-36.8%) confirming previous results. Tribendimidine administered to children infected with Enterobius vermicularis (two doses of 200mg each on consecutive days) resulted in a high cure rate (97.1%). Importantly, a series of randomised, exploratory trials revealed that tribendimidine shows interesting activity against the liver flukes Opisthorchis viverrini and Clonorchis sinensis, the tapeworm Taenia spp. and the threadworm Strongyloides stercoralis with respective cure rates of 70.0%, 40.0%, 53.3% and 36.4%. Pharmacokinetic studies in healthy Chinese volunteers indicated that after oral administration of tribendimidine, no parent drug was detected in plasma, but its primary metabolite, p-(1-dimethylamino ethylimino) aniline (aminoamidine, deacylated amidantel) (dADT), was found in plasma. dADT is then further metabolised to acetylated dADT (AdADT). dADT exhibits activity against several species of hookworm and C. sinensis in experimental studies, similar to that of tribendimidine. First studies elucidating the mechanism of action suggested that tribendimidine is an L-type nicotinic acetylcholine receptor agonist. Additional experimental studies revealed that the anti-parasite spectrum of tribendimidine is very broad. Indeed, to date, activity has been documented against 20 different nematode, trematode and cestode species. Taken together, tribendimidine warrants further scientific inquiry, including more comprehensive toxicity appraisals, mechanism of action studies and clinical investigation as it holds promise as a broad spectrum anthelminthics.
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Keiser J, Tritten L, Silbereisen A, Speich B, Adelfio R, Vargas M. Activity of oxantel pamoate monotherapy and combination chemotherapy against Trichuris muris and hookworms: revival of an old drug. PLoS Negl Trop Dis 2013; 7:e2119. [PMID: 23556013 PMCID: PMC3605275 DOI: 10.1371/journal.pntd.0002119] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 02/01/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND It is widely recognized that only a handful of drugs are available against soil-transmitted helminthiasis, all of which are characterized by a low efficacy against Trichuris trichiura, when administered as single doses. The re-evaluation of old, forgotten drugs is a promising strategy to identify alternative anthelminthic drug candidates or drug combinations. METHODOLOGY We studied the activity of the veterinary drug oxantel pamoate against Trichuris muris, Ancylostoma ceylanicum and Necator americanus in vitro and in vivo. In addition, the dose-effect of oxantel pamoate combined with albendazole, mebendazole, levamisole, pyrantel pamoate and ivermectin was studied against T. muris in vitro and additive or synergistic combinations were followed up in vivo. PRINCIPAL FINDINGS We calculated an ED50 of 4.7 mg/kg for oxantel pamoate against T. muris in mice. Combinations of oxantel pamoate with pyrantel pamoate behaved antagonistically in vitro (combination index (CI) = 2.53). Oxantel pamoate combined with levamisole, albendazole or ivermectin using ratios based on their ED50s revealed antagonistic effects in vivo (CI = 1.27, 1.90 and 1.27, respectively). A highly synergistic effect (CI = 0.15) was observed when oxantel pamoate-mebendazole was administered to T. muris-infected mice. Oxantel pamoate (10 mg/kg) lacked activity against Ancylostoma ceylanicum and Necator americanus in vivo. CONCLUSION/SIGNIFICANCE Our study confirms the excellent trichuricidal properties of oxantel pamoate. Since the drug lacks activity against hookworms it is necessary to combine oxantel pamoate with a partner drug with anti-hookworm properties. Synergistic effects were observed for oxantel pamoate-mebendazole, hence this combination should be studied in more detail. Since, of the standard drugs, albendazole has the highest efficacy against hookworms, additional investigations on the combination effect of oxantel pamoate-albendazole should be launched.
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Affiliation(s)
- Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
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