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McTier TL, Kryda K, Wachowski M, Mahabir S, Ramsey D, Rugg D, Mazaleski M, Therrien C, Adams E, Wolff T, Bowman DD. ProHeart® 12, a moxidectin extended-release injectable formulation for prevention of heartworm (Dirofilaria immitis) disease in dogs in the USA for 12 months. Parasit Vectors 2019; 12:369. [PMID: 31349867 PMCID: PMC6660952 DOI: 10.1186/s13071-019-3632-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/20/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The efficacy of an extended-release injectable moxidectin (0.5 mg/kg) suspension (ProHeart® 12) (PH 12) in preventing the development of Dirofilaria immitis in dogs for 12 months was investigated in laboratory and field studies in the USA. METHODS In each of two laboratory studies, 20 dogs ≥ 12 months of age were randomly allocated to receive a subcutaneous injection of saline or PH 12 on Day 0 and were then inoculated with 50 D. immitis third-stage larvae (L3) on Day 365. All dogs were necropsied ~ 5 months post-inoculation for adult worm counts. The field efficacy study included dogs ≥ 10 months of age from 19 veterinary clinics in the USA treated with either 20 monthly doses of Heartgard® Plus (HG Plus) (296 dogs) or two doses of PH 12 (297 dogs) on Days 0 and 365. Efficacy was determined on Days 365, 480 and 605 using adult HW antigen and microfilaria testing to assess adult HW infection. RESULTS PH 12 was 100% effective in preventing HW disease in all three of these studies. In the laboratory studies, no PH 12-treated dogs had any adult HWs, whereas all control dogs in both studies had adult HWs [geometric mean, 30.2 (range, 22-37) for Study 1 and 32.6 (22-44) for Study 2]. In the field study, all dogs treated with PH 12 tested negative for adult HW infection on all test days (Days, 365, 480 and 605), whereas four dogs receiving HG Plus (positive control) tested positive for HWs during the study (three dogs on Day 365 and one dog on Day 480). All four dogs treated with HG Plus that subsequently tested positive for HWs during the field study were from the lower Mississippi River Valley region, where HW resistance to macrocyclic lactone preventives has been confirmed to occur. PH 12 was significantly better than HG Plus in preventing heartworm disease in the field study (P = 0.0367). PH 12 was well-tolerated in both laboratory and field studies. CONCLUSIONS A single dose of ProHeart® 12 was 100% effective in preventing heartworm disease in dogs for a full year in both laboratory and field studies.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Eric Adams
- Northern Biomedical Research, Spring Lake, MI USA
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Njume FN, Ghogomu SM, Shey RA, Gainkam LOT, Poelvoorde P, Humblet P, Kamgno J, Robert A, Mutesa L, Lelubre C, Edelweiss E, Poterszman A, Anheuser S, Vanhamme L, Souopgui J. Identification and characterization of the Onchocerca volvulus Excretory Secretory Product Ov28CRP, a putative GM2 activator protein. PLoS Negl Trop Dis 2019; 13:e0007591. [PMID: 31329585 PMCID: PMC6675134 DOI: 10.1371/journal.pntd.0007591] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 08/01/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022] Open
Abstract
Onchocerca volvulus is the nematode pathogen responsible for human onchocerciasis also known as "River blindness", a neglected tropical disease that affects up to 18 million people worldwide. Helminths Excretory Secretory Products (ESPs) constitute a rich repertoire of molecules that can be exploited for host-parasite relationship, diagnosis and vaccine studies. Here, we report, using a range of molecular techniques including PCR, western blot, recombinant DNA technology, ELISA, high performance thin-layer chromatography and mass spectrometry that the 28 KDa cysteine-rich protein (Ov28CRP) is a reliable component of the O. volvulus ESPs to address the biology of this parasite. We showed that (1) Ov28CRP is a putative ganglioside GM2 Activator Protein (GM2AP) conserved in nematode; (2) OvGM2AP gene is transcriptionally activated in all investigated stages of the parasitic life cycle, including larval and adult stages; (3) The full-length OvGM2AP was detected in in-vitro O. volvulus ESPs of adult and larval stages; (4) the mass expressed and purified recombinant OvGM2AP purified from insect cell culture medium was found to be glycosylated at asparagine 173 and lacked N-terminal signal peptide sequence; (5) the recombinant OvGM2AP discriminated serum samples of infected and uninfected individuals; (6) OvGM2AP competitively inhibits MUG degradation by recombinant β-hexosaminidase A but not MUGS, and could not hydrolyze the GM2 to GM3; (7) humoral immune responses to the recombinant OvGM2AP revealed a negative correlation with ivermectin treatment. Altogether, our findings suggest for the first time that OvGM2AP is an antigenic molecule whose biochemical and immunological features are important to gain more insight into our understanding of host-parasite relationship, as well as its function in parasite development at large.
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Affiliation(s)
- Ferdinand Ngale Njume
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Stephen Mbigha Ghogomu
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Robert Adamu Shey
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
- Molecular and Cell Biology Laboratory, Biotechnology Unit, University of Buea, Buea, Cameroon
| | - Lea Olive Tchouate Gainkam
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Philippe Poelvoorde
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Perrine Humblet
- École de santé publique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Joseph Kamgno
- Department of Epidemiology, Centre for research on filariasis and other tropical diseases, Yaounde, Cameroon
| | - Annie Robert
- Faculté de santé publique, Institut de recherche expérimentale et clinique, Pôle d'épidémiologie et biostatistique, Université Catholique de Louvain, Clos Chapelle-aux-champs, Woluwe-Saint-Lambert, Belgium
| | - Leon Mutesa
- Center for Human Genetics, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Christophe Lelubre
- Laboratoire de Médecine Expérimentale, Université Libre de Bruxelles (ULB)—Unité 222, CHU Charleroi (Hôpital André Vésale), Rue de Gozée, Montigny-Le-Tilleul, Belgium
| | - Evelina Edelweiss
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Arnaud Poterszman
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale, UMR7104, Illkirch, France
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, UMR7104, Illkirch, France
| | - Susi Anheuser
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany
| | - Luc Vanhamme
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jacob Souopgui
- Department of Molecular Biology, Institute of Biology and Molecular Medicine, IBMM, Université Libre de Bruxelles, Gosselies, Belgium
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Prichard RK, Geary TG. Perspectives on the utility of moxidectin for the control of parasitic nematodes in the face of developing anthelmintic resistance. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 10:69-83. [PMID: 31229910 PMCID: PMC6593148 DOI: 10.1016/j.ijpddr.2019.06.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 06/12/2019] [Accepted: 06/12/2019] [Indexed: 12/22/2022]
Abstract
Macrocyclic lactone (ML) anthelmintics are the most important class of anthelmintics because of our high dependence on them for the control of nematode parasites and some ectoparasites in livestock, companion animals and in humans. However, resistance to MLs is of increasing concern. Resistance is commonplace throughout the world in nematode parasites of small ruminants and is of increasing concern in horses, cattle, dogs and other animals. It is suspected in Onchocerca volvulus in humans. In most animals, resistance first arose to the avermectins, such as ivermectin (IVM), and subsequently to moxidectin (MOX). Usually when parasite populations are ML-resistant, MOX is more effective than avermectins. MOX may have higher intrinsic potency against some parasites, especially filarial nematodes, than the avermectins. However, it clearly has a significantly different pharmacokinetic profile. It is highly distributed to lipid tissues, less likely to be removed by ABC efflux transporters, is poorly metabolized and has a long half-life. This results in effective concentrations persisting for longer in target hosts. It also has a high safety index. Limited data suggest that anthelmintic resistance may be overcome, at least temporarily, if a high concentration can be maintained at the site of the parasites for a prolonged period of time. Because of the properties of MOX, there are reasonable prospects that strains of parasites that are resistant to avermectins at currently recommended doses will be controlled by MOX if it can be administered at sufficiently high doses and in formulations that enhance its persistence in the host. This review examines the properties of MOX that support this contention and compares them with the properties of other MLs. The case for using MOX to better control ML-resistant parasites is summarised and some outstanding research questions are presented.
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Affiliation(s)
- Roger K Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada, H9X3V9.
| | - Timothy G Geary
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada, H9X3V9.
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104
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The current status of anthelmintic resistance in a temperate region of Australia; implications for small ruminant farm management. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2019; 17:100313. [PMID: 31303219 DOI: 10.1016/j.vprsr.2019.100313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 05/31/2019] [Accepted: 06/08/2019] [Indexed: 12/18/2022]
Abstract
Widespread anthelmintic resistance in small ruminants is a constraint on the profitability of the meat/wool industry. Limited published data is available on the prevalence and efficacy of anthelmintics, particularly in Australia where parasites affecting ruminant systems vary greatly between geographic regions. This paper reports on the anthelmintic resistance status in a temperate region of Victoria, Australia, a major sheep producing state largely affected by Trichostrongylus species and Teladorsagia circumcincta. The prevalence of anthelmintic resistance to any product was high (71%), with farms reporting varying levels of drug efficacies (21-100%). Resistance to older chemical groups (i.e. fenbendazole and levamisole) and single active macrocyclic lactone treatments was higher than newer chemical groups and combination treatments. This report provides clarity on anthelmintic resistance in the temperate region of Victoria and more importantly suggests that more comprehensive, regional specific anthelmintic resistance studies are required to understand the real level of chemical resistance threatening the effective control of worms.
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105
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Virkel G, Ballent M, Lanusse C, Lifschitz A. Role of ABC Transporters in Veterinary Medicine: Pharmaco- Toxicological Implications. Curr Med Chem 2019; 26:1251-1269. [DOI: 10.2174/0929867325666180201094730] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/14/2017] [Accepted: 12/22/2017] [Indexed: 01/10/2023]
Abstract
Unlike physicians, veterinary practitioners must deal with a number of animal species with crucial differences in anatomy, physiology and metabolism. Accordingly, the pharmacokinetic behaviour, the clinical efficacy and the adverse or toxic effects of drugs may differ across domestic animals. Moreover, the use of drugs in food-producing species may impose a risk for humans due to the generation of chemical residues in edible products, a major concern for public health and consumer's safety. As is clearly known in human beings, the ATP binding cassette (ABC) of transport proteins may influence the bioavailability and elimination of numerous drugs and other xenobiotics in domestic animals as well. A number of drugs, currently available in the veterinary market, are substrates of one or more transporters. Therefore, significant drug-drug interactions among ABC substrates may have unpredictable pharmacotoxicological consequences in different species of veterinary interest. In this context, different investigations revealed the major relevance of P-gp and other transport proteins, like breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs), in both companion and livestock animals. Undoubtedly, the discovery of the ABC transporters and the deep understanding of their physiological role in the different species introduced a new paradigm into the veterinary pharmacology. This review focuses on the expression and function of the major transport proteins expressed in species of veterinary interest, and their impact on drug disposition, efficacy and toxicity.
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Affiliation(s)
- Guillermo Virkel
- Laboratorio de Farmacologia, Centro de Investigacion Veterinaria de Tandil (CIVETAN-CONICETCICPBA), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (FCV-UNCPBA), Campus Universitario (Los Ombues y Reforma Universitaria), (7000) Tandil, Prov. de Buenos Aires, Argentina
| | - Mariana Ballent
- Laboratorio de Farmacologia, Centro de Investigacion Veterinaria de Tandil (CIVETAN-CONICETCICPBA), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (FCV-UNCPBA), Campus Universitario (Los Ombues y Reforma Universitaria), (7000) Tandil, Prov. de Buenos Aires, Argentina
| | - Carlos Lanusse
- Laboratorio de Farmacologia, Centro de Investigacion Veterinaria de Tandil (CIVETAN-CONICETCICPBA), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (FCV-UNCPBA), Campus Universitario (Los Ombues y Reforma Universitaria), (7000) Tandil, Prov. de Buenos Aires, Argentina
| | - Adrián Lifschitz
- Laboratorio de Farmacologia, Centro de Investigacion Veterinaria de Tandil (CIVETAN-CONICETCICPBA), Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (FCV-UNCPBA), Campus Universitario (Los Ombues y Reforma Universitaria), (7000) Tandil, Prov. de Buenos Aires, Argentina
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106
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Getachew B, Reyes RE, Davies DL, Tizabi Y. Moxidectin Effects on Gut Microbiota of Wistar-Kyoto Rats: Relevance to Depressive-Like Behavior. CLINICAL PHARMACOLOGY AND TRANSLATIONAL MEDICINE 2019; 3:134-142. [PMID: 31321385 PMCID: PMC6639013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND/AIMS The prevalent comorbidity between neuropsychiatric and gastrointestinal (GI) disorders is believed to be significantly influenced by gut microbiota (GM). GM may also play a substantial role in comorbidity between substance abuse (e.g. Alcohol Use Disorder, AUD) and depression. The anti-parasitic drug Moxidectin (MOX) has been reported to reduce alcohol intake in male and female mice. This effect is purported to be centrally mediated with a significant contribution linked to purinergic, P2X4 purinergic receptors. However, MOX's effects on GM in animal models of depression is not known. METHODS Adult male Wistar Kyoto (WKY) rats (5/group) were injected intraperitoneally (i.p.) once daily for 7 days with MOX (2.5mg/kg), or saline as control group. On day 8, approximately 20 h after the last MOX injection, animals were sacrificed, intestinal stools were collected and stored at -80°C DNA was extracted from the samples for 16S rRNA gene-based GM analysis using 16S Metagenomics application. RESULTS At taxa and species level, MOX affected a number of bacteria including a 30-fold increase in Bifidobacterium cholerium, a bacterium with a strong ability to degrade carbohydrates that resist digestion in the small intestine. There was a minimum of 2-fold increase in: five probiotic species of Lactobacillus, butyrate-forming Rosburia Facies and Butyrivibro proteovlasticus. In contrast, MOX depleted 11 species, including 2 species of Ruminoccus, which are positively associated with severity of irritable bowel syndrome, and 4 species of Provettela, which are closely associated with depressive-like behavior. CONCLUSION Thus, MOX enhanced probiotic species, and suppressed the opportunistic pathogens. Since overall effect of MOX appears to be promoting GM associated with mood enhancement (e.g. Bifidobacterium and Lactobacillus) and suppressing GM associated with inflammation (e.g. Ruminoccus), potential antidepressant and anti-inflammatory effects of MOX in suitable animal models should be investigated.
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Affiliation(s)
- Bruk Getachew
- Department of Pharmacology, Howard University College of Medicine, Washington, DC, USA
| | - Rachel E. Reyes
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Daryl L. Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Yousef Tizabi
- Department of Pharmacology, Howard University College of Medicine, Washington, DC, USA
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107
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Berrafato T, Coates R, Reaves BJ, Kulke D, Wolstenholme AJ. Macrocyclic lactone anthelmintic-induced leukocyte binding to Dirofilaria immitis microfilariae: Influence of the drug resistance status of the parasite. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 10:45-50. [PMID: 31054498 PMCID: PMC6500911 DOI: 10.1016/j.ijpddr.2019.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 12/19/2022]
Abstract
The macrocyclic lactone anthelmintics are the only class of drug currently used to prevent heartworm disease. Their extremely high potency in vivo is not mirrored by their activity against Dirofilaria immitis larvae in vitro, leading to suggestions that they may require host immune functions to kill the parasites. We have previously shown that ivermectin stimulates the binding of canine peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes (PMNs) to D. immitis microfilariae (Mf). We have now extended these studies to moxidectin and examined the ability of both drugs to stimulate canine PBMC and PMN attachment to Mf from multiple strains of D. immitis, including two that are proven to be resistant to ivermectin in vivo. Both ivermectin and moxidectin significantly increased the percentage of drug-susceptible parasites with cells attached at very low concentrations (<10 nM), but much higher concentrations of ivermectin (>100 nM) were required to increase the percentage of the two resistant strains, Yazoo-2013 and Metairie-2014, with cells attached. Moxidectin increased the percentage of the two resistant strains with cells attached at lower concentrations (<10 nM) than did ivermectin. The attachment of the PBMCs and PMNs did not result in any parasite killing in vitro. These data support the biological relevance of the drug-stimulated attachment of canine leukocytes to D. immitis Mf and suggest that this phenomenon is related to the drug resistance status of the parasites. Ivermectin promotes attachment of PMN and PBMC to D. immitis microfilariae in vitro. Moxidectin has a similar effect. Higher ivermectin concentrations are needed if Mf of ML-resistant strains are used. Moxidectin is more effective at promoting cell attachment to resistant Mf. Neither PMN nor PBMC attachment does not result in parasite death in vitro.
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Affiliation(s)
- Tessa Berrafato
- Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.
| | - Ruby Coates
- Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.
| | - Barbara J Reaves
- Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.
| | - Daniel Kulke
- Bayer Animal Health GmbH, 51373, Leverkusen, Germany.
| | - Adrian J Wolstenholme
- Department of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.
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108
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Fazzio L, Moreno L, Galvan W, Canton C, Alvarez L, Streitenberger N, Sánchez R, Lanusse C, Sanabria R. Pharmacokinetic profile and anthelmintic efficacy of moxidectin administered by different doses and routes to feedlot calves. Vet Parasitol 2019; 266:73-79. [DOI: 10.1016/j.vetpar.2018.12.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 11/30/2022]
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109
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Rohdich N, Zschiesche E, Wolf O, Loehlein W, Kirkova Z, Iliev P, Rapti D, Postoli R, Capári B, Farkas R, Roepke RKA. A randomized, blinded, controlled, multi-centered field study assessing the treatment of gastrointestinal nematode infections in cats with fluralaner plus moxidectin spot-on solution (Bravecto® Plus). Parasit Vectors 2018; 11:589. [PMID: 30449275 PMCID: PMC6240952 DOI: 10.1186/s13071-018-3169-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/25/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A spot-on formulation containing fluralaner (280 mg/ml) plus moxidectin (14 mg/ml) (Bravecto® Plus) was developed for the treatment of nematode infections as well as providing 12 weeks of protection against insect and acarine parasites in cats. The effectiveness and safety of this product against feline gastrointestinal nematodes was assessed in naturally-infested, client-owned cats under field conditions in Albania, Bulgaria, Germany and Hungary. METHODS To be eligible for enrollment in this investigator-blinded study cats had to be at least 10 weeks-old, weigh at least 1.2 kg, be clinically healthy, and have a faecal sample testing positive for nematodes no more than eight days prior to treatment. Cats were stratified into blocks of three in order of presentation at each center and randomly allocated in a 2:1 ratio to be treated topically on Day 0 with fluralaner plus moxidectin (minimum dose rates 40 mg/kg and 2 mg/kg, respectively) or emodepside plus praziquantel (minimum dose rates 3 mg/kg and 12 mg/kg, respectively) (Profender®). Faecal samples were collected from cats prior to treatment and 14 ± 4 days later. RESULTS There were 182 cats randomized to the fluralaner plus moxidectin group, and 91 to the emodepside plus praziquantel group. Prior to treatment the most commonly identified nematode egg was Toxocara cati, found in 79.1 and 82.4% of cats in the fluralaner plus moxidectin and emodepside plus praziquantel groups, respectively. Eggs of Toxascaris leonina were found in 8.2 and 6.6% of cats; of hookworms in 30.8 and 24.2%; and of Capillaria spp. in 7.1 and 4.3%, respectively. After treatment, faecal samples from 98.3% of fluralaner plus moxidectin treated and 96.6% of emodepside plus praziquantel-treated cats were free of nematode ova. Geometric mean faecal egg count reductions for T. cati, the only eggs found in post-treatment faecal samples, were 99.97% and 99.93%, respectively. Treatment with fluralaner plus moxidectin was non-inferior to emodepside plus praziquantel. Both products were safe and well tolerated by cats treated under field conditions. CONCLUSIONS This field study confirms that, in addition to 12-week extended duration flea and tick control, fluralaner plus moxidectin provides broad spectrum treatment of nematodes in cats.
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Affiliation(s)
- Nadja Rohdich
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
| | - Eva Zschiesche
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
| | - Oliver Wolf
- Loehlein & Wolf Vet Research, Maistrasse 69, 80337 Munich, Germany
| | | | - Zvezdelina Kirkova
- Department of Parasitology, Trakia University, Faculty of Veterinary Medicine, Student Campus, 6000 Stara Zagora, Bulgaria
| | - Petar Iliev
- Department of Parasitology, Trakia University, Faculty of Veterinary Medicine, Student Campus, 6000 Stara Zagora, Bulgaria
| | - Dhimitër Rapti
- Klinika Veterinare Xhimi, Bulevardi Bajram Curri Nr 2, Tirana, Albania
| | - Rezart Postoli
- Faculty of Veterinary Medicine, Agricultural University, Kodër Kamëz, Tirana, Albania
| | | | - Róbert Farkas
- Department of Parasitology and Zoology, Faculty of Veterinary Science, Szent István University, István u. 2, 1078 Budapest VII, Hungary
| | - Rainer K. A. Roepke
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
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Rohdich N, Zschiesche E, Wolf O, Loehlein W, Pobel T, Gil MJ, Roepke RKA. Field effectiveness and safety of fluralaner plus moxidectin (Bravecto® Plus) against ticks and fleas: a European randomized, blinded, multicenter field study in naturally-infested client-owned cats. Parasit Vectors 2018; 11:598. [PMID: 30454052 PMCID: PMC6240940 DOI: 10.1186/s13071-018-3175-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/28/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A spot-on formulation containing fluralaner (280 mg/ml) plus moxidectin (14 mg/ml) (Bravecto® Plus) has been developed to provide broad spectrum parasite protection for cats. The effectiveness and safety of this product against ticks and fleas was assessed in a randomized, controlled, 12-week study in client-owned cats in Germany and Spain. METHODS Eligible households containing at least one cat with at least two fleas and/or two ticks were allocated randomly in a 2:1 ratio to a single treatment with fluralaner plus moxidectin on Day 0, or three 4-weekly treatments with fipronil (Frontline®). Veterinary staff, masked to treatment, completed tick and flea counts on each cat at 14 ± 2 (2 weeks), 28 ± 2 (4 weeks), 56 ± 2 (8 weeks) and 84 ± 2 days (12 weeks) after the initial treatment. RESULTS In total, 707 cats (257 with ticks) from 332 households (236 with fleas) were included. Ixodes ricinus (78%) and Rhipicephalus sanguineus complex (18%) ticks were the most commonly identified. Tick and flea counts were lower in the fluralaner plus moxidectin group than in the fipronil group throughout the study and the efficacy of fluralaner plus moxidectin exceeded 97 and 98%, respectively. At 12 weeks, 94.1 and 93.3% of cats from the fluralaner plus moxidectin and 92.2 and 60.3% of cats from the fipronil group were free of ticks and fleas, respectively. Fluralaner plus moxidectin was non-inferior to fipronil (P < 0.0001) at all assessments and superior to fipronil at 2 and 8 weeks for the proportion of cats free of ticks (P < 0.0001). Fluralaner plus moxidectin was superior to fipronil for the proportion of both households and cats free of fleas (P < 0.0001). Both products were safe and well tolerated. CONCLUSIONS A single application of fluralaner plus moxidectin spot-on was well tolerated by cats and highly effective for 12 weeks against ticks and fleas. Fluralaner plus moxidectin was non-inferior to fipronil for the proportion of ectoparasite-free and consistently superior to fipronil in controlling fleas.
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Affiliation(s)
- Nadja Rohdich
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
| | - Eva Zschiesche
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
| | - Oliver Wolf
- Loehlein & Wolf Vet Research, Maistrasse 69, 80337 Munich, Germany
| | | | - Thierry Pobel
- TPC Biomed, C/Los Betetas 12-4°D, 42002 Soria, Spain
| | | | - Rainer K. A. Roepke
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany
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111
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Gopinath H, Aishwarya M, Karthikeyan K. Tackling scabies: novel agents for a neglected disease. Int J Dermatol 2018; 57:1293-1298. [PMID: 29663338 DOI: 10.1111/ijd.13999] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 02/07/2018] [Accepted: 03/17/2018] [Indexed: 10/17/2022]
Abstract
The scabies mite, Sarcoptes scabiei var hominis, is an obligate ectoparasite of humans. It has been a source of distress for humanity since antiquity. The troublesome mite is emerging triumphant over current acaricidal agents with reports of emerging resistance and treatment failures. Scabies in endemic areas and crusted scabies offer additional management challenges. Exploration of indigenous plants and better understanding of mite biology and pathogenesis provide opportunities for the development of novel agents for this common pest. We review the recent diverse approaches to scabies, including the use of novel plant products with a better safety profile, translating the use of moxidectin from veterinary practice to human scabies, vaccination, immunotherapy, and development of drugs that directly target mite molecules.
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Affiliation(s)
- Hima Gopinath
- Department of Dermatology, Venereology and Leprosy, Sri Manakula Vinayagar Medical College and Hospital, Pondicherry, Pondicherry University, Pondicherry, India
| | - Manju Aishwarya
- Department of Dermatology, Venereology and Leprosy, Sri Manakula Vinayagar Medical College and Hospital, Pondicherry, Pondicherry University, Pondicherry, India
| | - Kaliaperumal Karthikeyan
- Department of Dermatology, Venereology and Leprosy, Sri Manakula Vinayagar Medical College and Hospital, Pondicherry, Pondicherry University, Pondicherry, India
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112
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Smit MR, Ochomo EO, Waterhouse D, Kwambai TK, Abong'o BO, Bousema T, Bayoh NM, Gimnig JE, Samuels AM, Desai MR, Phillips-Howard PA, Kariuki SK, Wang D, Ter Kuile FO, Ward SA, Aljayyoussi G. Pharmacokinetics-Pharmacodynamics of High-Dose Ivermectin with Dihydroartemisinin-Piperaquine on Mosquitocidal Activity and QT-Prolongation (IVERMAL). Clin Pharmacol Ther 2018; 105:388-401. [PMID: 30125353 PMCID: PMC6585895 DOI: 10.1002/cpt.1219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/05/2018] [Indexed: 12/26/2022]
Abstract
High‐dose ivermectin, co‐administered for 3 days with dihydroartemisinin‐piperaquine (DP), killed mosquitoes feeding on individuals for at least 28 days posttreatment in a recent trial (IVERMAL), whereas 7 days was predicted pretrial. The current study assessed the relationship between ivermectin blood concentrations and the observed mosquitocidal effects against Anopheles gambiae s.s. Three days of ivermectin 0, 300, or 600 mcg/kg/day plus DP was randomly assigned to 141 adults with uncomplicated malaria in Kenya. During 28 days of follow‐up, 1,393 venous and 335 paired capillary plasma samples, 850 mosquito‐cluster mortality rates, and 524 QTcF‐intervals were collected. Using pharmacokinetic/pharmacodynamic (PK/PD) modeling, we show a consistent correlation between predicted ivermectin concentrations and observed mosquitocidal‐effects throughout the 28‐day study duration, without invoking an unidentified mosquitocidal metabolite or drug‐drug interaction. Ivermectin had no effect on piperaquine's PKs or QTcF‐prolongation. The PK/PD model can be used to design new treatment regimens with predicted mosquitocidal effect. This methodology could be used to evaluate effectiveness of other endectocides.
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Affiliation(s)
- Menno R Smit
- Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Eric O Ochomo
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | | | - Titus K Kwambai
- Liverpool School of Tropical Medicine (LSTM), Liverpool, UK.,Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya.,Kenya Ministry of Health (MoH), Kisumu County, Kisumu, Kenya
| | - Bernard O Abong'o
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Teun Bousema
- Radboud University Nijmegen Medical Center (Radboud), Nijmegen, The Netherlands.,London School of Hygiene and Tropical Medicine (LSHTM), London, UK
| | - Nabie M Bayoh
- US Centers for Disease Control and Prevention (CDC), Center for Global Health, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, USA
| | - John E Gimnig
- US Centers for Disease Control and Prevention (CDC), Center for Global Health, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, USA
| | - Aaron M Samuels
- US Centers for Disease Control and Prevention (CDC), Center for Global Health, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, USA
| | - Meghna R Desai
- US Centers for Disease Control and Prevention (CDC), Center for Global Health, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, USA
| | | | - Simon K Kariuki
- Kenya Medical Research Institute (KEMRI), Centre for Global Health Research, Kisumu, Kenya
| | - Duolao Wang
- Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | | | - Stephen A Ward
- Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
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Opoku NO, Bakajika DK, Kanza EM, Howard H, Mambandu GL, Nyathirombo A, Nigo MM, Kasonia K, Masembe SL, Mumbere M, Kataliko K, Larbelee JP, Kpawor M, Bolay KM, Bolay F, Asare S, Attah SK, Olipoh G, Vaillant M, Halleux CM, Kuesel AC. Single dose moxidectin versus ivermectin for Onchocerca volvulus infection in Ghana, Liberia, and the Democratic Republic of the Congo: a randomised, controlled, double-blind phase 3 trial. Lancet 2018; 392:1207-1216. [PMID: 29361335 PMCID: PMC6172290 DOI: 10.1016/s0140-6736(17)32844-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 09/25/2017] [Accepted: 11/02/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND The morbidity and socioeconomic effects of onchocerciasis, a parasitic disease that is primarily endemic in sub-Saharan Africa, have motivated large morbidity and transmission control programmes. Annual community-directed ivermectin treatment has substantially reduced prevalence. Elimination requires intensified efforts, including more efficacious treatments. We compared parasitological efficacy and safety of moxidectin and ivermectin. METHODS This double-blind, parallel group, superiority trial was done in four sites in Ghana, Liberia, and the Democratic Republic of the Congo. We enrolled participants (aged ≥12 years) with at least 10 Onchocerca volvulus microfilariae per mg skin who were not co-infected with Loa loa or lymphatic filariasis microfilaraemic. Participants were randomly allocated, stratified by sex and level of infection, to receive a single oral dose of 8 mg moxidectin or 150 μg/kg ivermectin as overencapsulated oral tablets. The primary efficacy outcome was skin microfilariae density 12 months post treatment. We used a mixed-effects model to test the hypothesis that the primary efficacy outcome in the moxidectin group was 50% or less than that in the ivermectin group. The primary efficacy analysis population were all participants who received the study drug and completed 12-month follow-up (modified intention to treat). This study is registered with ClinicalTrials.gov, number NCT00790998. FINDINGS Between April 22, 2009, and Jan 23, 2011, we enrolled and allocated 998 participants to moxidectin and 501 participants to ivermectin. 978 received moxidectin and 494 ivermectin, of which 947 and 480 were included in primary efficacy outcome analyses. At 12 months, skin microfilarial density (microfilariae per mg of skin) was lower in the moxidectin group (adjusted geometric mean 0·6 [95% CI 0·3-1·0]) than in the ivermectin group (4·5 [3·5-5·9]; difference 3·9 [3·2-4·9], p<0·0001; treatment difference 86%). Mazzotti (ie, efficacy-related) reactions occurred in 967 (99%) of 978 moxidectin-treated participants and in 478 (97%) of 494 ivermectin-treated participants, including ocular reactions (moxidectin 113 [12%] participants and ivermectin 47 [10%] participants), laboratory reactions (788 [81%] and 415 [84%]), and clinical reactions (944 [97%] and 446 [90%]). No serious adverse events were considered to be related to treatment. INTERPRETATION Skin microfilarial loads (ie, parasite transmission reservoir) are lower after moxidectin treatment than after ivermectin treatment. Moxidectin would therefore be expected to reduce parasite transmission between treatment rounds more than ivermectin could, thus accelerating progress towards elimination. FUNDING UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases.
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Affiliation(s)
- Nicholas O Opoku
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | | | - Eric M Kanza
- Centre de Recherche Clinique de Butembo (CRCB), Departement de la Recherche aux Cliniques du Graben, Université Catholique du Graben (UCG), Butembo, Democratic Republic of the Congo
| | | | - Germain L Mambandu
- Ministère Provincial de la Santé, Kisangani, Democratic Republic of the Congo
| | - Amos Nyathirombo
- Department of Ophthalmology, Faculty of Medicine, Gulu University, Gulu, Uganda
| | - Maurice M Nigo
- Nanomedicine Research Lab, CLINAM, University Hospital Basel, Basel, Switzerland
| | - Kambale Kasonia
- Centre de Recherche Clinique de Butembo (CRCB), Departement de la Recherche aux Cliniques du Graben, Université Catholique du Graben (UCG), Butembo, Democratic Republic of the Congo
| | - Safari L Masembe
- Centre de Recherche Clinique de Butembo (CRCB), Departement de la Recherche aux Cliniques du Graben, Université Catholique du Graben (UCG), Butembo, Democratic Republic of the Congo
| | - Mupenzi Mumbere
- Centre de Recherche Clinique de Butembo (CRCB), Departement de la Recherche aux Cliniques du Graben, Université Catholique du Graben (UCG), Butembo, Democratic Republic of the Congo
| | - Kambale Kataliko
- Centre de Recherche Clinique de Butembo (CRCB), Departement de la Recherche aux Cliniques du Graben, Université Catholique du Graben (UCG), Butembo, Democratic Republic of the Congo
| | | | - Mawolo Kpawor
- Liberia Institute for Biomedical Research (LIBR), Monrovia, Liberia
| | - Kpehe M Bolay
- Liberia Institute for Biomedical Research (LIBR), Monrovia, Liberia
| | - Fatorma Bolay
- Liberia Institute for Biomedical Research (LIBR), Monrovia, Liberia
| | - Sampson Asare
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD, USA
| | - Simon K Attah
- Department of Microbiology, University of Ghana Medical School, Accra, Ghana
| | - George Olipoh
- Ghana Institute of Management and Public Administration, Centre for Management Development, Accra, Ghana
| | - Michel Vaillant
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
| | - Christine M Halleux
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), WHO, Geneva, Switzerland
| | - Annette C Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), WHO, Geneva, Switzerland.
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First assessment of the comparative toxicity of ivermectin and moxidectin in adult dung beetles: Sub-lethal symptoms and pre-lethal consequences. Sci Rep 2018; 8:14885. [PMID: 30291291 PMCID: PMC6173729 DOI: 10.1038/s41598-018-33241-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/20/2018] [Indexed: 11/27/2022] Open
Abstract
Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM and MOX on adult dung beetles were assessed for the first time to determine both the physiological sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC50, as the concentration of each ML where the antennal response is inhibited by half; and pLC50, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles. Values of LOEC, IC50 and pLC50 obtained for IVM and MOX evaluated in an environmental context indicate that MOX, despite needing more time for its elimination in the faeces, would be half as harmful to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle health and to avoid the subsequent environmental consequences.
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115
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Gascoigne E, Morgan ER, Lovatt F, Vineer HR. Controlling nematode infections in sheep: application of HACCP. IN PRACTICE 2018. [DOI: 10.1136/inp.k3858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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116
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Nashat MA, Ricart Arbona RJ, Lepherd ML, Santagostino SF, Livingston RS, Riedel ER, Lipman NS. Ivermectin-compounded Feed Compared with Topical Moxidectin-Imidacloprid for Eradication of Demodex musculi in Laboratory Mice. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2018; 57:483-497. [PMID: 30185284 DOI: 10.30802/aalas-jaalas-18-000003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Demodex musculi is a prostigmatid follicular mite that has rarely been reported in laboratory mice. Although prevalence of this species has not been assessed formally, we have found that many imported mouse strains from noncommercial sources harbor Demodex mites. To assess whether an acaricide can be used to eradicate this mite, infested immunocompromised mice were provided ivermectin-compounded (12 ppm) feed without restriction for 8 wk (n = 10), were treated topically with moxidectin and imidacloprid (MI; 3 and 13 mg/kg, respectively) weekly for 8 wk (n = 10), or remained untreated (n = 10). Mice were confirmed to be mite-infested before treatment and were tested after treatment by using fur plucks (FP), deep skin scrapes (DSS), and PCR analysis of fur swabs. In addition, the presence of mites was confirmed through skin biopsies at 2 study endpoints (1 wk [n = 5] and 12 wk [ n = 5] after treatment). Samples collected before treatment and from untreated mice were positive for D. musculi at all time points and by all test modalities. After treatment, all ivermectin-treated animals remained infested, whereas mice treated with MI were repeatedly negative by all test modalities. An additional shortened treatment trial revealed that 4 wk of MI (n = 7) was insufficient to eradicate mites. Neither treatment produced any evidence of adverse effects according to hematology, serum chemistry parameters, behavior, body weight, and histopathology. Of the 70 PCR assays performed in treated mice, 14 were positive when FP+DSS was negative. In 6 cases where PCR results were negative, 5 were positive by FP+DSS and a single sample was positive on skin biopsy. Although PCR analysis has a high detection rate for D. musculi, FP+DSS can further enhance the detection rate. In conclusion, topical MI administered for 8 consecutive weeks can safely eradicate D. musculi from an immunocompromised mouse strain.
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Affiliation(s)
- Melissa A Nashat
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York
| | - Rodolfo J Ricart Arbona
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York, Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York
| | - Michelle L Lepherd
- Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York, Gribbles Veterinary, Christchurch, New Zealand
| | - Sara F Santagostino
- Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York, Department of Safety Assessment, Genentech, Inc., South San Francisco, California
| | - Robert S Livingston
- IDEXX BioResearch, Columbia, Missouri, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Elyn R Riedel
- Epidemiology and Biostatistics Department, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Neil S Lipman
- Tri-Institutional Training Program in Laboratory Animal Medicine and Science, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York, Center for Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medicine, and The Rockefeller University, New York, New York;,
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Maheu-Giroux M, Joseph SA. Moxidectin for deworming: from trials to implementation. THE LANCET. INFECTIOUS DISEASES 2018; 18:817-819. [DOI: 10.1016/s1473-3099(18)30270-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 04/11/2018] [Indexed: 12/17/2022]
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118
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Barda B, Ame SM, Ali SM, Albonico M, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and tolerability of moxidectin alone and in co-administration with albendazole and tribendimidine versus albendazole plus oxantel pamoate against Trichuris trichiura infections: a randomised, non-inferiority, single-blind trial. THE LANCET. INFECTIOUS DISEASES 2018; 18:864-873. [DOI: 10.1016/s1473-3099(18)30233-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 12/26/2022]
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Song D, Liang H, Qu B, Li Y, Liu J, Chen C, Zhang D, Zhang X, Gao A. Moxidectin inhibits glioma cell viability by inducing G0/G1 cell cycle arrest and apoptosis. Oncol Rep 2018; 40:1348-1358. [PMID: 30015956 PMCID: PMC6072399 DOI: 10.3892/or.2018.6561] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/26/2018] [Indexed: 01/16/2023] Open
Abstract
Moxidectin (MOX), a broad‑spectrum antiparasitic agent, belongs to the milbemycin family and is similar to avermectins in terms of its chemical structure. Previous research has revealed that milbemycins, including MOX, may potentially function as effective multidrug resistance agents. In the present study, the impact of MOX on the viability of glioma cells was examined by MTT and colony formation assay, and the molecular mechanisms underlying MOX‑mediated glioma cell apoptosis were explored by using flow cytometry and apoptosis rates. The results demonstrated that MOX exerts an inhibitory effect on glioma cell viability and colony formations in vitro and xenograft growth in vivo and is not active against normal cells. Additionally, as shown by western blot assay, it was demonstrated that MOX arrests the cell cycle at the G0/G1 phase by downregulating the expression levels of cyclin‑dependent kinase (CDK)2, CDK4, CDK6, cyclin D1 and cyclin E. Furthermore, it was revealed that MOX is able to induce cell apoptosis by increasing the Bcl‑2‑associated X protein/B‑cell lymphoma 2 ratio and activating the caspase‑3/‑9 cascade. In conclusion, these results suggest that MOX may inhibit the viability of glioma cells by inducing cell apoptosis and cell cycle arrest, and may be able to function as a potent and promising agent in the treatment of glioma.
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Affiliation(s)
- Dandan Song
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Hongsheng Liang
- Key Laboratory of Neurosurgery, College of Heilongjiang Province; The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Bo Qu
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Yijing Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Jingjing Liu
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Chen Chen
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Daming Zhang
- Key Laboratory of Neurosurgery, College of Heilongjiang Province; The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Xiangtong Zhang
- Key Laboratory of Neurosurgery, College of Heilongjiang Province; The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Aili Gao
- School of Life Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
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Sangster NC, Cowling A, Woodgate RG. Ten Events That Defined Anthelmintic Resistance Research. Trends Parasitol 2018; 34:553-563. [DOI: 10.1016/j.pt.2018.05.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/24/2018] [Accepted: 05/01/2018] [Indexed: 11/30/2022]
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121
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Crisi PE, Di Cesare A, Boari A. Feline Troglostrongylosis: Current Epizootiology, Clinical Features, and Therapeutic Options. Front Vet Sci 2018; 5:126. [PMID: 29974053 PMCID: PMC6019465 DOI: 10.3389/fvets.2018.00126] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/23/2018] [Indexed: 12/20/2022] Open
Abstract
Parasitic bronchopneumonia plays an important role in feline respiratory medicine, thus it is receiving growing attention by researchers and practitioners. In recent years, Troglostrongylus brevior, a lungworm usually infecting wild felids, has been recognized as an agent of the lower respiratory tract in domestic cats. In particular, as a likely consequence of a spill-over from wild reservoirs (e.g., the European wildcat), T. brevior infection is increasingly reported in cats from Mediterranean and Balkan countries. This parasitic nematode has an indirect life cycle, and its biology overlaps that of the better known "cat lungworm" Aelurostrongylus abstrusus. In fact, cases of co-infections caused by both lungworms are not infrequent in domestic cats. Knowledge on clinical features of troglostrongylosis is still incomplete. Available data indicates that clinical signs and radiographic evidence are severe especially in kittens and young cats, are non-specific and often overlap with those of other feline respiratory diseases, such as feline bronchial disease/asthma, or infectious pneumonia. These characteristics make a definitive diagnosis of troglostrongylosis challenging, this disease requires a timely ancillary therapy and an appropriate anthelminthic treatment. As feline troglostrongylosis is an emerging parasitic disease of domestic cats, it should be included in differential diagnosis for lower respiratory tract disease in cats from regions where this parasite is present but also where it is unexpected. This article reviews current knowledge on the pathogenic role of T. brevior in domestic cats and resulting respiratory illness, with a special focus on clinical aspects, diagnosis, and management of the disease.
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Affiliation(s)
- Paolo E. Crisi
- Faculty of Veterinary Medicine, Veterinary Teaching Hospital, University of Teramo, Teramo, Italy
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Cruz MDBA, Fernandes MÂM, Monteiro ALG, Teles JA, Anadón A, Reyes FGR. Tissue residue depletion of moxidectin in lambs (Ovis aries) following subcutaneous administration. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2018; 35:1278-1285. [DOI: 10.1080/19440049.2018.1465207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
| | - Maria Ângela M. Fernandes
- Department of Animal Science, Sheep and Goat Production and Research Center (LAPOC), Federal University of Paraná, Curitiba, PR, Brazil
| | - Alda Lúcia G. Monteiro
- Department of Animal Science, Sheep and Goat Production and Research Center (LAPOC), Federal University of Paraná, Curitiba, PR, Brazil
| | - Juliana A. Teles
- School of Food Engineering, Department of Food Sciences, University of Campinas – UNICAMP, Campinas, SP, Brazil
| | - Arturo Anadón
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - Felix G. R. Reyes
- School of Food Engineering, Department of Food Sciences, University of Campinas – UNICAMP, Campinas, SP, Brazil
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Song X, Zhang Y, Xue J, Li C, Wang Z, Wang Y. Enhancing nemadectin production by Streptomyces cyaneogriseus ssp. noncyanogenus through quantitative evaluation and optimization of dissolved oxygen and shear force. BIORESOURCE TECHNOLOGY 2018; 255:180-188. [PMID: 29414165 DOI: 10.1016/j.biortech.2017.09.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 06/08/2023]
Abstract
In this study, effects of oxygen supply and shear stress on nemadectin production by Streptomyces cyaneogriseus ssp. noncyanogenus (S. cyaneogriseus) fermentation were investigated in shake flasks and 5-L bioreactors. Results showed sufficient dissolved oxygen level was essential for cells growth and nemadectin biosynthesis, while strong shear stress had negative impacts on both cell growth and nemadectin synthesis. Furthermore, when a combined paddle type was applied in culturing S. cyaneogriseus, the nemadectin production was increased by 23.6%. The influence of different agitation rates and paddle types on volumetric oxygen transfers coefficient (KLa) and shear stress were quantitatively studied through computational fluid dynamics simulation (CFD). The results of CFD revealed that high KLa as well as low shear stress co-existed under the combined impeller configuration at 650rpm. This study is expected to be helpful to the scale-up of nemadectin fermentation and other stress-sensitive but high-oxygen-consumption filamentous microorganism.
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Affiliation(s)
- Xiaoqing Song
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Yun Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Jiayun Xue
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Chao Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Zejian Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
| | - Yonghong Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
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Cortés I, Kaufman TS, Bracca ABJ. A convenient and eco-friendly cerium(III) chloride-catalysed synthesis of methoxime derivatives of aromatic aldehydes and ketones. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180279. [PMID: 29892459 PMCID: PMC5990813 DOI: 10.1098/rsos.180279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/18/2018] [Indexed: 05/28/2023]
Abstract
The use of CeCl3·7H2O as an efficient and eco-friendly promoter for the convenient synthesis of methoximes derived from aromatic aldehydes and ketones, is reported. The transformations entail the use of equimolar amounts of MeONH2·HCl and NaOAc in EtOH at 50°C, and no special precautions are needed with regard to the presence of oxygen. The scope and limitations of the transformation were studied and a reaction mechanism was proposed.
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Pipette-tip solid-phase extraction using polypyrrole as efficient adsorbent for extraction of avermectins and milbemycins in milk. Anal Bioanal Chem 2018; 410:3361-3374. [DOI: 10.1007/s00216-018-1031-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 03/02/2018] [Accepted: 03/16/2018] [Indexed: 10/17/2022]
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Spampanato J, Gibson A, Dudek FE. The antihelminthic moxidectin enhances tonic GABA currents in rodent hippocampal pyramidal neurons. J Neurophysiol 2018; 119:1693-1698. [PMID: 29364072 DOI: 10.1152/jn.00587.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Macrocyclic lactones (MLs) are commonly used treatments for parasitic worm and insect infections in humans, livestock, and companion animals. MLs target the invertebrate glutamate-activated chloride channel that is not present in vertebrates. MLs are not entirely inert in vertebrates, though; they have been reported to have activity in heterologous expression systems consisting of ligand-gated ion channels that are present in the mammalian central nervous system (CNS). However, these compounds are typically not able to reach significant concentrations in the CNS because of the activity of the blood-brain barrier P-glycoprotein extrusion system. Despite this, these compounds are able to reach low levels in the CNS that may be useful in the design of novel "designer" ligand-receptor systems that can be used to directly investigate neuronal control of behavior in mammals and have potential for use in treating human neurological diseases. To determine whether MLs might affect neurons in intact brains, we investigated the activity of the ML moxidectin (MOX) at native GABA receptors. Specifically, we recorded tonic and phasic miniature inhibitory postsynaptic currents (mIPSCs) in ex vivo brain slices. Our data show that MOX potentiated tonic GABA currents in a dose-dependent manner but had no concomitant effects on phasic GABA currents (i.e., MOX had no effect on the amplitude, frequency, or decay kinetics of mIPSCs). These studies indicate that behavioral experiments that implement a ML-based novel ligand-receptor system should take care to control for potential effects of the ML on native tonic GABA receptors. NEW & NOTEWORTHY We have identified a novel mechanism of action in the mammalian central nervous system for the antihelminthic moxidectin, commonly prescribed to animals worldwide and currently being evaluated for use in humans. Specifically, moxidectin applied to rodent brain slices selectively enhanced the tonic GABA conductance of hippocampal pyramidal neurons.
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Affiliation(s)
- Jay Spampanato
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
| | - Anne Gibson
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
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Mermans C, Dermauw W, Geibel S, Van Leeuwen T. A G326E substitution in the glutamate-gated chloride channel 3 (GluCl3) of the two-spotted spider mite Tetranychus urticae abolishes the agonistic activity of macrocyclic lactones. PEST MANAGEMENT SCIENCE 2017; 73:2413-2418. [PMID: 28736919 DOI: 10.1002/ps.4677] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/10/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND The macrocyclic lactones abamectin and milbemectin are frequently used to control phytophagous mites such as Tetranychus urticae. Consequently, resistance has developed and was genetically linked with substitutions in the glutamate-gated chloride channel (GluCl) subunits TuGluCl1 and TuGluCl3. Here, we functionally validated a G326E substitution in TuGluCl3 by functional expression in Xenopus laevis oocytes followed by two-electrode voltage-clamp electrophysiology. RESULTS Homomeric wild-type and mutated GluCl3 were successfully expressed. l-glutamic-acid-induced currents exhibited a rapid onset equal in both channels and EC50 for l-glutamic-acid was in the micromolar range (384.2 μm and 292.7 μm, respectively). Abamectin and milbemycin A4 elicited sustained currents in wild-type GluCl3, but the G326E substitution completely abolished the agonistic activity of macrocyclic lactones. CONCLUSION A target-site mutation in Tu GluCl3 contributes to avermectin resistance in T. urticae. However, given the multitude of channel genes and the potential additive or synergistic effects of mutations, to what extent mutations determine the often extremely strong resistance phenotype in the field deserves further study. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Catherine Mermans
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Wannes Dermauw
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sven Geibel
- Bayer AG, CropScience Division, Monheim, Germany
| | - Thomas Van Leeuwen
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
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Fernandes MAM, Gilaverte S, Bianchi MD, da Silva CJA, Molento MB, Reyes FGR, Monteiro ALG. Moxidectin residues in tissues of lambs submitted to three endoparasite control programs. Res Vet Sci 2017; 114:406-411. [DOI: 10.1016/j.rvsc.2017.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/09/2017] [Accepted: 07/08/2017] [Indexed: 10/19/2022]
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Zha C, Wang C, Sheele JM. Effect of Moxidectin on Bed Bug Feeding, Development, Fecundity, and Survivorship. INSECTS 2017; 8:E106. [PMID: 28973981 PMCID: PMC5746789 DOI: 10.3390/insects8040106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/22/2017] [Accepted: 09/28/2017] [Indexed: 01/08/2023]
Abstract
The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), is a blood-feeding ectoparasite which experienced world-wide resurgence during recent decades. The control of bed bugs is often challenging, due to their cryptic nature and resistance to commonly used insecticides. In this study, we evaluated the effect of the antiparasitic drug moxidectin on bed bug survival, reproduction, and development. The LC50 (lethal concentration to kill half the members of a tested population) of moxidectin against bed bug male adults, female adults, and large nymphs were 52.7 (95% CI (confidence interval): 39.5-70.8), 29.3 (95% CI: 20.7-40.5), and 29.1 ng/mL (95% CI: 23.3-35.3), respectively. Moxidectin (≥ 25 ng/mL) reduced egg laying of bed bug females, but showed no significant effect on egg hatching. One time feeding on rabbit blood containing 20 and 40 ng/mL moxidectin showed no negative effects in bed bug feeding and blood meal ingestion, but significantly reduced digestion rates and nymph molting rates. Although moxidectin at concentrations of 20 and 40 ng/mL only caused moderate mortality in bed bugs, it significantly interrupted digestion, development, and oviposition of survived bed bugs for at least one week after feeding. Moxidectin is a promising supplement of the existing bed bug control materials if its use on humans can be approved in the future.
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Affiliation(s)
- Chen Zha
- Department of Entomology, Rutgers-The State University of New Jersey, New Brunswick, NJ 08901, USA.
| | - Changlu Wang
- Department of Entomology, Rutgers-The State University of New Jersey, New Brunswick, NJ 08901, USA.
| | - Johnathan Michael Sheele
- Department of Emergency Medicine, University Hospitals Cleveland Medical Center & Case Western Reserve University, Cleveland, OH 44106, USA.
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In Vitro Efficacy of Moxidectin versus Ivermectin against Sarcoptes scabiei. Antimicrob Agents Chemother 2017; 61:AAC.00381-17. [PMID: 28559258 DOI: 10.1128/aac.00381-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 05/22/2017] [Indexed: 10/19/2022] Open
Abstract
Moxidectin is under consideration for development as a treatment for human scabies. As some arthropods show decreased sensitivity to moxidectin relative to ivermectin, it was important to assess this for Sarcoptes scabieiIn vitro assays showed that the concentration of moxidectin required to kill 50% of mites was lower than that of ivermectin (0.5 μM versus 1.8 μM at 24 h; P < 0.0001). This finding provides further support for moxidectin as a candidate for the treatment of human scabies.
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131
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Polymorphism in ABC transporter genes of Dirofilaria immitis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2017; 7:227-235. [PMID: 28494332 PMCID: PMC5421822 DOI: 10.1016/j.ijpddr.2017.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 11/22/2022]
Abstract
Dirofilaria immitis, a filarial nematode, causes dirofilariasis in dogs, cats and occasionally in humans. Prevention of the disease has been mainly by monthly use of the macrocyclic lactone (ML) endectocides during the mosquito transmission season. Recently, ML resistance has been confirmed in D. immitis and therefore, there is a need to find new classes of anthelmintics. One of the mechanisms associated with ML resistance in nematodes has been the possible role of ATP binding cassette (ABC) transporters in reducing drug concentrations at receptor sites. ABC transporters, mainly from sub-families B, C and G, may contribute to multidrug resistance (MDR) by active efflux of drugs out of the cell. Gene products of ABC transporters may thus serve as the targets for agents that may modulate susceptibility to drugs, by inhibiting drug transport. ABC transporters are believed to be involved in a variety of physiological functions critical to the parasite, such as sterol transport, and therefore may also serve as the target for drugs that can act as anthelmintics on their own. Knowledge of polymorphism in these ABC transporter genes in nematode parasites could provide useful information for the process of drug design. We have identified 15 ABC transporter genes from sub-families A, B, C and G, in D. immitis, by comparative genomic approaches and analyzed them for polymorphism. Whole genome sequencing data from four ML susceptible (SUS) and four loss of efficacy (LOE) pooled populations were used for single nucleotide polymorphism (SNP) genotyping. Out of 231 SNPs identified in those 15 ABC transporter genes, 89 and 75 of them were specific to the SUS or LOE populations, respectively. A few of the SNPs identified may affect gene expression, protein function, substrate specificity or resistance development and may be useful for transporter inhibitor/anthelmintic drug design, or in order to anticipate resistance development. In the D. immitis genome, all ABC-A, -B, -C and -G transporter genes were identified. Within 15 ABC transporter genes identified in D. immitis, 231 SNP loci were found. Four exonic SNPs caused changes in predicted secondary structure of ABC proteins. D. immitis populations have low genetic variability among ABC transporter genes.
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132
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Laing R, Gillan V, Devaney E. Ivermectin - Old Drug, New Tricks? Trends Parasitol 2017; 33:463-472. [PMID: 28285851 PMCID: PMC5446326 DOI: 10.1016/j.pt.2017.02.004] [Citation(s) in RCA: 240] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/14/2017] [Accepted: 02/15/2017] [Indexed: 11/30/2022]
Abstract
Ivermectin is one of the most important drugs in veterinary and human medicine for the control of parasitic infection and was the joint focus of the 2015 Nobel Prize in Physiology or Medicine, some 35 years after its remarkable discovery. Although best described for its activity on glutamate-gated chloride channels in parasitic nematodes, understanding of its mode of action remains incomplete. In the field of veterinary medicine, resistance to ivermectin is now widespread, but the mechanisms underlying resistance are unresolved. Here we discuss the history of this versatile drug and its use in global health. Based on recent studies in a variety of systems, we question whether ivermectin could have additional modes of action on parasitic nematodes. Ligand-gated ion channels, particularly glutamate-gated chloride channels, are well characterised as the targets of IVM in nematodes and insects. Nematode genomes are helping to cast light on the diversity of ion-channel subunits in different parasite species of human and veterinary importance. Resistance to IVM is an increasing problem in the control of parasitic nematodes, and resolving the mechanisms is an important research priority. Recent studies in other biological systems suggest that IVM can affect a number of additional pathways. IVM may have novel applications in the treatment and control of important human diseases.
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Affiliation(s)
- Roz Laing
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK.
| | - Victoria Gillan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
| | - Eileen Devaney
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
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Brownjohn PW, Smith J, Portelius E, Serneels L, Kvartsberg H, De Strooper B, Blennow K, Zetterberg H, Livesey FJ. Phenotypic Screening Identifies Modulators of Amyloid Precursor Protein Processing in Human Stem Cell Models of Alzheimer's Disease. Stem Cell Reports 2017; 8:870-882. [PMID: 28285880 PMCID: PMC5390098 DOI: 10.1016/j.stemcr.2017.02.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 12/11/2022] Open
Abstract
Human stem cell models have the potential to provide platforms for phenotypic screens to identify candidate treatments and cellular pathways involved in the pathogenesis of neurodegenerative disorders. Amyloid precursor protein (APP) processing and the accumulation of APP-derived amyloid β (Aβ) peptides are key processes in Alzheimer's disease (AD). We designed a phenotypic small-molecule screen to identify modulators of APP processing in trisomy 21/Down syndrome neurons, a complex genetic model of AD. We identified the avermectins, commonly used as anthelmintics, as compounds that increase the relative production of short Aβ peptides at the expense of longer, potentially more toxic peptides. Further studies demonstrated that this effect is not due to an interaction with the core γ-secretase responsible for Aβ production. This study demonstrates the feasibility of phenotypic drug screening in human stem cell models of Alzheimer-type dementia, and points to possibilities for indirectly modulating APP processing, independently of γ-secretase modulation. Phenotypic drug screening of a human stem cell model of Alzheimer's disease Avermectins identified as modifiers of APP processing in health and disease Avermectins increase short Aβ peptides at the expense of longer, toxic forms Effect is independent of known avermectin targets and the core γ-secretase complex
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Affiliation(s)
- Philip W Brownjohn
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - James Smith
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - Erik Portelius
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 431 80 Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, 431 80 Mölndal, Sweden
| | - Lutgarde Serneels
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics (CME), Leuven Research Institute for Neuroscience and Disease (LIND), University of Leuven (KU Leuven), 3000 Leuven, Belgium
| | - Hlin Kvartsberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 431 80 Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, 431 80 Mölndal, Sweden
| | - Bart De Strooper
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium; Center for Human Genetics (CME), Leuven Research Institute for Neuroscience and Disease (LIND), University of Leuven (KU Leuven), 3000 Leuven, Belgium; Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 431 80 Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, 431 80 Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 431 80 Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, 431 80 Mölndal, Sweden; Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Frederick J Livesey
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK.
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Keegan JD, Keane OM, Good B, De Waal T, Denny M, Hanrahan JP, Fitzgerald W, Sheehan M. A nationwide survey of anthelmintic treatment failure on sheep farms in Ireland. Ir Vet J 2017; 70:7. [PMID: 28203368 PMCID: PMC5301387 DOI: 10.1186/s13620-017-0086-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/25/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Between 2013 and 2015 the Department of Agriculture, Food and the Marine (DAFM) administered a sheep technology adoption programme (STAP), with the aim of increasing profitability on Irish sheep farms by encouraging the adoption of best management practices. One of the options available to STAP participants was to test the efficacy of the anthelmintic treatment (benzimadazole, levamisole or macrocyclic lactone) used in their flocks by means of a drench test, which is a modification of the faecal egg count reduction test; individual faecal samples were collected from the same group of lambs before and after anthelmintic treatment, the number of eggs present pre and post treatment was subsequently determined from a pooled sample. RESULTS In total, 4211 drench tests were undertaken by farmers during the 3 years of the programme. Information on the anthelmintic product used was available for 3771 of these tests; anthelmintics from the classes benzimidazole (BZ), levamisole (LV) and macrocyclic lactone (ML) (avermectins (AVM) plus moxidectin (MOX)) were used in 42.0%, 23.4% and 32.5% of tests, respectively. The remaining 2.1% of tests involved an inappropriate product. The efficacy of treatment against 'other trichostrongyles' (excluding Nematodirus spp and Strongyloides papillosus.) could be established for 1446 tests, and 51% of these tests were considered effective (i.e. a reduction of faecal egg count (FEC) ≥ 95%). There was a significant difference among the drug groups in efficacy; 31.5%, 51.9%, 62.5% and 84% of treatments were considered effective for BZ, LV, AVM, MOX, respectively. The efficacy of treatment against Nematodirus spp. could be established for 338 tests and the overall efficacy was 96%. CONCLUSIONS Due to the significant difference among the anthelmintic classes for efficacy against 'other trichostrongyles' along with the high level of efficacy against Nematodirus spp., a genus for which anthelmintic resistance is rarely reported, it is concluded that anthelmintic resistance was responsible for the majority of the anthelmintic treatment failures observed.
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Affiliation(s)
- Jason D. Keegan
- Animal & Bioscience Department, Teagasc Grange, Dunsany, Co., Meath, Ireland
- Department of Agriculture, Food and the Marine, Central Veterinary Research Laboratory, Backweston, Co., Kildare, Ireland
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Orla M. Keane
- Animal & Bioscience Department, Teagasc Grange, Dunsany, Co., Meath, Ireland
| | - Barbara Good
- Animal & Grassland Research & Innovation Centre, Teagasc, Athenry, Co., Galway, Ireland
| | - Theo De Waal
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Marian Denny
- Kilkenny Regional Veterinary Laboratory, Hebron Road, Kilkenny, Co., Kilkenny, Ireland
| | - James P. Hanrahan
- Animal & Grassland Research & Innovation Centre, Teagasc, Athenry, Co., Galway, Ireland
| | - William Fitzgerald
- Limerick Regional Veterinary Laboratory, Knockalisheen, Co., Limerick, Ireland
| | - Maresa Sheehan
- Kilkenny Regional Veterinary Laboratory, Hebron Road, Kilkenny, Co., Kilkenny, Ireland
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Eichberg C, Wohde M, Müller K, Rausch A, Scherrmann C, Scheuren T, Düring RA, Donath TW. The Anthelmintic Ingredient Moxidectin Negatively Affects Seed Germination of Three Temperate Grassland Species. PLoS One 2016; 11:e0166366. [PMID: 27846249 PMCID: PMC5112930 DOI: 10.1371/journal.pone.0166366] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/27/2016] [Indexed: 11/19/2022] Open
Abstract
In animal farming, anthelmintics are regularly applied to control gastrointestinal nematodes. There is plenty of evidence that also non-target organisms, such as dung beetles, are negatively affected by residues of anthelmintics in faeces of domestic ungulates. By contrast, knowledge about possible effects on wild plants is scarce. To bridge this gap of knowledge, we tested for effects of the common anthelmintic formulation Cydectin and its active ingredient moxidectin on seed germination. We conducted a feeding experiment with sheep and germination experiments in a climate chamber. Three wide-spread plant species of temperate grasslands (Centaurea jacea, Galium verum, Plantago lanceolata) were studied. We found significant influences of both, Cydectin and moxidectin, on germination of the tested species. Across species, both formulation and active ingredient solely led to a decrease in germination percentage and synchrony of germination and an increase in mean germination time with the formulation showing a more pronounced response pattern. Our study shows for the first time that anthelmintics have the potential to negatively affect plant regeneration. This has practical implications for nature conservation since our results suggest that treatments of livestock with anthelmintics should be carefully timed to not impede endozoochorous seed exchange between plant populations.
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Affiliation(s)
- Carsten Eichberg
- Regional and Environmental Sciences, Geobotany, University of Trier, Trier, Germany
- * E-mail:
| | - Manuel Wohde
- Institute of Soil Science and Soil Conservation, Justus Liebig University, Gießen, Germany
| | - Kerstin Müller
- Regional and Environmental Sciences, Geobotany, University of Trier, Trier, Germany
| | - Anja Rausch
- Regional and Environmental Sciences, Geobotany, University of Trier, Trier, Germany
| | - Christina Scherrmann
- Regional and Environmental Sciences, Geobotany, University of Trier, Trier, Germany
| | - Theresa Scheuren
- Regional and Environmental Sciences, Geobotany, University of Trier, Trier, Germany
| | - Rolf-Alexander Düring
- Institute of Soil Science and Soil Conservation, Justus Liebig University, Gießen, Germany
| | - Tobias W. Donath
- Department of Landscape Ecology, Institute for Natural Resource Conservation, Christian Albrechts University Kiel, Kiel, Germany
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Bernigaud C, Fang F, Fischer K, Lespine A, Aho LS, Dreau D, Kelly A, Sutra JF, Moreau F, Lilin T, Botterel F, Guillot J, Chosidow O. Preclinical Study of Single-Dose Moxidectin, a New Oral Treatment for Scabies: Efficacy, Safety, and Pharmacokinetics Compared to Two-Dose Ivermectin in a Porcine Model. PLoS Negl Trop Dis 2016; 10:e0005030. [PMID: 27732588 PMCID: PMC5061321 DOI: 10.1371/journal.pntd.0005030] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/09/2016] [Indexed: 11/08/2022] Open
Abstract
Background Scabies is one of the commonest dermatological conditions globally; however it is a largely underexplored and truly neglected infectious disease. Foremost, improvement in the management of this public health burden is imperative. Current treatments with topical agents and/or oral ivermectin (IVM) are insufficient and drug resistance is emerging. Moxidectin (MOX), with more advantageous pharmacological profiles may be a promising alternative. Methodology/Principal Findings Using a porcine scabies model, 12 pigs were randomly assigned to receive orally either MOX (0.3 mg/kg once), IVM (0.2 mg/kg twice) or no treatment. We evaluated treatment efficacies by assessing mite count, clinical lesions, pruritus and ELISA-determined anti-S. scabiei IgG antibodies reductions. Plasma and skin pharmacokinetic profiles were determined. At day 14 post-treatment, all four MOX-treated but only two IVM-treated pigs were mite-free. MOX efficacy was 100% and remained unchanged until study-end (D47), compared to 62% (range 26–100%) for IVM, with one IVM-treated pig remaining infected until D47. Clinical scabies lesions, pruritus and anti-S. scabiei IgG antibodies had completely disappeared in all MOX-treated but only 75% of IVM-treated pigs. MOX persisted ~9 times longer than IVM in plasma and skin, thereby covering the mite’s entire life cycle and enabling long-lasting efficacy. Conclusions/Significance Our data demonstrate that oral single-dose MOX was more effective than two consecutive IVM-doses, supporting MOX as potential therapeutic approach for scabies. Scabies caused by the Sarcoptes scabiei mite affects many people worldwide and has been recently recognized by the WHO as a truly neglected tropical disease. Currently available treatments are insufficient to overcome this insidious disease and its co-morbidities for example impetigo, rheumatic heart disease and post-streptococcal glomerulonephritis. Treatment management is a major issue, as problems with compliance as well as mite resistance to current drugs are reported. Data have accumulated indicating that moxidectin could be a genuine new candidate drug for sustainable scabies control. To provide proof of concept, we utilized an experimental scabies pig model that closely resembles the human route of scabies infection. We demonstrated that a single moxidectin dose, when compared with the currently recommended two-doses ivermectin treatment routine, achieved a better and faster acaricidal efficacy. Importantly, the skin half-life of moxidectin is longer, potentially covering the entire mite life cycle. Our baseline data demonstrate in principle the potential and feasibility of moxidectin treatment for scabies, thereby enabling the move into larger high-powered efficacy and dose ranging studies in human populations. Moxidectin could indeed play a game-changing role in scabies control and has the potential to accelerate the steps towards elimination of this insidious disease.
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Affiliation(s)
- Charlotte Bernigaud
- Research Group Dynamyc, EA 7380, EnvA, Université Paris-Est (UPE), Maisons-Alfort & Créteil, France
- APHP, Hôpital Henri-Mondor, Department of Dermatology, UPEC, Créteil, France
- * E-mail:
| | - Fang Fang
- Research Group Dynamyc, EA 7380, EnvA, Université Paris-Est (UPE), Maisons-Alfort & Créteil, France
- Department of Parasitology, College of Animal Science and Technology, University of Guangxi, Nanning, China
| | - Katja Fischer
- Infections Diseases Department, Scabies Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Anne Lespine
- Toxalim, INRA, INP-ENVT, INP-EI-Purpan, Université de Toulouse III Paul Sabatier, Toulouse, France
| | - Ludwig Serge Aho
- Epidemiology and Infection Control Unit, University Hospital of Dijon, Dijon, France
| | | | - Andrew Kelly
- Department of Agriculture, Fisheries and Forestry, Queensland Animal Science Precinct, University of Queensland, Gatton Campus, Queensland, Australia
| | - Jean-François Sutra
- Toxalim, INRA, INP-ENVT, INP-EI-Purpan, Université de Toulouse III Paul Sabatier, Toulouse, France
| | - Francis Moreau
- Centre de Recherche BioMédicale (CRBM), EnvA, UPE, Maisons-Alfort, France
| | - Thomas Lilin
- Centre de Recherche BioMédicale (CRBM), EnvA, UPE, Maisons-Alfort, France
| | - Françoise Botterel
- Research Group Dynamyc, EA 7380, EnvA, Université Paris-Est (UPE), Maisons-Alfort & Créteil, France
- APHP, Hôpital Henri-Mondor, Parasitology and Mycology, Department of Microbiology, DHU VIC, UPEC, Créteil, France
| | - Jacques Guillot
- Research Group Dynamyc, EA 7380, EnvA, Université Paris-Est (UPE), Maisons-Alfort & Créteil, France
- Department of Parasitology and Mycology, Biopôle d'Alfort, Ecole nationale vétérinaire d'Alfort, UPE, Maisons-Alfort, France
| | - Olivier Chosidow
- APHP, Hôpital Henri-Mondor, Department of Dermatology, UPEC, Créteil, France
- EA EpiDermE (Epidémiologie en Dermatologie et Evaluation des Thérapeutiques) and INSERM, CIC 1430, UPE, Créteil, France
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Huynh N, Arabian N, Naito A, Louie S, Jakowec MW, Asatryan L, Davies DL. Preclinical development of moxidectin as a novel therapeutic for alcohol use disorder. Neuropharmacology 2016; 113:60-70. [PMID: 27641072 DOI: 10.1016/j.neuropharm.2016.09.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/14/2016] [Accepted: 09/15/2016] [Indexed: 02/08/2023]
Abstract
Current pharmacotherapies for alcohol used disorder (AUD) are few and relatively ineffective illustrating the need for the development of new, effective medications. Using a translational approach, our laboratory reported that ivermectin, an FDA-approved, human and animal anti-parasitic agent, can significantly reduce ethanol intake in male and female mice across different drinking paradigms. Extending this line of investigation, the current paper investigated the utility of moxidectin (MOX), an analogue of ivermectin, to reduce ethanol intake. Notably, MOX is widely held to have lower neurotoxicity potential and improved margin of safety compared to ivermectin. Using a 24-h-two-bottle choice paradigm, MOX significantly reduced ethanol intake in a dose dependent manner in both male and female C57BL/6J mice, respectively (1.25-7.5 mg/kg) and (1.25-10 mg/kg). Further, multi-day administration of MOX (2.5 mg/kg; intraperitoneal injection) for 5 consecutive days significantly reduced ethanol intake in both the 24-h-two-bottle choice and Drinking-in-the-Dark paradigms in female mice. No overt signs of behavioral toxicity were observed. Notably in both male and female mice, MOX significantly reduced ethanol intake starting approximately 4 h post-injection. Using a Xenopus oocyte expression system, we found that MOX significantly potentiated P2X4 receptor (P2X4R) function and antagonized the inhibitory effects of ethanol on ATP-gated currents in P2X4Rs. This latter finding represents the first report of MOX having activity on P2X4Rs. In addition, MOX potentiated GABAA receptors, but to a lesser degree as compared to ivermectin supporting the hypothesis that MOX would be advantageous (compared to ivermectin) with respect to reducing contraindications. Overall, the results illustrate the potential for development of MOX as a novel pharmacotherapy for the treatment of AUD.
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Affiliation(s)
- Nhat Huynh
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Natalie Arabian
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Anna Naito
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Stan Louie
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Michael W Jakowec
- Department of Neurology, Keck School of Medicine, University of Southern California, 1333 San Pablo Street, Los Angeles, CA 90033, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089, USA.
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In silico analysis of the binding of anthelmintics to Caenorhabditis elegansP-glycoprotein 1. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2016; 6:299-313. [PMID: 27746191 PMCID: PMC5196494 DOI: 10.1016/j.ijpddr.2016.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/07/2016] [Accepted: 09/09/2016] [Indexed: 11/23/2022]
Abstract
Macrocyclic lactones (ML) are important anthelmintics used in animals and humans against parasite nematodes, but their therapeutic success is compromised by the spread of ML resistance. Some ABC transporters, such as p-glycoproteins (Pgps), are selected and overexpressed in ML-resistant nematodes, supporting a role for some drug efflux proteins in ML resistance. However, the role of such proteins in ML transport remains to be clarified at the molecular level. Recently, Caenorhabditis elegans Pgp-1 (Cel-Pgp-1) has been crystallized, and its drug-modulated ATPase function characterized in vitro revealed Cel-Pgp-1 as a multidrug transporter. Using this crystal structure, we have developed an in silico drug docking model in order to study the binding of ML and other anthelmintic drugs to Cel-Pgp-1. All tested ML bound with high affinity in a unique site, within the inner chamber of the protein, supporting that ML may be transported by Cel-Pgp-1. Interestingly, interacting residues delineate a ML specific fingerprint involving H-bonds, including T1028. In particular, benzofurane and spiroketal moieties bound to specific sub-sites. When compared with the aglycone ML, such as moxidectin and ivermectin aglycone, avermectin anthelmintics have significant higher affinity for Cel-Pgp-1, likely due to the sugar substituent(s) that bind to a specific area involving H-bonds at Y771. Triclabendazole, closantel and emodepside bound with good affinities to different sub-sites in the inner chamber, partially overlapping with the ML binding site, suggesting that they could compete for Cel-Pgp-1-mediated ML transport. In conclusion, this work provides novel information on the role of nematode Pgps in transporting anthelmintics, and a valuable tool to predict drug-drug interactions and to rationally design new competitive inhibitors of clinically-relevant nematode Pgps, to improve anthelmintic therapeutics.
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139
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Ferreira LE, Benincasa BI, Fachin AL, França SC, Contini SS, Chagas AC, Beleboni RO. Thymus vulgaris L. essential oil and its main component thymol: Anthelmintic effects against Haemonchus contortus from sheep. Vet Parasitol 2016; 228:70-76. [DOI: 10.1016/j.vetpar.2016.08.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/08/2016] [Accepted: 08/13/2016] [Indexed: 11/27/2022]
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Mani T, Bourguinat C, Keller K, Ashraf S, Blagburn B, Prichard RK. Interaction of macrocyclic lactones with a Dirofilaria immitis P-glycoprotein. Int J Parasitol 2016; 46:631-40. [DOI: 10.1016/j.ijpara.2016.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 04/04/2016] [Accepted: 04/11/2016] [Indexed: 12/31/2022]
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Sheele JM, Ridge GE. Toxicity and potential utility of ivermectin and moxidectin as xenointoxicants against the common bed bug, Cimex lectularius L. Parasitol Res 2016; 115:3071-81. [PMID: 27090120 DOI: 10.1007/s00436-016-5062-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/08/2016] [Indexed: 12/30/2022]
Abstract
The recent resurgence of the common bed bug Cimex lectularius L. throughout western industrialized nations has been facilitated in part by the insect becoming pesticide-resistant. Novel control strategies, including xenointoxication, should be considered to combat C. lectularius. Ivermectin, a U.S. Food and Drug Administration (FDA)-approved treatment for several human parasites, and the antiparasitic drug moxidectin, currently being explored in human clinical trials, were evaluated for efficacy against C. lectularius. Results showed that C. lectularius fed on ivermectin or moxidectin blood concentrations of >25 ng/mL and had significantly higher mortality (50-100 %) than controls (0-6 %) by day 13. Bed bugs that survived a blood meal containing >2.5 ng/mL of ivermectin suffered long-term sequelae including reduced fecundity, feeding difficulty, and incomplete ecdysis. Some insects that survived a blood meal containing ≤75 ng/mL moxidectin were able to feed and reproduce.
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Affiliation(s)
- Johnathan M Sheele
- Department of Emergency Medicine, University Hospitals Case Medical Center and Case Western Reserve University, 11100 Euclid Ave. B-517K, Cleveland, OH, 44106, USA.
| | - Gale E Ridge
- The Connecticut Agricultural Experiment Station, 123 Huntington Street, P. O. Box 1106, New Haven, CT, 06504, USA
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Ballesteros C, Tritten L, O’Neill M, Burkman E, Zaky WI, Xia J, Moorhead A, Williams SA, Geary TG. The Effects of Ivermectin on Brugia malayi Females In Vitro: A Transcriptomic Approach. PLoS Negl Trop Dis 2016; 10:e0004929. [PMID: 27529747 PMCID: PMC4986938 DOI: 10.1371/journal.pntd.0004929] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/26/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Lymphatic filariasis and onchocerciasis are disabling and disfiguring neglected tropical diseases of major importance in developing countries. Ivermectin is the drug of choice for mass drug administration programs for the control of onchocerciasis and lymphatic filariasis in areas where the diseases are co-endemic. Although ivermectin paralyzes somatic and pharyngeal muscles in many nematodes, these actions are poorly characterized in adult filariae. We hypothesize that paralysis of pharyngeal pumping by ivermectin in filariae could result in deprivation of essential nutrients, especially iron, inducing a wide range of responses evidenced by altered gene expression, changes in metabolic pathways, and altered developmental states in embryos. Previous studies have shown that ivermectin treatment significantly reduces microfilariae release from females within four days of exposure in vivo, while not markedly affecting adult worms. However, the mechanisms responsible for reduced production of microfilariae are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS We analyzed transcriptomic profiles from Brugia malayi adult females, an important model for other filariae, using RNAseq technology after exposure in culture to ivermectin at various concentrations (100 nM, 300 nM and 1 μM) and time points (24, 48, 72 h, and 5 days). Our analysis revealed drug-related changes in expression of genes involved in meiosis, as well as oxidative phosphorylation, which were significantly down-regulated as early as 24 h post-exposure. RNA interference phenotypes of the orthologs of these down-regulated genes in C. elegans include "maternal sterile", "embryonic lethal", "larval arrest", "larval lethal" and "sick". CONCLUSION/SIGNIFICANCE These changes provide insight into the mechanisms involved in ivermectin-induced reduction in microfilaria output and impaired fertility, embryogenesis, and larval development.
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Affiliation(s)
- Cristina Ballesteros
- Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Lucienne Tritten
- Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Maeghan O’Neill
- Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Erica Burkman
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
- Filariasis Research Reagent Resource Center, Smith College, Northampton, Massachusetts, United States of America
| | - Weam I. Zaky
- Filariasis Research Reagent Resource Center, Smith College, Northampton, Massachusetts, United States of America
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Jianguo Xia
- Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Andrew Moorhead
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
- Filariasis Research Reagent Resource Center, Smith College, Northampton, Massachusetts, United States of America
| | - Steven A. Williams
- Filariasis Research Reagent Resource Center, Smith College, Northampton, Massachusetts, United States of America
| | - Timothy G. Geary
- Institute of Parasitology, Centre for Host-Parasite Interactions, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
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Acquired Tolerance to Ivermectin and Moxidectin after Drug Selection Pressure in the Nematode Caenorhabditis elegans. Antimicrob Agents Chemother 2016; 60:4809-19. [PMID: 27246778 DOI: 10.1128/aac.00713-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/22/2016] [Indexed: 11/20/2022] Open
Abstract
Ivermectin and moxidectin are the most widely administered anthelmintic macrocyclic lactones (MLs) to treat human and animal nematode infections. Their widespread and frequent use has led to a high level of resistance to these drugs. Although they have the same mode of action, differences in terms of selection for drug resistance have been reported. Our objective was to study and compare changes occurring upon ivermectin or moxidectin selection in the model nematode Caenorhabditis elegans C. elegans worms were submitted to stepwise exposure to increasing doses of moxidectin. The sensitivity of moxidectin-selected worms to MLs was determined in a larval development assay and compared with those of wild-type and ivermectin-selected strains. Selection with either ivermectin or moxidectin led to acquired tolerance to ivermectin, moxidectin, and eprinomectin. Importantly, moxidectin was the most potent ML in both ivermectin- and moxidectin-selected strains. Interestingly, this order of potency was also observed in a resistant Haemonchus contortus isolate. In addition, ivermectin- and moxidectin-selected strains displayed constitutive overexpression of several genes involved in xenobiotic metabolism and transport. Moreover, verapamil potentiated sensitivity to ivermectin and moxidectin, demonstrating that ABC transporters play a role in ML sensitivity in ML-selected C. elegans strains. Finally, both ivermectin- and moxidectin-selected strains displayed a dye-filling-defective phenotype. Overall, this work demonstrated that selection with ivermectin or moxidectin led to cross-resistance to several MLs in nematodes and that the induction of detoxification systems and defects in the integrity of amphidial neurons are two mechanisms that appear to affect the responsiveness of worms to both ivermectin and moxidectin.
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Elsheikha HM, Schnyder M, Traversa D, Di Cesare A, Wright I, Lacher DW. Updates on feline aelurostrongylosis and research priorities for the next decade. Parasit Vectors 2016; 9:389. [PMID: 27387914 PMCID: PMC4936016 DOI: 10.1186/s13071-016-1671-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/28/2016] [Indexed: 11/10/2022] Open
Abstract
Feline aelurostrongylosis, caused by the metastrongyloid nematode Aelurostrongylus abstrusus, is an important gastropod-borne parasitic lung disease in cats. Infection with A. abstrusus is widespread globally, but the increasing awareness of this parasite and the advent of more sensitive diagnostics have contributed to the apparent increase in its prevalence and geographic expansion. Clinical features may range in severity from subclinical to life-threatening respiratory disease. Parasitological standard techniques, such as visualization of the nematode first larval stage in faecal and respiratory (bronchial mucus or pleural fluid) samples, remain the mainstays of diagnosis. However, diagnosis is evolving with recent advances in serological and molecular testing, which can improve the time to initiation of effective anthelmintic therapy. Despite numerous anthelmintics that are now available as treatment options, the role of host immunity and lifestyle factors in selecting cats that may benefit from more targeted anthelmintic prophylaxis or treatment practice remains unclear and is likely to guide therapeutic choices as newer data become available. This review summarizes the biology, epidemiology, pathophysiology, diagnosis and treatment options currently available for feline aelurostrongylosis.
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Affiliation(s)
- Hany M. Elsheikha
- />School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD UK
| | - Manuela Schnyder
- />Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, Zürich, 8057 Switzerland
| | - Donato Traversa
- />Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Angela Di Cesare
- />Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Ian Wright
- />Withy Grove Veterinary Surgery, 39 Station Rd, Bamber Bridge, Preston, PR5 6QR UK
| | - David W. Lacher
- />Division of Molecular Biology, Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, Laurel, MD USA
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Polymorphism in ion channel genes of Dirofilaria immitis: Relevant knowledge for future anthelmintic drug design. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2016; 6:343-355. [PMID: 27682347 PMCID: PMC5196487 DOI: 10.1016/j.ijpddr.2016.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/22/2016] [Indexed: 11/24/2022]
Abstract
Dirofilaria immitis, a filarial parasite, causes cardiopulmonary dirofilariasis in dogs, cats and wild canids. The macrocyclic lactone (ML) class of drugs has been used to prevent heartworm infection. There is confirmed ML resistance in D. immitis and thus there is an urgent need to find new anthelmintics that could prevent and/or control the disease. Targeting ion channels of D. immitis for drug design has obvious advantages. These channels, present in the nematode nervous system, control movement, feeding, mating and respond to environmental cues which are necessary for survival of the parasite. Any new drug that targets these ion channels is likely to have a motility phenotype and should act to clear the worms from the host. Many of the successful anthelmintics in the past have targeted these ion channels and receptors. Knowledge about genetic variability of the ion channel and receptor genes should be useful information for drug design as receptor polymorphism may affect responses to a drug. Such information may also be useful for anticipation of possible resistance development. A total of 224 ion channel genes/subunits have been identified in the genome of D. immitis. Whole genome sequencing data of parasites from eight different geographical locations, four from ML-susceptible populations and the other four from ML-loss of efficacy (LOE) populations, were used for polymorphism analysis. We identified 1762 single nucleotide polymorphic (SNP) sites (1508 intronic and 126 exonic) in these 224 ion channel genes/subunits with an overall polymorphic rate of 0.18%. Of the SNPs found in the exon regions, 129 of them caused a non-synonymous type of polymorphism. Fourteen of the exonic SNPs caused a change in predicted secondary structure. A few of the SNPs identified may have an effect on gene expression, function of the protein and resistance selection processes. In the Dirofilaria immitis genome, 126 ion channel genes were identified. Within 126 ion channel genes, 1762 polymorphic loci were identified. Fourteen exonic SNPs caused a change in predicted secondary structure. SNPs may effect gene expression, protein function or resistance selection. D. immitis populations have low genetic variability among ion channel genes.
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146
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Zhao R, Grunke SD, Keralapurath MM, Yetman MJ, Lam A, Lee TC, Sousounis K, Jiang Y, Swing DA, Tessarollo L, Ji D, Jankowsky JL. Impaired Recall of Positional Memory following Chemogenetic Disruption of Place Field Stability. Cell Rep 2016; 16:793-804. [PMID: 27373150 PMCID: PMC4956499 DOI: 10.1016/j.celrep.2016.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/03/2016] [Accepted: 06/03/2016] [Indexed: 11/06/2022] Open
Abstract
The neural network of the temporal lobe is thought to provide a cognitive map of our surroundings. Functional analysis of this network has been hampered by coarse tools that often result in collateral damage to other circuits. We developed a chemogenetic system to temporally control electrical input into the hippocampus. When entorhinal input to the perforant path was acutely silenced, hippocampal firing patterns became destabilized and underwent extensive remapping. We also found that spatial memory acquired prior to neural silencing was impaired by loss of input through the perforant path. Together, our experiments show that manipulation of entorhinal activity destabilizes spatial coding and disrupts spatial memory. Moreover, we introduce a chemogenetic model for non-invasive neuronal silencing that offers multiple advantages over existing strategies in this setting.
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Affiliation(s)
- Rong Zhao
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Stacy D Grunke
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Michael J Yetman
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alexander Lam
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Cognitive Science, Rice University, Houston, TX 77251, USA
| | - Tang-Cheng Lee
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Yongying Jiang
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Deborah A Swing
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Lino Tessarollo
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Daoyun Ji
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Joanna L Jankowsky
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neurosurgery, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA.
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147
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Abstract
Cutaneous parasitic skin diseases are frequent in human pathology. There are few reliable epidemiological data on the prevalence and/or incidence of such diseases. Skin parasites are cosmopolitan but their global distribution is heterogenous; prevalence is especially high in subtropical and tropical countries. They are mainly due to arthropods (insects and mites). Many species of parasites are involved, explaining the diversity of their clinical signs. The most common are caused by ectoparasites such as scabies or pediculosis (head lice, body lice and pubic lice). Clinical signs may be related to the penetration of the parasite under the skin, its development, the inoculation of venom or allergic symptoms. Diagnosis can be easy when clinical signs are pathognomonic (e.g. burrows in the interdigital web spaces in scabies) or sometimes more difficult. Some epidemiological characteristics (diurnal or nocturnal bite, seasonality) and specific clinical presentation (single or multiple bites, linear or grouped lesions) can be a great diagnostic help. Modern non-invasive tools (dermoscopy or confocal microscopy) will play an important role in the future but the eye and experience of the specialist (dermatologist, parasitologist, infectious disease specialist or entomologist) remains for the time the best way to guide or establish a diagnosis. For most skin parasites, therapeutic proposals are rarely based on studies of high level of evidence or randomized trials but more on expert recommendations or personal experience.
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148
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Whittaker JH, Carlson SA, Jones DE, Brewer MT. Molecular mechanisms for anthelmintic resistance in strongyle nematode parasites of veterinary importance. J Vet Pharmacol Ther 2016; 40:105-115. [PMID: 27302747 DOI: 10.1111/jvp.12330] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/02/2016] [Indexed: 11/26/2022]
Abstract
Veterinarians rely on a relatively limited spectrum of anthelmintic agents to control nematode parasites in domestic animals. Unfortunately, anthelmintic resistance has been an emerging problem in veterinary medicine. In particular, resistance has emerged among the strongyles, a group of gastrointestinal nematodes that infect a variety of hosts that range from large herbivores to small companion animals. Over the last several decades, a great deal of research effort has been directed toward developing an understanding of the mechanisms conferring resistance against the three major groups of anthelmintics: macrocyclic lactones, benzimidazoles, and nicotinic agonists. Our understanding of anthelmintic resistance has been largely formed by determining the mechanism of action for each drug class and then evaluating drug-resistant nematode isolates for mutations or differences in expression of target genes. More recently, drug efflux pumps have been recognized for their potential contribution to anthelmintic resistance. In this mini-review, we summarize the evidence for mechanisms of resistance in strongyle nematodes.
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Affiliation(s)
- J H Whittaker
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - S A Carlson
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - D E Jones
- Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - M T Brewer
- Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA, USA
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149
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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: 50] [Impact Index Per Article: 5.6] [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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150
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Besier RB, Kahn LP, Sargison ND, Van Wyk JA. Diagnosis, Treatment and Management of Haemonchus contortus in Small Ruminants. ADVANCES IN PARASITOLOGY 2016; 93:181-238. [PMID: 27238006 DOI: 10.1016/bs.apar.2016.02.024] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Haemonchus contortus is a highly pathogenic, blood-feeding nematode of small ruminants, and a significant cause of mortalities worldwide. Haemonchosis is a particularly significant threat in tropical, subtropical and warm temperate regions, where warm and moist conditions favour the free-living stages, but periodic outbreaks occur more widely during periods of transient environmental favourability. The clinical diagnosis of haemonchosis is based mostly on the detection of anaemia in association with a characteristic epidemiological picture, and confirmed at postmortem by the finding of large numbers of H. contortus in the abomasum. The detection of impending haemonchosis relies chiefly on periodic monitoring for anaemia, including through the 'FAMACHA' conjunctival-colour index, or through faecal worm egg counts and other laboratory procedures. A range of anthelmintics for use against H. contortus is available, but in most endemic situations anthelmintic resistance significantly limits the available treatment options. Effective preventative programmes vary depending on environments and enterprise types, and according to the scale of the haemonchosis risk and the local epidemiology of infections, but should aim to prevent disease outbreaks while maintaining anthelmintic efficacy. Appropriate strategies include animal management programmes to avoid excessive H. contortus challenge, genetic and nutritional approaches to enhance resistance and resilience to infection, and the monitoring of H. contortus infection on an individual animal or flock basis. Specific strategies to manage anthelmintic resistance centre on the appropriate use of effective anthelmintics, and refugia-based treatment schedules. Alternative approaches, such as biological control, may also prove useful, and vaccination against H. contortus appears to have significant potential in control programmes.
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Affiliation(s)
- R B Besier
- Department of Agriculture and Food Western Australia, Albany, WA, Australia
| | - L P Kahn
- University of New England, Armidale, NSW, Australia
| | - N D Sargison
- University of Edinburgh, Roslin, Midlothian, United Kingdom
| | - J A Van Wyk
- University of Pretoria, Hatfield, South Africa
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