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1.
Parasit Vectors ; 12(1): 431, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488194

RESUMO

BACKGROUND: The southern African yellow dog tick, Haemaphysalis elliptica, occurs in eastern and southern Africa and adults infest domestic and wild carnivores. This tick species is also a vector of the highly virulent Babesia rossi pathogen, the causative agent of canine babesiosis in sub-Saharan Africa. Sustained high levels of efficacy of a parasiticide are not only important in protecting dogs against the direct effects of tick infestation, but also in reducing the risk of tick-borne diseases. Sarolaner (Simparica™ chewable tablets) has been reported to be effective against the major tick species infesting dogs in Europe and the USA, including representatives from the genera Amblyomma, Ixodes, Rhipicephalus and Dermacentor. Until now no efficacy evaluations have been reported against species of the genus Haemaphysalis. The objective of the study was to confirm the efficacy of a single 2 mg sarolaner/kg oral dose of Simparica™ against induced infestations with H. (R.) elliptica, an important parasite of dogs in southern Africa. METHODS: This blinded, randomised, single centre, placebo controlled efficacy study followed a parallel group design and was conducted on two groups consisting of eight purpose-bred dogs each. Animals were treated orally, once on Day 0, with either a placebo compound (Group 1) or Simparica™ (Group 2). Simparica™ was administered orally at a dose rate of 2 mg sarolaner/kg body weight. The dogs were infested with ticks on Days - 7, - 2, 5, 12, 19, 26 and 33, with removal counts conducted on Days - 5, 2, 7, 14, 21, 28 and 35. RESULTS: A single oral administration of Simparica™ (sarolaner) at a minimum dose of 2 mg/kg resulted in a 100% efficacy against existing infestations of H. (R.) elliptica on dogs and a 100% reduction in live ticks following weekly re-infestations for 35 days. Moreover, the immediate and persistent high levels of efficacy observed in this study for 35 days is consistent with those observed in previous studies against ticks in other genera. CONCLUSIONS: The efficacy of sarolaner (Simparica™), administered orally to dogs at the minimum label dose of 2.0 mg/kg, was demonstrated against existing and weekly re-infestations of H. (R.) elliptica for at least 5 weeks. Efficacy of 100% was achieved against existing infestations as well as weekly re-infestations.


Assuntos
Antiparasitários/uso terapêutico , Azetidinas/uso terapêutico , Doenças do Cão/tratamento farmacológico , Compostos de Espiro/uso terapêutico , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Administração Oral , África Austral , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Masculino , Distribuição Aleatória , Infestações por Carrapato/tratamento farmacológico , Fatores de Tempo , Resultado do Tratamento
2.
Toxins (Basel) ; 11(4)2019 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013660

RESUMO

Cantharidin (CTD) is a toxic monoterpene produced by blister beetles (Fam. Meloidae) as a chemical defense against predators. Although CTD is highly poisonous to many predator species, some have evolved the ability to feed on poisonous Meloidae, or otherwise beneficially use blister beetles. Great Bustards, Otis tarda, eat CTD-containing Berberomeloe majalis blister beetles, and it has been hypothesized that beetle consumption by these birds reduces parasite load (a case of self-medication). We examined this hypothesis by testing diverse organisms against CTD and extracts of B. majalis hemolymph and bodies. Our results show that all three preparations (CTD and extracts of B. majalis) were toxic to a protozoan (Trichomonas vaginalis), a nematode (Meloidogyne javanica), two insects (Myzus persicae and Rhopalosiphum padi) and a tick (Hyalomma lusitanicum). This not only supports the anti-parasitic hypothesis for beetle consumption, but suggests potential new roles for CTD, under certain conditions.


Assuntos
Acaricidas/toxicidade , Antiparasitários/toxicidade , Cantaridina/toxicidade , Besouros , Inseticidas/toxicidade , Animais , Afídeos/efeitos dos fármacos , Feminino , Larva/efeitos dos fármacos , Masculino , Nematoides/efeitos dos fármacos , Carrapatos/efeitos dos fármacos , Trichomonas vaginalis/efeitos dos fármacos
3.
Vet Parasitol ; 270 Suppl 1: S12-S18, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30914264

RESUMO

The efficacy of a single application of a new topical formulation containing selamectin plus sarolaner (Revolution® Plus / Stronghold® Plus, Zoetis) was evaluated against fleas and ticks infesting cats enrolled as veterinary patients in two field studies conducted in Japan and against Haemaphysalis longicornis ticks on cats in a laboratory study. In the laboratory study, sixteen cats were ranked based on pre-treatment tick counts and allocated randomly to treatment on Day 0 with either selamectin plus sarolaner or placebo. Cats were infested with adult H. longicornis on Days -2, 5, 12, 19, 26 and 33. Efficacy relative to placebo was based on live attached tick counts conducted 48 h after treatment and subsequent re-infestations. Selamectin plus sarolaner reduced live, attached H. longicornis counts by 96.4% within 48 h of treatment, and by ≥91.7% within 48 h of weekly re-infestation for 35 days, based on arithmetic means. In the field studies, 67 client-owned cats harboring six or more live fleas and 63 cats harboring four or more live attached ticks were enrolled to evaluate selamectin plus sarolaner for efficacy and safety compared with a registered product. Cats were allocated randomly to treatment with selamectin plus sarolaner or fipronil plus (S)-methoprene based on order of presentation. Treatment was administered once on Day 0 and efficacy was assessed by parasite counts conducted on Days 14 and 30 compared to the pre-treatment count. In the flea field study, live flea counts on Days 14 and 30 were reduced by 99.5% and 99.9% in the selamectin plus sarolaner group, and by 97.6% and 98.6% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Clinical signs typically associated with flea allergy dermatitis improved following treatment. In the tick field study, live tick counts on Days 14 and 30 were reduced by 97.5% and 97.7% in the selamectin plus sarolaner group, and by 91.5% and 93.4% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Selamectin plus sarolaner was determined to be non-inferior to fipronil plus (S)-methoprene in both field studies. There were no treatment-related adverse events in any study. A single topical dose of Revolution® Plus / Stronghold® Plus providing a minimum dosage of 6.0 mg/kg selamectin and 1.0 mg/kg sarolaner was confirmed to be effective against H. longicornis ticks on cats for one month and safe and effective in the treatment of fleas and ticks on cats enrolled as veterinary patients in Japan.


Assuntos
Azetidinas/administração & dosagem , Doenças do Gato/tratamento farmacológico , Infestações por Pulgas/veterinária , Ivermectina/análogos & derivados , Compostos de Espiro/administração & dosagem , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Acaricidas/administração & dosagem , Administração Tópica , Animais , Doenças do Gato/prevenção & controle , Gatos , Composição de Medicamentos/veterinária , Feminino , Infestações por Pulgas/tratamento farmacológico , Infestações por Pulgas/prevenção & controle , Inseticidas/administração & dosagem , Ivermectina/administração & dosagem , Japão , Masculino , Metoprene/administração & dosagem , Pirazóis/administração & dosagem , Distribuição Aleatória , Sifonápteros/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controle , Carrapatos/efeitos dos fármacos , Resultado do Tratamento
4.
Acta Trop ; 190: 159-165, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30465741

RESUMO

The study assessed an integrated trypanosomosis control strategy in drug-resistant hotspot villages of northern Togo. This strategy comprised (i) rational trypanocidal drug use in symptomatic cattle, (ii) vectors and ticks control by targeted bi-monthly insecticidal spraying of the lower body parts of cattle and (iii) strategic deworming with Albendazole in the beginning and the end of the rainy season. The program was implemented between June 2014 and October 2015 in four villages in northern Togo, which had been previously identified as drug resistant hotspots for diminazene diaceturate (DA) and isometamidium chloride (ISM). The integrated control strategy was implemented in eight cattle herds at risk of the disease from two villages. Twelve herds from two other villages served as controls where trypanosomosis management and deworming remained under control of the farmers. Trypanocidal drug use during the study period was recorded by the intervention team based on the farmers' reports and own observations. Cattle herds were followed-up for trypanosomosis symptoms which were recorded at 3 to 4-month intervals, while extensive trypanosome diagnostics and recording of the packed cell volume were done before and after the intervention. Intervention herds had a significantly lower risk of trypanosome infection with a risk ratio of 0.18 (95% CI: 0.04, 0.91; p = 0.03), but no significant effect on mean packed cell volume was observed. However, trypanocidal treatments per animal per year were lower in intervention herds compared to control herds (0.3 vs 5 for DA and 0.8 vs 2 for ISM). This study demonstrates that the implementation of an integrated best-bet strategy leads to a reduced trypanosome prevalence under lowered trypanocidal use.


Assuntos
Albendazol/uso terapêutico , Gestão de Antimicrobianos , Tripanossomicidas/uso terapêutico , Tripanossomíase Africana/veterinária , Tripanossomíase Bovina/prevenção & controle , Animais , Bovinos , Diminazena/análogos & derivados , Resistência a Medicamentos , Inseticidas/toxicidade , Masculino , Fenantridinas , Carrapatos/efeitos dos fármacos , Togo , Tripanossomíase Africana/tratamento farmacológico , Tripanossomíase Africana/prevenção & controle , Tripanossomíase Bovina/tratamento farmacológico
5.
PLoS One ; 13(12): e0208613, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30532255

RESUMO

To reduce morbidity and mortality caused by visceral leishmaniasis (VL), the Brazilian Visceral Leishmaniasis Control and Surveillance Program promotes the diagnosis and treatment of cases, vector control, euthanasia of seropositive dogs, and health education. Nevertheless, the effectiveness of these measures is questionable as they lead to little reduction in the transmission of the disease. Thus, the effectiveness of strategies such as insecticide-impregnated collars, spot-on insecticides, and immunization of dogs should be assessed. Herein, we evaluated the effectiveness of deltamethrin-impregnated collars on reducing the incidence of Leishmania infantum infection in dogs living in an endemic area of VL. An intervention study was conducted and a total 5,850 dogs were analyzed in baseline. Of these 3,742 seronegative dogs were divided into two groups: collared and uncollared (control). Dogs were followed for 12 months and three interventions were performed. The Cox regression model was used to evaluate the effectiveness of the collar. All analyzes were performed by Intention-to-treat and per-protocol. By intention-to-treat, the incidence rates of L. infantum infection were 7.5 and 7.9 in the collar group, and 6.5 and 13.2 per 1,000 dogs-months in the control group after 6 and 12 months, respectively. In the per-protocol analysis, the incidence rates in the control group were similar to those observed in the intention-to-treat analysis. In the collar group, the incidence rate was 5.1/1,000 dogs-months after 6 and 12 months. The effectiveness by intention-to-treat after adjustment by the multivariate Cox model was 48%. In the analysis per-protocol, the effectiveness increased to 63%. Although collar use was effective when it was evaluated by intention-to-treat, higher effectiveness was found in the per-protocol analysis after one year of follow-up. The data emphasize the importance of the uninterrupted use of deltamethrin-impregnated collars to increase protection against canine VL.


Assuntos
Doenças do Cão/epidemiologia , Inseticidas/química , Leishmaniose Visceral/epidemiologia , Nitrilos/química , Piretrinas/química , Animais , Brasil/epidemiologia , Doenças do Cão/patologia , Cães , Feminino , Incidência , Inseticidas/toxicidade , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/fisiologia , Leishmaniose Visceral/patologia , Masculino , Nitrilos/toxicidade , Controle de Pragas , Modelos de Riscos Proporcionais , Piretrinas/toxicidade , Sifonápteros/efeitos dos fármacos , Sifonápteros/parasitologia , Carrapatos/efeitos dos fármacos , Carrapatos/parasitologia
6.
Parasit Vectors ; 11(1): 581, 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30400923

RESUMO

BACKGROUND: Veterinary clinic transaction records from the USA were examined to determine dog owner purchase patterns for three prescription ectoparasiticides. In-clinic purchases of formulations of fluralaner (with 12-week duration per dose) were compared with dog owner purchases of afoxolaner and spinosad (both with 4 week duration per dose) in a population of 231,565 dogs over a 12 month period. Prior studies in human and animal medicine have suggested that patients more closely adhere to prescriber dosing recommendations when they receive a longer-duration medication. RESULTS: Veterinary clinic transaction records were examined for the period June 2014 through March 2017 using records from approximately 650 veterinary clinics. Ectoparasiticide purchase patterns were compared for two products (afoxalaner and spinosad) with monthly dosing and one product (fluralaner) with an extended (12 week) dosing interval. The average dog owner who obtained fluralaner purchased significantly more months of flea/tick protection (5.7 months) over the 12-month study period than the average dog owner that selected either afoxolaner (4.6 months) or spinosad (3.3 months). The proportion of dog owners who obtained only one dose of ectoparasiticide per 12-month period was 42% for fluralaner, 30% for afoxolaner and 37% for spinosad. The proportion of dog owners who obtained 2 doses or less per 12-month period was 67% for fluralaner, 52% for afoxoalaner and 67% for spinosad. Owners that obtained fluralaner were significantly more likely to obtain 7.0-12.0 months of flea and tick protection and significantly less likely to purchase 1.0-6.9 months compared with dog owners who purchased afoxolaner or spinosad. CONCLUSIONS: Dog owners who obtained a flea and tick medication with a longer duration of action acquired significantly more months of protection in a year than dog owners who obtained shorter duration (1 month) products. Dog owners were better able to adhere to veterinary recommendations on ectoparasites control with a longer-acting flea/tick medication.


Assuntos
Infestações por Pulgas/veterinária , Adesão à Medicação , Propriedade/estatística & dados numéricos , Registros , Drogas Veterinárias/uso terapêutico , Medicina Veterinária , Animais , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologia , Cães , Combinação de Medicamentos , Infestações por Pulgas/tratamento farmacológico , Hospitais Veterinários , Humanos , Inseticidas/administração & dosagem , Inseticidas/uso terapêutico , Isoxazóis/administração & dosagem , Isoxazóis/uso terapêutico , Macrolídeos/administração & dosagem , Macrolídeos/uso terapêutico , Naftalenos/administração & dosagem , Naftalenos/uso terapêutico , Medicamentos sob Prescrição/administração & dosagem , Medicamentos sob Prescrição/uso terapêutico , Sifonápteros/efeitos dos fármacos , Carrapatos/efeitos dos fármacos , Estados Unidos
7.
Vet Parasitol ; 263: 5-9, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30389024

RESUMO

Rhipicephalus (Boophilus) microplus is one of the most important ectoparasites in cattle breeding worldwide, causing direct and indirect losses to animals and producers. Chemical acaricides are utilized in the control of cattle tick and the increase in the development of resistance by ectoparasites makes new alternative necessary. Therefore, research studies have been carried out using bioactive molecules that are quickly degraded and that reduce poisoning to appliers and non-target organisms, environmental contamination and development of resistance. Thus, this study aimed to isolate piperovatine from the roots of Piper corcovadensis, a native species to Brazil, and to evaluate the larvicidal activity against Rhipicephalus (Boophilus) microplus by larval packet test and in ex situ in an open environment. Piperovatine was isolated by classical column chromatography, and identified by 1H and 13C NMR. The lethal concentration (LC) of piperovatine that killed 50% (LC50) and 99% (LC99) of the larvae was determined by Probit analysis. The results indicated LC50 5.17 and LC99 25.41 µg/mL. LC99 was tested in ex situ in an open environment, and an efficiency of 96.63% was found, indicating that piperovatine kept the larvicidal action determined in in vitro test and in open environment. Therefore, this study shows new perspectives to develop products that can be applied in natural conditions to control this ectoparasite.


Assuntos
Acaricidas/administração & dosagem , Ectoparasitoses/veterinária , Larva/efeitos dos fármacos , Ácido Sórbico/análogos & derivados , Acaricidas/química , Acaricidas/isolamento & purificação , Animais , Produtos Biológicos/administração & dosagem , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/epidemiologia , Descoberta de Drogas , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/epidemiologia , Feminino , Piper/anatomia & histologia , Piper/química , Ácido Sórbico/administração & dosagem , Ácido Sórbico/química , Ácido Sórbico/isolamento & purificação , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Carrapatos/fisiologia
8.
Sci Rep ; 8(1): 14053, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30232355

RESUMO

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effective and long-lasting repellent currently available commercially, has long been considered the gold standard in insect repellents, but with reported human health issues, particularly for infants and pregnant women. In the present study, we report fatty acids derived from coconut oil which are novel, inexpensive and highly efficacious repellant compounds. These coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes. The medium-chain length fatty acids from C8:0 to C12:0 were found to exhibit the predominant repellent activity. In laboratory bioassays, these fatty acids repelled biting flies and bed bugs for two weeks after application, and ticks for one week. Repellency was stronger and with longer residual activity than that of DEET. In addition, repellency was also found against mosquitoes. An aqueous starch-based formulation containing natural coconut fatty acids was also prepared and shown to protect pastured cattle from biting flies up to 96-hours in the hot summer, which, to our knowledge, is the longest protection provided by a natural repellent product studied to date.


Assuntos
Vetores Artrópodes/efeitos dos fármacos , Óleo de Coco/química , Ácidos Graxos/farmacologia , Mordeduras e Picadas de Insetos/prevenção & controle , Repelentes de Insetos/farmacologia , Animais , Percevejos-de-Cama/efeitos dos fármacos , Bovinos , Culicidae/efeitos dos fármacos , DEET/farmacologia , Ácidos Graxos/uso terapêutico , Feminino , Humanos , Mordeduras e Picadas de Insetos/veterinária , Masculino , Amido/química , Carrapatos/efeitos dos fármacos , Fatores de Tempo
9.
Ticks Tick Borne Dis ; 9(4): 945-955, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29606621

RESUMO

Tick acaricide failure is one of the leading challenges to cattle production in Uganda. To gain an understanding into the possible drivers of acaricide failure, this study characterized the current chemical tick control practices in the southwestern (Mbarara, Mitooma and Rukungiri districts) and northwestern (Adjumani district) regions of Uganda. A total of 85 farms participated in a survey that utilized a semi-structured questionnaire. Moreover, ticks were collected to determine the most common species on the farms. Tick acaricide failure was mainly encountered in the districts where 95% (60/63) of the farms reared exotic cattle (dairy cross-breeds) under a paddocking (fenced) system. In the northwestern region, local cattle were reared in communal grazing areas. All farms used chemical acaricides for tick control, predominantly amidine (amitraz) (48%, 41/85) and co-formulated organophosphates and pyrethroids (38%, 32/85). The spraying method was the most common (91%, 77/85) acaricide application technique, with cattle crush (81%, 69/85) as a common means of physical restraint. Less than optimal tick control practices encountered included use of substandard equipment for spraying, inappropriate dilutions, frequent interaction between animals in neighboring farms despite lack of synchronized chemical tick control and malpractices in acaricide rotation. Only Rhipicephalus appendiculatus and R. (Boophilus) decoloratus ticks were found in the southwestern region, where 51% (32/63) of the farmers used high acaricide concentrations above the manufacturers' recommendation. Farmers in the northwestern region used 2.2 times less acaricide volume per cattle than those in the southwestern region, and more diverse tick species were encountered. Toxic effects of acaricide to cattle and workers were reported by 13% (11/85) and 32% (27/85) of the respondents, respectively. All 27 cases of human acaricide toxicity reported were from the southwestern region. Overall, our findings may inform strategies for more prudent chemical tick control and safe acaricide handling to benefit animal welfare, food safety and public health.


Assuntos
Acaricidas/efeitos adversos , Doenças dos Bovinos/tratamento farmacológico , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Acaricidas/administração & dosagem , Acaricidas/toxicidade , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Estudos Transversais , Resistência a Medicamentos , Fazendas , Humanos , Saúde Pública , Piretrinas/administração & dosagem , Piretrinas/efeitos adversos , Rhipicephalus/efeitos dos fármacos , Inquéritos e Questionários , Controle de Ácaros e Carrapatos/estatística & dados numéricos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/prevenção & controle , Doenças Transmitidas por Carrapatos/veterinária , Toluidinas/administração & dosagem , Toluidinas/efeitos adversos , Uganda/epidemiologia
10.
Acta Trop ; 179: 47-54, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29287758

RESUMO

Ticks act as vectors of a wide range of infectious agents, far encompassing any other group of bloodsucking arthropods worldwide. The prevention of tick-borne diseases is strictly linked to the successful management of tick vector populations. The employ of repellents can represent a worth solution to avoid tick bites. It is widely adopted to protect travellers and pets exposed to ticks during limited periods of the year. The use of natural products as active ingredients in eco-friendly repellent formulations is currently a prominent research area, due to the wide diversity and high effectiveness of a number of plant-borne compounds, with special reference to essential oils (EOs) extracted from medicinal and aromatic species. Here, we reviewed current knowledge available on EOs tested as repellents against tick species of veterinary importance. Furthermore, we analysed the effectiveness of pure compounds isolated from EOs as tick repellents and their potential implications for practical use in the öreal world". A quantitative analysis of literature available is this research field was provided, along with its impact (i.e., in terms of citations over time) on the scientific community of researchers in tick control science and natural product chemistry. In the final sections, future outlooks are highlighted. We discussed major challenges to stabilize the most effective EOs and pure molecules, explore the synergistic and antagonistic effects in blends of EOs and/or pure constituents, standardize currently adopted testing methods, and evaluate non-target risks of herbal repellents.


Assuntos
Repelentes de Insetos/farmacologia , Óleos Voláteis/farmacologia , Doenças Transmitidas por Carrapatos/prevenção & controle , Carrapatos/efeitos dos fármacos , Animais , Vetores Artrópodes/efeitos dos fármacos , Humanos , Doenças Transmitidas por Carrapatos/veterinária
11.
Chem Biodivers ; 15(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28801935

RESUMO

This work presents the biocidal (insecticidal, ixodicidal, nematicidal, and phytotoxic) effects and chemical compositions of three essential oils obtained from the industrial steam distillation (IEOs) of hyssop (Hyssopus officinalis L.), lavandin (Lavandula × intermedia or L. × hybrida var. Super), and cotton lavender (Santolina chamaecyparissus L.). Their chemical composition analyzed by gas chromatography coupled to mass spectrometry showed 1,8-cineole (53%) and ß-pinene (16%) as the major components of H. officinalis, linalyl acetate (38%) and linalool (29%) of L. × intermedia; and 1,8-cineole (10%) and 8-methylene-3-oxatricyclo[5.2.0.02,4 ]nonane (8%) in S. chamaecyparissus. The biocidal tests showed that L. × intermedia IEO was the most active against the insect Spodoptera littoralis and toxic to the tick Hyalomma lusitanicum, IEO of H. officinalis was strongly active against S. littoralis, and finally, S. chamaecyparissus IEO was a strong antifeedant against the aphid Rhopalosiphum padi, toxic to H. lusitanicum and with moderate effects against Leptinotarsa decemlineata, S. littoralis, and Lolium perenne.


Assuntos
Asteraceae/química , Hyssopus/química , Inseticidas/farmacologia , Lavandula/química , Óleos Voláteis/farmacologia , Animais , Afídeos/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inseticidas/química , Inseticidas/isolamento & purificação , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Spodoptera/efeitos dos fármacos , Relação Estrutura-Atividade , Carrapatos/efeitos dos fármacos
12.
Parasit Vectors ; 10(1): 527, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29089050

RESUMO

BACKGROUND: There is a continuing need for novel approaches to tick control in dogs. One such approach lies in the ability of lotilaner (Credelio™), an isoxazoline with a rapid onset of action, to provide sustained efficacy against ticks. Two studies were undertaken to confirm lotilaner's efficacy, at the minimum dose rate of 20 mg/kg, against the three most common tick species in Europe. METHODS: In each of two studies, 16 Beagle dogs, at least 6 months old, were ranked and blocked by tick counts from infestations placed approximately 1 week before treatment. Within blocks, dogs were randomized to receive either lotilaner flavoured chewable tablets at as close as possible to, but not less than the minimum dose rate of 20 mg/kg, or to be sham-treated controls. Study 1 assessed lotilaner efficacy against concurrent infestations with 50 (± 6) Rhipicephalus sanguineus and 70 (± 6) Ixodes ricinus; Study 2 infestations were with 50 (± 2) Dermacentor reticulatus. Infestations were performed on Day -2 with counts on Day 2, 48 (± 2) hours post-treatment. Post-treatment infestations were performed on Days 7, 14, 21, 28 and 35, and ticks were counted 48 (±2) hours post-infestations. Efficacy was determined by the percent reduction in mean live tick counts. RESULTS: Control group infestations for each tick species were adequate for assessing lotilaner efficacy at all assessment times. On Day 2 no live ticks were found on any lotilaner-treated dog. For subsequent counts, in Study 1 lotilaner was 100% effective in eliminating live I. ricinus and R. sanguineus on all but two occasions for each tick; on each of those occasions efficacy was sustained at greater than 98.0%. In Study 2, except for a single unattached live tick found on Day 16, efficacy against D. reticulatus was 100% at every post-treatment assessment. CONCLUSION: The high and sustained efficacy against the three common species of ticks in Europe, R. sanguineus, I. ricinus and D. reticulatus, demonstrates that lotilaner can be a valuable tool in the treatment of canine tick infestations. Lotilaner flavoured chewable tablets were well tolerated and effectiveness was sustained through at least 35 days.


Assuntos
Acaricidas/uso terapêutico , Dermacentor/efeitos dos fármacos , Doenças do Cão/tratamento farmacológico , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Acaricidas/administração & dosagem , Acaricidas/efeitos adversos , Animais , Doenças do Cão/parasitologia , Cães , Europa (Continente) , Feminino , Ixodes/efeitos dos fármacos , Masculino , Rhipicephalus sanguineus/efeitos dos fármacos , Controle de Ácaros e Carrapatos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/parasitologia , Carrapatos/classificação , Fatores de Tempo
14.
Trop Anim Health Prod ; 49(8): 1613-1621, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28752214

RESUMO

Ticks and tickborne diseases (TBDs) are serious constraints to cattle production in Tanzania and other tropical and subtropical countries. Among the TBDs, East Coast fever (ECF) is the most important as it causes significant economic losses to the cattle industry in Tanzania. However, control of ECF in Tanzania has continued to be a challenge due to inadequate epidemiological information. The main objective of this study was to determine the epidemiological situation of Theileria parva infections in cattle kept under pastoral and agro-pastoral farming systems in Mara, Singida, and Mbeya regions of Tanzania. Blood samples were collected from 648 cattle in the three regions. Genomic DNA was extracted and amplified in a polymerase chain reaction (PCR) using T. parva-specific primers targeting the 104-kD antigen (P104) gene. In addition, information was collected on the possible risk factors of T. parva infection (animal age, region, animal sex, tick burden, tick control method, and frequency of acaricide application). The prevalence of T. parva across the three regions was 14.2%. There was variation in prevalence among the three regions with Mara (21.8%) having a significantly higher (p = 0.001) prevalence than the other regions. Moreover, Mbeya exhibited relatively lower prevalence (7.4%) compared to the other regions. Factors found to be significantly associated with an animal being PCR positive for T. parva were region (p = 0.001) and tick burden (p = 0.003). Other factors were not found to be significant predictors of being PCR positive for T. parva. The present study showed high variation in tick burden and T. parva prevalence across the regions. Therefore, different strategic planning and cost-effective control measures for ticks and T. parva infection should be implemented region by region in order to reduce losses caused by ticks and ECF in the study area.


Assuntos
Theileria parva , Theileriose/epidemiologia , Acaricidas/farmacologia , Animais , Bovinos , Reação em Cadeia da Polimerase/veterinária , Prevalência , Fatores de Risco , Tanzânia/epidemiologia , Theileriose/prevenção & controle , Controle de Ácaros e Carrapatos/métodos , Carrapatos/efeitos dos fármacos
15.
Arq. bras. med. vet. zootec. (Online) ; 69(3): 523-528, jun. 2017. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-846836

RESUMO

The acaricidal activity of crude ethanolic extract and fractions from the leaves of Morus nigra (Moraceae) was carried out on female cattle ticks Rhipicephalus microplus, using the adult immersion test. The mortality and fertility of females exposed to different concentrations of hexane, chloroform and ethyl acetate fractions, as well as ethanolic extract of M. nigra with concentrations of 5, 10 and 25mg/ml were evaluated using three treatment groups, two control groups and triplicate tests. The study also identified the main phenolic compounds of the extract and fractions of this species by HPLC. The chloroform fraction of leaves of M. nigra (25mg/mL) showed the best results for this species, obtaining 62.6% of inhibition of oviposition, 39.3% of eggs eclosion average and 65.4% of effectiveness. HPLC analysis revealed the presence of phenolic compounds, which may be related to biological activity shown by the extracts, which can be used as an alternative control against R. microplus adult tick.(AU)


A atividade acaricida do extrato etanólico bruto e das frações das folhas de Morus nigra (Moraceae) foi avaliada no carrapato Rhipicephalus microplus, utilizando-se o teste de imersão de fêmeas ingurgitadas. Foram avaliadas a mortalidade e a fertilidade das fêmeas ingurgitadas, expostas a diferentes concentrações (5, 10 e 25 mg/mL) das frações hexânica, clorofórmica e acetato de etila, bem como do extrato etanólico. Os testes foram realizados em triplicata. O estudo também identificou os principais compostos fenólicos do extrato e das frações dessa espécie por HPLC. A fração clorofórmica das folhas de M. nigra (25mg/mL) apresentou o melhor resultado para essa espécie, obtendo-se 62,6% de inibição da oviposição, 39,3% da eclosão dos ovos e 65,4% de eficácia. A análise por HPLC revelou a presença de compostos fenólicos, os quais podem estar relacionados com a atividade biológica demonstrada pelos extratos, que podem ser utilizados como auxiliar no controle contra carrapato adulto de R. microplus.(AU)


Assuntos
Animais , Acaricidas/análise , Morus/toxicidade , Extratos Vegetais/uso terapêutico , Rhipicephalus/efeitos dos fármacos , Controle de Ácaros e Carrapatos/métodos , Cromatografia Líquida de Alta Pressão/veterinária , Carrapatos/efeitos dos fármacos
16.
Vet Parasitol ; 238: 66-76, 2017 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-28385541

RESUMO

The present review documents the results of studies evaluating the acaricidal activity of different plant products and secondary metabolites against ticks that are resistant and susceptible to conventional acaricides. Studies published from 1998 to 2016 were included. The acaricidal activity of plant extracts, essential oils and secondary compounds from plants have been evaluated using bioassays with ticks in the larval and adult stages. There is variable effectiveness according to the species of plant and the concentrations used, with observed mortalities ranging from 5 to 100% against the Rhipicephalus (Boophilus), Amblyomma, Dermacentor, Hyalomma, and Argas genera. A number of plants have been reported to cause high mortalities and/or affect the reproductive capacity of ticks in the adult phase. In the majority of these trials, the main species of plants evaluated correspond to the families Lamiaceae, Fabaceae, Asteraceae, Piperaceae, Verbenaceae, and Poaceae. Different secondary metabolites such as thymol, carvacrol, 1,8-cineol and n-hexanal, have been found to be primarily responsible for the acaricidal activity of different essential oils against different species of ticks, while nicotine, dibenzyldisulfide and dibenzyltrisulfide have been evaluated for plant extracts. Only thymol, carvacrol and 1,8-cineol have been evaluated for acaricidal activity under in vivo conditions. The information in the present review allows the conclusion that the secondary metabolites contained in plant products could be used as an alternative for the control of ticks that are susceptible or resistant to commercial acaricides.


Assuntos
Acaricidas/farmacologia , Extratos Vegetais/farmacologia , Carrapatos/efeitos dos fármacos , Animais , Extratos Vegetais/química , Plantas Medicinais/química
17.
Exp Appl Acarol ; 71(3): 303-317, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28251408

RESUMO

Ticks and tick-borne diseases are a major constraint for the sustainable cattle industry in the tropical and subtropical regions including the Indian subcontinent. The development of resistance to most of the commonly used acaricides leads to an attempt to screen plant extracts and their combinations for their possible acaricidal activity to develop an eco-friendly tick control alternative. An alcoholic and various aqueous extracts of Piper longum, Piper nigrum and Zingiber officinale and their combinations were evaluated for acaricidal activity against the three-host ixodid tick, Hyalomma anatolicum by larval immersion test using 14-21 days old unfed larvae. The efficacy was assessed by measuring larval mortality (%) and the lethal concentrations for 50% (LC50) and 95% (LC95) with their 95% confidence limits (CL) values were estimated by applying regression equation analysis to the probit transformed data of mortality. A concentration-dependent mortality response was recorded in all extracts prepared from seeds of P. longum and P. nigrum and their combinations. The highest acaricidal property was exhibited by the alcoholic extract of P. longum seeds with the minimum LC50 and LC95 (95% CL) values of 0.071% (0.07-0.072) and 0.135% (0.13-0.14), respectively, followed by alcoholic combinations. Interestingly, no acaricidal activity was recorded in extracts prepared from the rhizome of Z. officinale. The results indicated that the ethanolic extracts of P. longum and P. nigrum and their combinations can be used effectively for tick control in an integrated format.


Assuntos
Acaricidas/farmacologia , Extratos Vegetais/farmacologia , Carrapatos/efeitos dos fármacos , Animais , Gengibre/química , Piper/química , Piper nigrum/química , Extratos Vegetais/química
18.
Chem Biol Interact ; 263: 1-6, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27986436

RESUMO

An outbreak of the southern cattle tick, Rhipicephalus (Boophilus) microplus, (Canestrini), in the United States would have devastating consequences on the cattle industry. Tick populations have developed resistance to current acaricides, highlighting the need to identify new biochemical targets along with new chemistry. Furthermore, acaricide resistance could further hamper control of tick populations during an outbreak. Botanically-based compounds may provide a safe alternative for efficacious control of the southern cattle tick. We have developed a heterologous expression system that stably expresses the cattle tick's tyramine receptor with a G-protein chimera, producing a system that is amenable to high-throughput screening. Screening an in-house terpenoid library, at two screening concentrations (10 µM and 100 µM), has identified four terpenoids (piperonyl alcohol, 1,4-cineole, carvacrol and isoeugenol) that we believe are positive modulators of the southern cattle tick's tyramine receptor.


Assuntos
Acaricidas/metabolismo , Óleos Voláteis/química , Receptores de Amina Biogênica/metabolismo , Terpenos/metabolismo , Carrapatos/enzimologia , Acaricidas/química , Acaricidas/toxicidade , Animais , Células CHO , Bovinos , Cricetinae , Cricetulus , Plasmídeos/genética , Plasmídeos/metabolismo , Ligação Proteica , Receptores de Amina Biogênica/antagonistas & inibidores , Receptores de Amina Biogênica/genética , Terpenos/química , Terpenos/toxicidade , Carrapatos/efeitos dos fármacos
19.
PLoS Negl Trop Dis ; 10(12): e0005248, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28027324

RESUMO

BACKGROUND: African animal trypanosomosis (AAT), transmitted by tsetse flies and tick-borne diseases are the main constraints to livestock production in sub-Saharan Africa. Vector control methods such as pour-on offer individual protection against ticks but not against tsetse so far, for which protection has always been communal, through a reduction of their density. The latter requires the treatment of a large part of the herd in a given landscape and is not instantaneous. METHODOLOGY/PRINCIPAL FINDINGS: Two prospective surveys were conducted to evaluate the efficacy and persistence of a pour-on formulation composed of cypermetrhin, chlorpyrifos, piperonyl butoxid and citronella (Vectoclor, CEVA Santé Animal). In experimental conditions, tsetse flies were exposed to treated and control cattle. Flies knockdown and engorgement rates were determined and the product persistence was assessed as the time for these parameters to drop below 50% (T50). T50 was 37 days (95%CI: [33-41] days) and 46 days (95%CI: [39-56] days) for the knockdown and engorgement rates respectively. In field conditions, two cattle herds were monitored following a case-control experimental design, in the Adamaoua region of Cameroon. One herd was treated once with Vectoclor pour-on (treated group) and the second used as a control group (not treated). Ticks infestation rate, trypanosomosis prevalence and packed-cell volume were measured over the two months following treatment. The treatment was highly effective against ticks with a complete elimination three days after application in the treated group. Trypanosomosis prevalence was also significantly reduced during the study (by 4, P<0.001) and PCV of the treated group increased significantly in the same time (P<0.001), contrary to the control group. CONCLUSIONS/SIGNIFICANCE: The protection of this new pour-on against tsetse bites and trypanosomosis is demonstrated here for the first time. Moreover, this insecticide and repellent mixture offer a longer persistence of the efficacy against both tsetse and ticks than similar products currently on the market. It offers a great new opportunity for an integrated AAT control strategy including the treatment of residual cases with trypanocides. It might also allow controlling the spread of resistance against these trypanocides.


Assuntos
Repelentes de Insetos/administração & dosagem , Inseticidas/administração & dosagem , Tripanossomicidas/administração & dosagem , Tripanossomíase Bovina/prevenção & controle , Animais , Camarões , Estudos de Casos e Controles , Bovinos , Controle de Insetos , Estudos Prospectivos , Estações do Ano , Carrapatos/efeitos dos fármacos , Trypanosoma , Tripanossomíase Bovina/epidemiologia , Moscas Tsé-Tsé/efeitos dos fármacos
20.
Res Vet Sci ; 109: 1-9, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27892855

RESUMO

Ticks transmit at least the same number or even more pathogens than any other group of blood-feeding arthropods worldwide affecting humans and animals. The eco-friendly control and management of tick vectors in a constantly changing environment is a crucial challenge. Besides the development of vaccines against ticks, IPM practices aimed at reducing tick interactions with livestock, emerging pheromone-based control tools, and few biological control agents, the extensive employment of acaricides and tick repellents still remain the most effective and ready-to-use strategies. However, the former is limited by the development of growing resistances as well as environmental concerns. Exploiting plants and plant products as sources of effective tick repellents and acaricides represents a promising strategy. In this scenario, the preservation of ethnobotanical information on repellent and acaricidal potential of plants is crucial. Here, we evaluated relevant information published in recent years, focused on plants used as repellents and acaricides against tick vectors in different regions worldwide. We selected a total of 238 plant species, which are traditionally used against ticks by native and local communities of Africa (Kenya, Uganda, Zimbabwe, South Africa), Europe (Serbia, Macedonia, Romania), Asia (Pakistan, India) and America (Brazil, Canada), from 56 families. However, only 7 families (i.e. Asteraceae, Euphorbiaceae, Fabaceae, Lamiaceae, Meliaceae, Apocynaceae and Solanaceae) represent the major quote (46%) of all plant species. We evaluated the differences in acaricidal and repellent efficacy of different formulations used. In the final section, implications arising from the surveyed anti-tick ethnobotanical knowledge and challenges for its future are discussed.


Assuntos
Acaricidas/farmacologia , Repelentes de Insetos/farmacologia , Gado , Infestações por Carrapato/veterinária , Carrapatos/efeitos dos fármacos , Animais , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controle
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