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1.
Viruses ; 12(2)2020 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-31991915

RESUMO

Ticks transmit a wide variety of pathogens including bacteria, parasites and viruses. Over the last decade, numerous novel viruses have been described in arthropods, including ticks, and their characterization has provided new insights into RNA virus diversity and evolution. However, little is known about their ability to infect vertebrates. As very few studies have described the diversity of viruses present in ticks from the Caribbean, we implemented an RNA-sequencing approach on Amblyomma variegatum and Rhipicephalus microplus ticks collected from cattle in Guadeloupe and Martinique. Among the viral communities infecting Caribbean ticks, we selected four viruses belonging to the Chuviridae, Phenuiviridae and Flaviviridae families for further characterization and designing antibody screening tests. While viral prevalence in individual tick samples revealed high infection rates, suggesting a high level of exposure of Caribbean cattle to these viruses, no seropositive animals were detected. These results suggest that the Chuviridae- and Phenuiviridae-related viruses identified in the present study are more likely tick endosymbionts, raising the question of the epidemiological significance of their occurrence in ticks, especially regarding their possible impact on tick biology and vector capacity. The characterization of these viruses might open the door to new ways of preventing and controlling tick-borne diseases.


Assuntos
Doenças dos Bovinos , Flaviviridae/isolamento & purificação , Ixodidae/virologia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , Rhipicephalus/virologia , Infestações por Carrapato/veterinária , Animais , Anticorpos Antivirais/sangue , Bovinos/imunologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Suscetibilidade a Doenças , Flaviviridae/genética , Flaviviridae/imunologia , Genoma Viral , Martinica , Filogenia , Vírus de RNA/genética , Vírus de RNA/imunologia , RNA Viral/análise , RNA Viral/genética , Estudos Soroepidemiológicos , Infestações por Carrapato/imunologia , Índias Ocidentais
2.
Exp Parasitol ; 208: 107812, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31809704

RESUMO

The bovine tick, Rhipicephalus microplus, is the main ectoparasite of cattle and causes loss of billions of dollars worldwide in lost meat, milk, and leather production, as well as control expenses. In addition to systemically impacting the host during the parasitic act, this parasite is also an important disease vector. Traditionally, the main commercial control of the tick is achieved through application of chemical acaricides, which can leave residues in the meat and milk. Moreover, ticks can become resistant to these chemicals due to their massive and incorrect use. Many alternative methods have been tested including vaccines and natural products from plant origin. However, the efficacy of these treatments is variable and limited, especially when used alone. Arthropod-pathogenic fungi, such as Metarhizium anisopliae, are among the natural microbial agents with promising potential to be used alone or in association with other products, for example with chemical acaricides. This article discusses several aspects of bovine tick control related to the use of M. anisopliae, which is one of the most studied and viable alternative tools for effective tick control.


Assuntos
Doenças dos Bovinos/prevenção & controle , Metarhizium/fisiologia , Controle Biológico de Vetores/métodos , Rhipicephalus , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/economia , Doenças dos Bovinos/parasitologia , Controle Biológico de Vetores/normas , Rhipicephalus/microbiologia , Rhipicephalus/fisiologia , Infestações por Carrapato/economia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
3.
Parasitol Int ; 74: 101980, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31518651

RESUMO

To date, no information is available regarding the infection of camels (Camelus dromedarius) by Anaplasma ovis in North African region. Several animal species can be infected by A. ovis which further complicates its natural infection cycle. In this paper, we investigated the occurrence and the genetic diversity of A. ovis in camels and ticks collected from them in Tunisia and the risk factor analysis. Camel blood samples (n = 412) and tick (n = 300) samples, identified as Hyalomma dromedarii (n = 149, 49.6%), H. impeltatum (n = 142, 47.3%) and H. excavatum (n = 9, 3%), were analyzed by conventional PCR followed by the sequencing of msp4 and groEL genes. A. ovis DNA was identified in five camels (1.2%), but not in infesting ticks (0%). The microscopic examination revealed the specific infection of camel erythrocytes by Anaplasma inclusions. The msp4 and groEL typing confirmed the natural infection of camels by A. ovis and revealed two different msp4 genotypes earlier detected in Tunisian small ruminants and their infested ticks, and five different and novel groEL genetic variants forming a separately sub-cluster within A. ovis cluster. The occurrence of different A. ovis strains specific to camels associated with a low prevalence of this Anaplasma species in camels may enrich knowledge regarding the distribution and the transmission cycle of this bacterium in arid and Saharan areas of Tunisia.


Assuntos
Anaplasma/genética , Proteínas de Bactérias/genética , Camelus/microbiologia , Chaperonina 60/genética , Variação Genética , Carrapatos/microbiologia , Anaplasmose/sangue , Anaplasmose/epidemiologia , Animais , Feminino , Genótipo , Masculino , Filogenia , RNA Ribossômico 16S/genética , Infestações por Carrapato/veterinária , Tunísia/epidemiologia
4.
Parasit Vectors ; 12(1): 509, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666109

RESUMO

BACKGROUND: Haemaphysalis longicornis is the major tick affecting dogs in most of the East Asia/Pacific region and has recently been detected in a number of areas of the USA. This tick is a vector for a number of pathogens of dogs, other mammals and humans. In this study, the efficacy of a single oral administration of sarolaner (Simparica®, Zoetis) at the minimum label dosage (2 mg/kg) was evaluated against an existing infestation of H. longicornis and subsequent weekly reinfestations for 5 weeks after treatment. METHODS: Sixteen dogs were ranked on pretreatment tick counts and randomly allocated to treatment on Day 0 with sarolaner at 2 mg/kg or a placebo. The dogs were infested with H. longicornis nymphs on Days - 2, 5, 12, 19, 26 and 33. Efficacy was determined at 48 hours after treatment and subsequent re-infestations based on live tick counts relative to placebo-treated dogs. RESULTS: There were no adverse reactions to treatment. A single dose of sarolaner provided 100% efficacy on Days 2, 7, 14 and 21; and ≥ 97.4% efficacy on Days 28 and 35. Considering only attached, live ticks, efficacy was 100% for the entire 35 days of the study. Geometric mean live tick counts for sarolaner were significantly lower than those for placebo on all days (11.62 ≤ t(df) ≤ 59.99, where 13.0 ≤ df ≤ 14.1, P < 0.0001). CONCLUSIONS: In this study, a single oral administration of sarolaner at 2 mg/kg provided 100% efficacy against an existing infestation of H. longicornis nymphs and ≥ 97.4% efficacy (100% against attached ticks) against weekly reinfestation for at least 35 days after treatment.


Assuntos
Antiparasitários/uso terapêutico , Vetores Aracnídeos , Azetidinas/uso terapêutico , Doenças do Cão/tratamento farmacológico , Ixodidae , Compostos de Espiro/uso terapêutico , Infestações por Carrapato/veterinária , Administração Oral , Animais , Antiparasitários/administração & dosagem , Azetidinas/administração & dosagem , Doenças do Cão/parasitologia , Doenças do Cão/prevenção & controle , Cães , Compostos de Espiro/administração & dosagem , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/prevenção & controle
5.
Parasit Vectors ; 12(1): 495, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640746

RESUMO

BACKGROUND: Our study aimed to assess the diversity of the species of Anaplasmataceae in Senegal that infect animals and ticks in three areas: near Keur Momar Sarr (northern region), Dielmo and Diop (Sine Saloum, central region of Senegal), and in Casamance (southern region of Senegal). METHODS: A total of 204 ticks and 433 blood samples were collected from ruminants, horses, donkeys and dogs. Ticks were identified morphologically and by molecular characterization targeting the 12S rRNA gene. Molecular characterization of species of Anaplasmataceae infecting Senegalese ticks and animals was conducted using the 23S rRNA, 16S rRNA, rpoB and groEL genes. RESULTS: Ticks were identified as Rhipicephalus evertsi evertsi (84.3%), Hyalomma rufipes (8.3%), Hyalomma impeltatum (4.9%), R. bursa (1.5%) and R. muhsamae (0.9%). The overall prevalence of Anaplasmataceae infection in ticks was 0.9%, whereas 41.1% of the sampled animals were found infected by one of the species belonging to this family. We identified the pathogen Anaplasma ovis in 55.9% of sheep, A. marginale and A. centrale in 19.4% and 8.1%, respectively, of cattle, as well as a putative new species of Anaplasmataceae. Two Anaplasma species commonly infecting ruminants were identified. Anaplasma cf. platys, closely related to A. platys was identified in 19.8% of sheep, 27.7% of goats and 22.6% of cattle, whereas a putative new species, named here provisionally "Candidatus Anaplasma africae", was identified in 3.7% of sheep, 10.3% of goats and 8.1% of cattle. Ehrlichia canis and Anaplasma platys were identified only from dogs sampled in the Keur Momar Sarr area. Ehrlichia canis was identified in 18.8% of dogs and two R. e. evertsi ticks removed from the same sheep. Anaplasma platys was identified in 15.6% of dogs. Neither of the dogs sampled from Casamance region nor the horses and donkeys sampled from Keur Momar Sarr area were found infected by an Anaplasmataceae species. CONCLUSIONS: This study presents a summary of Anaplasmataceae species that infect animals and ticks in three areas from the northern, central and southern regions of Senegal. To our knowledge, our findings demonstrate for the first time the presence of multiple Anaplasmataceae species that infect ticks and domestic animals in Senegal. We recorded two potentially new species commonly infecting ruminants named here provisionally as Anaplasma cf. platys and "Candidatus Anaplasma africae". However, E. canis was the only species identified and amplified from ticks. None of the other Anaplasmataceae species identified in animals were identified in the tick species collected from animals.


Assuntos
Infecções por Anaplasmataceae/veterinária , Anaplasmataceae/classificação , Anaplasmataceae/genética , Animais Domésticos/microbiologia , Carrapatos/microbiologia , Infecções por Anaplasmataceae/microbiologia , Animais , Animais Domésticos/parasitologia , Bovinos , Chaperonina 60/genética , DNA Ribossômico/sangue , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , RNA Polimerases Dirigidas por DNA/genética , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Equidae/microbiologia , Equidae/parasitologia , Feminino , Variação Genética , Cabras , Doenças dos Cavalos/microbiologia , Doenças dos Cavalos/parasitologia , Cavalos , Masculino , Filogenia , RNA Ribossômico/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Ruminantes/microbiologia , Ruminantes/parasitologia , Senegal , Alinhamento de Sequência/veterinária , Ovinos , Infestações por Carrapato/complicações , Infestações por Carrapato/veterinária
6.
Parasit Vectors ; 12(1): 489, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623642

RESUMO

BACKGROUND: Ticks and tick-borne diseases are a major impediment to livestock production worldwide. Cattle trade and transnational transhumance create risks for the spread of ticks and tick-borne diseases and threaten cattle production in the absence of an effective tick control program. Few studies have been undertaken on cattle ticks in the Central African region; therefore, the need to assess the occurrence and the spatial distribution of tick vectors with the aim of establishing a baseline for monitoring future spread of tick borne-diseases in the region is urgent. RESULTS: A total of 7091 ixodid ticks were collected during a countrywide cross-sectional field survey and identified using morphological criteria. Of these, 4210 (59.4%) ticks were Amblyomma variegatum, 1112 (15.6%) Rhipicephalus (Boophilus) microplus, 708 (10.0%) Rhipicephalus (Boophilus) decoloratus, 28 (0.4%) Rhipicephalus (Boophilus) annulatus, 210 (3.0%) Hyalomma rufipes, 768 (10.8%) Hyalomma truncatum, and 19 (0.3%) Rhipicephalus sanguineus. Three ticks of the genus Hyalomma spp. and 33 of the genus Rhipicephalus spp. were not identified to the species level. Cytochrome c oxidase subunit 1 (cox1) gene sequencing supported the data from morphological examination and led to identification of three additional species, namely Hyalomma dromedarii, Rhipicephalus sulcatus and Rhipicephalus pusillus. The finding of the invasive tick species R. microplus in such large numbers and the apparent displacement of the indigenous R. decoloratus is highly significant since R. microplus is a highly efficient vector of Babesia bovis. CONCLUSIONS: This study reports the occurrence and current geographical distribution of important tick vectors associated with cattle in Cameroon. It appears that R. microplus is now well established and may be displacing native Rhipicephalus (Boophilus) species, such as R. decoloratus. This calls for an urgent response to safeguard the livestock sector in western central Africa.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Infestações por Carrapato/veterinária , Carrapatos/fisiologia , Agricultura , Animais , Camarões/epidemiologia , Bovinos , Sequência Consenso , Estudos Transversais , Ciclo-Oxigenase 1/genética , Demografia , Feminino , Masculino , Filogenia , Prevalência , Alinhamento de Sequência/veterinária , Razão de Masculinidade , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Carrapatos/classificação , Carrapatos/crescimento & desenvolvimento
7.
Ticks Tick Borne Dis ; 10(6): 101285, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31494069

RESUMO

Two ticks were collected from a reticulated python (Malayopython reticulatus) caught in Tumpat District, Kelantan, Peninsular Malaysia. The ticks were first identified as Ambylomma sp. through morphological comparison with identification keys. Determination of the tick species was made through PCR and sequencing. However, BLAST analysis revealed 85-88% sequence nucleotide identity with Amblyomma nitidum and Amblyomma geoemydae. Additionally, the morphological features of the ticks collected in this study did not match either A. nitidum or A. geoemydae. Further examination of the ticks confirmed the species as Amblyomma cordiferum. This is the first record of A. cordiferum DNA sequence with morphological support of colour illustrations for adult A. cordiferum. This is also the most recent record of this host association in Peninsular Malaysia. Information from this report can serve as a reference for species identification using the described morphology or molecular sequences.


Assuntos
Boidae , Ixodidae/fisiologia , Infestações por Carrapato/veterinária , Animais , Feminino , Ixodidae/classificação , Malásia , Filogenia , Infestações por Carrapato/parasitologia
8.
Parasit Vectors ; 12(1): 434, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492171

RESUMO

BACKGROUND: The density of questing ticks infected with tick-borne pathogens is an important parameter that determines tick-borne disease risk. An important factor determining this density is the availability of different wildlife species as hosts for ticks and their pathogens. Here, we investigated how wildlife communities contribute to tick-borne disease risk. The density of Ixodes ricinus nymphs infected with Borrelia burgdorferi (sensu lato), Borrelia miyamotoi, Neoehrlichia mikurensis and Anaplasma phagocytophilum among 19 forest sites were correlated to the encounter probability of different vertebrate hosts, determined by encounter rates as measured by (camera) trapping and mathematical modeling. RESULT: We found that the density of any tick life stage was proportional to the encounter probability of ungulates. Moreover, the density of nymphs decreased with the encounter probability of hare, rabbit and red fox. The density of nymphs infected with the transovarially-transmitted B. miyamotoi increased with the density of questing nymphs and the encounter probability of bank vole. The density of nymphs infected with all other pathogens increased with the encounter probability of competent hosts: bank vole for Borrelia afzelii and N. mikurensis, ungulates for A. phagocytophilum and blackbird for Borrelia garinii and Borrelia valaisiana. The negative relationship we found was a decrease in the density of nymphs infected with B. garinii and B. valaisiana with the encounter probability of wood mouse. CONCLUSIONS: Only a few animal species drive the densities of infected nymphs in forested areas. There, foxes and leporids have negative effects on tick abundance, and consequently on the density of infected nymphs. The abundance of competent hosts generally drives the abundances of their tick-borne pathogen. A dilution effect was only observed for bird-associated Lyme spirochetes.


Assuntos
Doenças dos Animais/epidemiologia , Biota , Florestas , Ixodes/microbiologia , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/veterinária , Vertebrados/parasitologia , Anaplasma/isolamento & purificação , Animais , Borrelia/isolamento & purificação , Ehrlichia/isolamento & purificação , Ixodes/crescimento & desenvolvimento , Densidade Demográfica , Medição de Risco , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia
9.
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
10.
Exp Appl Acarol ; 79(1): 99-106, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489557

RESUMO

Given the difficulties of controlling the tick Rhipicephalus microplus due to acaricide resistance, this study aimed to ascertain whether shearing could reduce infestation in cattle. 17 taurine cattle were sheared on the anterior third of one randomly selected side. Shearing was undertaken using a machine with a blade, leaving coats with a thickness of 1 mm. Subsequently, eight evaluations were performed once a week, counting adult females of R. microplus with a diameter > 4.5 mm on the anterior third of both sides (shorn and unshorn). The coat length was also monitored by taking five hair samples from each animal fortnightly (1, 15, 29, 43 and 57 days post shorn) from a central area of both shoulders (shorn and unshorn). The tick counts and hair length data were transformed for normalisation and were analysed using mixed models. The tick and hair length means were significantly higher for the unshorn side. Tick counts were significantly lower on the sheared side until the fifth evaluation, with the final three presenting no differences between the sides. The hair length was significantly lower for the sheared side during the five evaluations. We conclude that as the hair length increased, there was also an increase in the number of ticks on the sheared side. Although this method is not practical for large herds, it can be deemed an option in extreme conditions of tick infestation. In addition, the study reinforces the suggestion that the selection and/or use of cattle with shorter hairs may contribute to reduced tick infestation.


Assuntos
Criação de Animais Domésticos/métodos , Doenças dos Bovinos/prevenção & controle , Cabelo , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle
11.
Exp Appl Acarol ; 79(1): 137-155, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489558

RESUMO

The objective of the present study was to detect the chosen nucleotide DNA or RNA sequences of the pathogens in ticks of domestic and wild animals of Kerala, South India based on molecular techniques. Among 602 ticks collected, 413 were from bovines (cattle and buffalo), 26 from goats, 101 from dogs and 62 from wild animals. Amblyomma integrum, Am. gervaisi, Dermacentor auratus, Haemaphysalis bispinosa, Ha. intermedia, Ha. shimoga, Ha. spinigera, Rhipicephalus annulatus, Rh. microplus, Rh. haemaphysaloides and Rh. sanguineus s.l. were identified from various domestic and wild animals of Kerala. The cDNA synthesized from the RNA isolated from fully or partially engorged adult female/nymphal ticks was used as template for the specific polymerase chain reactions (PCR). Out of 602 ticks examined, nucleotide sequences of pathogens were detected in 28 ticks (4.65%). The nucleotide sequences of tick-borne pathogens like Theileria orientalis, Babesia vogeli, Hepatozoon canis, Anaplasma marginale, An. bovis, Rickettsia sp. closely related to Ri. raoultii, Ri. massiliae, Ri. africae and Ri. slovaca were detected. The identification of the previously unreported nucleotide sequences of rickettsial pathogens from India is of particular interest due to their zoonotic significance. The phylogenetic analysis of the major piroplasm surface protein (MPSP) gene of T. orientalis amplified from Rh. annulatus ticks revealed that they were genetically close to type 7, which belong to the highly pathogenic Ikeda group.


Assuntos
Animais Selvagens , Eucoccidiida/isolamento & purificação , Interações Hospedeiro-Parasita , Ixodidae , Piroplasmida/isolamento & purificação , Rickettsiales/isolamento & purificação , Infestações por Carrapato/veterinária , Animais , Índia , Ixodidae/microbiologia , Ixodidae/parasitologia , Ixodidae/fisiologia , Filogenia , Infestações por Carrapato/parasitologia
12.
Vet Parasitol ; 273: 36-44, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442891

RESUMO

Rhipicephalus (Boophilus) microplus ticks cause major constraints to public and livestock health, and serious economic losses. It is well known that the immune response to infestations with cattle ticks is influenced by the host genetic background leading to distinct immunological profiles between bovine hosts genetically susceptible and resistant. The influence of Bos indicus (Bi) and Bos taurus (Bt) maternal lineage ancestry of mitochondrial DNA in the profile of the immune response of Zebu cattle to ticks remains unknown. The present work evaluated the hematological parameters and the immune response profile in the peripheral blood of a Guzerat dairy herd, further categorized into two maternal lineage ancestry subgroups (Bi-mtDNA and Bt-mtDNA) after experimental infestation with larvae of R. microplus. Our data demonstrated that although hematological and erythrogram analysis showed a similar profile throughout, some cell populations present a distinct profile between the groups. Especially MON, CD335+ and CD8+ T-cells are predominant in Bi-mtDNA. Moreover, an overall picture of R. microplus infestation demonstrated that Bi-mtDNA presented a more efficient and earlier innate immune response. Bi-mtDNA showed a greater number of connections with R. microplus counts and also with the CD25+ activation marker of the immune response. Bi-mtDNA showed greater number of connections, with an important participation of the innate immune while Bt-mtDNA showed a delay in the immune response. Elucidating the mechanisms by which resistant animals prevent heavy tick infestation is a crucial step in the development of predictive biomarkers for tick resistance for use in selective breeding programs, and is also potentially useful for the development of anti-tick vaccines.


Assuntos
Doenças dos Bovinos/imunologia , Interações Hospedeiro-Parasita/imunologia , Imunidade Inata/imunologia , Rhipicephalus/imunologia , Infestações por Carrapato/veterinária , Animais , Cruzamento , Bovinos , DNA Mitocondrial/genética , Indústria de Laticínios , Feminino , Perfilação da Expressão Gênica , Linfócitos T/imunologia , Infestações por Carrapato/imunologia
13.
Parasite ; 26: 49, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31432778

RESUMO

This experimental study aimed to determine the efficacy of Afoxolaner (NexGard®) to prevent Babesia rossi transmission by Haemaphysalis elliptica ticks on dogs. The study included three groups of seven dogs each. Groups 1 and 2 remained untreated, whereas group 3 dogs received NexGard® on Day 0. All dogs were infested by 50 Haemaphysalis elliptica adult ticks: Group 1 on Day 2, Group 2 on Day 28 and Group 3 on Days 2 and 28. The ticks were originally nymphs having fed on B. rossi infected donor dogs. Their infection rate, assessed by PCR, was 12.8% at Day 2 and 6% at Day 28. On Days 0, 7, 14, 21, 28, 35, 42, 49 and 56, and in case of suspicion of babesiosis, blood samples were collected for blood smears, PCR and ELISA. The B. rossi infection rate in the untreated group 1 was 100% (6/6, as one dog was inadvertently treated on Day 15 and removed from statistical analysis). The infection rate was 57.1% (4/7) in group 2, and 0% (0/7) in the afoxolaner treated group 3 at all time-points until the end of the study on Day 56. After tick removal and count 144 h after each infestation, the control groups had an arithmetic mean of ticks of 23.8 (group 1) and 26.8 (group 2). No tick was recovered from any treated dogs. This study demonstrated that NexGard® protected dogs against infection by B. rossi for at least 28 days.


Assuntos
Acaricidas/administração & dosagem , Babesiose/prevenção & controle , Doenças do Cão/prevenção & controle , Doenças do Cão/parasitologia , Isoxazóis/administração & dosagem , Naftalenos/administração & dosagem , Infestações por Carrapato/veterinária , Administração Oral , Animais , Babesia/genética , Babesiose/sangue , Babesiose/transmissão , Doenças do Cão/sangue , Cães/parasitologia , Feminino , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Resultado do Tratamento
14.
Vet Parasitol ; 273: 71-79, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31446256

RESUMO

Tick-borne diseases (TBD) constitute an important group of illness affecting animals and humans worldwide. In Brazil, carthorses are frequently exposed to ticks and tick-borne pathogens, leading to impairment of horse performance and imposing restrictions by the international veterinary authorities for the importation of horses. Accordingly, this study has aimed to i) determine the prevalence of the TBD agents Theileria equi, Babesia caballi, Ehrlichia spp., and hemotropic mycoplasmas in carthorses, ii) identify the tick species parasitizing the animals, and iii) determine factors associated with exposure/infection in Foz do Iguaçu City, Parana state, southern Brazil. A total of 103 carthorses were screened for anti-T. equi and anti-Ehrlichia spp. antibodies by indirect fluorescent antibody assays (IFA). Samples were also tested by PCR assays targeting the 18S rRNA gene of T. equi and B. caballi, and 16S rRNA gene of hemoplasmas. Additionally, PCR assays targeting the 16S rRNA, disulfide bond formation protein (dsb) and tandem repeat proteins 36 (trp36) genes of Ehrlichia spp. were also performed. Antibodies to T. equi and Ehrlichia spp. were detected in 43/103 (41.75%; 95% CI: 32.10-51.88%) and 5/103 (4.85%; 95% CI: 1.59-10.97%) horses by IFA, respectively. DNA of T. equi and B. caballi were found in 25/103 (24.27%; 95% CI: 16.36-33.71%) and 10/103 (9.71%; 95% CI: 4.75-17.13%) carthorses, respectively, and all tested negative for Ehrlichia spp. and hemoplasmas. All sequences showed ≥99% identity with multiple T. equi and B. caballi 18S rRNA gene sequences deposited in GenBank. Overall, 191 Dermacentor nitens ticks were collected from 25/103 (24.27%) animals. Carthorses older than 5 years were more likely to be positive for T. equi (p < 0.05). In conclusion, equine piroplasmosis agents are highly prevalent in carthorses from Foz do Iguaçu City. The low prevalence of Ehrlichia spp. found may be due to the absence of Amblyomma ticks infesting animals, which should be further investigated.


Assuntos
Doenças dos Cavalos/microbiologia , Doenças dos Cavalos/parasitologia , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos , Carrapatos/microbiologia , Carrapatos/parasitologia , Animais , Brasil , Técnica Indireta de Fluorescência para Anticorpo , Cavalos , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/genética , Theileria/genética , Infestações por Carrapato/microbiologia , Infestações por Carrapato/parasitologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia
15.
Ticks Tick Borne Dis ; 10(6): 101266, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31402227

RESUMO

The bacterium Rickettsia bellii has been detected in 25 species of ticks in the American continents, but its pathogenic potential is considered as undetermined. A possible role for this species in the phenomenon of transovarial exclusion of pathogenic members of the spotted fever group (SFG) of Rickettsia has been suggested and co-infections with pathogenic species have been reported infrequently in both North and South America. Traditional methods for the molecular detection of rickettsial agents in ticks focus largely on the identification of sequences found in SFG Rickettsia, an approach that may overlook the presence of co-infections with R. bellii. Two novel, species-specific polymerase chain reaction (PCR) assays, targeting the genes encoding the surface cell antigen (Sca), autotransporter proteins sca9 and sca14, were developed and validated for the detection of R. bellii using 150 Amblyomma ticks collected from wild birds in Brazil. Co-infection of R. bellii infected ticks was evaluated using a novel PCR assay targeting the ompA sequence characteristic of SFG Rickettsia. Preliminary species-level identification was achieved by restriction fragment length polymorphism (RFLP) analysis and subsequently confirmed by sequencing of amplicons. Nine out of seventy-three Amblyomma longirostre and one of two Amblyomma calcaratum ticks were shown to be co-infected with R. bellii and Rickettsia amblyommatis, while two out of sixty-seven Amblyomma sp. haplotype Nazaré ticks were recorded as co-infected with R. bellii and the Rickettsia parkeri-like bacterium, strain ApPR. Interestingly, our data represent the first records of R. bellii in association with A. calcaratum and Amblyomma sp. haplotype Nazaré. The novel PCR-RFLP systems reported herein, provide an alternative, rapid and cost-efficient (relative to strategies based on sequencing or real-time PCR), approach to evaluate rickettsial co-infection of ticks, a potentially significant phenomenon that has most likely been underestimated to date.


Assuntos
Ixodidae/microbiologia , Infecções por Rickettsia/veterinária , Rickettsia/isolamento & purificação , Animais , Doenças das Aves/diagnóstico , Doenças das Aves/microbiologia , Aves , Brasil , Coinfecção/veterinária , Rickettsia/genética , Infecções por Rickettsia/classificação , Infecções por Rickettsia/diagnóstico , Rickettsiose do Grupo da Febre Maculosa/classificação , Rickettsiose do Grupo da Febre Maculosa/diagnóstico , Rickettsiose do Grupo da Febre Maculosa/veterinária , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária
16.
Korean J Parasitol ; 57(3): 319-324, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31284358

RESUMO

This study aimed to investigate the tick species and give background for tick-borne investigations in Korea. Ticks were collected from the area within 2 km radius of the 4 domestic animal farms, where they were located in mountainous areas and raising animals on pasture, and from animal bodies in 2014 and 2015. In total, 7,973 nymphal and adult ticks were collected from the farms - 7,758 Haemaphysalis longicornis, 198 Haemaphysalis flava, and 17 Ixodes nipponensis, and 1,763 were collected from animals - 729 H. longicornis from cattle; 569 H. longicornis from goats; and 297 H. longicornis, 118 H. flava, 1 I. nipponensis, and 49 Amblyomma testudinarium from wild boars. As more species of ticks were collected from wild boars than domesticated animals and their habitats, various animal hosts should be considered while investigating tick species.


Assuntos
Bovinos/parasitologia , Cabras/parasitologia , Ixodidae/classificação , Sus scrofa/parasitologia , Infestações por Carrapato/veterinária , Animais , Animais Domésticos/parasitologia , Feminino , Ixodidae/genética , Ixodidae/fisiologia , Masculino , República da Coreia/epidemiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia
17.
Exp Appl Acarol ; 78(3): 431-442, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31270640

RESUMO

Tick-borne spotted fever in Brazil is known to be caused by two agents, Rickettsia rickettsii and Rickettsia parkeri. Nothing was known about these agents in one area of the Atlantic rainforest biome of Bahia state, where during March to June 2016, 356 rural dogs and 69 horses were sampled and their sera were processed through indirect immunofluorescence assay against antigens of R. rickettsii, R. parkeri, Rickettsia amblyommatis and Rickettsia bellii. Ticks collected from these dogs and horses were molecularly tested for the presence of rickettsial DNA. Overall, 16.4% (58/356) dogs and 24.6% (17/69) horses were seroreactive to Rickettsia spp. Five tick species, Rhipicephalus sanguineus sensu lato (s.l.), Amblyomma ovale, A. sculptum, R. microplus, and A. naponense, were collected from dogs, whereas horses were infested by A. sculptum and Dermacentor nitens. A total of 242 ticks from dogs and 62 from horses were analyzed by PCR targeting rickettsiae, which were detected in only 4/27 (14.8%) A. ovale. Fragments of the rickettsial gltA and ompA genes from these four ticks were 100% identical to the Atlantic rainforest strain of R. parkeri. The presence of A. ovale on dogs was positively associated with local canine seroreactivity to R. parkeri. Our results provide evidence for the transmission of R. parkeri strain Atlantic rainforest from A. ovale to domestic dogs within the rural area of Ilhéus, similarly to other areas of the Atlantic rainforest biome of Brazil, where human cases of R. parkeri-caused spotted fever have been reported.


Assuntos
Doenças do Cão/epidemiologia , Doenças dos Cavalos/epidemiologia , Ixodidae/microbiologia , Infecções por Rickettsia/veterinária , Rickettsia/isolamento & purificação , Infestações por Carrapato/veterinária , Animais , Brasil/epidemiologia , DNA Bacteriano/análise , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Feminino , Doenças dos Cavalos/microbiologia , Doenças dos Cavalos/parasitologia , Cavalos , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Prevalência , Rhipicephalus/crescimento & desenvolvimento , Rhipicephalus/microbiologia , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia
18.
Ticks Tick Borne Dis ; 10(6): 101260, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31327747

RESUMO

In camels and their infesting ectoparasites, specific detection of pathogenic Anaplasma platys and genetically related strains (A. platys-like strains) remains problematic. This requires sequencing of the hemi-nested PCR products specific to A. platys and related strains. In this study, a PCR/RFLP method, earlier developed for specific detection of A. platys-like strains in animal species other than camels, was adapted in order to subtype A. platys-like strains isolated from camels and their ticks and to differentiate them from pathogenic A. platys without going through a sequencing step. This approach was used for investigating the infections with A. platys and related strains in 412 Camelus dromedarius camels and 334 feeding ticks from five Tunisian governorates. Microscopic examination using Giemsa-stained blood smears was performed in order to specify which types of cells were infected. Ticks were identified as Hyalomma dromedarii (n = 164, 49%), H. impeltatum (n = 161, 48.3%) and H. excavatum (n = 9, 2.7%). A. platys was not detected in any of the tested camels or ticks. The overall prevalence of A. platys-like strains was 5.6% (23/412) in camels and microscopic examination of infected cells showed a tropism for neutrophil granulocytes. One tick identified as H. dromedarii out of 327 analyzed ticks was found to be infected with A. platys-like strains (0.3%). Alignment, identity comparison and phylogenetic analysis of the 16S rRNA partial sequences obtained in this study suggest that Tunisian dromedaries and feeding ticks are infected with different Anaplasma strains genetically related to A. platys. Sequence analysis and phylogenetic study based on the groEL gene confirm the RFLP results and show that camel strains formed a separate sub-cluster relatively close to A. platys-like strains infecting Tunisian cattle. This adapted RFLP assay allows fast and specific detection of pathogenic A. platys and A. platys-like strains in camels and infesting ticks and has the intrinsic potential of revealing co-infections with these two types of bacteria in the same sample, reducing the time and costs associated with cloning and sequencing during molecular diagnosis.


Assuntos
Anaplasma/isolamento & purificação , Anaplasmose/epidemiologia , Camelus , Ixodidae/microbiologia , Infestações por Carrapato/veterinária , Anaplasma/genética , Anaplasmose/microbiologia , Animais , Proteínas de Bactérias/análise , Sequência de Bases , Chaperonina 60/análise , DNA Bacteriano/análise , Feminino , Ixodidae/fisiologia , Masculino , Filogenia , Prevalência , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Infestações por Carrapato/epidemiologia , Tunísia/epidemiologia
19.
Exp Parasitol ; 204: 107729, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31348914

RESUMO

The objectives of this study are to: (1) evaluate the in vitro acaricidal effect of 54 Metarhizium anisopliae strains, six Beauveria bassiana strains and one Purpureocilium lilacinum strain, against the larvae of two populations of Rhipicephalus microplus (multi-resistant and susceptible to chemical acaricides); and (2) determine the lethal concentrations required to eliminate the 50% (LC50) and 99% (LC99) of larvae through the use of entomopathogenic fungi (EF) with high acaricidal effects. The mortality percentage was evaluated by larval immersion tests at a dose of 1 × 108 conidia/mL for each fungal strain. For calculating LC50 and LC99, four doses (1 × 108, 1 × 107, 1 × 106 and 1 × 105) were used. Nine strains of M. anisopliae and the P. lilacinum strain showed a high mortality percentage in the R. microplus larvae of both populations. The best strains that showed the lowest values of LC50 and LC99 for tick elimination were MaV50 and PlV01. In conclusion, several strains of entomopathogenic fungi showed a high acaricidal effect against the R. microplus larvae of both populations, suggesting that these fungi might be a promissory adjuvant in the control of R. microplus, including those who are resistant. Finally, the discovery of a P. lilacinum strain with a high acaricidal effect is also reported.


Assuntos
Acaricidas/farmacologia , Fungos/patogenicidade , Controle Biológico de Vetores/métodos , Rhipicephalus/microbiologia , Microbiologia do Solo , Animais , Beauveria/patogenicidade , Bioensaio/veterinária , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Feminino , Hypocreales/patogenicidade , Resistência a Inseticidas , Larva/efeitos dos fármacos , Larva/microbiologia , Dose Letal Mediana , Masculino , Metarhizium/patogenicidade , México , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Virulência
20.
Exp Appl Acarol ; 78(4): 579-593, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31352648

RESUMO

Rhipicephalus microplus causes high economic losses for Uruguay; the country is divided into a R. microplus-free area and an endemic area. The aim of this research was to evaluate the R. microplus and tick fever situation in Uruguay and the feasibility of implementing R. microplus control or elimination programs to reduce the number of infested farms. A representative survey was performed to determine the number of infested farms, the number of farms with outbreaks of tick fever and the control and preventive measures being used. Control or elimination programs using generational treatment were implemented on 30 farms. Previously, a situation diagnosis was performed by evaluating the background of each farm, identifying acaricide resistance, serologically evaluating the enzootic stability of tick fever, and analyzing the risk of R. microplus introduction to farms. According to the survey, R. microplus was present on 9544 (36%) farms, and 3436 (36%) of these farms experienced outbreaks of tick fever. Only 323 (9.4%) farmers used the tick fever vaccine. Of the 30 farms for which control or elimination programs were carried out, 18 reduced the number of treatments applied per year and six achieved the elimination of the cattle tick. It is concluded that by administering elimination or control programs, it is possible to reduce the number of infested farms and the number of treatments to maintain control. New surveys should be performed to measure the degree of technology adoption by farmers and to analyze the advances in tick control or elimination programs on farms.


Assuntos
Anaplasmose/epidemiologia , Babesiose/epidemiologia , Doenças dos Bovinos/prevenção & controle , Rhipicephalus/fisiologia , Controle de Ácaros e Carrapatos/estatística & dados numéricos , Infestações por Carrapato/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controle , Uruguai/epidemiologia
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