RESUMO
Hemotropic mycoplasmas are bacteria that attaches to erythrocytes surface, which some species presents zoonotic concerns. In the suborder Pinnipedia, genera Otaria and Arctocephalus are prominent in Brazil. This study investigated the occurrence of hemoplasmas in Arctocephalus sp. and Otaria flavescens found dead along the coast of a Southern Brazilian State. DNA from 135 spleen samples were extracted and subjected to conventional PCR protocols, targeting the 16â¯S rRNA and 23â¯S rRNA gene. Three (2.22â¯%) Arctocephalus australis were positive in the 16â¯S rRNA gene, and no samples amplified in the 23â¯S rRNA gene. Samples from this study clustered with Zalophus californianus and Arctocephalus tropicalis mycoplasmas on a Bayesian phylogenetic analysis. Genetic diversity analysis suggested distinct genotypes, indicating A. australis as a new host for hemoplasma, and also a potential putative novel hemoplasma genotype. These findings raises future awareness for pinnipeds conservation, and adds Mycoplasma spp. to be taken into consideration when clinically evaluating rescued animals.
Assuntos
DNA Bacteriano , Otárias , Infecções por Mycoplasma , Mycoplasma , Filogenia , RNA Ribossômico 16S , Baço , Animais , Brasil/epidemiologia , Mycoplasma/genética , Mycoplasma/isolamento & purificação , Mycoplasma/classificação , Otárias/microbiologia , Infecções por Mycoplasma/veterinária , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/epidemiologia , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Baço/microbiologia , RNA Ribossômico 23S/genética , Variação Genética , Genótipo , Teorema de Bayes , Autopsia/veterinária , Reação em Cadeia da PolimeraseRESUMO
We report a series of clinical cases associated with parasitism by the Ornithodoros brasiliensis tick in a group of travelers in the Caxias do Sul municipality, Southern Brazil. These cases draw attention to underdiagnosed noninfectious syndromes caused by ticks with restricted local distributions.
Assuntos
Dermatite/tratamento farmacológico , Dermatite/etiologia , Ornithodoros/fisiologia , Picadas de Carrapatos/tratamento farmacológico , Picadas de Carrapatos/patologia , Viagem , Animais , Antialérgicos/uso terapêutico , Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Brasil/epidemiologia , Dermatite/patologia , Dexametasona/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terfenadina/análogos & derivados , Terfenadina/uso terapêutico , Picadas de Carrapatos/epidemiologia , Adulto JovemRESUMO
The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro. In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus.
Assuntos
Acaricidas/uso terapêutico , Doenças dos Bovinos/terapia , Resistência a Medicamentos , Metarhizium/fisiologia , Rhipicephalus/microbiologia , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Acaricidas/farmacologia , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Clorpirifos/farmacologia , Clorpirifos/uso terapêutico , Feminino , Piretrinas/farmacologia , Piretrinas/uso terapêutico , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/terapia , Resultado do TratamentoRESUMO
The larval phase of Cochliomyia hominivorax (screwworm) is an obligate parasite of vertebrate animals, particularly mammals, and widespread in South America, where it remains one of the most important parasitic diseases of domestic animals. The skin of cattle highly infested by ticks, with cutaneous lesions, exudation of tissue fluid and blood scent seems to produce the ideal environment for fly attraction. However, an association between these parasites was never investigated. The aim of this work was to verify if there is an association between Rhipicephalus microplus tick load and the occurrence of C. hominivorax myiasis in cattle, and to quantify the risk. Sixty bovine (Bos taurus taurus, Angus breed) under field conditions were observed for 24 weeks, during which weekly tick counts and examination for the presence of myiasis were performed. There was a significant association between a high tick burden (24-week mean above 50 ticks per animal) and myiasis occurrence (P=0.0102). The calculated relative risk (RR) for C. hominivorax myiasis occurrence in cattle with high tick burden was 3.85 (CI95%=1.23-12.13); indicating that cattle highly parasitized by R. microplus have about four times more risk of myiasis than those with a low parasite load. As far as we aware, this is the first statistically based evidence of the relationship between R. microplus parasitic load and occurrence of myiasis by C. hominivorax. This result could be useful for the design of integrated control strategies for these parasites and to provide more information for the understanding of cattle tick parasitism in cattle production.