RESUMO

Leishmaniasis are neglected diseases transmitted by vectors that affect domestic and wild animals, including humans. Due to its incidence and lethality, this zoonosis is a worrying public health problem, making it essential to identify all links in the transmission chain. Infection of wild mammals by Leishmania spp. remains poorly understood, especially in southern Brazil. Therefore, the objective was to research, using the PCR technique, the presence of Leishmania spp. DNA in road-killed wild mammals in Southern Brazil. Carcasses of 96 animals were collected from highways in the Pelotas microregion, Rio Grande do Sul, southern Brazil and subjected to necropsies. Tissue fragments (spleen, skin, liver, kidney, heart, lung, lymph nodes, bone marrow and blood) were collected and genomic DNA was extracted. PCR protocols targeting the ITS1, kDNA and 18S genes were tested. We found no evidence of Leishmania spp. circulation in the studied population. However, epidemiological studies like this one are of great relevance, as they allow monitoring of the occurrence of pathogens and help identify possible risk areas. As these animals act as epidemiological markers for the presence of the microorganism, studies must be carried out continuously to understand whether there are sources of infection in the region.

Assuntos

RESUMO

Didelphis albiventris is considered the most common marsupial in Rio Grande do Sul. With omnivorous and synanthropic habits, it can serve as a host to various parasites, playing an important role in maintaining their biological cycle. Despite being a widespread and abundant species, it has a relatively little-known parasitic fauna. Therefore, the aim of this study was to report the diversity of parasites in a fecal sample from D. albiventris in Rio Grande do Sul, Southern Brazil. Modified Centrifugal-flotation and Spontaneous sedimentation techniques were used, revealing a high taxonomic diversity of parasites. Eggs of Ancylostoma spp., Toxocara spp., and Anoplocephalidae were reported for the first time in the host in the southern region of the country, along with the first report of pseudoparasitism by Syphacia spp. and Monocystis spp. in this animal species. The presence of different parasites in the feces of D. albiventris is of utmost importance, primarily for public health, but also for understanding the biodiversity of parasites present in wildlife, which has been poorly studied until now. This allows the implementation of effective strategies for controlling, preventing and treating these diseases.

Didelphis albiventris é considerado o marsupial mais comum no Rio Grande do Sul. Com hábitos onívoros e sinantrópicos, pode servir de hospedeiro para diversos parasitas, desempenhando importante papel na manutenção do seu ciclo biológico. Apesar de ser uma espécie difundida e abundante, possui uma fauna parasitária relativamente pouco conhecida. Portanto, o objetivo deste estudo foi relatar a diversidade de parasitas em uma amostra fecal de D. albiventris no Rio Grande do Sul, Sul do Brasil. Foram utilizadas técnicas modificadas de flutuação centrífuga e sedimentação espontânea, revelando uma alta diversidade taxonômica de parasitas. Ovos de Ancylostoma spp., Toxocara spp. e Anoplocephalidae foram relatados pela primeira vez no hospedeiro na região sul do país, juntamente com o primeiro relato de pseudoparasitismo por Syphacia spp. e Monocystis spp. nesta espécie animal. A presença de diferentes parasitas nas fezes de D. albiventris é de extrema importância, principalmente para a saúde pública, mas também para a compreensão da biodiversidade de parasitas presentes na vida selvagem, que tem sido pouco estudada até agora. Isto permite a implementação de estratégias eficazes para controlar, prevenir e tratar estas doenças.

RESUMO

Abstract Leishmaniasis are neglected diseases transmitted by vectors that affect domestic and wild animals, including humans. Due to its incidence and lethality, this zoonosis is a worrying public health problem, making it essential to identify all links in the transmission chain. Infection of wild mammals by Leishmania spp. remains poorly understood, especially in southern Brazil. Therefore, the objective was to research, using the PCR technique, the presence of Leishmania spp. DNA in road-killed wild mammals in Southern Brazil. Carcasses of 96 animals were collected from highways in the Pelotas microregion, Rio Grande do Sul, southern Brazil and subjected to necropsies. Tissue fragments (spleen, skin, liver, kidney, heart, lung, lymph nodes, bone marrow and blood) were collected and genomic DNA was extracted. PCR protocols targeting the ITS1, kDNA and 18S genes were tested. We found no evidence of Leishmania spp. circulation in the studied population. However, epidemiological studies like this one are of great relevance, as they allow monitoring of the occurrence of pathogens and help identify possible risk areas. As these animals act as epidemiological markers for the presence of the microorganism, studies must be carried out continuously to understand whether there are sources of infection in the region.

Resumo As leishmanioses são doenças negligenciadas, transmitidas por vetores que acometem animais domésticos e silvestres, incluindo os humanos. Devido a sua incidência e letalidade, essa zoonose consiste em um problema de saúde pública preocupante, sendo fundamental a identificação de todos os elos da cadeia de transmissão. A infecção de mamíferos silvestres por Leishmania spp. permanece pouco compreendida, especialmente no sul do Brasil. Portanto, objetivou-se pesquisar, por meio da técnica de PCR, a presença de DNA de Leishmania spp. em mamíferos silvestres atropelados no Sul do Brasil. Carcaças de 96 animais foram coletadas, em rodovias da microrregião de Pelotas, Rio Grande do Sul, sul do Brasil e submetidas a necropsias. Fragmentos de tecidos (baço, pele, fígado, rim, coração, pulmão, linfonodos, medula óssea e sangue) foram coletados e o DNA genômico foi extraído. Protocolos de PCR visando os genes ITS1, kDNA e 18S foram testados. Não foram encontradas evidências de circulação de Leishmania spp. na população estudada. Porém, estudos epidemiológicos como este são de grande relevância, pois permitem monitorar a ocorrência de patógenos e auxiliam na identificação de possíveis áreas de risco. Como esses animais atuam como marcadores epidemiológicos da presença do microrganismo, estudos devem ser realizados continuamente, para entender se existem fontes de infecção na região.

RESUMO

Didelphis albiventris is a marsupial with synanthropic habits, whose contact with domestic animals and humans is increasing. They are considered potential disseminators of diseases, present as definitive hosts or reservoirs of various pathogenic agents. The present study aim to report, for the first time, the parasitism by Ctenocephalides felis in D. albiventris in Rio Grande, Southern Rio Grande do Sul state, Brazil. An adult female White-eared Opossum (D. albiventris), killed by being run over, was collected on the roads of the city of Rio Grande, Rio Grande do Sul, Brazil and sent to the laboratory for necropsy. During external inspection, a flea was found, which was stored in 70o alcohol until taxonomic identification, being classified as C. felis. This study reports the occurrence of parasitism by C. felis in D. albiventris for the first time in the location studied, demonstrating that these arthropods circulate between the wild and urban environments, and play an important role in the cycle of zoonotic pathogens among wild fauna, companion animals and humans.

Didelphis albiventris é um marsupial de hábitos sinantrópicos, cujo contato com animais domésticos e humanos está aumentando. São considerados potenciais disseminadores de doenças, apresentando-se como hospedeiros definitivos ou reservatórios de vários agentes patogênicos. O presente estudo tem como objetivo relatar, pela primeira vez, o parasitismo por Ctenocephalides felis em D. albiventris em Rio Grande, Sul do Rio Grande do Sul, Brasil. Uma fêmea adulta de gambá-de-orelha-branca (D. albiventris), morta por atropelamento, foi recolhida nas estradas da cidade de Rio Grande, Rio Grande do Sul, Brasil e encaminhado ao laboratório para necropsia. Durante inspeção externa foi encontrada uma pulga que foi armazenada em álcool 70º até a identificação taxonômica sendo classificado como C. felis. Este estudo relata a ocorrência de parasitismo por C. felis em D. albiventris para o primeira vez no local estudado, demonstrando que esses artrópodes circulam entre a natureza e ambientes urbanos e desempenham um papel importante no ciclo de patógenos zoonóticos entre a fauna selvagem, animais de companhia e humanos.

RESUMO

Lucilia cuprina is a vector of important diseases in humans and animals that causes myiasis in sheep, leading to enormous damage to the sheep sector. Chemical products are used to control these flies; however, there are reports of resistance in addition to these products causing toxicity to the environment, humans, and animals, so alternative controls have been studied to reduce these impacts. Pleurotus spp. are basidiomycete fungi and present bioactive compounds with medicinal properties. Due to the potential use of fungi to control Diptera, this study aimed to verify the activity of Pleurotus florida, P. ostreatus, and P. djamor in the control of larvae and adults of L. cuprina, as well as the effects of aqueous extracts of the fungi P. ostreatus, P. djamor, and P. florida on larvae and adults of L. cuprina. The aqueous extract from P. florida was the only one that showed larvicidal activity against L. cuprina, with a half-maximal effective concentration of 11.42 mg/mL. In the test with adult stages, 30 insects were used for each solution concentration, sprinkled with 1 mL of the solution. All aqueous extracts showed adulticidal activity at all concentrations, P. ostreatus showing the best results, with adult mortality ranging from 75.86 to 100%. Our results demonstrated an important larvicidal effect of P. florida and an adulticidal effect of all AE, with emphasis on P. ostreatus.

Assuntos

RESUMO

Coendou spinosus is a species of rodent popularly known as porcupine, it has a great ability to adapt to different habitats and is found in tropical forests in countries such as Bolivia, Brazil, Venezuela and Guianas. This mammal has already been identified as a reservoir of several pathogenic agents for humans and other animals and has a variety of ectoparasites, endoparasites and hemoparasites little studied and described. Due to this, the objective was to report the parasitism by Eutrichophilus cercolabes in C. spinosus in the central region of Rio Grande do Sul, southern Brazil. In total, 16 lice were found, one male and 15 females of the species. This is the first report of the parasitism of this Phthiraptera on C. spinosus in Rio Grande do Sul. The scarcity of reports on the taxonomy and biotic characteristics, as well as the vector capacity of pathogens of most species of ectoparasites of wild animals, highlights the need for further studies on the distribution of these arthropods in different regions and host species.

Coendou spinosus é uma espécie de roedor conhecida popularmente por porco-espinho, possui uma grande capacidade de adaptação a diferentes habitats sendo encontrada em florestas tropicais de países como Bolívia, Brasil, Venezuela e Guianas. Esse mamífero já foi identificado como reservatório de vários agentes patogênicos para o homem e outros animais e possui uma variedade de ectoparasitos, endoparasitos e hemoparasitos pouco estudados e descritos. Devido a isso, objetivou-se relatar o parasitismo por Eutrichophilus cercolabes em C. spinosus na região central do Rio Grande do Sul, Sul do Brasil. Ao total, foram encontrados 16 piolhos, sendo um macho e 15 fêmeas da espécie. Esse é o primeiro relato do parasitismo deste Phthiraptera em C. spinosus no Rio Grande do Sul. A escassez de relatos sobre a taxonomia e características bióticas, bem como a capacidade vetorial de patógenos da maioria das espécies de ectoparasitos de animais silvestres evidencia a necessidade da realização de mais estudos sobre a distribuição desses artrópodes em diferentes regiões e espécies hospedeiras.

RESUMO

Trachemys dorbigni is the most abundant freshwater turtle species in Rio Grande do Sul, southern Brazil. Chelonians are known to host a wide variety of pathogens, including viruses, bacteria, hemoparasites and helminths. Among these, nine genera of polystomatid flatworms (Monogenoidea; Polystomatidae) infect freshwater turtles: Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Polystomoidella, Polystomoides, Uropolystomoides and Uteropolystomoides. However, little is known about the biology of these parasites in the Neotropical Realm. Through investigative cystoscopy, specimens of Polystomatidae were located inside the urinary bladder of the host T. dorbigni. Retrieved specimens were fixed and stained whole mounts prepared for taxonomic identification. In the present paper, a new species of Polystomoides (Monogenoidea: Polystomatidae) parasitizing the urinary bladder of a freshwater turtle of the species T. dorbigni in Brazil is described. Polystomoides santamariensis n. sp. differs from the congeneric species on the length of the genital spines, which are longer. Given the enormous diversity of freshwater turtles around the world, it is likely that a large number of chelonian polystomatids are still unknown.

Assuntos

RESUMO

Telmatoscopus albipunctata is an insect of the Psychodidae family, with a worldwide distribution, particularly in tropical and subtropical countries. Although it does not have hematophagous habits, it has veterinary medical importance due to the mechanical transmission of protozoa and bacteria, many of which cause nosocomial infections. This dipteran has been reported as one of the causative agents of accidental myiasis in humans in several countries, and since it has not been registered in South America, the objective of the present report was to describe a rare case of accidental urinary myiasis caused by T. albipunctata (Diptera: Psychodidae) in humans in Brazil. In the present report, a 25-year-old female patient, resident of the central region of the state of Rio Grande do Sul, Brazil, sought medical attention after finding larvae in her urine. She complained of vaginal itching and skin dermatitis. The larvae were sent to the Veterinary Parasitology Laboratory of the Federal University of Santa Maria, where they were mounted on permanent slides for further taxonomic identification. Morphological characteristics allowed the identification of fourth-stage larvae and pupae of T. albipunctata. Therefore, the present work reports the first record of accidental urinary myiasis caused by T. albipunctata infection in Brazil and South America.

Assuntos

RESUMO

Trachemys dorbigni is the most abundant freshwater turtle species in Rio Grande do Sul, southern Brazil. Chelonians are known to host a wide variety of pathogens, including viruses, bacteria, hemoparasites and helminths. Among these, nine genera of polystomatid flatworms (Monogenoidea; Polystomatidae) infect freshwater turtles: Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Polystomoidella, Polystomoides, Uropolystomoides and Uteropolystomoides. However, little is known about the biology of these parasites in the Neotropical Realm. Through investigative cystoscopy, specimens of Polystomatidae were located inside the urinary bladder of the host T. dorbigni. Retrieved specimens were fixed and stained whole mounts prepared for taxonomic identification. In the present paper, a new species of Polystomoides (Monogenoidea: Polystomatidae) parasitizing the urinary bladder of a freshwater turtle of the species T. dorbigni in Brazil is described. Polystomoides santamariensis n. sp. differs from the congeneric species on the length of the genital spines, which are longer. Given the enormous diversity of freshwater turtles around the world, it is likely that a large number of chelonian polystomatids are still unknown.(AU)

Trachemys dorbigni é a espécie de tartaruga de água doce mais abundante do Rio Grande do Sul, no Sul do Brasil. Sabe-se que os quelônios são hospedeiros de uma grande variedade de patógenos, incluindo vírus, bactérias, hemoparasitos e helmintos. Dentre estes, oito gêneros de Polystomatidae (Platyhelminthes: Monogenoidea) infectam tartarugas de água doce: Apaloneotrema, Aussietrema, Fornixtrema, Manotrema, Pleurodirotrema, Polystomoidella, Polystomoides, Uropolystomoides e Uteropolystomoides. No entanto, pouco ainda se sabe sobre a biologia destes parasitos na Região Neotropical. Durante uma citoscopia investigativa, foram observados espécimes de Polystomatidae localizados no interior da bexiga urinária de T. dorbigni. Os espécimes coletados foram fixados e corados para identificação taxonômica. No presente artigo, uma nova espécie de Polystomoides (Monogenoidea: Polystomatidae) parasitando a bexiga urinária de tartaruga de água doce da espécie T. dorbigni no Brasil é descrita. Polystomoides santamariensis n. sp. difere das demais espécies no tamanho dos espinhos genitais, que são maiores. Devido a enorme diversidade de tartarugas de água doce ao redor do mundo, é provável que um grande número de polistomatídeos de quelônios ainda seja desconhecido.(AU)

Assuntos

RESUMO

The demand for ornamental fish has increased in recent years in Brazil, however, the aquatic environment of artificial breeders facilitates the invasion of pathogens, including parasitic zoonoses, which are a limiting factor for production causing economic losses in creations. Knowledge of the distribution of agents causing parasitic diseases is important so that we can intervene in breeders, therefore, the objective of the present work is to report the occurrence of infection by Eustrongylides sp. (Nematoda: Eustrongylidae) in Polypterus endlicherii (Polypteriformes: Polypteridae) in central Rio Grande do Sul, Brazil. The nematode was identified after being released a cyst in the scales, of a fish of the species P. endlicherii. It can be concluded that this is the first record of the occurrence of Eustrongylides sp. larvae in fish in Rio Grande do Sul, showing that the parasite is present in the central region of the state. Therefore, further studies should be carried out in order to verify the presence of the parasites in fish intended for human consumption. It should also be noted the need to be more careful when feeding fish with oligochaetes, especially those intended for human consumption.

A criação de peixes para ornamentação teve sua demanda aumentada nos últimos anos no Brasil, no entanto, o ambiente aquático dos criatórios artificiais facilita a invasão por agentes patogênicos, incluindo zoonoses parasitárias, que são um fator limitante para produção causando perdas econômicas nas criações. O conhecimento da distribuição de agentes causadores de enfermidades parasitárias é importante para que se possa intervir nos criatórios, portanto, o objetivo do presente trabalho é relatar a ocorrência da infecção por larva de Eustrongylides sp. (Nematoda: Eustrongylidae) em Polypterus endlicherii (Polypteriformes: Polypteridae) na região central do Rio Grande do Sul, Brasil. O nematódeo foi identificado após ser liberado de um cisto nas escamas, de um peixe da espécie P. endlicherii. Pode-se concluir que este é o primeiro registro da ocorrência de larvas de Eustrongylides sp. em peixes no Rio Grande do Sul, evidenciando que o parasito está presente na região central do estado. Portanto, mais estudos devem ser realizados a fim de verificar a presença dos parasitos em peixes destinados ao consumo humano. Salienta-se ainda, a necessidade de se ter maior cuidado ao alimentar peixes com oligoquetas, principalmente os destinados para alimentação humana.

Assuntos

RESUMO

Culicoides have medical and veterinary importance, as they play a role as vectors of viruses, protozoa, and nematodes that cause diseases. Despite the relevance to public health, greater attention has been given to other insect vectors. Therefore, the objective of this study was to evaluate the efficiency of the Captor® light trap in capturing Culicoides that could be examined for the presence of Leishmania DNA. The insects were captured in a rural area of Santa Maria, Rio Grande do Sul, Brazil, where canine and human visceral leishmaniasis have been diagnosed. Adult insects were collected weekly, from 6:00 pm to 6:00 am, for a 12 month period using a Captor® brand suction light trap. All Culicoides were identified at species level. Pools of Culicoides were tested using the Polymerase Chain Reaction (PCR) technique for the detection of Leishmania DNA. A total of 16,016 specimens were collected (71.54% females and 28.39% males), divided among seven species. In the DNA analysis, none of the pools showed a positive result for Leishmania. The data presented demonstrate that the trap is efficient and can be an alternative for use in entomological research. They also demonstrate that, despite the females having hematophagous habits, similar to other vector insects, they did not have contact with Leishmania in the studied locality.

Culicoides têm importância médica e veterinária, pois desempenham um papel como vetores de vírus, protozoários e nematoides que causam doenças em animais e humanos. Apesar da relevância para a saúde pública, maior atenção tem sido dada a outros insetos vetores. Portanto, o objetivo do estudo foi avaliar a eficiência da armadilha luminosa Captor® na captura de Culicoides que pudesse ser verificada quanto à presença de DNA de Leishmania. Os insetos foram capturados em uma área rural de Santa Maria, Rio Grande do Sul, Brasil, onde foram diagnosticadas leishmaniose visceral canina e humana. Os insetos adultos foram coletados semanalmente, das 18h às 6h, com armadilha luminosa de sucção da marca Captor® por doze meses. Todos Culicoides foram identificados em nível de espécie. Pools de Culicoides foram testados pela técnica de PCR para detecção de DNA de Leishmania. Foram coletados 16.016 espécimes (71,54% fêmeas e 28,39% machos), divididos em sete espécies. Na análise de DNA, nenhum dos pools apresentou resultado positivo para Leishmania. Os dados apresentados demonstram que a armadilha é eficiente e pode ser uma alternativa para uso em pesquisas entomológicas. Demonstram também que, apesar das fêmeas apresentarem hábitos hematófagos, semelhantes a outros insetos vetores, não tiveram contato com Leishmania na localidade estudada.

RESUMO

Haemonchus contortus is a highly pathogenic and prevalent helminth that causes many deaths in sheep herds. Anthelmintics are usually employed to overcome this issue; however, they do not guarantee immediate and lasting efficacy because of the occurrence of drug-resistant parasites. Among substances that are used in scientific studies for parasitic control, essential oils are known to have different pharmacological properties. However, they demonstrate instability owing to several factors, and therefore, nanoemulsification is considered an alternative to control the instability and degradability of these compounds. The objective of this study was to evaluate the cytotoxicity of nanoemulsions containing essential oil of Eucalyptus globulus against the blood of healthy sheep and to verify their activity against the parasite H. contortus in sheep. The results presented adequate nanotechnological characteristics (diameter 72 nm, PDI 0.2, zeta -11 mV, and acidic pH) and adequate morphology. Further, the corona effect and cytotoxic profiles of the free oil and nanoemulsion against blood cells from healthy sheep were evaluated. The tests results did not present a toxicity profile. For evaluating efficacy, we observed an important anthelmintic action of the nanoemulsion containing oil in comparison to the free oil; the results demonstrate a potential role of the nanoemulsion in the inhibition of egg hatchability and the development of larvae L1 to L3 (infective stage). Based on these results, we developed an important and potential anthelmintic alternative for the control of the parasite H. contortus.

Assuntos

RESUMO

Cyathostomins are common intestinal nematodes that parasitize horses and can affect animal health and welfare. Alternative treatments are essential for sustainable parasite control, reducing the indiscriminate use of anthelmintics and their impacts on the environment, animals, and humans. Pleurotus spp. are edible medicinal mushrooms that possess several therapeutic properties, including antiparasitic and nematocidal activities. This study aimed to evaluate the antioxidant and nematocidal activity of aqueous extracts of three oyster species (P. florida, P. ostreatus, and P. djamor) on cyathostomine eggs in vitro. P. florida showed the highest activity against test organisms, inhibiting the hatching of eggs in up to 92.19% at the highest concentration (10%) of aqueous extract, with a mean lethal concentration (LC50) of 2.13%. In the aqueous extracts of P. ostreatus and P. djamor, nematocidal activity was reduced, inhibiting egg hatching by 55.46% (LC50, 7.44%) and 23.67%, respectively, at a concentration of 10%. P. florida showed higher antioxidant activity than that of the other species tested. Thus, P. florida may be considered a potential alternative for biological control in in vivo experiments with cyathostomins.

Assuntos

RESUMO

Chagas disease (CD) is caused by the parasite Trypanosoma cruzi. CD affects people worldwide, primarily in tropical areas. The central nervous system (CNS) is an essential site for T. cruzi persistence during infection. The protozoan may pass through the blood-brain barrier and may cause motor and cognitive neuronal damage. Once in the CNS, T. cruzi triggers immune responses that the purinergic system can regulate. Treatment for CD is based on benznidazole (BNZ); however, this agent has negative side-effects and is toxic to the host. For this reason, we investigated whether resveratrol (RSV), a potent antioxidant and neuroprotective molecule, would modulate purinergic signaling and RSV alone or in combination with BNZ would prevent changes in purinergic signaling and oxidative damage caused by T. cruzi. We infected mice with T. cruzi and treated them with RSV or BNZ for 8 days. Increases in ATP and ADP hydrolysis by NTPDase in the total cortex of infected animals were observed. The treatment with RSV in infected group diminished ATP, ADP, and AMP hydrolysis compared to infected group. The combination of RSV + BNZ decreased AMP hydrolysis in infected animals compared to the INF group, exerting an anti-inflammatory effect. RSV acted as a neuroprotector, decreasing adenosine levels. Infected animals presented an increase of P2X7 and A2A density of purine receptors. RSV reduced P2X7 and A2A and increased A1 density receptors in infected animals. In addition, infected animals showed higher TBARS and reactive oxygen species (ROS) levels than control. RSV diminished ROS levels in infected mice, possibly due to antioxidant properties. In short, we conclude that resveratrol could act as a neuroprotective molecule, probably preventing inflammatory changes caused by infection by T. cruzi, even though the mice experienced high levels of parasitemia.

Assuntos

RESUMO

The bioinsecticides, like essential oils, are a promising alternative in pest control. However, these oils have some limitations, such as instability and low solubility. These limitations can be circumvented through nanotechnology, with the nanoemulsification of these compounds. Therefore, the objective of this study was to prepare, characterize and explore the insecticidal activity against adult flies of nanoemulsions containing essential oil of lemongrass or eucalyptus. The nanoemulsions were prepared by the high-energy method and presented droplet size smaller than 125 nm, with polydispersity index of 0.2, pH acid and spherical morphology. The insecticidal activity was evaluated by the Topical Application Method and Exposure Impregnated Paper Exposure, where it was possible to demonstrate a potential insecticidal effect of lemongrass oil in the concentrations of 10, 30 and 50 µL/mL against Musca domestica and Lucilia cuprina and the potentiation of this effect when nanoemulsified this oil against L. cuprina.

Assuntos

RESUMO

The stable fly, Stomoxys calcitrans (Linnaeus 1758), is a hematophagous fly responsible for causing loss of performance in horses, causing losses in cattle productivity, and impacting the animals' health through the spread of pathogenic microorganisms. The objective of this work was to investigate the insecticidal activity of essential oil obtained from Melaleuca alternifolia (Cheel), presenting high 1,8-cineole content, against S. calcitrans adults. Insecticidal activity was determined using surface application methods and exposure to oil impregnated paper. It was observed that treatments at 25 and 50 µg/cm2 (P < 0.05) present fumigant activity through exposure to the impregnated paper, and in the first 15 min of exposure, the mortality rates obtained for these treatments were, respectively (96.6 ± 3.3% and 100%), equivalent to the positive control. Using the superficial application method, the only treatment concentration presenting adulticidal action was 5% (w/v) (P < 0.05). Respective toxicities LC50 (%, w/v) and LC80 for the impregnated paper method were 1.06 ± 0.02 and 1.47 ± 0.17; for the superficial application method, they were 3.82 ± 0.65 and 5.53 ± 0.74. As demonstrated, M. alternifolia essential oil presents adulticidal potential against S. calcitrans.

Assuntos

RESUMO

The nematocidal effect of Pleurotus ostreatus (white variety of oyster mushroom) aqueous extract (AE) was evaluated against Haemonchus contortus eggs and infective larvae (L3) in vitro and in artificially infected gerbils (Meriones unguiculatus). The chemical analyses indicated that constituents of AE are tridecanoic, tetradecanoic, linolelaidic, 9,15-octadecadienoic, and oxalic acids. P. ostreatus extract inhibited larval hatching by 100% at the concentration of 2.24 mg/mL and (50% effective concentration) EC50 of 0.73 mg/mL. In the larval development test, AE induced a larvicidal effect at the concentration of 50 mg/mL and EC50 of 17.24 mg/mL. The larval migration test revealed a reduction of 94.7% at a concentration of as low as 4 mg/mL and EC50 of 1.25 mg/mL. No significant effects of treatment with P. ostreatus AE were seen on H. contortus in the gerbil model. Thus, our results demonstrate an important nematocidal in vitro effect of P. ostreatus AE against the parasite H. contortus. However, further investigations are necessary to confirm the anthelmintic potential of P. ostreatus extract in small ruminants.

Assuntos

RESUMO

In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, s shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.(AU)

No presente estudo é relatado pela primeira vez Litomosoides silvai parasitando Akodon montensis coletados na região Sul do Brasil. Foram fornecidas novas informações morfológicas para algumas estruturas desta espécie de nematódeo, tais como extremidade cefálica achatada, a presença de duas papilas cefálicas dorsais, cauda das fêmeas com uma constrição na ponta da cauda, vagina em forma de s, espículas de característica do grupo de espécies de carinii e cauda da microfilária com constrição na ponta. Este nematódeo parasitava a cavidade torácica com uma prevalência de 10% (2/20), intensidade média de 4 (8/2) e abundância média de 0,4 (8/20), e intervalo de infecção de 2-6 espécimes por hospedeiro no Sul do Brasil. A ocorrência de L. silvai em A. montensis é um novo registro geográfico, no sul do Brasil, a noroeste do estado do Rio Grande do Sul, na ecorregião da Mata Atlântica do Alto Paraná, parte do bioma da Mata Atlântica.(AU)

Assuntos

RESUMO

Abstract In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, "s" shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Resumo No presente estudo é relatado pela primeira vez Litomosoides silvai parasitando Akodon montensis coletados na região Sul do Brasil. Foram fornecidas novas informações morfológicas para algumas estruturas desta espécie de nematódeo, tais como extremidade cefálica achatada, a presença de duas papilas cefálicas dorsais, cauda das fêmeas com uma constrição na ponta da cauda, vagina em forma de "s", espículas de característica do grupo de espécies de carinii e cauda da microfilária com constrição na ponta. Este nematódeo parasitava a cavidade torácica com uma prevalência de 10% (2/20), intensidade média de 4 (8/2) e abundância média de 0,4 (8/20), e intervalo de infecção de 2-6 espécimes por hospedeiro no Sul do Brasil. A ocorrência de L. silvai em A. montensis é um novo registro geográfico, no sul do Brasil, a noroeste do estado do Rio Grande do Sul, na ecorregião da Mata Atlântica do Alto Paraná, parte do bioma da Mata Atlântica.

Assuntos

RESUMO

In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, "s" shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Assuntos