Description of the parasitic fauna of a specimen of Didelphis albiventris at Rio Grande do Sul.

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.

Gallium maltolate, a promising low toxicity drug with curative effect on mice chronically infected with Trypanosoma evansi.

Trypanosoma evansi is a flagellate protozoan that infects a wide range of hosts, especially horses. Clinically, the infection is characterized by rapid weight loss, anemia and mobility disorders. This study evaluated the efficacy of treatment gallium maltolate (GaM) in rats infected with T. evansi in the acute and chronic phases of the disease and its influence on the enzyme and blood parameters. 48 animals (Rattus norvegicus) were divided into 8 groups (A-H) of 6 animals each, namely: A: (negative control) uninfected; B: acutely infected positive control; C: chronically infected positive control; D: acutely infected, treated with GaM for 7 days post infection (p.i.); E: acutely infected treated with GaM for 3 days before infection (b.i) and 7 days p.i.; F: chronically infected, treated with GaM for 7 days p.i.; G: chronically infected, treated with GaM for 3 days b.i. and 7 days p.i.; and H: uninfected treated with GaM for 10 days. Acute infected animals (B, D and E) had a progressive increase in parasitemia and were died or euthanized before completing treatment days (5th days p.i.) as they had high parasitemia (over 100 field trypanosomes in the blood smear). Thus, it can be concluded that GaM was not effective against an acute infection. In untreated chronically infected animals (C) the parasitemia also increased progressively and they were euthanized on the 7th day p.i.. The chronically infected and treated animals (F and G) showed low parasitemia and after treatment became negative, showing no trypanosomes in the bloodstream until the 50th day of the experiment. Thus, we conclude that GaM was effective against chronic infections. In uninfected and treated animals (H) hematological, biochemical and enzymatic parameters had no significant changes when compared to the negative control group (A) demonstrating the low toxicity of GaM.

Ctenocephalides felis (Siphonaptera, Pulicidae) parasitizing White-eared opossum (Didelphis albiventris) at Southern Brazil - Case report.

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.

First report of parasitism by Eutrichophilus cercolabes (Phthiraptera: Trichodectidae) on Coendou spinosus (Erethizontidae) in Rio Grande do Sul, Brazil - case report.

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.

Activity of Oyster Mushrooms, Genus Pleurotus (Agaricomycetes), on Lucilia cuprina (Diptera).

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.

New species of Polystomoides (Monogenoidea: Polystomatidae) parasitizing the urinary bladder of a freshwater turtle in Brazil.

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.

First record of a rare case of accidental urinary myiasis by Telmatoscopus albipunctata (Diptera: Psychodidae), with morphological description, in a human in Brazil.

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.

Culicoides' species from a Leishmania transmission hotspot and efficacy of the Captor® suction light trap.

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.

Eucalyptus oil nanoemulsions against eggs and larvae of Haemonchus contortus.

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.

Safety and efficacy of Lucilia cuprina maggots on treating an induced infected wound in Wistar rats.

Infection is one of the main complications that hinder wound healing. Currently, antibiotic-resistant bacteria, such as Methicilin-resistant Staphylococcus aureus (MRSA), are a concern worldwide for both humans and animals. Maggot therapy is re-emerging as an alternative to intractable wounds and may be an option to the traditional antibiotic treatment. Although the species of choice is Lucilia sericata, reports of clinical use have led us to evaluate the efficacy and safety of using Lucilia cuprina larvae on induced infected wounds in Wistar rats. In short, 32 male Wistar rats were divided into 4 groups: Group I - saline solution treated; Group II - antibiotic-treated; Group III - treated with larval debridement, and Group IV - without wound and treatment. Skin wounds were induced in groups I, II and III. All treatments were performed once and held for 48 h. Clinical, microbiological, histopathological, hematological, and biochemical analyses were done. Significant wound area contraction was found (>95%) in group III on day 9 compared to day 15 in group II. Complete elimination (0.0 ± 0.0 CFU/mL) of bioburden was achieved after the second treatment (day 6) in both the II and III groups, compared to an increase in Group I (6.51 ± 0.37 CFU/mL). A cleaner wound was also observed in the histopathological evaluation of group III, with adequate collagen formation and re-epithelialization on day 15. Furthermore, larvae increased blood platelet levels after the first treatment. L. cuprina larvae have proven safe and effective in accelerating wound treatment and eliminating MRSA.

Antioxidant and Nematocidal Effects of Several Oyster Mushroom Species of Genus Pleurotus (Agaricomycetes).

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.

A positive association of larval therapy and hyperbaric oxygen therapy in veterinary wound care.

The treatment of cutaneous wounds is part of the veterinary routine from initial scientific reports due to being regularly present condition. Currently, several types of treatments are available to accelerate the healing process. This report presents the case of a dog with multiple lesions in the thoracic limbs resulting from a car accident, who underwent larval therapy and hyperbaric oxygen therapy (HBOT). The animal was a 2-year-old female mixed breed dog presenting severe skin degloving, fracture in the left thoracic limb (LTL), with abrasion lesions and dislocation in the right thoracic limb (RTL). The animal underwent multiple modality therapies, such as HBOT sessions associated with larval therapy; even after the LTL presented gangrene, this treatment resulted in optimal viability of the non-necrotic tissue adjacent to the gangrene. Due to chronic pain unresponsive to drug control and the presence of a fracture at a location where a possible exoprosthesis was supposed to be fixed, the LTL ended up being amputated. There are several reports of the use of HBOT or larval therapy in traumatized limbs; however, the combination of both therapies has not been previously described in the veterinary literature. Thus, we demonstrate through this report that it was possible to quickly recover the animal with good wound resolution through tissue oxygenation and a healthy granulation bed, both provided by the therapeutic combination.

Involvement of ectonucleotidases and purinergic receptor expression during acute Chagas disease in the cortex of mice treated with resveratrol and benznidazole.

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.

Resveratrol impacts in oxidative stress in liver during Trypanosoma cruzi infection.

Trypanosoma cruzi is the causative agent of Chagas disease, infecting the heart, intestines and liver tissues. There is growing evidence that oxidative stress, defined as a persistent imbalance between highly oxidative compounds and antioxidant defenses, is a marker of tissue inflammation; it is related to immune responses such as damage, as well as to strand breaks in DNA contributing to disease progression. Antioxidant agents help mitigate the damage caused by inflammation, preventing or slowing damage to cells caused by free radicals. In this sense, resveratrol (RSV) is an important polyphenol that demonstrates antioxidant effects. It reverses damage caused by several infectious diseases. The aim of the present study was to determine whether treatment with RSV would prevent or minimize oxidative damage caused by T. cruzi. The animals were divided into four groups (n = 5): A) control; B) control + RSV; C) infected and D) infected + RSV. The infected groups received 1 x 104 Y strain trypomastigotes via intraperitoneal injection; after confirmation of infection, the mice received RSV 100 mg/kg for seven days orally. On the 8th day post-infection, we collected liver tissue for analysis of oxidant/antioxidant status: superoxide dismutase (SOD), catalase (CAT), and glutathione s-transferase (GST) activities, as well as reactive oxygen species (ROS), non-protein thiols (NPSH), thiols, carbonyl protein, thiobarbituric acid reactive substance (TBARS), and finally, the nitrite/nitrate ratio (NOx) levels were determined. The administration of RSV did not exert direct effect on parasitemia. The infection produced high levels of TBARS, NOx, and ROS levels in liver tissue, suggesting cellular injury with production of free radicals in animals infected by T. cruzi. RSV positively modulated SOD and aumenting GST activities enzymes in infected animals. Protein thiols levels in infected animals were lower than those of control. Taken together, the data suggest T. cruzi causes hepatic oxidative stress, and RSV 100 mg/kg for seven days it's dosen't seem minimized these negative effects in the acute phase of disease.

Nanobiopesticides: development and inseticidal activity of nanoemulsions containing lemongrass or eucalyptus oils.

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.

Adulticidal Activity of Melaleuca alternifolia (Myrtales: Myrtaceae) Essential Oil With High 1,8-Cineole Content Against Stable Flies (Diptera: Muscidae).

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.

Nematocidal Effect of Oyster Culinary-Medicinal Mushroom Pleurotus ostreatus (Agaricomycetes) against Haemonchus contortus.

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.

Litomosoides silvai (Nematoda: Onchocercidae) parasitizing Akodon montensis (Rodentia: Cricetidae) in the southern region of Brazil / Litomosoides silvai (Nematoda: Onchocercidae) parasitando Akodon montensis (Rodentia: Cricetidae) na região Sul do Brasil

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.

Litomosoides silvai (Nematoda: Onchocercidae) parasitizing Akodon montensis (Rodentia: Cricetidae) in the southern region of Brazil.

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.

Avian antibodies (IgY) against Trypanosoma cruzi: Purification and characterization studies.

Trypanosoma cruzi is a flagellated protozoan belonging to the Trypanosomatidae family, the etiologic agent of Chagas disease. Currently, there is neither a licensed vaccine nor effective treatment, characterizing an unmet clinical need. The IgY refers to the egg yolk immunoglobulin (Y=yolk) and its production and use are subjects of many studies due to the diversity of its diagnostic and therapeutic applications. Several researchers have shown that the use of specific IgY may prevent and/or control infectious and parasitic diseases. Based on these evidences, the aim of this study was to immunize chickens with trypomastigotes of T. cruzi in order to produce highly effective and pure antibodies (IgY), as well as extract, characterize, quantify, and verify cytotoxic effects of IgY anti-T. cruzi. After the induction of IgY production by chickens, the eggs were collected and the IgY was extracted by method of precipitation of polyethylene glycol 6000. The IgY anti-T. cruzi characterization was performed using polyacrylamide gel electrophoresis (SDS-PAGE), western-blot and enzyme-linked immunosorbent assay (ELISA). Moreover, the cytotoxic or proliferative effects of IgY anti-T. cruzi was verified by MTT assay. The concentration of IgY in yolk was 8.41±1.47mg/mL. The characterization of IgY reveled bands of stained peptides with molecular weight between 75 and 50kDa and 37 and 25kDa. In the ELISA test was observed that there was antigen-antibody reaction throughout the sample period. The concentrations of 1, 5 and 10mg/mL of IgY anti-T. cruzi presented no cytotoxic of proliferative effects in mononuclear and VERO cells in vitro. The results indicated that T. cruzi is able to generate a high production of specific immunoglobulins in chickens, it did not cause damage to the cell membrane and no proliferative effect.