Preclinical safety assessment in rats after dermal exposure to acetylcarvacrol, a potential acaricide against the brown dog tick.

Carvacrol, a phenolic monoterpene found in essential oils of plants of the Lamiaceae family, emerges as an alternative acaricide of plant origin. Its acetylation was proposed to obtain a derivative compound with a better pharmacological profile and lower toxicity to non-target organisms. The present study aimed to assess the preclinical safety of acetylcarvacrol after dermal application in Wistar rats, through the examination of hematological and biochemical parameters, as well as histopathological analysis of the skin, liver and kidney.

A putative new genus of avian schistosome transmitted by Biomphalaria straminea (Gastropoda: Planorbidae) in Brazil, with a discussion on the potential involvement in human cercarial dermatitis.

Human cercarial dermatitis (HCD) caused by avian schistosomes is an emerging health issue in different parts of the world. Nevertheless, parasite diversity, life cycle, and involvement in HCD remain poorly known or neglected in South America. Herein, we reported data obtained during a long-term malacological survey carried out in Pampulha Reservoir, an urban eutrophic waterbody from Brazil between 2009 and 2012.

Acute infection with Platynosomum illiciens (Trematoda: Dicrocoeliidae) as a clinically relevant and potentially fatal disease in Falco sparverius (Aves: Falconidae) in Brazil.

Platynosomum illiciens is a dicrocoeliid trematode from the biliary tract of warm-blooded vertebrates (felines, primates, marsupials, and birds) reported in different parts of the world. Although the veterinary relevance of platynosomosis in mammals, especially in domestic felines, has been increasingly evidenced in the scientific literature, studies involving avian disease caused by P. illiciens are comparatively scarce.

Treatment of primate platynosomosis: A word of caution about the use of praziquantel in marmosets.

Background: The successive reports of Platynosomum illiciens in Neotropical captive primates have increased interest in platynosomosis; however, its treatment is little known.

Methods: Callithrix penicillata (n = 10) naturally and chronically infected with P. illiciens were treated with praziquantel (25 mg/kg BW, three s.

DNA sequences confirm low specificity to definitive host and wide distribution of the cat pathogen Platynosomum illiciens (= P. fastosum) (Trematoda: Dicrocoeliidae).

Although feline platynosomosis has been commonly reported in several parts of the world, the taxonomy and epidemiological chain related to cat liver flukes remain controversial. In this study, nuclear ribosomal ITS, 28S, and mitochondrial cox1 sequences obtained for Platynosomum illiciens from cat, marmoset, lizard, and snail found naturally infected in Brazil reveal no significant molecular differences between these isolates. Moreover, sequence data confirm that Brazilian P.

Exploring possibilities for an alternative approach in experimental schistosomiasis mansoni: the peritoneal cavity of mice.

The schistosome oviposition and granuloma constitution in the peritoneal cavity of AKR/J mice were evaluated. Groups of mice intraperitoneally infected with cercariae of Schistosoma mansoni were weekly euthanized during the acute (56 to 84 days post-infection (DPI)) and chronic (147 to 175 DPI) phase of infection. Schistosome developmental stages obtained via peritoneal lavage and perfusion of the portal system were inspected, counted and fixed, and peritoneal granulomata were then processed for histology.

Platynosomum illiciens (Trematoda: Dicrocoeliidae) in Captive Black-Tufted Marmoset Callithrix penicillata (Primates: Cebidae) from Brazil: A Morphometric Analyses with Taxonomic Comments on Species of Platynosomum from Nonhuman Primates.

The trematodes belonging to the genus Platynosomum are biliary parasites of birds and mammals (domestic and wildlife) in tropical and subtropical areas of the globe. Despite several reports on platynosomosis in captive nonhuman primates, mainly in South America, the taxonomy of species of Platynosomum that infect these hosts remains confused, and it is not clear whether the species found in cats is the same that infects nonhuman primates. Because a detailed morphological study of Platynosomum from nonhuman primates is lacking, in this study we analyzed specimens of Platynosomum recovered from the biliary system of Callithrix penicillata kept in captivity in an animal facility.

Experimental platynosomosis: Characterization of parasite development in the mouse model.

Despite the veterinary importance of species of Platynosomum, biliary trematode parasites of birds and mammals with worldwide distribution and a growing role in feline practice, the basic parasitological aspects of platynosomosis is still not completely understood due to the scarcity of studies in experimental models. In the present study, metacercariae of Platynosomum illiciens obtained from naturally infected tropical house geckos (Hemidactylus mabouia) in an urban area of Brazil were force-fed to mice of the AKR/J strain (100 metacercariae/animal). Groups of mice were euthanized at 60, 120, 160 and 240 days post-infection (DPI), and the biliary tree of the animals (intrahepatic biliary ducts, common hepatic and bile ducts, cystic duct and gallbladder) were examined for the presence of adult parasites.

Evaluation of Kato-Katz and spontaneous sedimentation methods for the diagnosis of platynosomiasis in Neotropical primates.

Platynosomiasis is a parasitic infection reported in non-human primates, including marmosets, and is frequently difficult to diagnose. In this study, the Kato-Katz method and the spontaneous sedimentation method were evaluated for their usefulness in identifying Platynosomum eggs in fecal samples from Callithrix penicillata that naturally harbor Platynosomum illiciens. Spontaneous sedimentation allowed the diagnosis of 41.

Experimental centrocestiasis: Worm burden, morphology and fecundity of Centrocestus formosanus (Trematoda: Heterophyidae) in dexamethasone immunosuppressed mice.

Centrocestus formosanus is an intestinal foodborne trematode with medical and veterinary importance that remains with the pathological and immunological aspects of the infection in definitive host poorly studied. In the present study, we evaluated the effects of pharmacological immunosuppression by glucocorticoids in experimental centrocestiasis. Mice of the AKR/J strain were orally inoculated with 100 metacercariae of C.

Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism.

Eggs of Toxocara cati were found in the feces of Didelphis albiventris from a peridomestic urban environment in Brazil. Negative fecal tests following short-term captivity of the opossums, as well as the absence of ascaridids during necropsy, suggest the occurrence of pseudoparasitism. Implications of the findings for the epidemiology of toxocariasis are discussed.

Strongyloides stercoralis infection in marmosets: replication of complicated and uncomplicated human disease and parasite biology.

Background: Strongyloides stercoralis can undergo an alternative autoinfective life cycle in the host, which, in some individuals can lead to a lethal infection. However, due to a number of factors, such as, the majority of those infected are from low-income backgrounds and the limitation in experimental models for studying human S. stercoralis, strongyloidiasis remains neglected.

Metacercarial infection of wild Nile tilapia (Oreochromis niloticus) from Brazil.

Fingerlings of Oreochromis niloticus collected in an artificial urban lake from Belo Horizonte, Minas Gerais, Brazil, were evaluated for natural infection with trematodes. Morphological taxonomic identification of four fluke species was performed in O. niloticus examined, and the total prevalence of metacercariae was 60.

New insights into the life cycle of Platynosomum (Trematoda: Dicrocoeliidae).

The platynosomiasis, a worldwide parasitic disease with importance for domestic cat, has an etiological agent species of trematodes of the genus Platynosomum, whose complete life cycles are not yet known. The real role of lizards in the transmission of this dicrocoeliid parasite (as obligatory intermediate or paratenic host) still needs to be defined. In the present study, oval-shaped encysted metacercariae obtained from terrestrial isopods (Oniscidea sp.

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite.

Introduction: The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required.

Methods: The current distribution of Biomphalaria spp.

Strongyloides cebus (Nematoda: Strongyloididae) in Lagothrix cana (Primates: Atelidae) from the Brazilian Amazon: aspects of clinical presentation, anatomopathology, treatment, and parasitic biology.

Abstract :  Seven cases of parasitism by Strongyloides cebus were identified in Lagothrix cana from Brazil. Aspects of the clinical presentation, treatment, pathology, and parasitic biology of these infections are described. Moderate to severe disease was observed, requiring hospitalization of 3 primates, and diarrhea was the most common clinical sign described.

Trypanoxyuris (Paraoxyuronema) lagothricis (Nematoda: Oxyuridae) in Lagothrix cana (Primates: Atelidae) from Brazil.

During necropsy of a specimen of Lagothrix cana (É. Geoffroy, 1812) (Primates: Atelidae) from the Brazilian Amazon, pinworms were found in the large intestine. The intensity of infection was 64 parasites (17 males and 47 females) and there were no gross pathological changes related to parasitism.

Parasitological and immunological aspects of early Ascaris spp. infection in mice.

Studies related to the immunobiological aspects of an Ascaris spp. infection are still scarce, especially those that aim to elucidate the early events of the immune response. In this study, we demonstrated a novel standardized method for early experimental Ascaris infection, providing additional information about the infectivity of eggs embryonated in vitro as well as the influence of host age on development of the infection.

Experimental infection of Swiss and AKR/J mice with Centrocestus formosanus (Trematoda: Heterophyidae).

In order to better understand the biology of Centrocestus formosanus in a definitive host model, mice of Swiss and AKR/J strains were experimentally infected with 100 metacercariae of the parasite. Fourteen days post-infection, the rodents were killed and adult trematodes were recovered from the small intestine. The percentage of parasite recovery from AKR/J mice (11.

Callithrix penicillata as a nonhuman primate model for strongyloidiasis.

In order to better understand experimental strongyloidiasis in small New World primates, and to evaluate aspects of reinfection and immunosuppression induced by glucocorticoids, nine specimens of Callithrix penicillata (Primates: Cebidae) were administered (by subcutaneous injection, sc) 3000 infective larvae of a strain of Strongyloides venezuelensis (Rhabditida: Strongyloididae) that had been maintained in successive passages through AKR/J mice since 1987. The mean prepatent period was 5.6 ± 0.

Oral immunization with Salmonella harboring a Sm14-based DNA vaccine does not protect mice against Schistosoma mansoni infection.

The protection against Schistosoma mansoni infection was evaluated in SWISS mice orally vaccinated with an attenuated strain of Salmonella carrying a Sm14-based DNA vaccine. Although this formulation was not able to afford a reduction in the worm burden, a non-antigen-specific decrease in schistosome-induced granulomatous reaction was verified in livers of mice that received Salmonella.

Oral administration of a live Aro attenuated Salmonella vaccine strain expressing 14-kDa Schistosoma mansoni fatty acid-binding protein induced partial protection against experimental schistosomiasis.

We report the oral vaccination of SWISS mice with an Aro attenuated Salmonella enterica var. Typhimurium vaccine strain expressing the 14-kDa Schistosoma mansoni antigen, Sm14. Bacterial adjuvants, including (i) Lactococcus lactis expressing interleukin-12 (IL-12) and (ii) Lactobacillus delbrueckii UFV-H2b20, were also employed in oral immunization assays.