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Background: Tick feeding causes extreme morbidity and mortality to humans through transmission of pathogens and causes severe economic losses to the agricultural industry by reducing livestock yield. Salivary gland secretions are essential for tick feeding and thus, reducing or preventing saliva secretions into the vertebrate host is likely to reduce feeding and hinder pathogen life cycles. Unfortunately, the membrane physiology of tick salivary glands is underexplored and this gap in knowledge limits the development of novel therapeutics for inducing cessation of tick feeding. Methodology: We studied the influence of inward rectifier potassium (Kir) channel subtypes to the functional capacity of the isolated tick salivary gland through the use of a modified Ramsay assay. The secreted saliva was subsequently used for quantification of the elemental composition of the secreted saliva after the glands were exposed to K+ channel modulators as a measure of osmoregulatory capacity. Lastly, changes to blood feeding behavior and mortality were measured with the use of a membrane feeding system. Principal findings: In this study, we characterized the fundamental role of Kir channel subtypes in tick salivary gland function and provide evidence that pharmacological inhibition of these ion channels reduces the secretory activity of the salivary gland of Amblyomma americanum. The reduced secretory capacity of the salivary gland was directly correlated with a dramatic reduction of blood ingestion during feeding. Further, exposure to small-molecule modulators of Kir channel subtypes induced mortality to ticks that is likely resultant from an altered osmoregulatory capacity. Conclusions: Our data contribute to understanding of tick salivary gland function and could guide future campaigns aiming to develop chemical or reverse vaccinology technologies to reduce the worldwide burden of tick feeding and tick-vectored pathogens. [ABSTRACT FROM AUTHOR]

Here we propose a single acid digestion (SAD) sample preparation method for ICP-MS analysis of animal serum samples to determine trace element contents. The method was evaluated in comparison with a commonly used procedure involving dilution of samples in an alkaline solution (AKD). In the SAD procedure, aliquots (1 mL) of bovine serum samples were treated at low temperature with a mixture of concentrated nitric acid and hydrogen peroxide. Trace elements (As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, U, and Zn) were directly determined by ICP-MS analysis of diluted solutions of samples. Both methods were sufficiently sensitive to enable quantification of most trace elements, with the exception of the AKD method for Cd, Hg and Pb. The quality of the data was verified by using certified reference material. Good results were obtained for the SAD procedure and all elements, but recoveries were unacceptable with the AKD procedure for Se (recovery: 57%), Cd (154%) and Fe (139%). Strong associations (R2>0.90, P = 0.000) between the data obtained by both methods were demonstrated for the elements considered. The proposed SAD sample preparation method produced satisfactory results for determining most toxic and essential trace elements targeted in monitoring studies. [ABSTRACT FROM AUTHOR]

Rickettsia parkeri, a causative agent of spotted fever rickettsiosis, is transmitted by Amblyomma maculatum (Gulf Coast tick), a tick that may also carry a non-pathogenic spotted fever group Rickettsia, "Candidatus Rickettsia andeanae". Here, we evaluated R. parkeri and "Candidatus R. andeanae" in tissues from A. maculatum prior to, during, and after blood feeding on rabbits. Using colony-reared A. maculatum that were capillary-fed uninfected cells, R. parkeri, "Candidatus R. andeanae", or both rickettsiae, we detected higher levels of Rickettsia spp. in the respective treatment groups. Rickettsial levels increased during blood feeding for both R. parkeri and "Candidatus R. andeanae", with a greater increase in R. parkeri in co-infected ticks compared to singly-infected ticks. We detected transovarial transmission of "Candidatus R. andeanae" in egg and larval cohorts and confirmed vertical transmission of R. parkeri in one group of larvae. Rabbits from all Rickettsia-exposed groups seroconverted on immunofluorescent antibody testing using R. parkeri antigen. Visualization of "Candidatus R. andeanae" in tick salivary glands suggested potential transmission via tick feeding. Here, rickettsial levels in artificially infected ticks demonstrate changes during feeding and transovarial transmission that may be relevant for interpreting rickettsial levels detected in wild A. maculatum. [ABSTRACT FROM AUTHOR]

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The main motivation for this study was to determine the occurrence of Toxoplasma gondii, a cosmopolitan widespread zoonotic parasite distribution that can infect a wide variety of mammals and birds, in Magellanic penguins (Spheniscus magellanicus) in Brazil. In recent decades there has been a significant increase in the number of penguins originating from Argentinian and Chilean Patagonia, where these birds are born, that arrive on the Brazilian coast, where many of them are stranded and rescued. Tissue samples were collected from 330 individuals surveyed from 2012–2015 at the Institute for Marine Animal Research and Rehabilitation (IPRAM) located in Cariacica, state of Espirito Santo, Brazil. Serum were collected from 145 animals surveyed in 2015 for the detection of anti-T. gondii antibodies using the Modified Agglutination Test (MAT ≥20) and 18 birds were positive, with titers of 20 (7 birds), 40 (9 birds) and 80 (2 birds). Mouse bioassay for the isolation of T. gondii was performed using tissues from 54 penguins that were also surveyed in 2015, but no isolates were obtained. DNA from tissue samples of 330 individuals was PCR amplified and sequenced to detect tissue cyst forming coccidians by using pan sarcocystids-directed primers (based on 18S rDNA). These samples were from animals surveyed in 2015 and from frozen stocked tissues from animals surveyed in the years 2012 and 2013. The positives were PCR amplified and sequenced with genus Sarcocystis-specific primers (based on internal transcribed spacer 1, RNA polymerase beta subunit coding gene, and cytochrome B coding gene) and with Sarcocystis falcatula/Sarcocystis neurona- specific primers (based on surface antigens SAG2, SAG3 and SAG4). Sixteen (3.0%) of pectoral muscle samples were positive by all the seven molecular markers and all the samples were identical to each other. Organisms close related to Sarcocystis falcatula were confirmed in all cases. This is the first report on molecular detection of infection by S. falcatula-related organisms and the first report of seropositivity for T. gondii in free-living Magellanic penguins in Brazil. Felids and didephid opossums are definitive hosts of T. gondii and S. falcatula, respectively. Where the penguins acquire the infective forms of the parasites shed by the terrestrial mammals remains to be elucidated. [ABSTRACT FROM AUTHOR]

Leprosy is an infectious disease caused by Mycobacterium leprae and frequently resulting in irreversible deformities and disabilities. Ticks play an important role in infectious disease transmission due to their low host specificity, worldwide distribution, and the biological ability to support transovarial transmission of a wide spectrum of pathogens, including viruses, bacteria and protozoa. To investigate a possible role for ticks as vectors of leprosy, we assessed transovarial transmission of M. leprae in artificially-fed adult female Amblyomma sculptum ticks, and infection and growth of M. leprae in tick cell lines. Our results revealed M. leprae RNA and antigens persisting in the midgut and present in the ovaries of adult female A. sculptum at least 2 days after oral infection, and present in their progeny (eggs and larvae), which demonstrates the occurrence of transovarial transmission of this pathogen. Infected tick larvae were able to inoculate viable bacilli during blood-feeding on a rabbit. Moreover, following inoculation with M. leprae, the Ixodes scapularis embryo-derived tick cell line IDE8 supported a detectable increase in the number of bacilli for at least 20 days, presenting a doubling time of approximately 12 days. As far as we know, this is the first in vitro cellular system able to promote growth of M. leprae. Finally, we successfully transformed a clinical M. leprae isolate by inserting the reporter plasmid pCHERRY3; transformed bacteria infected and grew in IDE8 cells over a 2-month period. Taken together, our data not only support the hypothesis that ticks may have the potential to act as a reservoir and/or vector of leprosy, but also suggest the feasibility of technological development of tick cell lines as a tool for large-scale production of M. leprae bacteria, as well as describing for the first time a method for their transformation. [ABSTRACT FROM AUTHOR]

In Brazil, at least 14 species of soft ticks (Argasidae) are associated with bats. While Ornithodoros hasei seems to be abundant among foliage-roosting bats, other groups of ticks are found exclusively inside caves. In this paper, noteworthy records of soft ticks infesting bats are documented in new localities from Bahia, Pernambuco, Piauí, and Rondônia states. Out of 201 bats examined, 25 were infested by 152 ticks belonging to seven taxa: Ornithodoros cavernicolous, O. hasei, Ornithodoros marinkellei, Ornithodoros cf. fonsecai, Ornithodoros cf. clarki, Antricola sp., and Nothoaspis amazoniensis. These findings provide new insights into the geographical distribution and host association of soft ticks occurring in the Neotropical region. Remarkably, morphological and biological observations about O. hasei are inferred based on the examination of on-host-collected first stage nymphs. [ABSTRACT FROM AUTHOR]

We report tick infestations and rickettsial detection in ticks infesting free-living wild mammals (Monodelphis domestica, Tolypeutes tricinctus, Thrichomys inermis and Kerodon rupestris) captured in the Caatinga ecoregion of Bahia state, northeastern Brazil, during September to December 2016. Overall, 117 ticks (61 larvae, 25 nymphs, 25 males, 6 females) belonging to two genera, and at least three species were collected: Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros rietcorreai and an unidentified Ornithodoros sp. We provide new host records to the rodent T. inermis parasitized by larva and nymphs of A. auricularium and to the marsupial M. domestica infested by larvae of A. auricularium. Furthermore, we describe new tick-host association for larvae of O. rietcorreai on the rodents K. rupestris and T. inermis. Concerning tick-Rickettsia associations, we detected Rickettsia amblyommatis and an uncharacterized species of Rickettsia belonging to the spotted fever group (SFG) in both A. auricularium and A. parvum. Additionally, 'Candidatus Rickettsia andeanae' was detected in A. parvum as well. [ABSTRACT FROM AUTHOR]

We report the full polyprotein genomic sequence of a West Nile virus strain isolated from Eurasian magpies dying with neurologic signs in Greece. Our findings demonstrate the local genetic evolution of the West Nile virus strain responsible for a human disease outbreak in the country that began in 2010. [ABSTRACT FROM AUTHOR]

The Cerrado Biome is the second largest in Brazil covering roughly 2 million km2, with varying features throughout its area. The Biome is endangered but it is also source of animal species for rural, green urban and degraded rainforest areas. Ticks are among Cerrado species that establish at anthropogenic sites and although information about them is steadily increasing, several features are unknown. We herein report tick species, abundance and some ecological relationships within natural areas of the Cerrado at higher altitudes (800-1500 m) within and around Serra da Canastra National Park, in Minas Gerais State Brazil. In total of 1196 ticks were collected in the environment along 10 campaigns held in 3 years (2007-2009). Amblyomma sculptum was the most numerous species followed by Amblyomma dubitatum and Amblyomma brasiliense. Distribution of these species was very uneven and an established population of A. brasiliense in the Cerrado is reported for the first time. Other tick species (Amblyomma ovale, Amblyomma nodosum, Amblyomma parvum, Ixodes schulzei and Haemaphysalis leporispalustris) were found in lesser numbers. Domestic animals displayed tick infestations of both rural and urban origin as well as from natural areas (Rhipicephalus sanguineus sensu lato, Rhipicephalus microplus, Dermacentor nitens, A. sculptum, A. ovale, Amblyomma tigrinum, Argas miniatus). Amblyomma sculptum had the widest domestic host spectrum among all tick species. DNA of only one Rickettsia species, R. bellii, was found in an A. dubitatum tick. Several biological and ecological features of ticks of the studied areas are discussed. [ABSTRACT FROM AUTHOR]

Amblyomma aureolatum ticks are vectors of Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever in Brazil. Maintenance of R. rickettsii in nature depends on horizontal transmission along tick generations. Although such transmission is known to occur when uninfected and infected ticks feed simultaneously on susceptible animals (co-feeding systemic transmission), we investigated co-feeding nonsystemic transmission, which was based on R. rickettsii-infected and -uninfected A. aureolatum ticks feeding simultaneously on guinea pigs immune to R. rickettsii. Our acquisition and transmission infestations demonstrated that horizontal transmission of R. rickettsii by co-feeding ticks on immune hosts with no systemic infection did not occur when uninfected larvae fed distantly from infected nymphs but did occur in a few cases when uninfected larvae fed side-by-side with infected nymphs, suggesting that they shared the same feeding site. The co-feeding nonsystemic transmission type might have no epidemiologic importance for Rocky Mountain spotted fever. [ABSTRACT FROM AUTHOR]

Lyme Borreliosis and granulocytic anaplasmosis are less extensively studied in horses than in dogs and humans. Equine ehrlichiosis is not known in Europe and is in the initial stage of investigation in South, Central, and North America. The aim of this study was to determine the seroprevalence of these infections in Bulgaria. A total of 155 horses were investigated from five regions in Southeastern Bulgaria. Horses were tested for Borrelia burgdorferi, Anaplasma phagocytophilum, and Ehrlichia spp. antibodies by a commercial rapid ELISA test. B. burgdorferi and A. phagocytophilum antibodies were found in all five regions (Burgas, Sliven, Stara Zagora, Haskovo, and Kardzhali) at frequencies of 36/155 (23.2%; 95% CI: 16.8–30.7%; ranging by region from 6.4% to 50%) and 31/155 (20%; 95% CI: 14–27.2%; ranging by region from 10% to 30.8%), respectively. Antibodies against Ehrlichia spp. were found in horses from three regions (Burgas, Stara Zagora, and Haskovo) at a rate of 6/155 (3.9%; 95% CI: 1.4–8.2%; ranging by region from 5.7% to 6.4%). The combination of B. burgdorferi/A. phagocytophilum (11/155; 7.1%; 95% CI: 3.6–12.3%) was the most common coexposure observed, followed by B. burgdorferi/Ehrlichia spp. (2/155; 1.3%; 95% CI: 0.2–4.6%) and A. phagocytophilum/Ehrlichia spp. (1/155; 0.6%; 95% CI: 0–3.5%). The study shows that horses in Bulgaria are exposed or coexposed to three tick-transmitted zoonotic bacterial species. Furthermore, it reports Ehrlichia spp. seroreactivity in equines in Europe. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Infections occur via the ingestion of oocysts, consumption of cysts containing bradyzoites, and transplacental transmission of tachyzoites. Diversity in T. gondii strains may affect the outcome of clinical toxoplasmosis. The consumption of horse meat is a common practice in some parts of the world. The objectives of the present study were to isolate and genotype T. gondii from horses from an abattoir in the state of Rio Grande do Sul in southern Brazil that exports horse meat to Europe. Antibodies to T. gondii were found in 32.5% (13/40) of the horses using the modified agglutination test (MAT) with a cut-off of 1:25. Tissues from the 13 seropositive horses were bioassayed in mice, and one isolate, designated TgHorseBrRS1, was obtained. PCR-RFLP of the isolate revealed the ToxoDB-RFLP #228 genotype, a typical non-archetypal Brazilian genotype, and microsatellite analysis showed a unique non-archetypal genotype. This study showed that horses from Brazil can harbor viable T. gondii in their tissues, suggesting that recommendations to consumers should be made, especially in European countries where consumption of raw horse meat is common. [ABSTRACT FROM AUTHOR]

Spotted fever (SF) is a tick-borne disease associated with Rickettsia spp.. In the Pampa biome, Southern Brazil, cases of SF seem to be strongly linked with the practice of hunting wild animals. An investigation of rickettsiae in tick species found on wild animals could provide more information regarding the rickettsiosis enzootic cycle. The aim of this study is to describe the results of a molecular survey of Rickettsia spp. in the Neotropical deer tick, Haemaphysalis juxtakochi Cooley, 1946 (Acari: Ixodidae), from the Brazilian Pampa. Ticks were obtained from 14 road-killed gray brocket deer, Mazama gouazoubira (Artiodactyla: Cervidae), found in nine different municipalities of Rio Grande do Sul state, Southern Brazil. Ticks were processed individually to obtain genomic DNA, and then Rickettsia spp. was investigated using a set of PCR reactions that amplified the rickettsial fragments of the gltA, ompA, and htrA genes. Of the 24 tick samples tested, DNA of Rickettsia parkeri sensu stricto (s.s.) was found in 11 H. juxtakochi specimens collected in two different areas of the Brazilian Pampa. This is the first report of R. parkeri s.s. (the main agent associated with SF in the Uruguayan, Argentinian, and Brazilian Pampa) in H. juxtakochi ticks. These findings indicate that R. parkeri s.s. may be much more common and widely distributed in the Pampa biome than previously assumed. Moreover, H. juxtakochi ticks and gray brocket deer could participate in the potential spillover of R. parkeri s.s. from endemic to non-endemic areas in the South American Pampa. [ABSTRACT FROM AUTHOR]

Hemoparasites are vector-borne parasites that infect wild carnivores worldwide. Since data on hemoparasite infections in Nasua nasua from Brazil are lacking, the aim of this study was to investigate the occurrence of hemoparasites and ectoparasites in N. nasua from different areas of Brazil. Blood samples and ectoparasites from 83 N. nasua were collected in Botucatu, Palmital, and São Paulo municipalities. Samples were screened via microscopy and molecular methods to detect hemoparasites. Tissues from two N. nasua were obtained for histopathological and molecular analyses. All 83 samples were negative for piroplasms on morphological and molecular examination. Thin blood smears of nine animals were positive for Hepatozoon gamonts. The gamonts shared morphological characteristics of Hepatozoon procyonis. Meronts were detected in the liver and spleen tissue of one animal. Twenty-one blood samples and four tissue samples were PCR positive for Hepatozoon sp. The sequences obtained were 97% identical to those of Hepatozoon felis, Hepatozoon ursi, and Hepatozoon sp. Based on searches for similarity and morphology, we identified the sequences as belonging to H. procyonis. This study provides epidemiological data on hemoparasite infections and redescribe H. procyonis based on morphological, morphometrical, and molecular analyses. [ABSTRACT FROM AUTHOR]

Copyright of Archivos Venezolanos de Farmacología y Terapéutica is the property of Archivos Venezolanos de Farmacologia y Terapeutica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Toxoplasma gondii is a protozoon parasite that causes congenital toxoplasmosis, as well as other serious clinical presentations, in immune compromised humans. Analyses of the prevalence and genotyping of strains from the definitive host and intermediate hosts will help to understanding the circulation of the different strains and elucidating the role of the genotype(s) in human toxoplasmosis. Turkey has a specific geographic location bridging Africa, Europe, and Asia. We hypothesized that T. gondii strains may have been transferred to Turkey from these continents via migratory birds or vice versa. The present study aimed to assess the prevalence of toxoplasmosis in wild birds of prey of İzmir and Manisa provinces as well as genetically characterize T. gondii strains from these wild birds to show the relation between bird strains and neighboring stray cats as well as human strains previously isolated in Turkey. Tissues obtained from 48 wild birds were investigated for the presence of T. gondii DNA and then bioassayed in mouse. Isolated strains were genotyped using 15 microsatellite markers. The prevalence of T. gondii DNA was found to be 89.6% (n: 43/48) in wild birds. Out of 43 positive samples, a total of 14 strains were genotyped by 15 microsatellite markers. Among them, eight were type II, three were type III and three were mixture of genotypes (two type II/II and one was II/III). These are the first data that showed the presence of T. gondii and types II and III genotypes in wild birds of Turkey. Moreover, Africa 1 was not detected. In addition, cluster analysis showed that T. gondii strains within type II and III lineage have close relation with strains previously isolated from stray cats in İzmir. Further studies are required to isolate more strains from human cases, other intermediate hosts, and water sources to reveal this relation. [ABSTRACT FROM AUTHOR]

Abstract: We report the pathological, immunohistochemical, and molecular features of fatal acute systemic toxoplasmosis in an adult, female, free‐living southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil. PCR‐RFLP genotyping analysis identified the #21 genotype of Toxoplasma gondii. This represents the first report of acute toxoplasmosis involving this genotype in humans and animals. [ABSTRACT FROM AUTHOR]

The degree of conservation and evolution of cytoplasmic mRNA metabolism pathways across the eukaryotes remains incompletely resolved. In this study, we describe a comprehensive genome and transcriptome-wide analysis of proteins involved in mRNA maturation, translation, and mRNA decay across representative organisms from the six eukaryotic super-groups. We demonstrate that eukaryotes share common pathways for mRNA metabolism that were almost certainly present in the last eukaryotic common ancestor, and show for the first time a correlation between intron density and a selective absence of some Exon Junction Complex (EJC) components in eukaryotes. In addition, we identify pathways that have diversified in individual lineages, with a specific focus on the unique gene gains and losses in members of the Excavata and SAR groups that contribute to their unique gene expression pathways compared to other organisms. [ABSTRACT FROM AUTHOR]

Several bat species can be infected by trypanosomes, but there is not much information about which of these parasites infect bats from Triângulo Mineiro and Alto Paranaíba, Minas Gerais state, Brazil, a formerly endemic region for Trypanosoma cruzi, the causative agent of Chagas disease. The aim of this study was to describe, characterize, and identify the presence of trypanosomes in bats. The captured bats (448) belong to four families and to 19 different species. Of those, 37 bats were found to be positive for trypanosomes by microhematocrit, (infection rate 8.3%) and 27 were positive after hemoculture analysis. Initially, the isolates were identified by PCR (18S rDNA, 24Sα rDNA, spliced leader, COII RFLP-PCR) using primers originally designed for T. cruzi. PCRs (18S rDNA, 24Sα rDNA) showed compatible bands for TcI, whereas COII RFLP-PCR showed a similar pattern associated to TcII. However, there was no DNA amplification using spliced leader as a target, revealing a discrepancy between the results. Phylogenetic analysis of Cathepsin L-like and 18S rDNA sequences proved that 15 of the isolates corresponded to Trypanosoma cruzi marinkellei and one to Trypanosoma dionisii. These results revealed that the diversity of trypanosome species in a region considered endemic for Chagas disease is greater than previous descriptions. All this can confirm the necessity of using DNA sequencing approaches in order to determinate trypanosomes species isolated from bats. [ABSTRACT FROM AUTHOR]

This study describes experimental infection of guinea pigs (Cavia porcellus) infested with naturally infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain), and the capacity of A. ovale nymphs to transmit this bacterium. Twenty-six guinea pigs were divided into the following groups: G1, 10 animals infested with uninfected A. ovale nymphs; G2, 10 animals infested with nymphs infected with Rickettsia sp. (Atlantic rainforest strain); and G3, 6 animals without tick infestation. Blood samples were taken 7, 14, 21, and 28 days post-infestation for serological and hematological tests. For histopathological analysis and rickettsial DNA detection, fragments of the spleen, lung, brain, and liver were harvested after euthanasia. The average feeding period for nymphs was 6.6 days for G1 and 6 days for G2. Hemolymph and PCR assays, performed to detect the causative agent in ticks, indicated that in G1, all ticks were negative, and in G2, all nymphs were positive by PCR and 80% (8/10) was positive by hemolymph tests. The only clinical change was skin scarring at the tick attachment site. Hematological parameters indicated leukopenia and total plasma protein (TPP) increased with decreased platelets in G1. In G2, leukocytosis, neutrophilia, monocytosis, an increase in platelets, and reduced TPP were observed. Only G2 guinea pigs were seroconverted (80%; 8/10). Histopathology tests indicated mild, diffuse hemosiderosis and mild, multifocal, follicular hyperplasia in the spleen. Molecular analysis did not detect Rickettsia sp. DNA in C. porcellus tissues. We demonstrated the capacity of A. ovale nymphs to transmit Rickettsia sp. (Atlantic rainforest strain) to guinea pigs. [ABSTRACT FROM AUTHOR]

Chiropteran mammals worldwide harbour trypanosomes (Euglenozoa: Kinetoplastea: Trypanosomatida) of the subgenus ‘Schizotrypanum’ in the classical sense. Latterly, these trypanosomes have been referred to as members of the ‘Trypanosoma cruzi clade’ as their phylogenetic relationships, structure and life cycle conform to T. cruzi, parasitising various terrestrial mammals as well as humans in Latin America. Little is known, however, about the trypanosome species in Asian bats. During a survey on Borrelia spp. in the Eastern bent-winged bat (Miniopterus fuliginosus) living in a cave in Wakayama Prefecture, Japan, incidental proliferation of trypanosomes was detected in two of 94 haemocultures. Squat or slender trypanosomes that proliferated in the cultures were 7.5–20.5 μm in length between both body ends and 1.0–3.8 μm in width with/without free flagella up to 14.5 μm (n = 29). The nucleotide sequences of the small subunit ribosomal RNA gene (SSU rDNA; 2176 bp), large subunit ribosomal RNA gene (1365 bp) and glycosomal glyceraldehyde-3-phosphate dehydrogenase gene (gGAPDH; 843 bp) of the present isolates were characterized to clarify their molecular phylogenetic position in T. cruzi-like trypanosomes. The newly obtained SSU rDNA and gGAPDH nucleotide sequences showed the highest identities with Brazilian and European isolates of Trypanosoma dionisii of the T. cruzi clade, ranging between 99.4 and 99.7% or between 95.6 and 99.3% identities, respectively. Although multiple T. dionisii isolates from the North and South American continents showed the closest molecular genetic relatedness to the present Far East isolates, only short SSU rDNA segments of the former isolates were deposited. Therefore, a definitive conclusion cannot be made until full nucleotide sequencing of at least the American isolates’ SSU rDNA is available. This is the first confirmation of a Far East distribution of T. dionisii, demonstrating a wide geographical distribution of the species in the Eurasian and American continents with a limited nucleotide variation. [ABSTRACT FROM AUTHOR]

The tick fauna of Brazil is currently composed by 72 species. The state of Amazonas is the largest of Brazil, with an area of ≈ 19% of the Brazilian land. Besides its vast geographic area, only 19 tick species have been reported for Amazonas. Herein, lots containing ticks from the state of Amazonas were examined in three major tick collections from Brazil. A total of 5933 tick specimens were examined and recorded, comprising 2693 males, 1247 females, 1509 nymphs, and 484 larvae. These ticks were identified into the following 22 species: Amblyomma cajennense sensu lato, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma dissimile, Amblyomma dubitatum, Amblyomma geayi, Amblyomma goeldii, Amblyomma humerale, Amblyomma latepunctatun, Amblyomma longirostre, Amblyomma naponense, Amblyomma oblongoguttatum, Amblyomma ovale, Amblyomma rotundatum, Amblyomma scalpturatum, Amblyomma varium, Dermacentor nitens, Haemaphysalis juxtakochi, Ixodes cf. Ixodes fuscipes, Ixodes luciae, Rhipicephalus microplus, Rhipicephalus sanguineus sensu lato. Ticks were collected from 17 (27.4%) out of the 62 municipalities that currently compose the state of Amazonas. The following four species are reported for the first time in the state of Amazonas: A. coelebs, A. dubitatum, H. juxtakochi, and Ixodes cf. I. fuscipes. The only tick species previously reported for Amazonas and not found in the present study is Amblyomma parvum. This study provides a great expansion of geographical and host records of ticks for the state of Amazonas, which is now considered to have a tick fauna composed by 23 species. It is noteworthy that we report 1391 Amblyomma nymphs that were identified to 13 different species. [ABSTRACT FROM AUTHOR]

Background: This study was designed to assess the ability of fed male Dermacentor reticulatus ticks to transmit Babesia canis to dogs after being detached from previous canine or ovine hosts. Methods: The study was an exploratory, parallel group design conducted in two trials. All the animals were sero-negative for babesiosis prior to enrolment. In a first trial, donor dogs and donor sheep were infested with Babesia canis infected male and uninfected female ticks for 72 h. The ticks were detached and the second group of host dogs were infested for 24 h before tick removal. In a second trial, the experiment was repeated but the donor animals were infested for 88 h and the second group of host dogs were infested for 8 h prior to tick removal. After infestation, the dogs were maintained under clinical surveillance and blood samples were collected for blood smear, IFA and PCR analysis. A dog was considered infected if any of these tests were positive. Results: All of the dogs (6 out of 6) were infected after being exposed to pre-activated male ticks for 24 h. Half of the dogs were infected after being exposed to pre-activated ticks for 8 h: 1 out of 3 dogs infested with ticks removed from sheep and 2 out of 3 dogs infested with ticks removed from dog. All the infected dogs were positive to blood smear, IFA and PCR. Three of these dogs exhibited elevated body temperature (> 39.4 °C). Conclusions: This study demonstrates the ability of male D. reticulatus to transmit B. canis to dogs. The study also illustrates for the first time that, regardless of the first host on which ticks may attach and start feeding, Babesia canis can be transmitted to dogs within 8 h of infestation. Since no minimal transmission time can be established for all possible natural situations, a strategy of prevention based on anti-attachment or repellency is recommended. [ABSTRACT FROM AUTHOR]

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Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was performed to determine the tick species that infest cattle and humans throughout an altitudinal gradient in the Yungas Biogeographic Province of Argentina. The presence of tick-borne bacteria of the genera Rickettsia, Ehrlichia and Borrelia in the collected ticks was also evaluated. Samples of ticks parasitizing cattle and humans were carried out in different seasons. Questing ticks (adults and nymphs) were collected from vegetation and analyzed to detect the presence of Rickettsia, Ehrlichia and Borrelia by a battery of different PCRs. Five species of hard ticks were found parasitizing cattle: Amblyomma sculptum, Amblyomma tonelliae, Amblyomma hadanii, Haemaphysalis juxtakochi and Ixodes pararicinus. Amblyomma sculptum (immature and adults), A. tonelliae (immature and adults), A. hadanii (larvae) and one nymph of I. pararicinus were found attached to humans. Rickettsia amblyommatis was detected in one nymph of A. hadanii. DNA of a Borrelia genospecies belonging to the B. burgdorferi s.l. complex (phylogenetically related to haplotypes previously reported in Ixodes aragaoi from Uruguay and I. pararicinus from Argentina) was detected in adults of I. pararicinus. Amblyomma sculptum and I. pararicinus appear to be the tick species more frequent on cattle in the YBP from Argentina, and A. sculptum and A. tonelliae, were the main ticks found attached to humans. The medical importance of the bacteria of the genus Rickettsia and Borrelia detected in this work remains unknown. [ABSTRACT FROM AUTHOR]

Background: It is well known that reactive oxygen species (ROS) and reactive nitrogen species (RNS) are involved in the control of pathogens and microbiota in insects. However, the knowledge of the role of ROS and RNS in tickpathogen and tick-microbiota interactions is limited. Here, we evaluated the immune-related redox metabolism of the embryonic cell line BME26 from the cattle tick Rhipicephalus microplus in response to Anaplasma marginale infection. Methods: A high-throughput qPCR approach was used to determine the expression profile of 16 genes encoding proteins involved in either production or detoxification of ROS and RNS in response to different microbial challenges. In addition, the effect of RNAi-mediated gene silencing of catalase, glutathione peroxidase, thioredoxin and protein oxidation resistance 1 in the control of infection with A. marginale was evaluated. Results: Infection with A. marginale resulted in downregulation of the genes encoding ROS-generating enzymes dual oxidase and endoplasmic reticulum oxidase. In contrast, the genes encoding the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, thioredoxin, thioredoxin reductase and peroxiredoxin were upregulated. The gene expression pattern in response to infection with Rickettsia rickettsii and exposure to heat-killed microorganisms, Micrococcus luteus, Enterobacter cloacae or S. cerevisiae was the opposite of that triggered by A. marginale challenge. The simultaneous silencing of three genes, catalase, glutathione peroxidase, and thioredoxin as well as the oxidation resistance 1 gene by RNAi apparently favoured the colonization of BME26 cells by A. marginale, suggesting that the antioxidant response might play a role in the control of infection. Conclusions: Taken together, our results suggest that a general response of tick cells upon microbial stimuli is to increase ROS/RNS production. In contrast, A. marginale infection triggers an opposite profile, suggesting that this pathogen might manipulate the tick redox metabolism to evade the deleterious effect of the oxidant-based innate immune response. [ABSTRACT FROM AUTHOR]

Context:Leishmania amazonensisis the main agent of diffuse cutaneous leishmaniasis, a disease characterized by lesional polymorphism and the commitment of skin surface. Previous reports demonstrated that theCitrusgenus possess antimicrobial activity. Objective:This study evaluated the anti-L. amazonensisactivity ofCitrus sinensis(L.) Osbeck (Rutaceae) extracts. Materials and methods:Citrus sinensisdried leaves were subjected to maceration with hexane (CH), ethyl acetate (CEA), dichloromethane/ethanol (CD/Et – 1:1) or ethanol/water (CEt/W – 7:3).Leishmania amazonensispromastigotes were treated withC. sinensisextracts (1–525 μg/mL) for 120 h at 27 °C. Ultrastructure alterations of treated parasites were evaluated by transmission electron microscopy. Cytotoxicity of the extracts was assessed on RAW 264.7 and J774.G8 macrophages after 48-h treatment at 37 °C using the tetrazolium assay. In addition,Leishmania-infected macrophages were treated with CH and CD/Et (10–80 μg/mL). Results:CH, CD/Et and CEA displayed antileishmanial activity with 50% inhibitory activity (IC50) of 25.91 ± 4.87, 54.23 ± 3.78 and 62.74 ± 5.04 μg/mL, respectively. Parasites treated with CD/Et (131.2 μg/mL) presented severe alterations including mitochondrial swelling, lipid body formation and intense cytoplasmic vacuolization. CH and CD/Et demonstrated cytotoxic effects similar to that of amphotericin B in the anti-amastigote assays (SI of 2.16, 1.98 and 1.35, respectively). Triterpene amyrins were the main substances in CH and CD/Et extracts. In addition, 80 μg/mL of CD/Et reduced the number of intracellular amastigotes and the percentage of infected macrophages in 63% and 36%, respectively. Conclusion:The results presented here highlightC. sinensisas a promising source of antileishmanial agents. [ABSTRACT FROM PUBLISHER]

Anemia is a common clinical pathological finding in stranded loggerhead sea turtles ( Caretta caretta) secondary to trauma and chronic debilitation. These animals may benefit from species-specific blood product administration, yet few studies have evaluated the effects of anticoagulants on loggerhead sea turtle blood storage. Sea turtles in managed collections may serve as healthy blood donors, allowing for short-term blood storage with transfer of blood products within 24 h to rehabilitation facilities. The objective of this study was to compare the packed cell volume (PCV), total solids (TS), electrolytes, glucose, and venous blood gas analytes over a 24 h storage of loggerhead sea turtle whole blood in three anticoagulants: sodium heparin, sodium citrate, and citrate-phosphate-dextrose-adenine (CPDA-1). Blood from eight loggerhead sea turtles at the Karen Beasley Sea Turtle Rescue and Rehabilitation Center (Surf City, NC) was used following routine venipuncture for health assessment. Whole blood was placed into vacutainer tubes containing sodium heparin, sodium citrate, or CPDA-1 and stored at 4-8°C (39-46°F). PCV and TS were evaluated at 0, 3, 6, 12, and 24 h. Blood gas, electrolyte, and glucose analyses using i-STAT CG8+ cartridges were performed at 0 and 24 h. There were no significant differences in PCV and TS over time. At 24 hours, pink plasma was observed in 62.5% (5/8) of CPDA-1 and 12.5% (1/8) of citrate specimens. CPDA-1 and citrate specimens had a significant increase in potassium at 24 h. Both heparin and citrate specimens had a significant decrease in pH and increase in partial pressure of carbon dioxide at 24 h. Sodium values decreased over time in citrate and CPDA-1 specimens. Loggerhead sea turtle blood stored in CPDA-1, and sodium citrate had more significant blood gas and electrolyte changes over 24 h, indicating a greater degree of erythrocyte leakage or lysis. For the purposes of collection and short-term storage of loggerhead sea turtle blood, sodium heparin is preferable. [ABSTRACT FROM AUTHOR]

Background Toxoplasma gondii infections in captive non-human primates are of interest because often they die due to severe toxoplasmosis. Thus, we aimed to evaluate samples from a serum bank to T. gondii antibodies. Methods Serum samples of 179 monkeys from the National Center of Primates, Brazil, were retrospective analyzed for T. gondii IgG antibodies by modified agglutination test using formalin-fixed whole parasites as antigen (cutoff 1:25). Results Among the 179 samples tested, 88 (49.2%) were positive. Twelve of the 18 evaluated species presented at least one positive animal. A higher occurrence of positive animals was found in New World (52.2%) than Old World (22.2%) monkeys ( P = .023) and in the animals from domestic donation origin, which had lived in human homes as pets ( P = .004). Conclusions We confirm the widespread presence of T. gondii in captive monkeys and contribute to the range of species that can be infected by this parasite. [ABSTRACT FROM AUTHOR]

Background: Neospora caninum is a cyst-forming, coccidian parasite which is known to cause neurological disorders in dogs and abortion and neonatal mortality in cows and other livestock. This study reports the development of a loop-mediated isothermal amplification (LAMP) assay based on the Neospora caninum Nc-5 gene and compares its efficacy for detecting DNA to that of a semi-nested PCR test. Results: Six primers were designed based on the Nc-5 repeat region of N. caninum. Specific LAMP primers led to successful amplification of N. caninum DNA at 63 °C in 30 min. The LAMP assay was highly specific (i.e. it did not reveal cross-reactivity with other parasite species) and had a low N. caninum plasmid DNA limit of detection (1 fg), which is ten times higher than that for the semi-nested PCR. LAMP applicability was evaluated using a set of naturally-infected samples (59 from canine faeces and five from bovine abortions). Thirty-nine percent (25/64) of the naturally-infected samples were positive for N. caninum DNA by LAMP and 36% (23/64) by semi-nested PCR. However, the LAMP assay is much faster to perform than semi-nested PCR and provides results in 30 min. Conclusion: The optimized reaction conditions described in this study resulted in a sensitive, specific and rapid technique for detecting N. caninum DNA. Considering the advantages of LAMP for detecting N. caninum DNA, further assays aimed at testing its usefulness on a wider range of field samples are recommended. [ABSTRACT FROM AUTHOR]

The aim of this study was to reevaluate the ecology of an area in the Atlantic Forest, southeast Brazil, where Chagas disease (CD) has been found to occur. In a previous study, immediately after the occurrence of a CD case, we did not observe any sylvatic small mammals or dogs with Trypanosoma cruzi cruzi infections, but Triatoma vitticeps presented high T. c. cruzi infection rates. In this study, we investigated bats together with non-volant mammals, dogs, and triatomines to explore other possible T. c. cruzi reservoirs/hosts in the area. Seventy-three non-volant mammals and 186 bats were captured at three sites within the Guarapari municipality, Espírito Santo state. Rio da Prata and Amarelos sites exhibited greater richness in terms of non-volant mammals and bats species, respectively. The marsupial Metachirus nudicaudatus, the rodent Trinomys paratus, and the bats Artibeus lituratus and Carollia perspicillata were the most frequently captured species. As determined by positive hemocultures, only two non-volant mammals were found to be infected by Trypanosoma species: Monodelphis americana, which was infected by T. cascavelli, T. dionisii and Trypanosoma sp., and Callithrix geoffroyi, which was infected by T. minasense. Bats presented T. c. cruzi TcI and TcIII/V, T. c. marinkellei, T. dionisii, T. rangeli B and D, and Trypanosoma sp. infections. Seven dogs were infected with T. cruzi based only on serological exams. The triatomines T. vitticeps and Panstrongylus geniculatus were found to be infected by trypanosomes via microscopy. According to molecular characterization, T. vitticeps specimens were infected with T. c. cruzi TcI, TcII, TcIII/V, and TcIV, T. c. marinkellei and T. dionisii. We observed high trypanosome diversity in a small and fragmented region of the Atlantic Forest. This diversity was primarily maintained by bats and T. vitticeps. Our findings show that the host specificity of the Trypanosoma genus should be thoroughly reviewed. In addition, our data show that CD cases can occur without an enzootic cycle near residential areas. [ABSTRACT FROM AUTHOR]

Background: Benzimidazoles (BZ) are a class of drugs widely used in veterinary and human medicine, creating a great selection pressure and the emergence of BZ resistance. We conducted a systematic review to assess the status of resistance and/or effectiveness reduction of BZ drugs in animal nematodes in Brazil, and make information accessible to the scientific community, as many studies are published in Portuguese. PubMed, SciELO Brasil, LILACS/Bireme, GNTD database, and Google Scholar were searched with no language restrictions. Results: A total of 40 studies met our eligibility criteria (from the year 1989 forward). Sheep was the host most frequently analysed, and albendazole was the most frequently drug studied. The majority of studies (75.7%) showed that BZ drugs are insufficiently active (FECRT <80%) against nematode parasites of livestock. The mean FECRT for fenbendazole, thiabendazole, albendazole, mebendazole, oxfendazole, and ricobendazole were 71.8%, 71.8%, 58.6%, 53.9%, 46.9%, and 41.5%, respectively. It was observed through linear regression that FECRT is significantly reduced over time between 2007 and 2014 (R = −0.653 p = 0.021) for the treatment of cattle with BZ, suggesting progressive loss of effectiveness and increased resistance for these hosts. Conclusions: The scenario of BZ resistance in nematode populations in Brazil is not favourable. Given the high cost of drug discovery and development, it is urgent to implement control measures and to monitor the effectiveness/ resistance to nematodes in livestock in Brazil. [ABSTRACT FROM AUTHOR]

Background: With the geographical expansion of tick species and increased recognition of pathogens they transmit, there is a requirement for safe and rapidly effective control measures for dogs. Lotilaner, a novel isoxazoline, is rapidly absorbed following administration of a flavored chewable tablet formulation (Credelio™), providing at least 98% efficacy for at least 1 month following assessments at 48 h post-treatment, and following subsequent challenges. A study was conducted to determine the speed with which lotilaner kills ticks. Methods: From 38 dogs, the 32 with the highest Ixodes ricinus counts from a Day -4 infestation were randomized among four groups: two groups were untreated controls, two received lotilaner tablets at a minimum dose rate of 20 mg/kg. Infestations with I. ricinus were performed on Days -2, 7, 14, 21, 28 and 35. Counts were completed 4 and 8 h post-treatment (Day 0), and 8 and 12 h following subsequent infestations. All live ticks were incubated for 24 h following removal from study dogs. Results: At 4 h post-treatment, there was a 69.8% reduction in geometric mean live tick counts in treated dogs compared to controls. After incubation, the reduction increased to 97.2%. At 8 h after treatment, pre-and post-incubation reductions were 99.2 and 100%, respectively. Following post-treatment challenges, post-incubation efficacy through Day 28 at 8 and 12 h was at least 94.3 and 98.0%, respectively, and was 85.7 and 94.2% at 8 and 12 h after the Day 35 challenge. Mean live tick counts in the lotilaner groups were significantly lower than in the control groups at all assessments through Day 35 at 8 (t(7) ≥ 9, P < 0.0001, Days 0 to 28; (t(7) = 3.54, P ≤ 0.0095, Day 35) and 12 h post-treatment and after subsequent infestations (t(7) ≥ 10, P < 0.0001, all days). There were no treatment-related adverse events. Conclusion: Lotilaner at a minimum dose rate of 20 mg/kg began to kill ticks on dogs within 4 h of treatment and efficacy was 100% within 8 h. Lotilaner sustained a rapid kill of newly infesting I. ricinus through 35 days. By quickly killing ticks that infest dogs, lotilaner has potential to help limit the transmission of tick-borne pathogens. [ABSTRACT FROM AUTHOR]

The lifecycle of Rickettsia rickettsii includes infection of both mammalian and arthropod hosts, with each environment presenting distinct challenges to survival. As such, these pathogens likely have distinctive transcriptional strategies for infection of each host. Herein, we report the utilization of next generation sequencing (RNAseq) and bioinformatic analysis techniques to examine the global transcriptional profile of R. rickettsii within an infected animal, and to compare that data to transcription in tissue culture. The results demonstrate substantial R. rickettsii transcriptional alteration in vivo, such that the bacteria are considerably altered from cell culture. Identification of significant transcriptional changes and validation of RNAseq by quantitative PCR are described with particular emphasis on known antigens and suspected virulence factors. Together, these results suggest that transcriptional regulation of a distinct cohort of genes may contribute to successful mammalian infection. [ABSTRACT FROM AUTHOR]

Background: Bats are a highly successful, globally dispersed order of mammals that occupy a wide array of ecological niches. They are also intensely parasitized and implicated in multiple viral, bacterial and parasitic zoonosis. Trypanosomes are thought to be especially abundant and diverse in bats. In this study, we used 18S ribosomal RNA metabarcoding to probe bat trypanosome diversity in unprecedented detail. Methodology/Principal Findings: Total DNA was extracted from the blood of 90 bat individuals (17 species) captured along Atlantic Forest fragments of Espírito Santo state, southeast Brazil. The 18S ribosomal RNA was amplified by standard and/or nested PCR, then deep sequenced to recover and identify Operational Taxonomic Units (OTUs) for phylogenetic analysis. Blood samples from 34 bat individuals (13 species) tested positive for infection by 18S rRNA amplification. Amplicon sequences clustered to 14 OTUs, of which five identified as Trypanosoma cruzi I, T. cruzi III/V, Trypanosoma cruzi marinkellei, Trypanosoma rangeli, and Trypanosoma dionisii, and seven identified as novel genotypes monophyletic to basal T. cruzi clade types of the New World. Another OTU was identified as a trypanosome like those found in reptiles. Surprisingly, the remaining OTU was identified as Bodo saltans–closest non-parasitic relative of the trypanosomatid order. While three blood samples featured just one OTU (T. dionisii), all others resolved as mixed infections of up to eight OTUs. Conclusions/Significance: This study demonstrates the utility of next-generation barcoding methods to screen parasite diversity in mammalian reservoir hosts. We exposed high rates of local bat parasitism by multiple trypanosome species, some known to cause fatal human disease, others non-pathogenic, novel or yet little understood. Our results highlight bats as a long-standing nexus among host-parasite interactions of multiple niches, sustained in part by opportunistic and incidental infections of consequence to evolutionary theory as much as to public health. [ABSTRACT FROM AUTHOR]

Background: Brazilian Spotted Fever (BSF), caused by the bacterium Rickettsia rickettsii, is the tick-borne disease that generates the largest number of human deaths in the world. In Brazil, the current increase of BSF human cases has been associated with the presence and expansion of capybaras Hydrochoerus hydrochaeris, which act as primary hosts for the tick Amblyomma sculptum, vector of the R. rickettsii in this area. Methods: We proposed a semi-discrete-time stochastic model to evaluate the role of capybaras in the transmission dynamics of R. rickettsii. Through a sensitivity analysis, we identified the parameters with significant influence on the R. rickettsii establishment. Afterward, we implemented the Gillespie’s algorithm to simulate the impact of potential public health interventions to prevent BSF human cases. Results: The introduction of a single infected capybara with at least one infected attached tick is enough to trigger the disease in a non-endemic area. We found that to avoid the formation of new BSF-endemic areas, it is crucial to impede the emigration of capybaras from endemic areas by reducing their birth rate by more than 58%. Model results were corroborated by ex-situ data generated from field studies, and this supports our proposal to prevent BSF human cases by implementing control strategies focused on capybaras. Conclusion: The proposed stochastic model illustrates how strategies for the control and prevention of vector-borne infectious diseases can be focused on amplifier hosts management practices. This work provides a basis for future prevention strategies for other neglected vector-borne diseases. [ABSTRACT FROM AUTHOR]

Vaccinia virus (VACV) is a zoonotic agent that causes a disease called bovine vaccinia, which is detected mainly in milking cattle and humans in close contact with these animals. Even though many aspects of VACV infection have been described, much is still unknown about its circulation in the environment and its natural hosts/reservoirs. To investigate the presence of Orthopoxvirus antibodies or VACV DNA, we captured small rodents and marsupials in 3 areas of Minas Gerais state, Brazil, and tested their samples in a laboratory. A total of 336 animals were tested; positivity ranged from 18.1% to 25.5% in the 3 studied regions located in different biomes, including the Atlantic Forest and the Cerrado. Analysis of nucleotide sequences indicated co-circulation of VACV groups I and II. Our findings reinforce the possible role played by rodents and marsupials in VACV maintenance and its transmission chain. [ABSTRACT FROM AUTHOR]

This study evaluated for the first time the life cycle of Amblyomma oblongoguttatum in the laboratory. For this purpose, larvae and nymphs were exposed to Gallus gallus (chicks), Rattus norvegicus (wistar rat), Calomys callosus (vesper mouse), Oryctolagus cuniculus (domestic rabbit), Cavia porcellus (guinea pig), and Didelphis albiventris (white-eared opossum). Nymphs were exposed to G. gallus, C. callosus, C. porcellus, O. cuniculus, R. norvegicus, and Nectomys squamipes (water rat). Adult ticks were exposed to domestic dogs. The life-cycle of A. oblongoguttatum in the laboratory could be completed in an average period of 188 days, considering prefeeding periods of 25 days for each of the parasitic stages. Under laboratory conditions, none of the host species was highly suitable for A. oblongoguttatum larvae, since the recovery rates of engorged larvae were always <15%, or most of the times ≤5%. Similar results were obtained for nymphs, with recovery rates of engorged nymphs always <6%. Our results, coupled with literature data, suggest that small mammals, especially small rodents, do not have an important role in the life-cycle of A. oblongoguttatum under field conditions. Domestic dogs showed to be highly suitable for the adult stage of A. oblongoguttatum, in agreement with literature data that have appointed dogs as important hosts for the adult stage of A. oblongoguttatum in South America. [ABSTRACT FROM AUTHOR]

Background: Toxoplasma gondii is a protozoan with a worldwide distribution, in warm-blood animals, including humans. Local conditions and environmental disturbances may influence transmission dynamics of a zoonotic agent. This study evaluates the epidemiology of T. gondii based on toxoplasmosis prevalence in two populations of cats living in distinct urbanization conditions in Rio de Janeiro, Brazil. Methods: Among 372 domestic cats sampled, 265 were from a public shelter located downtown Rio and 107 from a relatively preserved wild environment in a residential area. Sera and eluates from dried blood spots were tested for detection of IgG antibodies against T. gondii by modified agglutination test (MAT). Results: Antibodies to T. gondii were detected in 32/265 (12.08%) animals from the public shelter and in 4/107 (3.74%) cats from the residential area. Identical results were observed for sera and eluates. Conclusions: Filter paper provides a reliable accurate alternative storage option when conditions of sample collection and transportation in the field are unfavorable. The significantly lower prevalence in the residential area is discussed in terms of environmental, biological and behavioral features. [ABSTRACT FROM AUTHOR]

Vaccinia virus (VACV) is responsible for outbreaks in Brazil and has immense potential as an emerging virus. VACV can be found naturally circulating in India, Pakistan and South America, where it causes infections characterised by exanthematic lesions in buffaloes, cattle and humans. The transmission cycle of Brazilian VACV has still not been fully characterised; one of the most important gaps in knowledge being the role of wild animals. Capybaras, which are restricted to the Americas, are the world's largest rodents and have peculiar characteristics that make them possible candidates for being part of a natural VACV reservoir. Here, we developed a method for detecting orthopoxvirus DNA in capybara stool samples, and have described for the first time the detection of orthopoxvirus DNA in capybaras samples from three different regions in Brazil. These findings strongly suggest that capybaras might be involved in the natural transmission cycle of VACV and furthermore represent a public health problem, when associated with Brazilian bovine vaccinia outbreaks. This makes infected animals an important factor to be considered when predicting and managing Brazilian VACV outbreaks. [ABSTRACT FROM AUTHOR]

The genus Leishmania includes approximately 53 species, 20 of which cause human leishmaniais; a significant albeit neglected tropical disease. Leishmaniasis has afflicted humans for millennia, but how ancient is Leishmania and where did it arise? These questions have been hotly debated for decades and several theories have been proposed. One theory suggests Leishmania originated in the Palearctic, and dispersed to the New World via the Bering land bridge. Others propose that Leishmania evolved in the Neotropics. The Multiple Origins theory suggests that separation of certain Old World and New World species occurred due to the opening of the Atlantic Ocean. Some suggest that the ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia evolved on Gondwana between 90 and 140 million years ago. In the present study a detailed molecular and morphological characterisation was performed on a novel Australian trypanosomatid following its isolation in Australia’s tropics from the native black fly, Simulium (Morops) dycei Colbo, 1976. Phylogenetic analyses were conducted and confirmed this parasite as a sibling to Zelonia costaricensis, a close relative of Leishmania previously isolated from a reduviid bug in Costa Rica. Consequently, this parasite was assigned the name Zelonia australiensis sp. nov. Assuming Z. costaricensis and Z. australiensis diverged when Australia and South America became completely separated, their divergence occurred between 36 and 41 million years ago at least. Using this vicariance event as a calibration point for a phylogenetic time tree, the common ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia appeared in Gondwana approximately 91 million years ago. Ultimately, this study contributes to our understanding of trypanosomatid diversity, and of Leishmania origins by providing support for a Gondwanan origin of dixenous parasitism in the Leishmaniinae. [ABSTRACT FROM AUTHOR]