Helminth community of Nectomys squamipes naturally infected by Schistosoma mansoni in an endemic area in Brazil: A comparison of 22 years apart.

The municipality of Sumidouro in the state of Rio de Janeiro, southeastern Brazil, is considered an area with low endemicity of Schistosoma mansoni. In this municipality, the wild water rat Nectomys squamipes is a wild reservoir of S. mansoni. A helminth community survey was carried out on N. squamipes populations in Sumidouro from 1997 to 1999. In the present study, we compared the helminth fauna and the helminth community structure of N. squamipes with a recent survey after a 22-year time interval, considering that the prevalence of S. mansoni infection in humans remained stable and that the area showed the same environmental characteristics. Seventy-three host specimens of N. squamipes collected between 1997 and 1999 and 21 specimens collected in 2021 were analyzed in this study. Seven helminth species were found in each collection period. The nematode Syphacia evaginata was recorded for the first time in N. squamipes in 2021. Syphacia venteli was the most abundant species in both periods and the most prevalent in 2021. During the period from 1997 to 1999, the most prevalent species was Hassalstrongylus epsilon. Significant differences in prevalence and abundance in relation to host sex were observed only for S. mansoni in 1997-1999. Significant differences in the abundance of the helminth species over time were observed only in Physaloptera bispiculata. Hassalstrongylus epsilon, S. venteli and S. mansoni were the dominant species in both periods. Litomosoides chagasfilhoi, Echinostoma paraensei paraensei and P. bispiculata became dominant, codominant and subordinate, respectively, over time. In conclusion, the helminth community of N. squamipes remained stable, with similar species richness, prevalence and abundance values and low beta-diversity over time. The occurrence of S. mansoni in the water rat has remained stable for decades, highlighting its importance for schistosomiasis control.

Population genetic structure and morphological diversity of Cruzia tentaculata (Nematoda: Ascaridida), a parasite of marsupials (Didelphinae), along the Atlantic Forest on the eastern coast of South America.

Cruzia tentaculata is a helminth parasite of marsupials and has a wide geographic distribution from Mexico to Argentina. The aim of this study was to analyse the genetic population structure of this nematode along the Atlantic Forest biome. Cruzia tentaculata specimens were recovered from Didelphis aurita, Didelphis albiventris and Philander quica in 9 localities. Morphological and morphometric data were investigated for phenotypic diversity among localities and hosts using multivariate discriminant analysis of principal components. Phylogenetic relationships of C. tentaculata were determined using maximum likelihood and Bayesian inference. The population structure was analysed by fixation indices, molecular variance analysis, Tajima's D and Fu's Fs neutrality tests, Mantel tests and Bayesian clustering analysis. A higher significant morphometric difference for males was observed between localities. In the haplogroup networks, 2 groups were recovered, separating locations from the north and from the south/southeast. The morphometric variation in C. tentaculata between different localities was compatible with this north and southeast/south pattern, suggesting adaptation to different ecological conditions. Population genetic analyses suggested a pattern of evolutionary processes driven by Pleistocene glacial refugia in the northeast and southeast of the Atlantic Forest based on the distribution of genetic diversity.

Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil's South and Southeast Atlantic Forest.

BACKGROUND: The population genetics of parasites may be influenced by host specificity, life cycle, host geographical range, evolutionary history, and host population structure. The nematode Aspidodera raillieti infects different marsupial and rodent hosts in the Nearctic and Neotropical regions, implying a gene flow among populations. However, niche diversification of the main hosts of A. raillieti in superimposed areas may provide conditions for population genetic structuring within this parasite species. We examined the genetic structuring of A. raillieti infecting three marsupial species co-occurring along the South and Southeast Brazilian Atlantic Forest, a hotspot of biodiversity. METHODS: We employed morphometric analyses and partial mitochondrial cytochrome c oxidase I gene sequences (MT-CO1) to characterize populations via phylogenetic and phylogeographic analyses. RESULTS: Among 175 A. raillieti specimens recovered from the marsupial hosts Didelphis aurita, D. albiventris, and Philander quica, we identified 99 MT-CO1 haplotypes forming four haplogroups and four clades in networks and phylogenetic trees, respectively. Clades I and II encompassed parasites of D. albiventris from the South region, clade III comprised parasites of D. aurita from the South and Southeast regions, and clade IV encompassed parasites of D. aurita and D. albiventris from the South and Southeast regions and parasites of P. quica from the South region. High genetic differentiation between clades, with a high fixation index and greater genetic variation in the analysis of molecular variance (AMOVA), indicated low gene flow between clades. Haplotypes shared among host species revealed a lack of host specificity. A significant correlation in the Mantel test suggested parasite isolation by distance, while there was no evidence of geographical structure between populations. Negative neutrality test values for clades III and IV suggested recent population expansion. Morphometric differentiation between A. raillieti specimens recovered from different host species, as well as from different localities, was more evident in males. CONCLUSION: The genetic structure of A. raillieti populations in the South and Southeast Atlantic Forest resulted from historical events rather than from current geographical distribution or host specificity. We also demonstrate morphometric variation associated with host species and localities, suggesting phenotypic plasticity to host attributes and to spatial variables.

Helminths of sigmodontine rodents in an agroforestry mosaic in the Brazilian Atlantic Forest: Patterns and processes of the metacommunity structure.

Phylogenetically or taxonomically related hosts may harbour similar parasite communities due to phylogenetic conservatism. In addition, host attributes may favour their exposure to parasites. This study aimed to characterize the helminth fauna of sigmodontine rodents in an Atlantic Forest area in northeastern Brazil and determine the pattern of the helminth metacommunity structure. The influence of host attributes and host taxonomy on the metacommunity structure was also investigated. The most abundant helminth species were Raillietina sp. and Hassalstrongylus lauroi. Euryoryzomys russatus was the most infected host species for helminth parasites, as approximately 81% (35/43) of the animals were infected by at least one helminth species. The helminth metacommunity structure was coherent at both the infracommunity and the component community scales, indicating that species responded to the same environmental gradient. A quasi-Clementsian pattern was observed for the infracommunities, indicating the occurrence of compartments of parasite species that were substituted along the environmental gradient, which was formed by host individuals. A quasi-Gleasonian pattern was found at the component community scale, showing random boundary clumping, which is consistent with the individualistic responses of parasite species to each host species. These patterns corroborated the high values of beta-diversity observed, indicating high species turnover among communities at both scales. Host taxonomic distance was the most important variable explaining the patterns of the helminth metacommunity structure.

Survey of medium- and large-sized mammals in Atlantic Forest remnants of Conceição dos Ouros, Minas Gerais, Brazil.

Conceição dos Ouros is located in the Mantiqueira mountain range (elevation: 831‒1443 m a.s.l.), State of Minas Gerais, southeast Brazil. The largest two Atlantic Forest remnants of the Municipality of Conceição dos Ouros total more than 2,000 ha and the main vegetation type is seasonal semi-deciduous forest, isolated by a matrix of agricultural fields and pasture. The Municipality does not have any protected areas and is located in a highly fragmented region, albeit considered of special importance for the conservation of terrestrial vertebrates in the State of Minas Gerais. Due to a cooperation with the Municipality of Conceição dos Ouros to carry out a survey of the local biodiversity, in this study we present the results of the survey of medium- and large-sized terrestrial mammals from the two forest remnants in the region. Sampling was performed from July 2019 to August 2021 and comprised a camera trap survey, active searching including direct (e.g. carcass sightings) and indirect (e.g. footprints and faeces) evidence of species presence and interviews with residents. Twenty-nine native and two non-native species were documented. Ten species are in some category of threat of extinction at regional, national or global levels. This is the first survey of the terrestrial mammal fauna in the area of Conceição dos Ouros and results could be helpful in designing conservation strategies at the local scale.

Medium- and large-sized mammals from Estação Biológica Fiocruz Mata Atlântica, Rio de Janeiro, south-eastern Brazil.

The Pedra Branca Forest is in a highly urbanised region of the central portion of Rio de Janeiro City and comprises the largest urban forest in the world (> 12,000 ha). The local flora and fauna are protected by three conservation units and the Estação Biológica Fiocruz Mata Atlântica (EFMA), which comprises 462 hectares on the east side of the remnant. The local biodiversity is still little known compared to other Atlantic Forest remnants from the Rio de Janeiro State. Here, we provide results of a survey of medium- and large-sized terrestrial mammals from the EFMA. In addition, we analysed the distribution of this fauna along three habitat types defined as Peridomicile, Transitional Forest and Forest Core. Sampling was performed from 2017 to 2020 and comprised a camera-trap survey, interviews with residents and local workers and occasional records. Results include occurrence records for 16 autochthonous and one allochthonous (Callithrix sp.) wild mammals, which are distributed into 14 families and seven orders, in addition to the presence of free-ranging domestic dogs and cats. Four species are in some category of threat of extinction at national or global levels. Amongst them, Leontopithecusrosalia (first record for the Rio de Janeiro City in more than a century) and Leopardusguttulus are classified as Vulnerable by IUCN. Most wild native species were registered in the three habitat types, but with differences in the frequency of records. Our results indicate that the presence of domestic dogs and cats influenced the species composition in each area, with Nasuanasua, Dasyproctaleporina and Didelphisaurita less frequent in places where domestic dogs and cats are more frequent. This is the first systematic effort to understand the occurrence and distribution of mid- and large-sized mammals in the Pedra Branca Forest.

Bats from the Pedra Branca Forest, Rio de Janeiro, Brazil.

The Pedra Branca Forest is located in a highly-urbanised region of the central portion of Rio de Janeiro City, comprises the largest urban forest on the continent and is isolated from other Atlantic Forest remnants. The local flora and fauna are protected by three conservation units (Pedra Branca State Park, Prainha Municipal Natural Park and Guaratiba State Biological Reserve) and one biological station (Fiocruz Atlantic Forest Biological Station-EFMA). Here, we provide an updated list of the bat fauna for the remnant. The results are based on samplings at EFMA and literature data from Pedra Branca State Park and Prainha Natural Park. The three sampling sites combined resulted in 31 species, 23 genera and four families. Phyllostomidae was the richest family with 24 species, followed by Vespertilionidae with five species (3%) and Molossidae and Noctilionidae with one species. The local bat fauna was predominantly composed of species with a broad geographic distribution.

First study on the helminth community structure of the neotropical marsupial Metachirus myosuros (Didelphimorphia, Didelphidae).

Metachirus myosuros is a marsupial species widely distributed in South America. Despite this, there is a lack of knowledge about its helminth parasites and helminth community structure. The aims of this study were to describe the species composition and determine the parasitological parameters of helminth communities of M. myosuros in preserved areas of the Atlantic Forest, Igrapiúna, Bahia state, northeastern Brazil. Parasites were searched from 19 specimens of this marsupial (18 were infected with at least one species), counted and identified. Ten species of helminth parasites were obtained: 7 nematodes, 2 platyhelminths and 1 acanthocephalan. The most abundant species were Aspidodera raillieti, Cruzia tentaculata, Physaloptera mirandai and Viannaia conspicua (Nematoda). These species were also the only dominant ones in the component community. Male hosts had higher prevalence of P. mirandai and greater abundance of V. conspicua. We observed a relationship between host body size and helminth abundance in both male and female hosts, and between host body size and helminth species richness in female hosts. This was the first study to analyze the helminth fauna and helminth community structure of M. myosuros. This was the first report of occurrences of A. raillieti and Didelphonema longispiculata in M. myosuros.

Investigation of Bartonella spp. in brazilian mammals with emphasis on rodents and bats from the Atlantic Forest.

The Bartonella species are zoonotic agents that infect mammals and are transmitted by arthropod vectors. Approximately 18 distinct genotypes cause diseases in humans, and may be spread by both domestic and wild animals. In Brazil, Bartonella genotypes have been identified in several species of wild mammals, and in the present study, we analyzed samples from non-human primates (marmosets), marsupials, rodents, and bats, and compared them with the genotypes described in mammals from Brazil, to examine the distribution of Bartonella genotypes in two impacted areas of Rio de Janeiro state, in southeastern Brazil. We used polymerase chain reaction (PCR) methods to detect the Bartonella DNA using partial sequences of the gltA, ftsZ, and groEL genes. We generated Bayesian inference and maximum likelihood trees to characterize the positive PCR samples and infer the phylogenetic relationships of the genotypes. A total of 276 animals were captured, including 110 bats, 91 rodents, 38 marsupials, and 37 marmosets. The DNA of Bartonella was amplified from tissue samples collected from 12 (4.34%) of the animals, including eight rodents - Akodon cursor (5/44) and Nectomys squamipes (3/27) - and four bats, Artibeus lituratus (3/58) and Carollia perspicillata (1/15). We identified Bartonella genotypes closely related to those described in previous studies, as well as new genotypes in both the rodent and the bat samples. Considering the high diversity of the Bartonella genotypes and hosts identified in the present study, further research is needed to better understand the relationships between the different Bartonella genotypes and their vectors and host species. The presence of Bartonella in the wild rodents and bats from the study area indicates that the local human populations may be at risk of infection by Bartonella due to the spillover of these strains from the wild environment to domestic and peri-domestic environments.

Three new species of Eimeria Schneider 1875 in the montane grass mouse, Akodon montensis (Rodentia: Cricetidae: Sigmodontinae), and redescription of Eimeria zygodontomyis Lainson and Shaw 1990 from southeastern Brazil.

We describe three new coccidian species of the genus Eimeria Schneider 1875 (Apicomplexa: Eimeriidae) and redescribe and report Eimeria zygodontomyis Lainson and Shaw, 1990 in the montane grass mouse, Akodon montensis Thomas, 1913 from the Serra dos Órgãos National Park in southeastern Brazil. Sporulated oocysts of Eimeria zygodontomyis are ellipsoidal to cylindrical with a 0.6 (0.5-0.8) µm thick very delicate bi-layered wall; length × width (n = 49) 18.3 × 12.5 (16-20 × 11-13) µm; length/width ratio of 1.4 (1.2-1.6); 1 polar granule occasionally present; micropyle, residuum both absent. Sporocysts are ellipsoidal; length × width 8.5 × 5.2 (8-11 × 5-6) µm; length/width ratio of 1.5 (1.3-1.7) µm; Stieda body is prominent; sub-Stieda body is absent; sporocyst residuum is compact. Sporulated oocysts of Eimeria montensis n. sp. are spheroidal to subspheroidal with a 1.2 (1.0-1.4) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 30) 16.3 × 12.5 (15-17 × 13-15) µm; length/width ratio of 1.3 (1.0-1.4); 1 polar granule present; micropyle, residuum both absent. Sporocysts are ellipsoidal; length × width 7.2 × 5.1 (6-8 × 4-6) µm; length/width ratio of 1.4 (1.2-1.6); Stieda body is present, sub-Stieda body is absent; sporocyst residuum consists of small, scattered granules. Sporulated oocysts of Eimeria uricanensis n. sp. are ovoidal to pyriform with a 1.4 ( 1.3-1.6) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 40) 26.6 × 18.6 (23-30 × 17-20) µm; length/width ratio of 1.4 (1.3-1.6); 1 polar granule present; micropyle, residuum both absent. Sporocysts are ellipsoidal, length × width 13.3 × 8.0 (10-16 × 7-9) µm; length/width ratio of 1.7 (1.5-1.9); Stieda body, sub-Stieda body both absent; sporocyst residuum consists of a cluster of granules, forming a spheroid mass. Sporulated oocysts of Eimeria parnasiensis n. sp. are subspheroidal to ellipsoidal with a 1.8 ( 1.3-2.4) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 54) 28.2 × 21.9 (26-32 × 19-28) µm; length/width ratio of 1.3 (1.2-1.4); 1 polar granule present; micropyle is absent; oocyst residuum is present and consists of a cluster of granules of varying thickness. Sporocysts are ovoidal, tapering towards the Stieda body; length × width 12.2 × 7.6 (10-13 × 6-9) µm; length/width ratio of 1.6 (1.4-1.9); Stieda body is present; sub-Stieda body is absent; sporocyst residuum is present and consists of an aggregate of thin granules.

Hematological values for free-living great fruit-eating bats, Artibeus lituratus (Chiroptera: Phyllostomidae) / Perfil hematológico de morcegos frugívoros, Artibeus lituratus (Chiroptera: Phyllostomidae)

It was provide a hematological profile of Artibeus lituratus (Phyllostomidae: Stenodermatinae). Animals were collected from October 2017 to February 2018 in an urban forest in the city of Rio de Janeiro, Southeastern Brazil. Males and females showed similar overall mean values for the parameters analyzed. Males had higher values for erythrocytes (RBC), hematocrit and basophils. Females had higher levels of eosinophils than males. The hematological values reported here will serve as reference for future research on health conditions of free-living and captive populations of Artibeus lituratus, as well as for research on pathogens associated with these bats.(AU)

O presente trabalho estabeleceu o perfil hematológico de morcegos frugívoros de vida livre, A. lituratus (Phyllostomidae: Stenodermatinae). As amostragens foram realizadas de outubro de 2017 a fevereiro de 2018 em uma floresta urbana na cidade do Rio de Janeiro, Sudeste do Brasil. Machos e fêmeas apresentaram valores médios gerais semelhantes para os parâmetros analisados. Os machos apresentaram valores de eritrócitos (RBC), hematócrito e basófilos mais altos. As fêmeas apresentaram níveis mais elevados de eosinófilos que os machos. Os valores hematológicos aqui reportados servirão de referência para pesquisas sobre condições de saúde de populações de Artibeus lituratus em vida livre e de cativeiro, assim como para pesquisas sobre patógenos associados a esses morcegos.(AU)

First study on the helminth community structure of the neotropical marsupial Metachirus myosuros (Didelphimorphia, Didelphidae) / Primeiro estudo sobre a estrutura da comunidade de helmintos do marsupial neotropical Metachirus myosuros (Didelphimorphia, Didelphidae)

Abstract Metachirus myosuros is a marsupial species widely distributed in South America. Despite this, there is a lack of knowledge about its helminth parasites and helminth community structure. The aims of this study were to describe the species composition and determine the parasitological parameters of helminth communities of M. myosuros in preserved areas of the Atlantic Forest, Igrapiúna, Bahia state, northeastern Brazil. Parasites were searched from 19 specimens of this marsupial (18 were infected with at least one species), counted and identified. Ten species of helminth parasites were obtained: 7 nematodes, 2 platyhelminths and 1 acanthocephalan. The most abundant species were Aspidodera raillieti, Cruzia tentaculata, Physaloptera mirandai and Viannaia conspicua (Nematoda). These species were also the only dominant ones in the component community. Male hosts had higher prevalence of P. mirandai and greater abundance of V. conspicua. We observed a relationship between host body size and helminth abundance in both male and female hosts, and between host body size and helminth species richness in female hosts. This was the first study to analyze the helminth fauna and helminth community structure of M. myosuros. This was the first report of occurrences of A. raillieti and Didelphonema longispiculata in M. myosuros.

Resumo Metachirus myosuros é uma espécie de marsupial amplamente distribuída na América do Sul. Apesar disso, existe pouca informação sobre seus helmintos parasitos e estrutura da comunidade de helmintos. Os objetivos deste estudo foram descrever a composição e determinar os parâmetros parasitológicos em comunidades de helmintos de M. myosuros, em áreas preservadas de Mata Atlântica, Igrapiúna, Bahia, Nordeste do Brasil. Os parasitos foram procurados em 19 espécimes desse marsupial (18 estavam infectados com pelo menos uma espécie), contados e identificados. Dez espécies de helmintos foram coletadas: 7 nematoides, 2 platelmintos e 1 acantocéfalo. As espécies mais abundantes foram Aspidodera raillieti, Cruzia tentaculata, Physaloptera mirandai e Viannaia conspicua (Nematoda). Estas espécies também foram as únicas dominantes na comunidade componente. Os hospedeiros machos tiveram maior prevalência de P. mirandai e maior abundância de V. conspicua. Foi observada uma relação significativa entre o tamanho do corpo do hospedeiro e a abundância de helmintos em hospedeiros machos e fêmeas, e entre o tamanho do corpo do hospedeiro e a riqueza de espécies de helmintos em fêmeas. Este foi o primeiro estudo a analisar a helmintofauna e a estrutura da comunidade de helmintos de M. myosuros. E também foi o primeiro relato da ocorrência de A. raillieti e Didelphonema longispiculata em M. myosuros.

Metacommunity Structure of Helminths of Necromys lasiurus (Rodentia: Sigmodontinae) in Different Land Use Areas in the Brazilian Cerrado.

The ecology of host-parasite interactions can be studied in the infracommunity and component community scales, which may show different patterns in species distributions, interacting and affecting each other on a regional scale. Few studies have been carried out concerning the structure and variation of the helminth communities of wild rodents in Brazil. The rodent Necromys lasiurus is typical from the mammalian fauna of the Cerrado biome; however, the environmental disturbances are making this species occur in rural areas and in other biomes where it may act as host/reservoir of many diseases. This study aimed to describe the composition and structure of the helminth metacommunity in the rodent N. lasiurus in the Brazilian Cerrado, Uberlândia, State of Minas Gerais, using the analysis of metacommunity structure. Rodents were sampled in 3 habitat types: borders of soybean and corn plantations, pasturelands, and preserved areas of Cerrado borders. Adult helminths of 8 species were found in the gastrointestinal tract: Protospirura numidica criceticola, Physaloptera sp., Pterygodermatites ( Paucipectines) zygodontomis (Spirurida), Stilestrongylus freitasi (Rhabditida), Trichuris navonae (Trichurida) and Syphacia ( Syphacia) alata (Oxiurida) of the Phylum Nematoda; Rodentolepis akodontis (Cyclophyllidea) of the Phylum Platyhelminthes; and Moniliformis sp. (Moniliformida) of the Phylum Acanthocephala. Season and the kind of land use favored some helminths species in this rodent, especially in the plantation area, although diversity was not largely influenced by the land use. Plantation areas could provide an increase in the host abundance and the occurrence of other rodent species, favoring a higher rate of parasite exchange among different hosts. A checkerboard structure of metacommunity was found on the infracommunity scale, which suggests the existence of interspecific competition. A quasi-nested structure of metacommunity was observed on the component community scale showing that most species were influenced by the same environmental gradient and that the species-poor communities were subsets of species-rich communities. Syphacia alata, P. zygodontomis, S. freitasi, and R. akodontis were dominant species in all habitats and represented the core-species in the metacommunity.

Helminth metacommunity structure of wild rodents in a preserved area of the Atlantic Forest, Southeast Brazil / Estrutura da metacomunidade de helmintos de roedores silvestres em uma área preservada da Floresta Atlântica, sudeste do Brasil

Abstract The helminth fauna and metacommunity structure of eight sympatric sigmodontine rodents were investigated at the Serra dos Órgãos National Park, an Atlantic Forest reserve located in the State of Rio de Janeiro, southeast Brazil. Rodents of the species Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps , Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor and Thaptomys nigrita were found infected with helminths. Akodon montensis presented the highest total helminth species richness, with six different species of helminths. The nematode Stilestrongylus lanfrediae was the most abundant and prevalent helminth species observed. The host-parasite network analysis showed little interactions among host species. Akodon montensis seems to act as a keystone-species in the rodent community. This species shared the nematodes Stilestrongylus aculeata with A. ruschii and Protospirura numidica criceticola with T. nigrita, and the cestode Rodentolepis akodontis with D. dorsalis. The congeners host species O. flavescens and O. nigripes shared the nematodes Guerrerostrongylus zetta and S. lanfrediae. The rodents B. breviceps and O. quaestor did not share any helminths with other hosts. The helminth metacommunity showed a random pattern on both infracommunity and component community levels, indicating different responses by each helminth species to the environmental gradient.

Resumo Foram investigadas a helmintofauna e suas estruturas da metacomunidade em oito roedores sigmodontíneos simpátricos ao longo do Parque Nacional da Serra dos Órgãos, uma reserva de Mata Atlântica no estado do Rio de Janeiro, Brasil. Roedores das espécies Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps, Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor e Thaptomys nigrita foram infectados por helmintos. Akodon montensis apresentou a maior riqueza total de espécies de helmintos, com seis espécies. O nematoide Stilestrongylus lanfrediae foi a espécie de helminto com maior abundância e prevalência. A análise de rede parasito-hospedeiro mostrou poucas interações entre as espécies hospedeiras e A. montensis atuou como uma espécie-chave na comunidade de roedores. Esta espécie compartilhou os nematoides Stilestrongylus aculeata com A. ruschii e Protospirura numidica criceticola com T. nigrita, e o cestoide Rodentolepis akodontis com D. dorsalis. As espécies congêneres O. flavescens e O. nigripes compartilharam os nematoides Guerrerostrongylus zetta e S. lanfrediae. Os roedores B. breviceps e O. quaestor não compartilharam helmintos com outros hospedeiros. A metacomunidade de helmintos mostrou um padrão aleatório em ambos os níveis, comunidade componente e infracomunidade, indicando diferentes respostas de cada espécie de helminto ao gradiente ambiental.

Helminth metacommunity structure of wild rodents in a preserved area of the Atlantic Forest, Southeast Brazil.

The helminth fauna and metacommunity structure of eight sympatric sigmodontine rodents were investigated at the Serra dos Órgãos National Park, an Atlantic Forest reserve located in the State of Rio de Janeiro, southeast Brazil. Rodents of the species Abrawayaomys ruschii, Akodon montensis, Blarinomys breviceps , Delomys dorsalis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus quaestor and Thaptomys nigrita were found infected with helminths. Akodon montensis presented the highest total helminth species richness, with six different species of helminths. The nematode Stilestrongylus lanfrediae was the most abundant and prevalent helminth species observed. The host-parasite network analysis showed little interactions among host species. Akodon montensis seems to act as a keystone-species in the rodent community. This species shared the nematodes Stilestrongylus aculeata with A. ruschii and Protospirura numidica criceticola with T. nigrita, and the cestode Rodentolepis akodontis with D. dorsalis. The congeners host species O. flavescens and O. nigripes shared the nematodes Guerrerostrongylus zetta and S. lanfrediae. The rodents B. breviceps and O. quaestor did not share any helminths with other hosts. The helminth metacommunity showed a random pattern on both infracommunity and component community levels, indicating different responses by each helminth species to the environmental gradient.

Ticks parasitizing wild mammals in Atlantic Forest areas in the state of Rio de Janeiro, Brazil / Carrapatos parasitando mamíferos silvestres em áreas da Floresta Atlântica no estado do Rio de Janeiro, Brasil

Abstract Mammals captured in the Serra dos Órgãos National Park (PARNASO) and the Pedra Branca State Park (PBSP) between 2012 and 2015 were examined for the presence of ticks. In total, 140 mammals were examined, and 34 specimens were found to be parasitized by ticks. Didelphis aurita, Akodon montensis and Oligoryzomys nigripes were the species most parasitized. From these specimens, 146 ticks were collected, including 10 larvae. The ticks belonged to eight species: one in the genus Ixodes and seven in the genus Amblyomma. This study reports new associations of ticks and wild mammals in Brazil.

Resumo Mamíferos capturados no Parque Nacional da Serra dos Órgãos (PARNASO) e no Parque Estadual Pedra Branca (PBSP) entre 2012 e 2015 foram examinados quanto à presença de carrapatos. No total, 140 mamíferos foram examinados, e 34 espécimes foram parasitados por carrapatos. Didelphis aurita, Akodon montensis e Oligoryzomys nigripes foram as espécies mais parasitadas. A partir desses espécimes, 146 carrapatos foram coletados, incluindo 10 larvas. Os carrapatos pertenciam a oito espécies: uma no gênero Ixodes e sete no gênero Amblyomma. Este estudo relata novas associações de carrapatos e mamíferos silvestres no Brasil.

Ticks parasitizing wild mammals in Atlantic Forest areas in the state of Rio de Janeiro, Brazil.

Mammals captured in the Serra dos Órgãos National Park (PARNASO) and the Pedra Branca State Park (PBSP) between 2012 and 2015 were examined for the presence of ticks. In total, 140 mammals were examined, and 34 specimens were found to be parasitized by ticks. Didelphis aurita, Akodon montensis and Oligoryzomys nigripes were the species most parasitized. From these specimens, 146 ticks were collected, including 10 larvae. The ticks belonged to eight species: one in the genus Ixodes and seven in the genus Amblyomma. This study reports new associations of ticks and wild mammals in Brazil.

A new species of Eimeria Schneider, 1875 from the Serra dos Órgãos National Park, Rio de Janeiro, Brazil, with notes on its endogenous development in the montane grass mouse, Akodon montensis Thomas, 1913 (Rodentia: Sigmodontinae).

A total of 53 specimens of the montane grass mouse, Akodon montensis Thomas, 1913 were collected in the Serra dos Órgãos National Park (SONP) in November 2014 and July 2015. The fecal material was analyzed, and a prevalence of 7.5% was recorded for a new coccidian species of the genus Eimeria Schneider, 1875, with part of its endogenous development recorded in the small intestine. The oocysts of a new coccidian species of genus Eimeria are ellipsoidal to subspherical. The wall is bi-layered, c. 1.5 µm (1.3-1.6 µm) thick, outer layer rough. Oocyst (n = 126) mean length is 25.3 µm (21.0-28.0 µm), with a width of 20.2 µm (17.0-22.0 µm) and mean length/width (L:W) ratio of 1.3 (1.2-1.4). Polar granule is present, with the oocyst residuum as a large spherical to subspherical globule. Sporocyst shape (n = 126) is ellipsoidal, with a mean length of 11.8 µm (9.3-14.4 µm), width of 7.9 µm (6.7-9.3 µm), and mean L:W ratio of 1.5 (1.4-1.7). Sporocysts with nipple-like Stieda body and sub-Stieda body are absent. A sporocyst residuum formed by several globules, usually along the sporocyst wall. This is the first record of Eimeria in the montane grass mouse from Brazil.

Lungworm Heterostrongylus heterostrongylus Travassos, 1925 from the black-eared opossum in South America: Morphologic, histopathological and phylogenetic aspects.

Nematode parasites of the cardiopulmonary system of livestock and pet animals have been receiving attention due to the pathogenic effects they produce in the course of the infection. However, parasitism in wild animals by metastrongilid nematodes has been neglected, resulting in potential risk to wildlife. Heterostrongylus heterostrongylus is the etiological agent of bronchial pneumonia in the black-eared opossum, Didelphis aurita, a widely distributed marsupial frequently reported to inhabit areas from wild environments to peri-urban spaces. In this study, we reassessed the taxonomy of H. heterostrongylus, describing and comparing morphology of L1 and L3 larvae and adult worms with closely related angiostrongilids, and inferring phylogenetic affinities within the family Angiostrongylidae; we also detailed histopathological reactions under natural infection. Ultrastructural morphology and light microscopy confirmed cephalic structures with well-developed trilobed lips, patterns of caudal bursa rays, spicules shape, terminal anal aperture and presence of the ventral protuberance in L3 larvae, characteristics present for the family Angiostrongylidae. Our molecular phylogenetic analyses, based on the partial small subunit (SSU) 18S rRNA gene, suggested that H. heterostrongylus and Didelphostrongylus hayesi are closely related. Pathological analyses agreed with previous findings, showing that cardiopulmonary parasitism provokes verminous pneumonia and mucous bronchiolitis with hypertrophy of the smooth bronchiolar muscle. These data confirmed that H. heterostrongylus represents a pulmonary pathogen in D. aurita, produces severe pathological effects, and may represent risk to domestic and wild animals.

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil.

INTRODUCTION: Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time. METHODOLOGY: Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates. RESULTS: Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii. CONCLUSIONS: Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.