| pericentric inversion in natural populations of oligoryzomys nigripes (rodentia: sigmodontinae). | we analysed polymorphism for pericentric inversion in chromosome 3 of oligoryzomys nigripes (rodentia: sigmodontinae) in several populations in brazil and examined the meiotic behaviour of this chromosome in heterozygotes. we observed an orderly pairing of all chromosomes at pachytene in heterozygotes for the inverted chromosome 3. no indication of meiotic arrest and germ-cell death was found. electron microscopy of synaptonemal complexes and conventional meiotic analysis indicated strictly nonh ... | 2001 | 11681602 |
| a new species, litomosoides odilae n. sp (nematoda: onchocercidae) from oligoryzomys nigripes (rodentia: muridae) in the rainforest of misiones, argentina. | a new species of litomosoides was collected from the abdominal cavity of oligoryzomys nigripes (rodentia: muridae) in a semideciduous secondary rainforest of misiones, argentina. litomosoides odilae n. sp. belongs to the carinii group and is characterized by the amphids displaced dorsally; buccal capsule with an anterior segment transparent and an annular asymmetrical thickening; esophagus divided, with the posterior glandular portion slightly wider than the muscular; male cloacal aperture stron ... | 2002 | 12435138 |
| nectomys squamipes microsatellites and homologous loci in sigmodontine rodents. | three monomorphic and four highly polymorphic microsatellites of nectomys squamipes were isolated and characterised in a sample of 141 specimens from eight different brazilian localities. these seven microsatellites and four others previously described in this species were tested in seven other nonfocus sigmodontine species. at least three loci were successfully amplified in every species, but none was amplified in all species. all sequenced products in nonfocus species showed (gt)(n) motifs as ... | 2003 | 12721229 |
| identifying rodent hantavirus reservoirs, brazil. | we describe the genetic analysis of samples from hantavirus pulmonary syndrome (hps) patients from southern and southeastern states of brazil and rodents captured at the presumed site of infection of these patients. a total of 65 samples that were antibody-positive for sin nombre or laguna negra virus by enzyme-linked immunosorbent assay were processed by nested reverse transcription-polymerase chain reaction (rt-pcr) by using several primer combinations in the m and s genome segments. pcr produ ... | 2004 | 15663849 |
| hantaviruses in central south america: phylogenetic analysis of the s segment from hps cases in paraná, brazil. | we sequenced the complete s segments of hantaviruses detected from 12 hps patients living in southern of brazil. samples were obtained from patients diagnosed in different years, in distinct areas, and with a broad spectrum of clinical signs. despite these differences, all the s proteins of hantavirus from paraná were identical, except for one amino acid substitution. phylogenetic analyses of the complete s segment nucleotide and amino acid sequences indicated that hantaviruses from paraná form ... | 2005 | 15977228 |
| small mammal populations of an agroecosystem in the atlantic forest domain, southeastern brazil. | this study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. the study was conducted in a rural area of the atlantic forest, in sumidouro, rio de janeiro state, brazil. the population sizes, age structure and reproduction were studied for the four most common species in the study area. the overall diversity was 1.67 and ranged between 0.8 to 1.67. the species richness was 13 considering the whole study. the most abundant species wer ... | 2007 | 17505767 |
| a new species of syphacia (nematoda: oxyuridae) from oligoryzomys nigripes (rodentia: cricetidae) in argentina. | the aim of this paper is to describe syphacia kinsellai n. sp. (nematoda: oxyuridae) from the cecum of oligoryzomys nigripes (olfers 1818) (sigmodontinae: oryzomyini) captured in misiones province, argentina. the new species can be differentiated from other species of the genus principally by the shape of the cephalic plate; distribution of submedian papillae and amphids; development of porous badge; presence of derids in females; absence of cervical and lateral alae; shape and structure of acce ... | 2007 | 17541641 |
| pathogenic hantaviruses, northeastern argentina and eastern paraguay. | we describe the first, to our knowledge, cases of han-tavirus pulmonary syndrome in northeastern argentina and eastern paraguay. andes and juquitiba (juq) viruses were characterized. juqv was also confirmed in 5 oligoryzomys nigripes reservoir species from misiones. a novel akodon-borne genetic hantavirus lineage was detected in 1 rodent from the biologic reserve of limoy. | 2007 | 17953094 |
| habitat associations of small mammals in southern brazil and use of regurgitated pellets of birds of prey for inventorying a local fauna. | we inventoried terrestrial small mammals in an agricultural area in southern brazil by using trapping and prey consumed by barn owls (tyto alba) and white-tailed kites (elanus leucurus). small mammals were trapped in three habitat types: corn fields, uncultivated fields ("capoeiras"), and native forest fragments. a total of 1,975 small mammal specimens were trapped, another 2,062 identified from the diet of barn owls, and 2,066 from the diet of white-tailed kites. both trapping and prey in the p ... | 2007 | 18278312 |
| juquitiba-like hantavirus from 2 nonrelated rodent species, uruguay. | serologic and genetic analyses indicate that a juquitiba-like hantavirus circulates in maldonado, uruguay. this virus is carried by 2 rodent species, oligoryzomys nigripes and oxymycterus nasutus. the same hantavirus in 2 nonrelated species can be explained by a spillover infection or a host-switching event. | 2008 | 18760017 |
| barn owl (tyto alba) predation on small mammals and its role in the control of hantavirus natural reservoirs in a periurban area in southeastern brazil. | the aim of this study was to inventory the species of small mammals in uberlândia, minas gerais, brazil, based on regurgitated pellets of the barn owl and to compare the frequency of rodent species in the diet and in the environment. since in the region there is a high incidence of hantavirus infection, we also evaluate the importance of the barn owl in the control of rodents that transmit the hantavirus. data on richness and relative abundance of rodents in the municipality were provided by the ... | 2008 | 19197490 |
| phylogenetic characterization of hantaviruses from wild rodents and hantavirus pulmonary syndrome cases in the state of parana (southern brazil). | over 1,100 cases of hantavirus pulmonary syndrome (hps) have occurred in brazil since 1993, but little is known about brazilian hantaviruses, and many of their rodent hosts remain unknown. the araucaria hantavirus (arauv) was described recently from hps patients from paraná, in southern brazil, but its host could not be identified. in this study, rodents were captured from regions with high hps prevalence to address this issue. arauv rna was detected in three distantly related rodent species: ol ... | 2009 | 19439554 |
| a new heligmonellid species (nematoda) from oligoryzomys nigripes (rodentia: sigmodontinae) in the atlantic forest, brazil. | stilestrongylus lanfrediae n. sp. is described from the small intestine of oligoryzomys nigripes (cricetidae: sigmodontinae) collected in the atlantic forest (rio de janeiro state, teresópolis, brazil). the new species shows some similarities to stilestrongylus stilesi, stilestrongylus freitasi, stilestrongylus inexpectatus, stilestrongylus moreli, and stilestrongylus andalgala, but it can be distinguished from these species by the following combination of characters: 26 ridges in males and 25 i ... | 2009 | 19642806 |
| genetic characterization of a juquitiba-like viral lineage in oligoryzomys nigripes in rio de janeiro, brazil. | hantaviruses, family bunyaviridae, are rodent-borne rna viruses that have caused cases of hantavirus cardiopulmonary syndrome (hcps) in various regions of the americas. there are five hantaviral lineages associated with hcps in brazil: juquitiba virus (juqv), araraquara virus (arav), laguna negra-like virus (lnv), castelo dos sonhos virus (casv), and anajatuba virus (anajv). three additional hantaviruses have been described in rodents alone: rio mearim virus, jaborá virus, and a hantavirus linea ... | 2009 | 19660427 |
| genetic characterization of hantaviruses associated with sigmodontine rodents in an endemic area for hantavirus pulmonary syndrome in southern brazil. | an ecological assessment of reservoir species was conducted in a rural area (jaborá) in the mid-west of the state of santa catarina in southern brazil, where hantavirus pulmonary syndrome is endemic, to evaluate the prevalence of hantavirus infection in wild rodents. blood and tissue samples were collected from 507 rodents during seven field trips from march 2004 to april 2006. some of the animals were karyotyped to confirm morphological identification. phylogenetic reconstructions of rodent spe ... | 2010 | 21138380 |
| detection of hantaviruses in brazilian rodents by sybr-green-based real-time rt-pcr. | current knowledge of the pathogenic hantavirus indicates that wild rodents are its primary natural reservoir. specific primers to detect the presence of viral genomes were developed using an sybr-green-based real-time rt-pcr protocol. one hundred sixty-four rodents native to the atlantic forest biome were captured in são paulo state, brazil, and their tissues were tested. the presence of hantavirus rna was detected in sixteen rodents: three specimens of akodon montensis, three of akodon cursor, ... | 2011 | 21442233 |
| seasonal dynamics and hosts of amblyomma triste (acari: ixodidae) in argentina. | the seasonal dynamics and host usage of amblyomma triste in argentina were analyzed. adults of a. triste were present from early winter to mid-summer, with the peak of abundance from late winter to mid-spring (august to october). larvae and nymphs were found from december to june, with the peak of abundance in summer. there were no differences among the biological parameters (pre-moult period of larvae and nymphs, pre-oviposition period of females, and minimum incubation period of eggs) of engor ... | 2011 | 21536384 |
| hantavirus ecology in rodent populations in three protected areas of argentina. | in this study, we identified hantavirus genotypes and their reservoirs and evaluated the spatial and temporal distribution of the virus in rodent population in three protected areas of argentina over 3ôçâyears (2007-2010). a total of 837 rodents were captured with an effort of 22ôçâ117 trap-nights. we detected the genotype lechiguanas in oligoryzomys nigripes and o.-áflavescens and pergamino in akodon azarae. there was no correlation between seroprevalence and trap success of the host. the propo ... | 2011 | 21733047 |
| characterization of juquitiba virus in oligoryzomys fornesi from brazilian cerrado. | the juquitiba virus, an agent of hantavirus cardiopulmonary syndrome, is one of the most widely distributed hantavirus found in south america. it has been detected in oligoryzomys nigripes, akodon montensis, oxymycterus judex, akodon paranaensis in brazil and in o. nigripes, oryzomys sp. and oligoryzomys fornesi rodents in argentine, paraguay and uruguay. here, we report the genomic characterization of the complete s segment from the juquitiba strain, isolated from the lung tissues of o. fornesi ... | 2014 | 24674957 |
| the influence of habitat fragmentation on helminth communities in rodent populations from a brazilian mountain atlantic forest. | the influence of habitat structure on helminth communities of three sigomdontinae rodent species (akodon cursor, a. montensis and oligoryzomys nigripes) was investigated in forest fragments within an agricultural landscape in south-eastern brazil. this is a pionner study correlating the occurrence of helminth species of rodent hosts with microhabitat characteristics. rodents were collected from 12 fragments and in a continuous conserved area. up to 13 nematode, three cestode and two trematode sp ... | 2016 | 26206199 |
| hantavirus infection prevalence in wild rodents and human anti-hantavirus serological profiles from different geographic areas of south brazil. | paraná state presents the fourth highest number of accumulated cases of hantavirus pulmonary syndrome in brazil. to map the risk areas for hantavirus transmission we carried out a study based on rodent trapping and determined the anti-hantavirus seroprevalence in these animals and in the inhabitants of these localities. overall seroprevalence in rodents and humans were 2.5% and 2.4%, respectively. eighty-two percent of the seropositive rodents were genetically analyzed. phylogenetic analyses rev ... | 2012 | 22855773 |
| ecological study of hantavirus infection in wild rodents in an endemic area in brazil. | a 3-year ecological study of small mammals was carried out in an endemic area for hantavirus pulmonary syndrome in the state of santa catarina in southern brazil. a total of 994 rodents of 14 different species corresponding to the subfamilies of sigmodontinae, murinae, eumysopinae, and caviinae were captured during 2004-2006. oligoryzomys nigripes and akodon montensis were the most abundant species and showed a clear seasonal pattern with higher population sizes during the winter. rodent populat ... | 2014 | 24291677 |
| phylogenetic analysis of the s segment from juquitiba hantavirus: identification of two distinct lineages in oligoryzomys nigripes. | the purpose of this study was to investigate the phylogenetic relationship of the juquitiba virus (juqv) carried by oligoryzomys nigripes in endemic and non-endemic areas of brazil. wild rodents infected with the juquitiba virus (juqv) were sampled from a non-hantavirus cardiopulmonary syndrome endemic area in brazil. three strains from o. nigripes were identified by the sequencing of the complete s segment and compared to previous studies of juqv available in genbank. the phylogenetic analysis ... | 2013 | 23751399 |
| paracoccidioides brasiliensis infection in small wild mammals. | paracoccidioidomycosis (pcm) is a systemic mycosis prevalent in brazil and other latin american countries. the etiological agents of pcm are the thermo-dimorphic fungi paracoccidioides brasiliensis and p. lutzii. taking into account that the natural habitat of paracoccidioides spp. is still undefined, domestic and wild animals could be useful as indicators of paracoccidioides spp. presence in endemic areas. the objective of this study was to evaluate the infection of small wild mammals by p. bra ... | 2015 | 26232125 |
| toxoplasma gondii antibodies in wild rodents and marsupials from the atlantic forest, state of são paulo, brazil. | toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. small rodents and marsupials play an important role in the epidemiology of t. gondii because they are sources of infection for domestic and feral cats. serum samples from 151 rodents and 48 marsupials, captured in the atlantic forest, são paulo state, southeastern brazil, were analyzed for the presence of t. gondii antibodies. antibodies detected by the modified agglutination test ( ... | 2015 | 26444068 |
| the role of sigmodontine rodents as sylvatic hosts of trypanosoma cruzi in the argentinean chaco. | the role of rodents in the sylvatic transmission of trypanosoma cruzi has seldom been investigated using parasitological and molecular methods. we assessed the occurrence of t. cruzi in wild small rodents from pampa del indio, in the argentinean chaco, and identified the taxonomic status of positive rodents by sequencing a fragment of cytochrome b gene (cytb) and performing blast searches and phylogenetic analyses. a total of 176 sigmodontinae rodents was captured in six surveys using 5425 trap- ... | 2014 | 24394448 |
| evaluation of habitat requirements of small rodents and effectiveness of an ecologically-based management in a hantavirus-endemic natural protected area in argentina. | hantavirus pulmonary syndrome is a severe cardio pulmonary disease transmitted to humans by sylvan rodents found in natural and rural environments. disease transmission is closely linked to the ecology of animal reservoirs and abiotic factors such as habitat characteristics, season or climatic conditions. the main goals of this research were: to determine the biotic and abiotic factors affecting richness and abundance of rodent species at different spatial scales, to evaluate different methodolo ... | 2017 | 27135773 |
| helminth communities in three sympatric rodents from the brazilian atlantic forest: contrasting biomass and numerical abundance. | the study of parasite body size is an important approach to understand the different patterns of helminth community structure, once it is usually analysed using only numerical descriptors which do not capture size heterogeneity among parasite species. in the present study, we compared the pattern in the helminth community of three sympatric wild rodent species akodon cursor, a. montensis and oligoryzomys nigripes using numerical abundance and biomass approaches. the cestode rodentolepis akodonti ... | 2012 | 23295521 |
| variation in the helminth community structure of three sympatric sigmodontine rodents from the coastal atlantic forest of rio de janeiro, brazil. | one hundred and eighty specimens of sigmodontine rodents living in sympatric conditions were collected in the atlantic forest in the state of rio de janeiro, brazil (25 akodon cursor, 98 akodon montensis and 57 oligoryzomys nigripes) to examine whether the helminth structure and component communities can be characterized among these three closely related rodents. the parasite species richness was 9 in a. cursor, 12 in a. montensis and 12 in o. nigripes. five species were common to the three rode ... | 2011 | 20701831 |
| differences in physiological traits associated with water balance among rodents, and their relationship to tolerance of habitat fragmentation. | physiological concepts and tools can help us to understand why organisms and populations respond to habitat fragmentation in the way they do, and allow us to determine the mechanisms or individual characteristics underlying this differential sensitivity. here, we examine food intake, relative medullary thickness and distribution/expression of water channel aquaporin-1 in three species of south american rodents that have been reported to have different levels of tolerance to habitat fragmentation ... | 2015 | 26349625 |
| population ecology of hantavirus rodent hosts in southern brazil. | in this study we analyze population dynamics of hantavirus rodent hosts and prevalence of infection over a 2-year period in southern brazil, a region with a high incidence of hantavirus pulmonary syndrome. the 14 small mammal species captured were composed of 10 rodents and four marsupials, the six most abundant species being akodon serrensis, oxymycterus judex, akodon montensis, akodon paranaensis, oligoryzomys nigripes, and thaptomys nigrita. these species displayed a similar pattern with incr ... | 2014 | 24935954 |
| microhabitat of small mammals at ground and understorey levels in a deciduous, southern atlantic forest. | each animal species selects specific microhabitats for protection, foraging, or micro-climate. to understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern brazil. ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and piper sp. shrubs. seven fiel ... | 2013 | 23828340 |
| differences in richness and composition of gastrointestinal parasites of small rodents (cricetidae, rodentia) in a continental and insular area of the atlantic forest in santa catarina state, brazil. | the first and only study on gastrointestinal parasites of wild rodents in the island of santa catarina was done in 1987. the aim of this study was to identify intestinal parasites from wild rodents in santo amaro da imperatriz and santa catariana island, and to compare the richness and composition of the gastrointestinal parasite community of both areas. rodents were captured with live traps, and feces were screened using the sedimentation method and optical microscopy. the following species of ... | 2012 | 22990827 |
| potential geographic distribution of hantavirus reservoirs in brazil. | hantavirus cardiopulmonary syndrome is an emerging zoonosis in brazil. human infections occur via inhalation of aerosolized viral particles from excreta of infected wild rodents. necromys lasiurus and oligoryzomys nigripes appear to be the main reservoirs of hantavirus in the atlantic forest and cerrado biomes. we estimated and compared ecological niches of the two rodent species, and analyzed environmental factors influencing their occurrence, to understand the geography of hantavirus transmiss ... | 2013 | 24391989 |
| allometric relations of neotropical small rodents (sigmodontinae) in anthropogenic environments. | the present study aims at assessing allometric relationships in the sigmodontinae rodents (calomys tener, akodon cf. montensis, necromys lasiurus, oligoryzomys flavescens, and oligoryzomys nigripes), and morphological variation among different habitats in human-dominated environments in southeastern brazil. we captured rodents using pitfall traps placed in eucalyptus plantations, abandoned pastures, and remnants of secondary native vegetation, and took the following measurements: body mass, tota ... | 2013 | 23829219 |
| genetic structure of sigmodontine rodents (cricetidae) along an altitudinal gradient of the atlantic rain forest in southern brazil. | the population genetic structure of two sympatric species of sigmodontine rodents (oligoryzomys nigripes and euryoryzomys russatus) was examined for mitochondrial dna (mtdna) sequence haplotypes of the control region. samples were taken from three localities in the atlantic rain forest in southern brazil, along an altitudinal gradient with different types of habitat. in both species there was no genetic structure throughout their distribution, although levels of genetic variability and gene flow ... | 2009 | 21637469 |
| description of litomosoides ysoguazu n. sp. (nematoda, onchocercidae), a parasite of the tuft-toed rice rat sooretamys angouya (fischer) (rodentia: cricetidae), and a first record of l. esslingeri bain, petit & berteaux, 1989 in paraguay. | paraguay is a small landlocked country whose mammalian fauna is among the least studied in south america, as well as their parasites. as a result of a study of the effects of habitat fragmentation on small mammal biodiversity in eastern paraguay, we have collected some parasites of cricetid rodents. herein, we describe a new species of litomosoides chandler, 1931 parasitising the body cavity of the tuft-toed rice rat sooretamys angouya (fischer) and litomosoides esslingeri bain, petit & diagne, ... | 2015 | 25962465 |
| the genus guerrerostrongylus (nematoda: heligmonellidae) in cricetid rodents from the atlantic rain forest of misiones, argentina: emended description of guerrerostrongylus zetta (travassos, 1937) and description of a new species. | two species of guerrerostrongylus sutton and durette-desset, 1991, are reported in cricetid rodents from the atlantic rain forest of misiones, argentina. guerrerostrongylus zetta (travassos, 1937) is redescribed on the basis of material collected from oligoryzomys nigripes from argentina and material loaned by chioc from brazil. it is characterized by a synlophe with about 40-45 (35-48) well-developed cuticular ridges, caudal bursa with long rays 6 and dorsal ray divided at mid-length, and well- ... | 2012 | 22494032 |
| a new heligmonellid (nematoda: heligmonellidae) from oecomys mamorae (rodentia: sigmodontinae) in the pantanal and new data on the synlophe of guerrerostrongylus zetta from the atlantic forest, brazil. | a new species of heligmonellidae nematode, guerrerostrongylus gomesae n. sp., is described from specimens collected from the small intestine of the rodent oecomys mamorae thomas, 1906 in the brazilian pantanal. it differs from the 2 other species of the genus by the number of ridges in the synlophe 35-46 and 40-48 at the midbody in the male and female, respectively, by rays 8 arising at midlength of the dorsal trunk, ending near the margin of the caudal bursa, and the dorsal ray divided at the s ... | 2012 | 22468958 |
| co-circulation of araraquara and juquitiba hantavirus in brazilian cerrado. | hantavirus cardiopulmonary syndrome is an emerging serious disease in the americas, transmitted from wild rodents to humans through inhalation of aerosol containing virus. herein, we characterized two distinct hantaviruses circulating in rodent species form central plateau, midwestern region of brazil in the cerrado (savanna-like) biome, an area characterized by small trees and grasses adapted to climates with long dry periods. in this study, we identified the co-circulation of the araraquara vi ... | 2017 | 28856421 |
| a fatal hantavirus pulmonary syndrome misdiagnosed as dengue: an investigation into the first reported case in rio de janeiro state, brazil. | we report the results of an investigation into a fatal case of hantavirus pulmonary syndrome (hps) in rio de janeiro state, brazil, where the disease had not been reported previous to 2015. following the notification of an hps case, serum samples were collected from the household members and work contacts of the hps patient and tested for antibody to hantaviruses. seroprevalence of 22% (10/45) was indicated for hantavirus out of 45 human samples tested. blood and tissue samples were collected fr ... | 2017 | 28719302 |
| leishmania (viannia) braziliensis infection in wild small mammals in ecotourism area of brazil. | leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (diptera: psychodidae). despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. the reserva particular do patrimônio natural santuário do caraça (rppnsc) is one of the largest ecotourism attractions in the state of minas ... | 2017 | 29284049 |
| description of the helminth communities of sympatric rodents (muroidea: cricetidae) from the atlantic forest in northeastern argentina. | taxonomic and ecological aspects of the helminths found in the assemblage of sigmodontine rodents (cricetidae-muroidea) of the atlantic forest in argentina are studied in this paper. the following species akodon montensis, brucepattersonius sp. and thaptomys nigrita (tribe akodontini), as well as, euryoryzomys russatus, nectomys squamipes, oligoryzomys nigripes, and sooretamys angouya (tribe oryzomyini) are analyzed. a complete taxonomic list with a total of 25 species of helminths, including di ... | 2017 | 29242441 |
| vaccinia virus in feces and urine of wild rodents from são paulo state, brazil. | the origin of vaccinia virus (vacv) outbreaks in brazil remains unknown, but since the isolation of vacv in mus musculus mice during a zoonotic outbreak affecting cattle and milkers, peridomestic rodents have been suggested to be a link between cows and wild animals. considering that experimentally infected mice eliminate viral particles in their feces, we investigated the presence of vacv in the feces and urine of wild rodents that were captured in the forest areas surrounding milking farms in ... | 2018 | 29360742 |
| evaluating host-parasite co-adaptation relationships involving angiostrongylus costaricensis. | angiostrongylus costaricensis is a parasite that infects rodents, including the wild cotton rat sigmodon hispidus and pygmy rice rats oligoryzomys spp., among others. however, urban rattus norvegicus and mus musculus have not been identified as important hosts of a. costaricensis. in this study, swiss mice (sw), wistar r. norvegicus (rn), wild oligoryzomys nigripes (on) and a local strain of m. musculus (rgs) were experimentally infected with a. costaricensis. survival, elimination of l1 (total ... | 2017 | 29254509 |
| pattern of protein expression in the epididymis of oligoryzomys nigripes (cricetidae, sigmodontinae). | in the epididymis, epithelial cells work in a concerted manner to create a luminal environment for sperm maturation, transport, and storage. however, the cell functions may be affected by anthropogenic factors, causing negative impacts on male fertility. in our study, we describe the pattern of protein expression in the epithelium and luminal fluid from epididymis of oligoryzomys nigripes, a south american sigmodontine rodent whose reproductive biology has been little studied. nine animals were ... | 2017 | 29119327 |
| atlantic small-mammal: a dataset of communities of rodents and marsupials of the atlantic forests of south america. | the contribution of small mammal ecology to the understanding of macroecological patterns of biodiversity, population dynamics, and community assembly has been hindered by the absence of large datasets of small mammal communities from tropical regions. here we compile the largest dataset of inventories of small mammal communities for the neotropical region. the dataset reviews small mammal communities from the atlantic forest of south america, one of the regions with the highest diversity of sma ... | 2017 | 28500789 |
| effect of body size on the abundance of ectoparasitic mites on the wild rodent oligoryzomys nigripes. | the abundance of parasites on a host can be affected by several factors; in this study, we investigated the influence of sex and body size of the host rodent oligoryzomys nigripes on the abundance of ectoparasitic mites (acari: mesostigmata). the generalized linear model indicated that body size (indicative of age) of the host rodent o. nigripes significantly contributed to the variation in the abundance of mites on host rodents at the experimental station of itirapina. this trend of increased p ... | 2015 | 26204011 |
| comparison between oligoryzomys nigripes and o. flavescens by rapd and genetic diversity in o. nigripes (rodentia, cricetidae). | the genus of oligoryzomys includes species of small size, morphologically similar, which may impede taxonomic identification, mainly between o. flavescens (waterhouse, 1837) and o. nigripes (olfers, 1818). the main objective of this work was to investigate whether the rapd markers are capable of genetically differentiating the specimens o. nigripes and o. flavescens, coming from rio grande do sul (rs) and santa catarina (sc) states, and also to estimate the genetic variability among populations ... | 2014 | 25296222 |
| effects of sex and locality on the abundance of lice on the wild rodent oligoryzomys nigripes. | various factors can affect the parasite distribution on a host. in this study, the influence of sex, body size, and locality of a rodent host, oligoryzomys nigripes, on lice abundance was investigated. a generalized linear model indicated that the sex and locality of o. nigripes significantly contributed to the variation in lice abundance on the host. the male bias of lice parasitizing the rodent host o. nigripes may be associated with intersexual differences in physiology and behavior, while lo ... | 2012 | 22740295 |
| trypanosomatids in small mammals of an agroecosystem in central brazil: another piece in the puzzle of parasite transmission in an anthropogenic landscape. | we surveyed infection by trypanosoma spp. and leishmania spp. in small wild mammals from cumari, goiás state aiming to investigate the diversity of trypanosomatid in a modified landscape of the brazilian cerrado (and possible infection overlapping with canids from the same area). blood, skin, spleen, and liver samples were collected for parasitological, serological, and molecular assays. gracilinanusagilis was the most abundant species (n = 70; 48.6%) and it was the only one with patent parasite ... | 2019 | 31615153 |
| 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 t ... | 2019 | 30427522 |
| orthohantavirus genotype lechiguanas in oligoryzomys nigripes (rodentia: cricetidae): new evidence of host-switching. | to identify and predict situations of increased risk of orthohantavirus infection in humans, it is necessary to study the relationships between the virus and its rodent hosts. the present study investigated orthohantavirus infection in an assemblage of wild sigmodontinae rodents of the paraná delta, argentina, and providing new evidence of host-switching events. rodents belonging to the species oxymycterus rufus (n = 187), akodon azarae (n = 82), oligoryzomys flavescens (n = 80), oligoryzomys ni ... | 2019 | 30599176 |
| silent orthohantavirus circulation among humans and small mammals from central minas gerais, brazil. | new world orthohantaviruses are emerging rna viruses that cause hantavirus cardiopulmonary syndrome (hcps). these viruses are a burden to public health around the world with a lethality rate of around 60%. in south america, rodents of sigmodontinae subfamily are the main reservoirs of orthohantaviruses. we described a serosurvey for orthohantaviruses circulation in an apparently healthy human population and small mammals from rural areas in central minas gerais state, brazil. a total of 240 indi ... | 2018 | 30105563 |
| calodium hepaticum (nematoda: capillariidae) in wild rodent populations from argentina. | calodium hepaticum (nematoda; capillariidae) is a parasitic nematode of mammals with a cosmopolitan distribution. adults of this nematode can infect the liver of many mammalian species, including humans, but the main hosts are members of the superfamily muroidea. among these, rattus spp. have the highest apparent prevalences reported worldwide. there are only two reports of c. hepaticum infecting sigmodontinae species (muroidea: cricetidae). in this survey, we examined the occurrence of c. hepat ... | 2018 | 29951708 |
| a novel hepacivirus in wild rodents from south america. | the hepacivirus genus comprises single-stranded positive-sense rna viruses within the family flaviviridae. several hepaciviruses have been identified in different mammals, including multiple rodent species in africa, asia, europe, and north america. to date, no rodent hepacivirus has been identified in the south american continent. here, we describe an unknown hepacivirus discovered during a metagenomic screen in akodon montensis, calomys tener, oligoryzomys nigripes, necromys lasiurus, and mus ... | 2019 | 30909631 |
| new host species for leptospira borgpetersenii and leptospira interrogans serovar copenhageni. | we investigated the presence of infection by leptospira spp. in an assembly of sigmodontinae rodents from the paraná delta, argentina. rodents were captured in places with natural grassland, implanted forest, with and without raising cattle and in sites prone and not prone to flooding. the dna was amplified from cultured isolates by pcr and leptospira spp. strains were genotyped using multiple - locus variable number tandem repeat analysis (mlva). we isolated leptospira interrogans serovar copen ... | 2018 | 29426412 |
| helminth communities of sigmonontine rodents in cocoa agroforestry systems in brazil. | agroforestry is an alternative kind of land use where the native vegetation is surrounded or intercalated by crops of economic interest. this system may maintain species richness by promoting the habitat heterogeneity or serving as ecological corridors. the aim of this study was to describe the gastrointestinal helminth fauna and to analyse the parasitological parameters of the helminth communities of six sigmodontine rodents in a cocoa agroforestry system in the municipality of ilhéus, state of ... | 2020 | 32274328 |
| moving to healthier landscapes: forest restoration decreases the abundance of hantavirus reservoir rodents in tropical forests. | hantavirus cardiopulmonary syndrome (hcps) is a disease with high human lethality rates, whose transmission risk is directly related to the abundance of reservoir rodents. in the brazilian atlantic forest, the main reservoirs species, oligoryzomys nigripes and necromys lasiurus, are thought to increase in abundance with deforestation. therefore, forest restoration may contribute to decrease hcps transmission risk, a topic still unexplored, especially in tropical regions. aiming at filling this r ... | 2020 | 32892056 |
| sigmodontine community and species responses to el niño and precipitation in different levels of forest degradation. | few studies have focused on rodent communities at the margins of an ecoregion or the limits of species' distributions, where the community may be more sensitive to extrinsic variables, both biotic and abiotic. this study evaluates sigmodontine rodent species diversity and overall abundance, and variation associated with climatic variables, in three locations with differing levels of habitat degradation. the study was conducted in northeastern paraguay, near the western limit of the upper paraná ... | 2019 | 32905550 |
| habitat, species richness and hantaviruses of sigmodontine rodents within the interior atlantic forest, paraguay. | four of the nine sigmodontine tribes have species that serve as reservoirs of rodent-borne hantaviruses (rbo-hv), few have been studied in any depth. several viruses have been associated with human cases of hantavirus pulmonary syndrome often through peridomestic exposure. jabora (jabv) and juquitiba (juqv), harbored by akodon montensis and oligoryzomys nigripes, respectively, are endemic and sympatric in the reserva natural de bosque mbaracayú (rnbm), paraguay, a protected area of the interior ... | 2018 | 30067840 |
| morphology of the oligoryzomys nigripes respiratory system. | rodents are important in the transmission of infectious diseases that affect the respiratory tract, including simple infections and those caused by specific pathogens. these animals are natural reservoirs of zoonoses that cause many public health diseases. basic knowledge on the morphology of these animals is important as basic research is useful for applied studies, such as the development of clinical, therapeutic, surgical and clinical models. morphological data of respiratory tract in oligory ... | 2018 | 29869399 |
| 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 t ... | 2019 | 29846459 |