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1.
Acta Trop ; 225: 106177, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34627759

RESUMO

We investigated the patterns of flea infestation in wild populations of eight Sigmodontinae rodent species: Akodon azarae, Calomys callidus, Calomys venustus, Holochilus chacarius, Necromys lasiurus, Oligoryzomys flavescens, Oligoryzomys nigripes and Oxymycterus rufus. Rodents were captured in systematic trapping sessions carried out along 2 years at two localities from El Espinal Ecoregion, Argentina. Mean flea intensity, occurrence (presence/absence) of flea infestation, richness and diversity were compared for different ages, body condition, sex and rodent tribes (Akodontini, Oryzomyini and Phyllotini). A total of 376 fleas of the following species and subspecies were collected: Craneopsylla minerva wolffhuegeli, Polygenis (Neopolygenis) pradoi, Polygenis (Polygenis) axius axius, and Polygenis (Polygenis) byturus. The most important factor driving flea infestation was the rodent tribe, with Phyllotini showing the highest values of occurrence, abundance and species richness. Only C. m. wolffhuegeli was affected by the sex of the host. Age and body condition of the hosts did not affect flea infestation. Our results contribute to knowledge of the ecology of fleas on rodent hosts in El Espinal Ecoregion. The relevance of host taxonomy as driver of flea dynamics highlight the importance of considering host community structures at the time of studying the ecology of parasites.


Assuntos
Infestações por Pulgas , Doenças dos Roedores , Sifonápteros , Animais , Argentina , Arvicolinae , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Doenças dos Roedores/epidemiologia , Roedores , Sigmodontinae
2.
PLoS One ; 16(10): e0258474, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34634084

RESUMO

Rhipidomys (Sigmodontinae, Thomasomyini) has 25 recognized species, with a wide distribution ranging from eastern Panama to northern Argentina. Cytogenetic data has been described for 13 species with 12 of them having 2n = 44 with a high level of autosomal fundamental number (FN) variation, ranging from 46 to 80, assigned to pericentric inversions. The species are grouped in groups with low FN (46-52) and high FN (72-80). In this work the karyotypes of Rhipidomys emiliae (2n = 44, FN = 50) and Rhipidomys mastacalis (2n = 44, FN = 74), were studied by classical cytogenetics and by fluorescence in situ hybridization using telomeric and whole chromosome probes (chromosome painting) of Hylaeamys megacephalus (HME). Chromosome painting revealed homology between 36 segments of REM and 37 of RMA. We tested the hypothesis that pericentric inversions are the predominant chromosomal rearrangements responsible for karyotypic divergence between these species, as proposed in literature. Our results show that the genomic diversification between the karyotypes of the two species resulted from translocations, centromeric repositioning and pericentric inversions. The chromosomal evolution in Rhipidomys was associated with karyotypical orthoselection. The HME probes revealed that seven syntenic probably ancestral blocks for Sigmodontinae are present in Rhipidomys. An additional syntenic block described here is suggested as part of the subfamily ancestral karyotype. We also define five synapomorphies that can be used as chromosomal signatures for Rhipidomys.


Assuntos
Sigmodontinae , Animais , Hibridização in Situ Fluorescente , Roedores
3.
Mol Ecol ; 30(17): 4245-4258, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34219316

RESUMO

When organisms experience secondary contact after allopatric divergence, genomic regions can introgress differentially depending on their relationships with adaptation, reproductive isolation, recombination, and drift. Analyses of genome-wide patterns of divergence and introgression could provide insight into the outcomes of hybridization and the potential relationship between allopatric divergence and reproductive isolation. Here, we generate population genetic data (26,262 SNPs; 353 individuals) using a reduced-representation sequencing approach to quantify patterns of ancestry, differentiation, and introgression between a pair of ecologically distinct mammals-the desert woodrat (N. lepida) and Bryant's woodrat (N. bryanti)-that hybridize at a sharp ecotone in southern California. Individual ancestry estimates confirmed that hybrids were rare in this bimodal hybrid zone, and entirely consisted of a few F1 individuals and a broad range of multigenerational backcrosses. Genomic cline analyses indicated more than half of loci had elevated introgression from one genomic background into the other. However, introgression was not associated with relative or absolute measures of divergence, and loci with extreme values for both were not typically found near detoxification enzymes previously implicated in dietary specialization for woodrats. The decoupling of differentiation and introgression suggests that processes other than adaptation, such as drift, may underlie the extreme clines at this contact zone.


Assuntos
Genoma , Isolamento Reprodutivo , Animais , Genética Populacional , Humanos , Hibridização Genética , Sigmodontinae/genética
4.
Rev Bras Parasitol Vet ; 30(2): e000521, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076045

RESUMO

A new species of Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., is described from specimens collected from the small intestine of the rodent Hylaeamys seuanezi in the Atlantic Forest of northeastern Brazil (Igrapiúna, state of Bahia). The genus Hassalstrongylus includes 17 species, which parasitize rodents occurring in the Neotropical and Nearctic regions. It differs from the genus Stilestrongylus through its smaller number of ridges in the synlophe and through the size of the genital cone. The main taxonomic characteristics of this new species are the subsymmetrical caudal bursa of type 2-2-1, ray 8 branching out at the base of the dorsal trunk, right lobe smaller than the left, and rays 4 and 5 of robust nature. In addition, the ornamental ray 5 and the robustness of ray 4 on the male caudal bursa, along with the modification of the ridges of the posterior end of the female, allow us to consider the specimens found to be a new species.


Assuntos
Doenças dos Roedores , Trichostrongyloidea , Tricostrongiloidíase , Animais , Brasil , Feminino , Florestas , Masculino , Sigmodontinae , Tricostrongiloidíase/veterinária
5.
Sci Rep ; 11(1): 12635, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34135378

RESUMO

The study of ancient DNA is revolutionizing our understanding of paleo-ecology and the evolutionary history of species. Insects are essential components in many ecosystems and constitute the most diverse group of animals. Yet they are largely neglected in ancient DNA studies. We report the results of the first targeted investigation of insect ancient DNA to positively identify subfossil insects to species, which includes the recovery of endogenous content from samples as old as ~ 34,355 ybp. Potential inhibitors currently limiting widespread research on insect ancient DNA are discussed, including the lack of closely related genomic reference sequences (decreased mapping efficiency) and the need for more extensive collaborations with insect taxonomists. The advantages of insect-based studies are also highlighted, especially in the context of understanding past climate change. In this regard, insect remains from ancient packrat middens are a rich and largely uninvestigated resource for exploring paleo-ecology and species dynamics over time.


Assuntos
Artrópodes/genética , DNA Antigo/análise , Análise de Sequência de DNA/veterinária , Sigmodontinae/parasitologia , Animais , DNA Mitocondrial/genética , Fósseis , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , RNA Ribossômico 28S/genética , Sigmodontinae/genética
6.
J Virol ; 95(16): e0001021, 2021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34037420

RESUMO

Respiratory syncytial virus (RSV) has been reported to use CX3CR1 in vitro as a receptor on cultured primary human airway epithelial cultures. To evaluate CX3CR1 as the receptor for RSV in vivo, we used the cotton rat animal model because of its high permissiveness for RSV infection. Sequencing the cotton rat CX3CR1 gene revealed 91% amino acid similarity to human CX3CR1. Previous work found that RSV binds to CX3CR1 via its attachment glycoprotein (G protein) to infect primary human airway cultures. To determine whether CX3CR1-G protein interaction is necessary for RSV infection, recombinant RSVs containing mutations in the CX3CR1 binding site of the G protein were tested in cotton rats. In contrast to wild-type virus, viral mutants did not grow in the lungs of cotton rats. When RSV was incubated with an antibody blocking the CX3CR1 binding site of G protein and subsequently inoculated intranasally into cotton rats, no virus was found in the lungs 4 days postinfection. In contrast, growth of RSV was not affected after preincubation with heparan sulfate (the receptor for RSV on immortalized cell lines). A reduction in CX3CR1 expression in the cotton rat lung through the use of peptide-conjugated morpholino oligomers led to a 10-fold reduction in RSV titers at day 4 postinfection. In summary, these results indicate that CX3CR1 functions as a receptor for RSV in cotton rats and, in combination with data from human airway epithelial cell cultures, strongly suggest that CX3CR1 is a primary receptor for naturally acquired RSV infection. IMPORTANCE The knowledge about a virus receptor is useful to better understand the uptake of a virus into a cell and potentially develop antivirals directed against either the receptor molecule on the cell or the receptor-binding protein of the virus. Among a number of potential receptor proteins, human CX3CR1 has been demonstrated to act as a receptor for respiratory syncytial virus (RSV) on human epithelial cells in tissue culture. Here, we report that the cotton rat CX3CR1, which is similar to the human molecule, acts as a receptor in vivo. This study strengthens the argument that CX3CR1 is a receptor molecule for RSV.


Assuntos
Receptor 1 de Quimiocina CX3C/metabolismo , Receptores Virais/metabolismo , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/fisiologia , Animais , Anticorpos Antivirais/farmacologia , Sítios de Ligação , Receptor 1 de Quimiocina CX3C/antagonistas & inibidores , Receptor 1 de Quimiocina CX3C/química , Linhagem Celular , Modelos Animais de Doenças , Células Epiteliais/virologia , Heparitina Sulfato/metabolismo , Humanos , Mutação , Receptores Virais/antagonistas & inibidores , Receptores Virais/química , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sincicial Respiratório Humano/crescimento & desenvolvimento , Vírus Sincicial Respiratório Humano/metabolismo , Sistema Respiratório/metabolismo , Sistema Respiratório/virologia , Sigmodontinae , Proteínas do Envelope Viral/antagonistas & inibidores , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Replicação Viral/genética
7.
Zootaxa ; 4951(3): zootaxa.4951.3.2, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33903389

RESUMO

The Lesser Antillean island chain in the eastern Caribbean formerly supported a diverse rodent fauna including multiple endemic genera of oryzomyine rice rats. The Caribbean rice rats are now all extinct, with most island populations known only from Holocene palaeontological and zooarchaeological material and with many remaining taxonomically undescribed. Rice rat material is reported from several pre-Columbian Ceramic Age (late Holocene) archaeological sites on the Grenada Bank, including sites on Grenada and Carriacou, but the taxonomic identity and diversity of the Grenada Bank rice rats has remained uncertain. We provide a morphology-based description of rice rats from Grenada and Carriacou, and analyze their phylogenetic and biogeographical affinities to other Caribbean and mainland Neotropical oryzomyines. We recognize two taxa from the Grenada Bank: we describe the new species Megalomys camerhogne from Pearls (Grenada), representing the largest-bodied member of the extinct endemic Caribbean genus Megalomys, and we refer smaller-bodied oryzomyine material from Pearls and Sabazan (Carriacou) to the widespread extant Neotropical species Zygodontomys brevicauda. Body size variation within Megalomys correlates with island bank area and might thus reflect historical rather than modern biogeography. Zygodontomys specimens from the Grenada Bank fall within the upper end of size variation in extant populations and may constitute an example of 'island gigantism', but it is possible that occurrence of this widespread species on the Grenada Bank might reflect prehistoric human-mediated translocation. We predict further endemic Caribbean rice rat taxa remain to be discovered, including a possible species of Megalomys on the neighbouring island of St. Vincent.


Assuntos
Sigmodontinae , Animais , Região do Caribe , Extinção Biológica , Granada , Filogenia , Roedores , Sigmodontinae/anatomia & histologia , Sigmodontinae/classificação
8.
Zootaxa ; 4920(4): zootaxa.4920.4.1, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33756643

RESUMO

Neacomys Thomas, 1900 is an oryzomyine genus comprising at least 17 lineages distributed from easternmost Panama to northern Bolivia. As is the case for other groups of the subfamily Sigmodontinae, Neacomys have experienced a substantial increase in the rate of species descriptions in the last two decades, prompted by the progressive generation of morphological, molecular and karyological data. Nevertheless, most of the studies related to the genus have focused on the assessment of Cis-Andean populations, so that the Trans-Andean ones have been relegated to the background. In more than a century, only two species have been described from that region, one of them present in Colombia (N. tenuipes Thomas, 1900). Here, a new species of Neacomys is named and described based on samples collected in montane ecosystems of the Serranía de los Yariguíes, an isolated massif in the Magdalena Valley (Trans-Andean Colombia). Its validity is supported by a unique combination of morphological and molecular characters: Neacomys sp. nov. can be distinguished from other congeners mainly by the presence of broad ochraceous-orange patches on the sides of the muzzle, a gray-based ochraceous buff ventral fur, a thick hamular process of the squamosal, an opened ectotympanic ring, and a narrow anterocone of M1. The species is recovered as a clearly divergent and well-supported monophyletic group in the phylogenies, which implies it is not closely related to any other species in the genus and probably represents an early radiation within it. The new species of Neacomys constitutes the only rodent described from Colombia in more than 50 years and brings the list of mammals of the country to 529 species. Its discovery evidences that Trans-Andean region could be an important source of hidden diversity for the genus, and in Colombia, for rodents in general. Thus, further inventories, especially into remote areas, are needed to unveil this diversity. The fact that the new species seems to be endemic to an isolated mountain range implies it merits attention in terms of conservation.


Assuntos
Arvicolinae , Roedores , Animais , Colômbia , Ecossistema , Filogenia , Sigmodontinae
9.
PLoS One ; 16(3): e0248204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33720946

RESUMO

Copper (Cu), iron (Fe), and zinc (Zn) are essential trace minerals for the reproduction, growth, and immunity of mammalian herbivore populations. We examined the relationships between Cu, Fe, and Zn in soils, common plants, and hepatic stores of two wild herbivores to assess the effects of weather, sex, and population density on the transfer of trace minerals from soils to mammals during the growing season. Soils, grasses, woody browse, hispid cotton rats (Sigmodon hispidus), and white-tailed deer (Odocoileus virginianus) were sampled across 19 sites. Concentrations of Cu, Fe, and Zn in grasses and browse species were not correlated with concentrations of those minerals in soils sampled from the same areas. Leaves of woody browse were higher in Cu, lower in Fe, and similar in Zn when compared with grasses. Available concentrations of soils were positively related to liver Cu and Zn in hispid cotton rats, which was consistent with the short lives and high productivity of these small mammals that rely on grass seed heads. Interactions between soil concentrations and weather also affected liver Cu and Fe in deer, which reflected the greater complexity of trophic transfers in large, long-lived, browsing herbivores. Population density was correlated with liver concentrations of Cu, Fe, and Zn in hispid cotton rats, and concentrations of Cu and Fe in deer. Liver Cu was < 5 mg/kg wet weight in at least 5% of animals at two of eight sites for hispid cotton rats and < 3.8 mg/kg wet weight in at least 5% of animals at three of 12 sites for deer, which could indicate regional limitation of Cu for populations of mammalian herbivores. Our data indicate that supplies of trace minerals may contribute to density dependence of herbivore populations. Local population density may therefore influence the prevalence of deficiency states and disease outbreak that exacerbate population cycles in wild mammals.


Assuntos
Cobre/metabolismo , Cervos/fisiologia , Ferro/metabolismo , Sigmodontinae/fisiologia , Zinco/metabolismo , Animais , Cobre/análise , Feminino , Herbivoria , Ferro/análise , Fígado/química , Fígado/metabolismo , Masculino , Estações do Ano , Solo/química , Oligoelementos/análise , Oligoelementos/metabolismo , Zinco/análise
10.
PLoS One ; 16(2): e0246770, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33600439

RESUMO

Human respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in infants and young children worldwide. The attachment (G) protein of RSV is synthesized by infected cells in both a membrane bound (mG) and secreted form (sG) and uses a CX3C motif for binding to its cellular receptor. Cell culture and mouse studies suggest that the G protein mimics the cytokine CX3CL1 by binding to CX3CR1 on immune cells, which is thought to cause increased pulmonary inflammation in vivo. However, because these studies have used RSV lacking its G protein gene or blockade of the G protein with a G protein specific monoclonal antibody, the observed reduction in inflammation may be due to reduced virus replication and spread, and not to a direct role for G protein as a viral chemokine. In order to more directly determine the influence of the soluble and the membrane-bound forms of G protein on the immune system independent of its attachment function for the virion, we expressed the G protein in cotton rat lungs using adeno-associated virus (AAV), a vector system which does not itself induce inflammation. We found no increase in pulmonary inflammation as determined by histology and bronchoalveolar lavage after inoculation of AAVs expressing the membrane bound G protein, the secreted G protein or the complete G protein gene which expresses both forms. The long-term low-level expression of AAV-G did, however, result in the induction of non-neutralizing antibodies, CD8 T cells and partial protection from challenge with RSV. Complete protection was accomplished through co-immunization with AAV-G and an AAV expressing cotton rat interferon α.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sincicial Respiratório Humano/imunologia , Proteínas do Envelope Viral/imunologia , Motivos de Aminoácidos , Animais , Biomimética , Linfócitos T CD8-Positivos , Quimiocina CX3CL1/química , Quimiocina CX3CL1/imunologia , Dependovirus , Feminino , Vetores Genéticos , Imunização , Imuno-Histoquímica , Inflamação/metabolismo , Inflamação/virologia , Interferon-alfa/metabolismo , Masculino , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Sigmodontinae , Vacinação , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/metabolismo , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Proteínas Virais de Fusão/metabolismo , Vírion/metabolismo
11.
J Med Entomol ; 58(3): 1166-1170, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33565596

RESUMO

South American chiggers have historically been poorly studied, and this has continued into present times. Of the 33 genera in the family Leeuwenhoekiidae Womersley, only Odontacarus Ewing and Sasacarus Brennan & Jones have been reported in Peru. Here, we describe a new genus, Peruacarus n. gen., and a new species, Peruacarus anthurium n. sp., parasitizing Koford's grass mouse, Akodon kofordi Myers & Patton, in Peru.


Assuntos
Interações Hospedeiro-Parasita , Sigmodontinae/parasitologia , Trombiculidae/classificação , Animais , Larva/anatomia & histologia , Larva/classificação , Larva/crescimento & desenvolvimento , Peru , Trombiculidae/anatomia & histologia , Trombiculidae/crescimento & desenvolvimento
12.
J Evol Biol ; 34(2): 391-402, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33617138

RESUMO

The mandible of vertebrates serves as insertion area for masticatory muscles that originate on the skull, and its functional properties are subject to selective forces related to trophic ecology. The efficiency of masticatory muscles can be measured as mechanical advantage on the mandible, which, in turn, has the property of correlating with bite force and shape. In the present work, we quantify the mechanical advantage of the mandible of akodontine rodents, which present a diverse radiation of insectivorous specialists, to assess their relationship to the estimated bite force and diet. We also tested the degree of morphofunctional convergence in response to insectivory on the group. We found the mechanical advantages to be convergent on insectivorous species, and associated with the estimated bite force, with higher mechanical advantages in species with a stronger bite and short, robust mandibles and lower mechanical advantages in insectivorous species with weaker bites and more elongated, dorso-ventrally compressed mandibles. Insectivorous species of Akodontini are functional specialists for the consumption of live prey and may exploit the resources that shrews, moles and hedgehogs consume elsewhere.


Assuntos
Evolução Biológica , Força de Mordida , Comportamento Alimentar/fisiologia , Mandíbula/fisiologia , Sigmodontinae/fisiologia , Animais , Dieta , Insetos
13.
Mol Phylogenet Evol ; 159: 107120, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33610650

RESUMO

The tribe Oryzomyini is an impressive group of rodents, comprising 30 extant genera and an estimated 147 species. Recent remarkable advances in the understanding of the diversity, taxonomy and systematics of the tribe have mostly derived from analyses of single or few genetic markers. However, the evolutionary history and biogeography of Oryzomyini, its origin and diversification across the Neotropics, remain unrevealed. Here we use a multi-locus dataset (over 400 loci) obtained through anchored phylogenomics to provide a genome-wide phylogenetic hypothesis for Oryzomyini and to investigate the tempo and mode of its evolution. Species tree and supermatrix analyses produced topologies with strong support for most branches, with all genera confirmed as monophyletic, a result that previous studies failed to obtain. Our analyses also corroborated the monophyly and phylogenetic relationship of three main clades of Oryzomyini (B, C and D). The origin of the tribe is estimated to be in the Miocene (8.93-5.38 million years ago). The cladogenetic events leading to the four main clades occurred during the late Miocene and early Pliocene and most speciation events in the Pleistocene. Geographic range estimates suggested an east of Andes origin for the ancestor of oryzomyines, most likely in the Boreal Brazilian region, which includes the north bank of Rio Amazonas and the Guiana Shield. Oryzomyini rodents are an autochthonous South America radiation, that colonized areas and dominions of this continent mainly by dispersal events. The evolutionary history of the tribe is deeply associated with the Andean cordillera and the landscape history of Amazon basin.


Assuntos
Especiação Genética , Filogenia , Sigmodontinae/classificação , Distribuição Animal , Animais , Teorema de Bayes , Brasil , Filogeografia
14.
J Morphol ; 282(4): 563-573, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33547822

RESUMO

We present a topological analysis of the third upper molars (M3) using the recently developed ICAMER nomenclatural system as a way to understand the dental morphological similarity in sigmodontine rodents, the most speciose subfamily of cricetids. The method is explored in Scapteromys aquaticus and Abrothrix olivacea, taxa belonging to two diverse tribes, Akodontini and Abrotrichini, respectively, which exhibit high similarity regarding several craniodental traits as well as external anatomy. Both species show morphologically similar M3 in adults characterized by cylindrification and the isolation of a large central fossette arising from the marginal fusion of the anterior and posterior lobes. The results indicate that, before the wear, these rodents have a strongly different topological pattern at the cuspal level, mostly involving production of the connection between the main cusps. The central fossette derives from the isolation of part of the metaflexus in Scapteromys, while in Abrothrix it originates from the hypoflexus. The topological analysis provides a new approach to sigmodontine systematics, including the ability to detect diagnostic characters of both tribes. More important, it constitutes a new step toward an integrative phylogeny of fossil and living cricetids.


Assuntos
Filogenia , Sigmodontinae/anatomia & histologia , Dente/anatomia & histologia , Animais , Dente Molar/anatomia & histologia , Especificidade da Espécie
15.
J Virol ; 95(6)2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33408176

RESUMO

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract (LRT) infections, with increased severity in high-risk human populations, such as infants, the immunocompromised, and the elderly. Although the virus was identified more than 60 years ago, there is still no licensed vaccine available. Over the years, several vaccine delivery strategies have been evaluated. In this study, we developed two recombinant vesicular stomatitis virus (rVSV) vector-based vaccine candidates expressing the RSV-G (attachment) protein (rVSV-G) or F (fusion) protein (rVSV-F). All vectors were evaluated in the cotton rat animal model for their in vivo immunogenicity and protective efficacy against an RSV-A2 virus challenge. Intranasal (i.n.) delivery of rVSV-G and rVSV-F together completely protected the lower respiratory tract (lungs) at doses as low as 103 PFU. In contrast, doses greater than 106 PFU were required to protect the upper respiratory tract (URT) completely. Reimmunization of RSV-immune cotton rats was most effective with rVSV-F. In immunized animals, overall antibody responses were sufficient for protection, whereas CD4 and CD8 T cells were not necessary. A prime-boost immunization regimen increased both protection and neutralizing antibody titers. Overall, mucosally delivered rVSV-vector-based RSV vaccine candidates induce protective immunity and therefore represent a promising immunization regimen against RSV infection.IMPORTANCE Even after decades of intensive research efforts, a safe and efficacious RSV vaccine remains elusive. Expression of heterologous antigens from rVSV vectors has demonstrated several practical and safety advantages over other virus vector systems and live attenuated vaccines. In this study, we developed safe and efficacious vaccine candidates by expressing the two major immunogenic RSV surface proteins in rVSV vectors and delivering them mucosally in a prime-boost regimen. The main immune parameter responsible for protection was the antibody response. These vaccine candidates induced complete protection of both the upper and lower respiratory tracts.


Assuntos
Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/administração & dosagem , Vírus Sincicial Respiratório Humano/imunologia , Vesiculovirus/genética , Proteínas do Envelope Viral/imunologia , Proteínas Virais de Fusão/imunologia , Administração através da Mucosa , Animais , Modelos Animais de Doenças , Vetores Genéticos , Imunidade Celular , Imunidade Humoral , Imunização , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Infecções por Vírus Respiratório Sincicial/imunologia , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano/genética , Sistema Respiratório/imunologia , Sistema Respiratório/virologia , Sigmodontinae , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vesiculovirus/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/metabolismo
16.
Bone ; 145: 115866, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33515777

RESUMO

INTRODUCTION: Osteonecrosis of the jaw (ONJ) is an adverse event that requires association of both systemic risk factors, such as powerful anti-resorptives (pARs; e.g. zoledronic acid [ZOL]), and local oral risk factors (e.g. tooth extraction, periodontitis). Whereas optimal oral health prior to initiate pARs is recognized as critically important for minimizing ONJ risk, the efficacy of preventive/maintenance measures in patients who are taking pARs is understudied. Rice rats fed a standard diet (STD), rich in insoluble fiber, develop localized periodontitis. STD-rats with localized periodontitis treated with ZOL for 18-24 wk develop ONJ. Hence, we hypothesized that controlling/preventing localized periodontitis in the ZOL-treated rats, reduces ONJ occurrence. METHODS: We used two approaches to attempt reducing periodontitis prevalence: 1) periodontal cleaning (PC); and 2) replacing the STD-diet with a nutritionally-equivalent diet high in soluble fiber (SF). 75 four-week-old male rats were weight-randomized into five groups (n = 15) in a 24-week experiment. Three groups ate the STD-diet and two the high SF-diet. STD-diet groups received intravenous (IV) vehicle (VEH) q4wks (STD + VEH), 80 µg/kg ZOL q4wks IV (STD + ZOL), or ZOL plus PC q2wks (STD + ZOL + PC). The SF-diet groups received VEH (SF + VEH) or ZOL (SF + ZOL). Jaws were processed for histopathology and evaluated for ONJ prevalence and tissue-level periodontitis. RESULTS: 1) 40% of STD + VEH rats developed maxillary localized periodontitis with no ONJ; 2) 50% of STD + ZOL rats developed ONJ; 3) 7% of STD + ZOL + PC rats developed ONJ (p < 0.01 vs. STD + ZOL); and 4) one SF + ZOL rat developed localized periodontitis, and no SF + VEH or SF + ZOL rats developed ONJ (p < 0.001 vs. STD + ZOL). CONCLUSIONS: 1) Periodontal cleaning in ZOL-treated rats decreases localized periodontitis severity and reduces ONJ prevalence; and 2) feeding a SF-diet to ZOL-treated rats reduces both incidence of localized periodontitis and ONJ. Our data indicates strong oral microbial community shifts according to oral health condition and trends in the shifts associated with diet.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Conservadores da Densidade Óssea , Osteonecrose , Periodontite , Animais , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/prevenção & controle , Difosfonatos/uso terapêutico , Humanos , Arcada Osseodentária , Masculino , Periodontite/prevenção & controle , Ratos , Sigmodontinae , Ácido Zoledrônico
17.
Mol Phylogenet Evol ; 155: 106992, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33096231

RESUMO

Taxa with broad geographic ranges that occur in different biomes and exhibit plastic morphological traits and/or adaptations to particular habitats make inferences about species boundaries especially challenging. However, technological and conceptual advances in the generation and analysis of genomic data have advanced the description of biodiversity. Here we address the outstanding questions about the delimitation of species in the genus Holochilus, a rodent with morphological specializations to wetland habitats distributed throughoutthe South America, using genome-wide SNP and morphometric data. Specifically, we apply a Bayesian model-based species delimitation that revealed significant re-arrangements of species boundaries based on consideration of both morphometric and genomic data alone, or in combination. With these shifts in species boundaries, our results provide an insightful framework for inferring the group's biogeographic history and considering possible connections between disjoint biomes in South America. Because of the ecological constraints of the marsh rats, and with the proposed taxonomic re-arrangements, the significance of our findings extends beyond systematics and suggests how diversification might be associated with past ecological/environmental changes during the Pleistocene. Overall, this study highlights how genomic data can provide phylogenetic information for resolving relationships among species of Holochilus, but also the importance of integrative approaches to identify evolutionary independent species. For the relatively understudied vast wetlands of South America, a robust species delimitation framework therefore becomes a critical source of data relevant to hypotheses about the history of the biomes themselves.


Assuntos
Biodiversidade , Filogeografia , Sigmodontinae/classificação , Áreas Alagadas , Animais , Teorema de Bayes , Análise Discriminante , Filogenia , América do Sul , Especificidade da Espécie , Fatores de Tempo
18.
Mol Phylogenet Evol ; 155: 107007, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33160039

RESUMO

Murine rodents are one of the most evolutionary successful groups of extant mammals. They are also important for human as vectors and reservoirs of zoonoses and agricultural pests. Unfortunately, their fast and relatively recent diversification impedes our understanding of phylogenetic relationships and species limits of many murine taxa, including those with very conspicuous phenotype that has been frequently used for taxonomic purposes. One of such groups are the striped grass mice (genus Lemniscomys), distributed across sub-Saharan Africa in 11 currently recognized species. These are traditionally classified into three morphological groups according to different pelage colouration on the back: (a) L. barbarus group (three species) with several continuous pale longitudinal stripes; (b) L. striatus group (four species) with pale stripes diffused into short lines or dots; and (c) L. griselda group (four species) with a single mid-dorsal black stripe. Here we reconstructed the most comprehensive molecular phylogeny of the genus Lemniscomys to date, using the largest currently available multi-locus genetic dataset of all but two species. The results show four main lineages (=species complexes) with the distribution corresponding to the major biogeographical regions of Africa. Surprisingly, the four phylogenetic lineages are only in partial agreement with the morphological classification, suggesting that the single-stripe and/or multi-striped phenotypes evolved independently in multiple lineages. Divergence dating showed the split of Lemniscomys and Arvicanthis genera at the beginning of Pleistocene; most of subsequent speciation processes within Lemniscomys were affected by Pleistocene climate oscillations, with predominantly allopatric diversification in fragmented savanna biome. We propose taxonomic suggestions and directions for future research of this striking group of African rodents.


Assuntos
Loci Gênicos , Filogenia , Sigmodontinae/anatomia & histologia , Sigmodontinae/classificação , África ao Sul do Saara , Animais , Teorema de Bayes , Calibragem , Clima , DNA Mitocondrial/genética , Variação Genética , Geografia , Haplótipos/genética , Mitocôndrias/genética , Especificidade da Espécie , Fatores de Tempo
19.
Transbound Emerg Dis ; 68(3): 1263-1274, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32772436

RESUMO

Borrelia burgdorferi s.s. is a Gram-negative spirochaete, the aetiological agent of Lyme disease, the most common vector-borne disease in the Northern hemisphere. Reports on the presence of B. burgdorferi in central Mexico have been strongly criticized, since these were based only on unspecific serological methods. Furthermore, the worldwide genetic diversity of B. burgdorferi s.s. has not been evaluated. For this reason, the aim of the present study was to confirm the presence of B. burgdorferi in the central area of Mexico and to evaluate its relationship with regard to the global genetic diversity of B. burgdorferi s.s. To achieve this, fragments of the flagellin and the outer surface protein A genes were amplified from ear biopsies of the arboreal wild endemic mice Habromys schmidlyi. With these sequences, a concatenated Bayesian analysis was performed to confirm the identity of B. burgdorferi s.s. Afterwards, the global genetic diversity of this bacterial species was evaluated using our sequences and those available in GenBank. A prevalence of 10.4% (5/48) of H. schmidlyi infected with Borrelia sp. was detected, and the phylogenetic analyses confirmed the identity of B. burgdorferi s.s. Using both genes, the genetic diversity was low. However, genetic structuring analyses revealed that populations of western United States and those from Mexico formed slightly different genetic groups, separated from the populations of the rest of the world. Our study not only confirms the presence of this bacterium in central Mexico, but also shows the most southern record of this bacterium so far. It also highlights the importance of H. schmidlyi as a new potential host of this bacterial species. Our study also provides first genetic data on an incipient process of divergence in B. burgdorferi s.s. populations of eastern United States and central Mexico.


Assuntos
Antígenos de Superfície/genética , Proteínas da Membrana Bacteriana Externa/genética , Vacinas Bacterianas/genética , Borrelia burgdorferi/genética , Flagelina/genética , Variação Genética , Lipoproteínas/genética , Doença de Lyme/veterinária , Doenças dos Roedores/epidemiologia , Sigmodontinae , Animais , Doença de Lyme/epidemiologia , Doença de Lyme/microbiologia , México , Doenças dos Roedores/microbiologia
20.
Hum Vaccin Immunother ; 17(1): 133-145, 2021 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-32614696

RESUMO

Inactivated influenza vaccines are known to be less immunogenic in human elderly in regards to serologic antibody response induced by vaccination. Accumulating evidence, however, points to a comparable effectiveness of influenza vaccines in the young and the elderly individuals. In the current study, we assessed immunogenicity and effectiveness of trivalent inactivated vaccine FluLaval in young and aged cotton rats Sigmodon hispidus and found that while serologic response to immunization was indeed reduced in older animals, comparable protection against influenza infection was afforded by prime-boost vaccination in both young and aged cotton rats. Both hemagglutination inhibition (HAI) titers and seroconversion rates were lower in the aged animals compared to the young ones. Reduction of viral load in the lung and nose, however, was comparable between young and aged animals vaccinated twice. One-time immunization with FluLaval was less efficacious at protecting the nose of aged animals, indicating that boosting of preexisting immunity can be particularly important for nasal protection in the elderly. Coincidentally, a one-time immunization with FluLaval had a detrimental effect on pulmonary pathology in the young animals, suggesting that boosting of immunity is essential for the young as well. Overall, these results suggest that reduced antibody response to and sufficient efficacy of influenza vaccines in the elderly are not two irreconcilable phenomena and that incomplete immunity to influenza can be detrimental at any age.


Assuntos
Vacinas contra Influenza , Influenza Humana , Envelhecimento , Animais , Anticorpos Antivirais , Testes de Inibição da Hemaglutinação , Sigmodontinae , Vacinas de Produtos Inativados
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