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host interactions of aedes albopictus, an invasive vector of arboviruses, in virginia, usa.as an invasive mosquito species in the united states, aedes albopictus is a potential vector of arboviruses including dengue, chikungunya, and zika, and may also be involved in occasional transmission of other arboviruses such as west nile, saint louis encephalitis, eastern equine encephalitis, and la crosse viruses. aedes albopictus feeds on a wide variety of vertebrate hosts, wild and domestic, as well as humans.202133600413
detection of hemotropic mycoplasma sp. in white-eared opossums (didelphis albiventris) from southern brazil.opossums are marsupials from the new world of the genus didelphis and known as synanthropic animals due to their proximity with human beings. to date, 'candidatus mycoplasma haemodidelphis' has been solely found infecting the north american opossum (didelphis virginiana). accordingly, the aim of this study was to screen eight white-eared opossums (didelphis albiventris) from a public park in maringa city, paraná state, southern brazil, for hemoplasma infection. blood samples were taken from caud ...202031390439
landscape-scale differences among cities alter common species' responses to urbanization.understanding how biodiversity responds to urbanization is challenging, due in part to the single-city focus of most urban ecological research. here, we delineate continent-scale patterns in urban species assemblages by leveraging data from a multi-city camera trap survey and quantify how differences in greenspace availability and average housing density among ten north american cities relate to the distribution of eight widespread north american mammals. to do so, we deployed camera traps at 56 ...202033141996
association of the invasive haemaphysalis longicornis tick with vertebrate hosts, other native tick vectors, and tick-borne pathogens in new york city, usa.haemaphysalis longicornis, the asian longhorned tick, is an invasive ixodid tick that has rapidly spread across the northeastern and southeastern regions of the united states since first reported in 2017. the emergence of h. longicornis presents a potential threat for livestock, wildlife, and human health as the host associations and vector potential of this invasive pest in the united states are poorly understood. previous field data from the united states has shown that h. longicornis was not ...202033130214
dracunculus species in meso-mammals from georgia, united states, and implications for the guinea worm eradication program in chad, africa.the prevalence and diversity of parasitic nematodes in wildlife have been well studied for certain species, yet for others considerable gaps in knowledge exist. the parasitic nematode dracunculus insignis infects north american wildlife, and past research on this species has led to an increased understanding of the potential host diversity and transmission of the closely related human guinea worm, dracunculus medinensis (which is currently the focus of a global eradication program). many definit ...202033009554
canine dracunculus nematode infection, toledo, spain.a fragment of a dracunculus-like worm was extracted from the hind limb of a 2-year-old dog from toledo, spain. cytochrome oxidase i and rrna sequences confirmed an autochthonous mammalian dracunculus worm infection in europe. sequence analyses suggest close relation to a parasite obtained from a north american opossum.202032687046
morphological and molecular data reveal a new species of lueheia (acanthocephala: plagiorhynchidae) from turdus migratorius (turdidae) in central mexico and its phylogenetic implications within the family.members of the genus lueheia travassos, 1919, are endoparasites of birds, particularly passerines, throughout the americas. adults of lueheia sp., (plagiorhynchidae golvan, 1960; porrorchinae golvan, 1956) were recovered from the intestine of the american robin (turdus migratorius phillipsi bangs) in mexico city, and two other species of acanthocephalans identified as porrorchis nickoli, (plagiorhynchidae: porrorchinae) salgado-maldonado and cruz-reyes, 2002 and centrorhynchus microcephalus (bra ...202032671541
'candidatus mycoplasma haemoalbiventris', a novel hemoplasma species in white-eared opossums (didelphis albiventris) from brazil.opossums of the genus didelphis are considered synanthropic animals due to their close contact with human beings. previously, two species of hemotropic mycoplasmas (hemoplasmas) have been detected in opossums: 'candidatus mycoplasma haemodidelphidis' in the north american opossum (didelphis virginiana) and a potentially novel hemotropic mycoplasma sp. in the white-eared opossums (didelphis albiventris) from brazil. accordingly, the aims of this study were as follows: (a) to determine the prevale ...202032644252
surveys for ticks on wildlife hosts and in the environment at asian longhorned tick (haemaphysalis longicornis)-positive sites in virginia and new jersey, 2018.haemaphysalis longicornis, the asian longhorned tick (alt), is native to eastern asia, but it has become invasive in several countries, including australia, new zealand and recently in the eastern united states (us). to identify wild mammal and avian host species in the us, we conducted active wildlife surveillance in two states with known alt infestations (virginia and new jersey). in addition, we conducted environmental surveys in both states. these surveillance efforts resulted in detection o ...202032639639
letter to the editor: venezuelan equine encephalitis virus 1b invasion and epidemic control-south texas, 1971.the epidemic strain of venezuelan equine encephalitis virus (vee) 1b invaded south texas in 1971. the success of the eventual containment and control of the virus invasion was the early recognition and immediate detection, cooperation, coordination, and participation among multiple federal agencies. there were 4739 wild vertebrate animals trapped on a ranch in the area with only 1 vee virus isolation from a virgina opossum (didelphis virginiana). a large number of mosquitoes were also collected ...202032580287
ectoparasites of didelphis virginiana from yucatan, mexico.a faunal study is presented to determine the species of ectoparasites found in the opossum didelphis virginiana (kerr) (marsupialia: didelphidae). for this, tomahawk traps were placed in the peridomiciles of a rural town in yucatán, to capture individuals of this marsupial and proceed to the collection of their ectoparasites. a total of 3,023 arthropods were collected from 145 opossums. the most frequent ectoparasites were the acarines ornithodoros (alectorobius) nr. talaje (64.8%) (argasidae); ...202032504090
comparative metal analysis in a species assemblage of mammals from the southeastern united states.metal pollution commonly occurs in many terrestrial environments and may pose a threat for the animals inhabiting such areas. here, we present concentrations of six metals (cadmium [cd], copper [cu], nickel [ni], lead [pb], selenium [se], and zinc [zn]) in the liver tissues of seven species of mammals obtained from a study that examined the impact of mesopredator removal on northern bobwhite (colinus virginianus) populations. a total of 1326 samples were collected from 2003 to 2006 at four sites ...202032323028
trypanosoma cruzi infections and associated pathology in urban-dwelling virginia opossums (didelphis virginiana).trypanosoma cruzi, a zoonotic protozoan parasite, infects a wide range of mammals. the southern united states has endemic sylvatic transmission cycles maintained by several species of wildlife and domestic dogs. we hypothesized that urban-dwelling opossums (didelphis virginiana) in south texas are infected with t. cruzi, and that tissue pathology would be associated with infection. in 2017, we collected blood, heart tissue and anal gland secretions from 100 wild opossums across three seasons tha ...202032215248
resistance of south american opossums to vwf-binding venom c-type lectins.opossums in the clade didelphini are well known to be resistant to snake venom due to endogenous circulating inhibitors which target metalloproteinases and phospholipases. however, the mechanisms through which these opossums cope with a variety of other damaging venom proteins are unknown. a protein involved in blood clotting (von willebrand factor) has been found to have undergone rapid adaptive evolution in venom-resistant opossums. this protein is a known target for a subset of snake venom c- ...202032135198
broad similarities in shoulder muscle architecture and organization across two amniotes: implications for reconstructing non-mammalian synapsids.the evolution of upright limb posture in mammals may have enabled modifications of the forelimb for diverse locomotor ecologies. a rich fossil record of non-mammalian synapsids holds the key to unraveling the transition from "sprawling" to "erect" limb function in the precursors to mammals, but a detailed understanding of muscle functional anatomy is a necessary prerequisite to reconstructing postural evolution in fossils. here we characterize the gross morphology and internal architecture of mu ...202032117627
characterization of antimicrobial resistance genes in enterobacteriaceae carried by suburban mesocarnivores and locally owned and stray dogs.the role of wildlife in the dissemination of antimicrobial-resistant bacteria and antimicrobial resistance genes (args) in the environment is of increasing concern. we investigated the occurrence, richness and transmissibility potential of args detected in the faeces of three mesocarnivore species: the coyote (canis latrans), raccoon (procyon lotor) and virginia opossum (didelphis virginiana), and of stray and owned dogs in suburban chicago, il, usa. rectal swabs were collected from live-capture ...202032034890
the embryo of the silky shrew opossum, caenolestes fuliginosus (tomes, 1863): first description of the embryo of paucituberculata.the development of caenolestid marsupials (order paucituberculata) is virtually unknown. we provide here the first description of caenolestes fuliginosus embryos collected in the colombian central andes. our sample of four embryos comes from a single female caught during a fieldtrip at río blanco (manizales, caldas), in 2014. the sample was processed for macroscopic description using a standard event system and for histological descriptions (sectioning and staining). the grade of development of ...202031984547
arthropods associated with mammals. their importance as part of the richness in a biosphere reserve in mexico.the chamela biological station (chbs) is located in the pacific coast of mexico in the state of jalisco. this represents one of the core areas of the chamela-cuixmala biosphere reserve, characterized by one of the most threatened ecosystems, the tropical dry forest. although accumulated knowledge of biological diversity, only few studies have been focused on ectoparasites or ectodytes associated with mammals, only 23 arthropod taxa had been recorded. in order to increase knowledge about arthropo ...202031880772
organochlorine pesticides residues in blood of peridomestic populations of virginia opossum (didelphis virginiana) from ex-henequen rural localities of yucatan, mexico.organochlorine pesticides (ocps) have been used for many decades, both for the control of pests in agriculture and for the control of vectors of human and animal diseases. several recent studies have reported significant concentrations of these compounds in multiple environmental substrates due to their persistence, as well as the effect they have on ecosystem health, human health, and wildlife populations. in the present study, organochlorine pesticide residues were determined and quantified in ...202031701182
evidence of leptospira serovars in wildlife and leptospiral dna in water sources in a natural area in east-central illinois, usa.we identified seven leptospira serovars in wildlife and the presence of leptospiral dna in water sources at a natural area within a fragmented habitat in illinois, us. these serovars have been implicated in domestic animal and human leptospirosis, a reemerging zoonotic disease, whose reservoirs include wildlife and domestic animals. we live trapped medium-sized mammals (n=351) near building (h-sites) or forest sites (f-sites). using serology, we evaluated exposure to leptospira (l. interrogans s ...202031622185
helminth community structure of the gray four-eyed opossum philander opossum (mammalia: didelphidae) in the neotropical portion of mexico.studies on helminth communities associated with didelphids are scarce; the majority of works have focused at taxonomic level. to increase the ecological knowledge of these host-parasite associations, during march (dry season) of 3 consecutive years (2013-2015) a total of 49 adults of the gray four-eyed opossum (philander opossum) was collected in the neotropical portion of mexico (agua fría, chiapas state) and examined for helminths. the main objectives of this study were to describe the infra- ...201931418650
onrab® oral rabies vaccine is shed from, but does not persist in, captive mammals.onrab® is a human adenovirus rabies glycoprotein recombinant vaccine developed to control rabies in wildlife. to support licensing and widespread use of the vaccine, safety studies are needed to assess its potential residual impact on wildlife populations. we examined the persistence of the onrab® vaccine virus in captive rabies vector and non-target mammals. this research complements work on important rabies vector species (raccoon, striped skunk, and red fox) but also adds to previous findings ...201931248686
redescription of cruzia americana maplestone, 1930 (nematoda: kathlaniidae) a parasite of didelphis virginiana (kerr) (mammalia: didelphidae) in the usa.cruzia americana maplestone, 1930 is a common nematode parasite of opossums in north america. however, our present knowledge on the morphology of this species is still limited and its validity is uncertain. in the present study, specimens of c. americana collected from the type-host didelphis virginiana (kerr) (mammalia: didelphidae) in the usa were studied using light microscopy and, for the first time, scanning electron microscopy (sem). the sem observations revealed the internal structures of ...201931087202
sarcocystis neurona-induced myeloencephalitis relapse following anticoccidial treatment.sarcocystis neurona is a ubiquitous parasite in the eastern united states, which is the principal causative agent in the neurologic disorder equine protozoal myeloencephalitis (epm). while much is known about this protozoa's life cycle in its natural host, the opossum (didelphis virginiana), little is known of how it acts in the aberrant equine host, which displays a high incidence of exposure with a relatively low rate of morbidity. for this study, we employed the popular interferon gamma knock ...201931033388
biomonitoring organochlorine pesticides in didelphis virginiana from yucatan, mexico by gc-ecd.the aim of the present work was to apply a validated methodology for the detection of organochlorine pesticides in didelphis virginiana (virginia opossum) serum samples collected in yucatan, mexico. recent studies performed to investigate the presence of organochlorines (ocls) in water, human blood and milk, and animal tissues from yucatan have shown that the ocls concentrations are high and can be associated with potential human health risk. since opossum is considered an important synanthropic ...201930989282
salmonella, campylobacter, clostridium difficile, and anti-microbial resistant escherichia coli in the faeces of sympatric meso-mammals in southern ontario, canada.the role of free-ranging wildlife in the epidemiology of enteropathogens causing clinical illness in humans and domestic animals is unclear. salmonella enterica and anti-microbial resistant bacteria have been detected in the faeces of raccoons (procyon lotor), but little is known about the carriage of these bacteria in other sympatric meso-mammals. our objectives were to: (a) report the prevalence of salmonella and associated anti-microbial resistance, campylobacter spp, clostridium difficile, a ...201930985994
potential effects of blood meal host on bacterial community composition in ixodes scapularis nymphs.tick microbiomes may play an important role in pathogen transmission. however, the drivers of microbiome variation are poorly understood, and this limitation has impeded mechanistic understanding of the functions of microbial communities for pathogen acquisition. the goal of this research was to characterize the role of the blood meal host in structuring the microbiome of ixodes scapularis, the primary vector of lyme disease in the eastern united states, and to determine if ticks that fed from d ...201930660375
effect of high-density oral rabies vaccine baiting on rabies virus neutralizing antibody response in raccoons ( procyon lotor).from 2014 to 2016, we examined the effect of distributing oral rabies vaccine baits at high density (150 baits/km2) in an area of virginia, us that was naïve to oral rabies vaccination prior to the study. we also compared the effect of baiting at high density in a naïve area to baiting at standard density (75 baits/km2) in an area that had been baited annually for 12 yr. our results suggested that rabies virus seroconversion in raccoons ( procyon lotor) gradually increased each year under the hi ...201930507337
west nile virus associations in wild mammals: an update.although west nile virus (wnv) is generally thought to circulate among mosquitoes and birds, several historic and recent works providing evidence of wnv activity in wild mammals have been published. indeed, a previous review tabulated evidence of wnv exposure in at least 100 mammalian species. herein, we provide an update on wnv activity in wild and select other mammals that have been reported since the last major review article on this subject was published in early 2013. of interest, new speci ...201931117189
fatal west nile virus infection in a virginia opossum (didelphis virginiana) with pulmonary lepidic-predominant adenocarcinoma.a fatal case of west nile virus (wnv) infection was diagnosed based on histopathologic findings and the presence of wnv rna by reverse transcription pcr in the affected organs in a virginia opossum (didelphis virginiana) in quebec, canada in 2017. disease caused by wnv has not been described in a marsupial species.201931008678
development and evaluation of a duplex taqman qpcr assay for detection and quantification of trypanosoma cruzi infection in domestic and sylvatic reservoir hosts.a question of epidemiological relevance in chagas disease studies is to understand trypanosoma cruzi transmission cycles and trace the origins of (re)emerging cases in areas under vector or disease surveillance. conventional parasitological methods lack sensitivity whereas molecular approaches can fill in this gap, provided that an adequate sample can be collected and processed and a nucleic acid amplification method can be developed and standardized. we developed a duplex qpcr assay for accurat ...201931783770
trypanosoma cruzi strain tciv infects raccoons from illinois.the northern limits of trypanosoma cruzi across the territory of the united states remain unknown. the known vectors triatoma sanguisuga and t. lecticularia find their northernmost limits in illinois; yet, earlier screenings of those insects did not reveal the presence of the pathogen, which has not been reported in vectors or reservoir hosts in this state.201829211106
factors influencing experimental estimation of scavenger removal and observer detection in bird-window collision surveys.wildlife collisions with human-built structures are a major source of direct anthropogenic mortality. understanding and mitigating the impact of anthropogenic collisions on wildlife populations require unbiased mortality estimates. however, counts of collision fatalities are underestimated due to several bias sources, including scavenger removal of carcasses between fatality surveys and imperfect detection of carcasses present during surveys. these biases remain particularly understudied for bir ...201830194798
survey of baylisascaris spp. in eastern tennessee wildlife and detection of baylisascaris spp. eggs in virginia opossum ( didelphis virginiana) feces.we analyzed 69 eastern tennessee wildlife samples for baylisascaris spp. during 2011. the prevalence of baylisascaris spp. in raccoons ( procyon lotor) was 16% (8/49), an increase compared to previous surveys in this region. one virginia opossum ( didelphis virginiana) had eggs in its feces, indicating that opossums can play a role in baylisascaris spp. transmission.201829902128
physiological basal parameters of free-ranging opossums ( didelphis virginiana) in the yucatan peninsula, mexico.the aim of the present study is to determine the basal parameters in opossums ( didelphis virginiana) during physical examination in yucatan, mexico. sixty-six opossums were captured and manually handled for physical examinations. sex, age, cardiac and respiratory rate, body temperature, pulse, mucous membranes, capillary refill time, hydration, size of superficial lymph nodes, mental status, and body condition were evaluated. also, comparisons between rectal and auricular temperatures were perf ...201829900782
prevalence, abundance and intensity of eggs and oocysts of gastrointestinal parasites in the opossum didelphis virginiana kerr, 1792 in yucatan, mexico.virginia opossum, didelphis virginiana, is a synanthropic mammal associated with peridomestic areas of yucatán, however, little is known about the gastrointestinal parasite infections of this species. the infection prevalence, mean abundance and mean intensity of eggs and oocysts of gastrointestinal parasites, in opossums captured in the peridomestic areas were estimated in six rural localities of yucatán, mexico. eighty-four faecal samples were processed by flotation technique. mcmaster test wa ...201831662637
transcriptomic analysis of skin pigmentation variation in the virginia opossum (didelphis virginiana).skin pigmentation and coat pigmentation are two of the best-studied examples of traits under natural selection given their quantifiable fitness interactions with the environment (e.g., camouflage) and signalling with other organisms (e.g., warning coloration). previous morphological studies have found that skin pigmentation variation in the virginia opossum (didelphis virginiana) is associated with variation in precipitation and temperatures across its distribution range following gloger's rule ...201829742302
playing by the rules? phenotypic adaptation to temperate environments in an american marsupial.phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. these differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. the virginia opossum (didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. it is unknown, ...201829607255
parotid salivary gland basal cell adenocarcinoma in a big-eared opossum (didelphis aurita).the opossum (family didelphidae) is a marsupial endemic to the americas. apart from the south american short-tailed opossum (monodelphis domestica) and the virginia opossum (didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. among these, the big-eared opossum (didelphis aurita) is found in argentina, brazil and paraguay. natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic ...201829599001
trypanosoma cruzi transmission among captive nonhuman primates, wildlife, and vectors.natural infection of captive nonhuman primates (nhps) with trypanosoma cruzi (agent of chagas disease) is an increasingly recognized problem in facilities across the southern usa, with negative consequences for nhp health and biomedical research. we explored a central texas nhp facility as a nidus of transmission by characterizing parasite discrete typing units (dtu) in seropositive rhesus macaques (macaca mulatta), identifying the wildlife reservoirs, and characterizing vector infection. in ser ...201829497880
progress towards bait station integration into oral rabies vaccination programs in the united states: field trials in massachusetts and florida.bait stations for distribution of oral rabies vaccine baits are designed for rabies management in highly-developed areas where traditional distribution of oral rabies vaccine baits may be difficult. as part of national efforts to contain and eliminate the raccoon (procyon lotor) variant of the rabies virus (raccoon rabies) in the eastern united states, the united states department of agriculture, animal and plant health inspection service, wildlife services program, distributed vaccine baits by ...201730270897
eosinophilic meningoencephalitis associated with rat lungworm (angiostrongylus cantonensis) migration in two nine-banded armadillos (dasypus novemcinctus) and an opossum (didelphis virginiana) in the southeastern united states.angiostrongylus cantonensis, the rat lungworm, was the cause of neural larval migrans in two nine-banded armadillos (dasypus novemcinctus) and one virginia opossum (didelphis virginiana) from the southeastern united states. histologic findings in all three cases included eosinophilic meningoencephalitis with variable numbers of nematode larvae in the meninges or the neuroparenchyma. in two of the three cases, nematodes were extracted from brain tissue via a "squash prep" method. identification o ...201728626635
pulmonary lesions caused by the lungworm (didelphostrongylus hayesi) in the opossum (didelphis virginiana) in colima, mexico.didelphostrongylus hayesi is an important and prevalent pulmonary nematode in the opossum ( didelphis virginiana ). an in-depth description of the pulmonary lesions caused by this nematode is lacking. the objective of this investigation was to make a detailed account of the gross, subgross, and microscopic changes that occur in the lungs of opossums naturally infected with d. hayesi. forty-four opossums trapped in the state of colima, mexico, were euthanized by an overdose of barbiturates. follo ...201728749264
sarcocystis neurona and neospora caninum in brazilian opossums (didelphis spp.): molecular investigation and in vitro isolation of sarcocystis spp.sarcocystis neurona and neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. opossums (didelphis albiventris and didelphis virginiana) are definitive hosts of s. neurona, which is the major cause of equine protozoal myeloencephalitis (epm). neospora caninum causes abortion in cattle and infects a wide range of animal species, while n. hughesi is known to induce neurologic disease in equids. the aims of this study were to investigate s. neuro ...201728807293
seed dispersal of diospyros virginiana in the past and the present: evidence for a generalist evolutionary strategy.several north american trees are hypothesized to have lost their co-evolved seed disperser during the late-pleistocene extinction and are therefore considered anachronistic. we tested this hypothesis for the american persimmon (diospyros virginiana) by studying the effects of gut passage of proposed seed dispersers on seedling survival and growth, natural fruiting characteristics, and modern animal consumption patterns. we tested gut passage effects on persimmon seeds using three native living s ...201728616198
camera trap arrays improve detection probability of wildlife: investigating study design considerations using an empirical dataset.camera trapping is a standard tool in ecological research and wildlife conservation. study designs, particularly for small-bodied or cryptic wildlife species often attempt to boost low detection probabilities by using non-random camera placement or baited cameras, which may bias data, or incorrectly estimate detection and occupancy. we investigated the ability of non-baited, multi-camera arrays to increase detection probabilities of wildlife. study design components were evaluated for their infl ...201728422973
abiotic and biotic contributors to support inter-epidemic francisella tularensis in an agricultural peri-urban environment.to characterize the inter-epidemic ecology of francisella tularensis, we surveyed vertebrates and invertebrates for the abundance, spatial distribution, and status of infection at a site in northern california that had evidence of endemic type b tularemia. we collected 2910 mosquitoes, 77 biting flies, 704 ticks, 115 mammals, and 1911 aquatic invertebrates in 2013-2014. real-time pcr on all mosquitoes, 40 biting flies, 113 aquatic invertebrates, and 650 ticks did not detect f. tularensis dna. in ...201728968195
sarcocystis neurona manipulation using culture-derived merozoites for bradyzoite and sporocyst production.equine protozoal myeloencephalitis (epm) remains a significant central nervous system disease of horses in the american continents. sarcocystis neurona is considered the primary causative agent and its intermediate life stages are carried by a wide host-range including raccoons (procyon lotor) in north america. s. neurona sarcocysts mature in raccoon skeletal muscle and can produce central nervous system disease in raccoons, mirroring the clinical presentation in horses. the study aimed to devel ...201728372843
amblyomma auricularium (ixodida: ixodidae) in florida: new hosts and distribution records.previous published evidence for the occurrence of an exotic armadillo tick, amblyomma auricularium (conil), in florida is scant, but we found it is fully established and integrated into the state's tick fauna. we collected 11,192 specimens of this tick from naturalized nine-banded armadillos, dasypus novemcinctus l., and 14 other species of wild native mammals and birds in florida, while sampling statewide during 2004 through 2007. in all, we document its specific presence only in 14 contiguous ...201728082640
spontaneous neoplasms in captive virginia opossums ( didelphis virginiana): a retrospective case series (1989-2014) and review of the literature.this retrospective project summarizes the types of neoplasms identified in virginia opossums ( didelphis virginiana) presented to the university of tennessee, college of veterinary medicine (utcvm) postmortem service in 1989-2014 and serves as a review of the literature. of the 85 virginia opossums identified from the utcvm case database, there were 17 diagnoses of neoplasia from 12 cases (14%). these cases included 8 females, 2 males, and 2 neutered males. all opossums with known ages (11 of 12 ...201728375825
prevalence of trypanosoma cruzi and organ alterations in virginia opossums (didelphis virginiana) from western mexico - short communication.small populations of virginia opossum (didelphis virginiana) in western mexico are endangered by hunting and natural predators as well as by different kinds of diseases. after two serological analyses using serodia® latex particle agglutination and indirect haemagglutination (iha) tests, 35 (53.03%) of 66 collected opossums in two small towns in western mexico were positive for the presence of trypanosoma cruzi. twenty-eight of the 35 seropositive opossums had pathological lesions: 11 had change ...201729256285
toward an ecological framework for assessing reservoirs of vector-borne pathogens: wildlife reservoirs of trypanosoma cruzi across the southern united states.wildlife species are critical for both feeding vectors and serving as reservoirs of zoonotic vector-borne pathogens. transmission pathways leading to disease in humans or other target taxa might be better understood and managed given a complete understanding of the relative importance of different reservoir species in nature. using the conceptual framework of "reservoir potential," which considers elements of both reservoir competence and vector-host contact, we review the wildlife reservoirs of ...201729106561
histopathological changes in the liver and stomach of didelphis virginiana (didelphimorphia: didelphidae) during natural infection with gnathostoma turgidum (nematoda: gnathostomidae).gnathostoma turgidum is a nematode parasite that exploits the stomach of virginian opossums, didelphis virginiana, in latin america. the opossum is the definitive host of g. turgidum in the wild. intrahepatic growth and maturation of the parasite, subsequent migration to the stomach and spontaneous expulsion are common. however, the histopathological lesions caused by g. turgidum are poorly described. a better understanding of the life cycle of this parasite and the pathological changes in natur ...201729103381
the transcriptome of thedidelphis virginianaopossum kidney ok proximal tubule cell line.the ok cell line derived from the kidney of a female opossumdidelphis virginianahas proven to be a useful model in which to investigate the unique regulation of ion transport and membrane trafficking mechanisms in the proximal tubule (pt). sequence data and comparison of the transcriptome of this cell line to eutherian mammal pts would further broaden the utility of this culture model. however, the genomic sequence ford. virginianais not available and although a draft genome sequence for the opo ...201728615248
reproductive disorders of marsupials.marsupial reproduction differs significantly in anatomy and physiology from that of placental mammals. the gastrointestinal and urogenital tracts empty into a cloaca. reproductive parameters include gestation and pouch time, as the fetus develops outside of the uterus. captive marsupials discussed include sugar gliders), short-tailed opossums, virginia opossums, and tammar and bennett's wallabies. common disease conditions include joey eviction, pouch infections, mastitis, metritis, prostatitis, ...201728169182
rickettsial infections among ctenocephalides felis and host animals during a flea-borne rickettsioses outbreak in orange county, california.due to a resurgence of flea-borne rickettsioses in orange county, california, we investigated the etiologies of rickettsial infections of ctenocephalides felis, the predominant fleas species obtained from opossums (didelphis virginiana) and domestic cats (felis catus), collected from case exposure sites and other areas in orange county. in addition, we assessed the prevalence of igg antibodies against spotted fever group (sfgr) and typhus group (tgr) rickettsiae in opossum sera. of the 597 flea ...201627537367
metal accumulation in bobcats in the southeastern usa.bobcats (lynx rufus) are wide-ranging mammals found throughout the continental usa. as carnivores near the top of their food chain, bobcats would seem to be a useful bioindicator of metal pollution in terrestrial environments. however, there is very limited research on bobcats in toxicology studies. here, we offer the first analysis of metal (copper, selenium, silver, and zinc) contaminants in the livers of wild bobcats. liver tissues from 120 adult bobcats (i.e., estimated to be ≥1 year old) we ...201627629555
metal accumulation in wild-caught opossum.the virginia opossum (didelphis virginiana) is widespread in the usa, ranging south through latin america. the ecology of opossums is such that they are in frequent contact with soils, suggesting that they may function as a valuable bioindicator for chemical contamination in terrestrial environments. surprisingly, there have been virtually no toxicology studies on opossums. here, we provide the first analysis of metal contaminants in opossum liver tissues. liver samples were obtained from 471 op ...201627138002
urinary bladder incarceration and infarction by an intra-abdominal fat pad in a virginia opossum (didelphis virginiana).a 2.5-year-old, female opossum had acute stranguria. based on radiography and ultrasonographic examination a cystic structure was identified in the caudal abdomen associated with bilateral hydroureter and hydronephrosis. this structure contained a neutrophilic fluid, determined to be urine. there was a neutrophilic leukocytosis. serum chemistry values were within normal limits. the opossum was euthanized. an intra-abdominal fat pad incarceration of the urinary bladder above the trigone was prese ...201615373255
postmortem scavenging by the virginia opossum (didelphis virginiana): impact on taphonomic assemblages and progression.the virginia opossum (didelphis virginiana) is a highly active scavenger whose behavior has significant impacts on rates of decomposition and skeletonization, which have previously not been addressed. in this study, scavenging by the opossum led to the skeletonization of carcasses in half of the accumulated degree days (add) of a comparable non-scavenged control carcass. opossums used body orifices, as well as natural tears caused by the decomposition process, to access internal tissues and cons ...201627430919
comparative myology and evolution of marsupials and other vertebrates, with notes on complexity, bauplan, and "scala naturae".opossums are frequent subjects of developmental studies because marsupials share developmental features not seen in placentals and because didelphimorpha is the sister-group of other extant marsupialia. but is the adult marsupial muscular system markedly different from that of placentals or is it, like the skeletal system, very similar? we provide, for the first time, a brief description of all head and limb muscles of didelphis virginiana based on our dissections and using a unifying nomenclatu ...201627342702
carcass type affects local scavenger guilds more than habitat connectivity.scavengers and decomposers provide an important ecosystem service by removing carrion from the environment. scavenging and decomposition are known to be temperature-dependent, but less is known about other factors that might affect carrion removal. we conducted an experiment in which we manipulated combinations of patch connectivity and carcass type, and measured responses by local scavenger guilds along with aspects of carcass depletion. we conducted twelve, 1-month trials in which five raccoon ...201626886299
antibody detection and molecular characterization of toxoplasma gondii from bobcats (lynx rufus), domestic cats (felis catus), and wildlife from minnesota, usa.little is known of the epidemiology of toxoplasmosis in minnesota. here, we evaluated toxoplasma gondii infection in 50 wild bobcats (lynx rufus) and 75 other animals on/near 10 cattle farms. antibodies to t. gondii were assayed in serum samples or tissue fluids by the modified agglutination test (mat, cut-off 1:25). twenty nine of 50 bobcats and 15 of 41 wildlife trapped on the vicinity of 10 farms and nine of 16 adult domestic cats (felis catus) and six of 14 domestic dogs resident on farms we ...201626824935
infection by rickettsia felis in opossums (didelphis sp.) from yucatan, mexico.rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the americas. its transmission cycle involves fleas as biological vectors (mainly ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. nonetheless, the role of mammals in the cycle of r. felis is not well understood and many efforts are ongoing in different countries of america to clarify it. the present study describes for the first time in mexico the infection of two specie ...201627074326
first molecular evidence of toxoplasma gondii in opossums (didelphis virginiana) from yucatan, mexico.toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including mexico. different species of animals participate in the wild cycle infection, including opossums of the species didelphis virginiana. thirteen d. virginiana were captured in yucatan, mexico. detection of t. gondii was achieved by polymerase chain reaction, which determined an infection of 76.9% (10/13) in brains. positive amplicons ...201627200271
spino-bulbar, spino-thalamic and medical lemniscal connections in the american opossum, didelphis marsupialis virginiana. 20165071890
quantifying dilution and amplification in a community of hosts for tick-borne pathogens.recent controversy over whether biodiversity reduces disease risk (dilution effect) has focused on the ecology of lyme disease, a tick-borne zoonosis. a criticism of the dilution effect is that increasing host species richness might amplify disease risk, assuming that total host abundance, and therefore feeding opportunities for ticks, increase with species richness. in contrast, a dilution effect is expected when poor quality hosts for ticks and pathogens (dilution hosts) divert tick blood meal ...201627209790
evaluating wildlife-cattle contact rates to improve the understanding of dynamics of bovine tuberculosis transmission in michigan, usa.direct and indirect contacts among individuals drive transmission of infectious disease. when multiple interacting species are susceptible to the same pathogen, risk assessment must include all potential host species. bovine tuberculosis (btb) is an example of a disease that can be transmitted among several wildlife species and to cattle, although the potential role of several wildlife species in spillback to cattle remains unclear. to better understand the complex network of contacts and factor ...201627931926
[the jaguar panthera onca (carnivora: felidae) in “el cielo” biosphere reserve, tamaulipas, mexico].information on the ecology of jaguars (panthera onca) in “el cielo” biosphere reserve in tamaulipas, mexico is scant and limited to anecdotic records in a handful of publications. the objectives of our study were to: a) determine population density and structure of jaguars, b) compare their activity patterns with that of pumas (puma concolor), c) ascertain potential prey relative abundance, and d) evaluate local resident’s perception on loss of domestic animals due to jaguar predation. between a ...201629465909
the opossum (didelphis virginiana kerr) as a biomedical model. 3. breeding the opossum in captivity: methods. 20154362895
serological investigation of heartland virus (bunyaviridae: phlebovirus) exposure in wild and domestic animals adjacent to human case sites in missouri 2012-2013.heartland virus (hrtv; bunyaviridae: phlebovirus) has recently emerged as a causative agent of human disease characterized by thrombocytopenia and leukopenia in the united states. the lone star tick (amblyomma americanum l.) has been implicated as a vector. to identify candidate vertebrate amplification hosts associated with enzootic maintenance of the virus, sera and ticks were sampled from 160 mammals (8 species) and 139 birds (26 species) captured near 2 human case residences in andrew and no ...201525870419
association between body size and reservoir competence of mammals bearing borrelia burgdorferi at an endemic site in the northeastern united states.the reservoirs for the lyme disease agent, borrelia burgdorferi, are dominated by several different small to medium sized mammals in eastern north america.201526024881
detection of sarcocystis spp. infection in bobcats (lynx rufus).the protozoan sarcocystis neurona is an important cause of severe clinical disease of horses (called equine protozoal myeloencephalitis, epm), marine mammals, companion animals, and several species of wildlife animals in the americas. the virginia opossum (didelphis virginiana) is its definitive host in the usa and other animals act as intermediate or aberrant hosts. samples of tongue and heart from 35 bobcats hunted for fur and food from mississippi state, usa in february, 2014 were used for th ...201526138150
sarcocyst development in raccoons (procyon lotor) inoculated with different strains of sarcocystis neurona culture-derived merozoites.sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (epm), a neurological disease in horses. raccoon ( procyon lotor ) is considered the most important intermediate host in the life cycle of s. neurona in the united states; s. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating epm. the focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different ...201525811893
molecular characterization and development of sarcocystis speeri sarcocysts in gamma interferon gene knockout mice.the north american opossum (didelphis virginiana) is the definitive host for at least three named species of sarcocystis: sarcocystis falcatula, sarcocystis neurona and sarcocystis speeri. the south american opossums (didelphis albiventris, didelphis marsupialis and didelphis aurita) are definitive hosts for s. falcatula and s. lindsayi. the sporocysts of these sarcocystis species are similar morphologically. they are also not easily distinguished genetically because of the difficulties of dna e ...201526303093
cutaneous epitheliotropic t-cell lymphoma with metastases in a virginia opossum (didelphis virginiana).a 2-yr-old, captive, intact female virginia opossum ( didelphis virginiana ) with a 7-mo history of ulcerative dermatitis and weight loss was euthanatized for progressive worsening of clinical signs. initially the opossum was treated with several courses of antibiotics, both topically and systemically; systemic nonsteroidal anti-inflammatory medication; and, later, systemic glucocorticoids, with no improvement in clinical signs. histopathologic samples of skin lesions taken 3 mo into the course ...201526056906
high prevalence of porocephalus crotali infection on a barrier island (cumberland island) off the coast of georgia, with identification of novel intermediate hosts.porocephalus crotali is a pentastomid parasite that uses crotaline snakes as definitive hosts and a variety of rodents as intermediate hosts. a study of definitive and intermediate pentastome hosts on cumberland island, georgia, revealed high prevalence of p. crotali infection in crotalid snakes as well as several mammalian species. despite the presence of numerous nymphs in some animals, clinical signs of disease were not observed. in intermediate hosts, the liver, mesentery, and reproductive o ...201526042344
development of an automated dispenser for the delivery of medicinal or vaccine-laden baits to raccoons (procyon lotor).medicinal baits are distributed to manage zoonotic diseases, including raccoon (procyon lotor) rabies, but efficient distribution strategies are needed for suburban environments. we developed an automated dispenser that transfers fishmeal polymer baits at user-specified intervals from a magazine to a receptacle fitted with a filter that exploits raccoon dexterity to limit consumption by nontarget species. we introduce the concept of automated dispensers and describe bait removal success rates fo ...201525647587
a behaviorally-explicit approach for delivering vaccine baits to mesopredators to control epizootics in fragmented landscapes.despite the widespread use of aerial baiting to manage epizootics among free-ranging populations, particularly in rabies management, bait acceptance and seroconversion rates often are lower than required to eliminate spread of disease. our objectives in this study, therefore, were to evaluate the performance of stratified bait distribution models derived from resource selection functions (rsf) on uptake of placebo rabies baits by raccoons (procyon lotor) and virginia opossums (didelphis virginia ...201525587900
use of medicinal fauna in mexican traditional medicine.mexico has great biodiversity of fauna. the use of fauna with medicinal properties is a common practice since pre-hispanic times. in the last decade, there has been an interest in ethnozoological studies in mexico. therefore, more studies are needed in order to gather information regarding the use of fauna with medicinal properties in méxico. ethnozoological studies are necessary in order to discover new medications for human health. this review presents current information in terms of ethnozool ...201424440438
[diversity, relative abundance and activity patterns of medium and large mammals in a tropical deciduous forest in the isthmus of tehuantepec, oaxaca, mexico].the use of camera traps and mammal track search are complementary methods to monitoring species of which is not well documented their natural history, as in the case of medium and large mammals. to ensure its conservation and good management, it is necessary to generate information about the structure of the community and their populations. the objective of the present study was to estimate the diversity, relative abundance and activity patterns of medium and large mammals in a tropical deciduou ...201425720178
spontaneous cure after natural infection with gnathostoma turgidum (nematoda) in virginia opossums (didelphis virginiana).seasonality of the nematode gnathostoma turgidum in virginia opossums (didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. we monitored the parasitologic and biologic changes in four virginia opossums naturally infected with g. turgidum by coproparasitologic examination and abdominal ultrasonography. eggs became detectable in the feces of opossums in may, peaked in july and august, and suddenly decreased in october. adults of g. turgidu ...201424506422
west nile virus isolated from a virginia opossum (didelphis virginiana) in northwestern missouri, usa, 2012.we describe the isolation of west nile virus (wnv; flaviviridae, flavivirus) from blood of a virginia opossum (didelphis virginiana) collected in northwestern missouri, usa in august 2012. sequencing determined that the virus was related to lineage 1a wnv02 strains. we discuss the role of wildlife in wnv disease epidemiology.201425098303
hematologic parameters of the opossum (didelphis virginiana). 20144145239
myosin isoform expression in the prehensile tails of didelphid marsupials: functional differences between arboreal and terrestrial opossums.prehensile tails are defined as having the ability to grasp objects and are commonly used as a fifth appendage during arboreal locomotion. despite the independent evolution of tail prehensility in numerous mammalian genera, data relating muscle structure, physiology, and function of prehensile tails are largely incomplete. didelphid marsupials make an excellent model to relate myosin heavy chain (mhc) isoform fiber type with structure/function of caudal muscles, as all opossums have a prehensile ...201424832677
prevalence of antibodies to leptospira in wild mammals trapped on livestock farms in ontario, canada.to determine the prevalence and diversity of leptospira serogroups circulating in wildlife on farms in ontario, we tested samples from 51 raccoons (procyon lotor), seven skunks (mephitis mephitis), four rats (rattus norvegicus), and three opossums (didelphis virginiana) that were trapped on 27 livestock (swine [sus scrofa], cattle [bos taurus]) farms in 2010. seventeen of 51 raccoons (33%; 95% confidence interval [ci], 21-48%) sampled were positive for at least one leptospira serogroup using the ...201424807356
unique regional distribution of delta 4-3-ketosteroid-5 alpha-oxidoreductase and associated epididymal morphology in the marsupial, didelphis virginiana.the epididymal epithelial ultrastructure has been described in the adult male north american opossum, didelphis virginiana. morphological results have suggested that absorptive activity is prominent in the proximal epididymal region by virtue of numerous microvilli, an endocytotic complex, dense granules, and multivesicular bodies in the apical cytoplasm. in contrast, the middle and distal epididymal regions exhibit ultrastructural features indicative of protein synthesis such as large invaginat ...20133676395
the safety of onrab® in select non-target wildlife.onrab(®) is a recombinant human adenovirus type 5 (had5) with the rabies glycoprotein gene incorporated into its genome. onrab(®) has been used in canada as an oral rabies vaccine in target wildlife species such as: red fox (vulpes vulpes), raccoon (procyon lotor), and striped skunk (mepthis mephitis). we evaluated the safety of onrab(®) in non-target wildlife species likely to contact the vaccine baits during oral rabies vaccine campaigns in the united states. we investigated the effects of ora ...201323831321
surveillance and movements of virginia opossum (didelphis virginiana) in the bovine tuberculosis region of michigan.wildlife reservoir hosts of bovine tuberculosis (btb) include eurasian badgers (meles meles) and brushtail possum (trichosurus vulpecula) in the uk and new zealand, respectively. similar species warrant further investigation in the northern lower peninsula of michigan, usa due to the continued presence of btb on cattle farms. most research in michigan, usa has focused on interactions between white-tailed deer (odocoileus virginianus) and cattle (bos taurus) for the transmission of the infectious ...201323531427
isolation of deer tick virus (powassan virus, lineage ii) from ixodes scapularis and detection of antibody in vertebrate hosts sampled in the hudson valley, new york state.deer tick virus, dtv, is a genetically and ecologically distinct lineage of powassan virus (powv) also known as lineage ii powv. human incidence of pow encephalitis has increased in the last 15 years potentially due to the emergence of dtv, particularly in the hudson valley of new york state. we initiated an extensive sampling campaign to determine whether powv was extant throughout the hudson valley in tick vectors and/or vertebrate hosts.201324016533
initial experiments with cyproterone acetate and 1-amino-3-chloro-2-propanol hydrochloride in the male virginia opossum (didelphis virginiana).cyproterone acetate (ca) was toxic for didelphis virginiana at a dose range of 22-28 mg/kg im. a loss of spermatozoal pairing int the cauda epididymidis did not occur until 2 wk after testicular degeneration caused by ca. the isomers of 1-amino-3-chloro-2-propanol hydrochloride (cl 88,236 and cl 88,237) were well tolerated by the opossum at doses up to 30 mg/kg im. after 8 days of cl 88,236 and cl 88,237 treatment there was no effect on spermatozoal pairing in the cauda epididymidis or on the se ...20136220622
gastric ischemic conditioning increases neovascularization and reduces inflammation and fibrosis during gastroesophageal anastomotic healing.the incidence of anastomotic leak and stricture after esophagectomy remains high. gastric devascularization followed by delayed esophageal resection has been proposed to minimize these complications. we investigated the effect of ischemic conditioning duration on anastomotic wound healing in an animal model of esophagogastrectomy.201323247735
wildlife contact rates at artificial feeding sites in texas.given the popularity of feeding white-tailed deer (odocoileus virginianus) in texas and the increasing amount of corn that is distributed, more information is needed on the impacts of this activity on non-target wildlife. our objectives were to report visitation, intra- and interspecific contact, and contact rates of wildlife at artificial feeding sites in texas. our study was conducted at three sites in kleberg and nueces counties, texas. we trapped animals from february to april and august to ...201323609307
myosin isoform fiber type and fiber size in the tail of the virginia opossum (didelphis virginiana).muscle fiber type is a well studied property in limb muscles, however, much less is understood about myosin heavy chain (mhc) isoform expression in caudal muscles of mammalian tails. didelphid marsupials are an interesting lineage in this context as all species have prehensile tails, but show a range of tail-function depending on either their arboreal or terrestrial locomotor habits. differences in prehensility suggest that mhc isoform fiber types may also be different, in that terrestrial oposs ...201323152195
trypanosoma cruzi infection in didelphis virginiana in relation to population parameters and variables associated with presence in rural community dwellings in yucatan, mexico. 201323404037
development of raphe-spinal connections in the north american opossum.the falck-hillarp technique, serotonin (5-ht) immunohistochemistry and the retrograde transport of horseradish peroxidase (hrp) were utilized to investigate the development of raphe-spinal connections in the pouch-young opossum. the brainstem raphe and adjacent reticular formation contain 5-ht immunoreactive neurons in the newborn opossum (12 days after conception) and processes from these cells can be visualized in the marginal zone of the spinal cord. between eight and 15 days after birth 5-ht ...20136756557
rickettsia felis in cat fleas, ctenocephalides felis parasitizing opossums, san bernardino county, california.los angeles and orange counties are known endemic areas for murine typhus in california; however, no recent reports of flea-borne rickettsioses are known from adjacent san bernardino county. sixty-five opossums (didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of san bernardino county in 2007. sixty out of 65 opossums were infested with fleas, primarily cat fleas, ctenocephalides felis (bouché, 1835). the flea minimum infection rate wit ...201222712460
anthropogenic influences on macro-level mammal occupancy in the appalachian trail corridor.anthropogenic effects on wildlife are typically assessed at the local level, but it is often difficult to extrapolate to larger spatial extents. macro-level occupancy studies are one way to assess impacts of multiple disturbance factors that might vary over different geographic extents. here we assess anthropogenic effects on occupancy and distribution for several mammal species within the appalachian trail (at), a forest corridor that extends across a broad section of the eastern united states. ...201222880038
effects of climate and exurban development on nest predation and predator presence in the southern appalachian mountains (usa).in the eastern united states, land-use and climate change have likely contributed to declines in the abundance of neotropical migrant birds that occupy forest interiors, but the mechanisms are not well understood. we conducted a nest-predation experiment in southern appalachian mountain forests (north carolina, u.s.a.) during the 2009 and 2010 breeding seasons to determine the effects of exurban development and temperature on predator presence and the average number of days until eggs in an arti ...201222624665
experimental aerosol inoculation and investigation of potential lateral transmission of mycobacterium bovis in virginia opossum (didelphis virginiana).an endemic focus of mycobacterium bovis (m. bovis) infection in the state of michigan has contributed to a regional persistence in the animal population. the objective of this study was to determine if virginia opossums (didelphis virginiana) contribute to disease persistence by experimentally assessing intraspecies lateral transmission. one wild caught pregnant female opossum bearing 11 joeys (young opossum) and one age-matched joey were obtained for the study. four joeys were aerosol inoculate ...201222701815
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