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isolation of sarcocystis speeri dubey and lindsay, 1999 parasite from the south american opossum (didelphis albiventris) from argentina.sarcocystis sporocysts from the intestines of 2 opossums (didelphis albiventris) from argentina were fed to gamma-interferon knockout (ko) and nude mice. protozoal schizonts were seen in brain, liver, spleen, and adrenal glands of mice examined 33-64 days after feeding sporocysts. sarcocysts were seen in skeletal muscles of ko mice 34-71 days after feeding sporocysts. schizonts and sarcocysts were structurally similar to sarcocystis speeri dubey and lindsay, 1999 seen in mice fed sporocysts from ...200010701583
streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (didelphis virginiana) with suppurative dermatitis and liver fibrosis.beta-haemolytic, catalase-positive, gram-positive cocci that formed chains in broth media but did not react with lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. the isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this activity was lost in subsequent passages. the use of standard phenotypic ...200010758886
experimental transmission of sarcocystis speeri dubey and lindsay, 1999 from the south american opossum (didelphis albiventris) to the north american opossum (didelphis virginiana).sarcocystis speeri dubey and lindsay, 1999 from the south american opossum didelphis albiventris was successfully transmitted to the north american opossum didelphis virginiana. sporocysts from a naturally infected d. albiventris from argentina were fed to 2 gamma-interferon knockout (ko) mice. the mice were killed 64 and 71 days after sporocyst feeding (daf). muscles containing sarcocysts from the ko mouse killed 71 daf were fed to a captive d. virginiana; this opossum shed sporocysts 11 days a ...200010864267
why fuse the mandibular symphysis? a comparative analysis.fused symphyses, which evolved independently in several mammalian taxa, including anthropoids, are stiffer and stronger than unfused symphyses. this paper tests the hypothesis that orientations of tooth movements during occlusion are the primary basis for variations in symphyseal fusion. mammals whose teeth have primarily dorsally oriented occlusal trajectories and/or rotate their mandibles during occlusion will not benefit from symphyseal fusion because it prevents independent mandibular moveme ...200010918127
light and electron microscopic features of eperythrozoon-like parasites in a north american opossum (didelphis virginiana).epierythrocytic parasites associated with a severe anemic episode have not been previously reported in the opossum. a wright-giemsa-stained peripheral blood smear from an anemic north american opossum (didelphis virginiana) revealed numerous organisms attached to red blood cells either singularly or in chains. ring forms of the organism were common and could be found free in the plasma. electron microscopy revealed that these organisms were attached to the intact plasma membrane in depressions o ...200010982141
a staging scheme for assessing development in vitro of organogenesis stage embryos of the stripe-faced dunnart, sminthopsis macroura (marsupialia: dasyuridae).the inaccessibility of mammalian organogenesis stage embryos has precluded their widespread use in embryological and teratological studies. as organogenesis occurs during the last 1.5 days of the 10. 7 days of gestation in the stripe-faced dunnart (sminthopsis macroura), the aim of the present study was to investigate whether day 9 and day 10 embryos and fetuses could be grown to term in vitro. high glucose dulbecco's modified eagle's medium with 10% fetal calf serum (fcs) supported embryonic gr ...200011006151
prevalence of sarcocystis species sporocysts in wild-caught opossums (didelphis virginiana).sarcocystis sporocysts were found in intestinal scrapings from 24 (54.5%) of 44 opossums (didelphis virginiana). the number of sporocysts varied from a few (< 10,000) to 245 million. sporocysts from 23 of 24 opossums were fed to captive budgerigars (melopsittacus undulatas), and the inocula from 21 opossums were infective, indicating the presence of sarcocystis falcatula. sporocysts from 24 opossums were fed to gamma-interferon-knockout (ko) or nude mice; inocula from 14 opossums were infective ...200010958444
the south american opossum, didelphis marsupialis, from brazil as another definitive host for sarcocystis speeri dubey and lindsay, 1999.the north american opossum, didelphis virginiana, is a definitive host for at least 3 species of sarcocvstis: s. falcatula stiles 1983, s. neurona dubey, davis, speer, bowman, de lahunta, granstrom, topper, hamir, cummings, suter 1991, and s. speeri dubey and lindsay 1999. in order to identify species of sarcocystis in the south american opossum, d. inarsupialis, sarcocystis sporocysts from the intestines of a naturally infected opossum (d. marsupialis) from brazil were fed to 4 gamma-interferon ...200011155929
completion of the life cycle of sarcocystis neurona.sarcocystis neurona is the most important cause of a neurologic disease in horses, equine protozoal myeloencephalitis (epm). the complete life cycle of s. neurona, including the description of sarcocysts and intermediate hosts, has not been completed until now. opossums (didelphis spp.) are definitive hosts, and horses and other mammals are aberrant hosts. in the present study, laboratory-raised domestic cats (felis domesticus) were fed sporocysts from the intestine of a naturally infected oposs ...200011191904
host utilization and seasonal occurrence of dermacentor species (acari:ixodidae) in missouri, usa.a total of 3,235 dermacentor variabilis (say) specimens were collected from birds, mammals, and by dragging vegetation, and 2,683 d. albipictus (packard) ticks were collected from deer from 1993 to 1996. peak seasonal occurrence of adult d. variabilis was from may through july with a precipitous decrease in august. nymphal d. variabilis populations peaked in june. peak activity of larvae was bimodal, with one activity peak during late summer (september) and a second peak in winter or early sprin ...200011201355
a review of sarcocystis neurona and equine protozoal myeloencephalitis (epm).equine protozoal myeloencephalitis (epm) is a serious neurological disease of horses in the americas. the protozoan most commonly associated with epm is sarcocystis neurona. the complete life cycle of s. neurona is unknown, including its natural intermediate host that harbors its sarcocyst. opossums (didelphis virginiana, didelphis albiventris) are its definitive hosts. horses are considered its aberrant hosts because only schizonts and merozoites (no sarcocysts) are found in horses. epm-like di ...200111223193
immunoconversion against sarcocystis neurona in normal and dexamethasone-treated horses challenged with s. neurona sporocysts.equine protozoal myeloencephalitis is a common neurologic disease of horses in the americas usually caused by sarcocystis neurona. to date, the disease has not been induced in horses using characterized sporocysts from didelphis virginiana, the definitive host. s. neurona sporocysts from 15 naturally infected opossums were fed to horses seronegative for antibodies against s. neurona. eight horses were given 5x10(5) sporocysts daily for 7 days. horses were examined for abnormal clinical signs, an ...200111223200
prevalence of neospora hughesi and sarcocystis neurona antibodies in horses from various geographical locations.parasite-specific antibody responses to neospora antigens were detected using the immunofluorescent antibody test (ifat) and immunoblot analysis in select equine populations. for comparison, a naturally infected neospora hughesi horse and an experimentally inoculated neospora caninum horse were used. in addition, all samples were tested for antibodies to sarcocystis neurona by immunoblot analysis. a total of 208 samples was evaluated. the equine populations were derived from five distinct geogra ...200111223207
prevalence of sarcocystis neurona sporocysts in opossums (didelphis virginiana) from rural mississippi.sarcocystis species sporocysts were found in intestinal scrapings from 24 of 72 opossums (didelphis virginiana) from rural mississippi. the number of sporocysts in each opossum varied from a few ( < 100000) to 187 million. sporocysts from 24 opossums were bioassayed for sarcocystis neurona infections by feeding to gamma-interferon knockout (ko) mice. s. neurona was detected in the brains of ko mice fed sporocysts from 19 opossums by immunohistochemical staining with anti-s. neurona specific poly ...200111223208
sporocyst size of isolates of sarcocystis shed by the virginia opossum (didelphis virginiana).the virginia opossum (didelphis virginiana) is a definitive host for multiple sarcocystis species including sarcocystis neurona, one of the causative agents of equine protozoal myeloencephalitis (epm), a severe, neuromuscular disease of horses. size and morphologic characteristics of isolates of sarcocystis shed by the opossum were examined to determine if differences were useful in discriminating between the isolates and/or species. collections of sporocysts from 17 opossums were molecularly ch ...200111223210
evaluation of the shedding of sarcocystis falcatula sporocysts in experimentally infected virginia opossums (didelphis virginiana).five virginia opossums (didelphis virginiana) were fed muscles of brown-headed cowbirds (molothrus ater) containing sarcocysts of sarcocystis falcatula. shedding of sporocysts was confirmed in all five opossums by fecal flotation. counts were conducted daily for 2 weeks and then biweekly until the animals were euthanized and necropsied. the average prepatent period was 9.8 (7-16) days. the number of sporocysts shed varied greatly between the opossums with maximum mean shedding occurring at 71.6 ...200111223211
development of sarcocystis falcatula in its intermediate host, the brown-headed cowbird (molothrus ater).sporocysts of sarcocystis falcatula obtained from experimentally infected virginia opossums (didelphis virginiana) were inoculated orally to 60 wild-caught brown-headed cowbirds (molothrus ater). another 30 brown-headed cowbirds were not challenged and served as uninfected controls. two inoculated and one control cowbird were necropsied every 2 weeks and the pectoral and thigh muscles were examined grossly for cyst development. stained histologic sections of pectoral muscle, thigh muscle, and lu ...200111223213
bovine tuberculosis in free-ranging carnivores from michigan.during a survey of carnivores and omnivores for bovine tuberculosis conducted in michigan (usa) since 1996, mycobacterium bovis was cultured from lymph nodes pooled from six coyotes (canis latrans) (four adult female, two adult male), two adult male raccoons (procyon lotor), one adult male red fox (vulpes vulpes), and one 1.5-yr-old male black bear (ursus americanus). one adult, male bobcat (felis rufus) with histologic lesions suggestive of tuberculosis was negative on culture but positive for ...200111272505
the nine-banded armadillo (dasypus novemcinctus) is an intermediate host for sarcocystis neurona.the nine-banded armadillo (dasypus novemcinctus) is an intermediate host of at least three species of sarcocystis, sarcocystis dasypi, sarcocystis diminuta, and an unidentified species; however, life cycles of these species have not been determined. following feeding of armadillo muscles containing sarcocysts to the virginia opossum (didelphis virginiana), the opossums shed sporulated sarcocystis sporocysts in their faeces. mean dimensions for sporocysts were 11.0x7.5 microm and each contained f ...200111306111
spotted fever group rickettsia in dermacentor variabilis (acari: ixodidae) infesting raccoons (carnivora: procyonidae) and opossums (marsupialia: didelphimorphidae) in tennessee.spotted fever group rickettsia were present in 13 of 1,171 (1.1%) of adult dermacentor variabilis say removed from raccoons (procyon lotor l.) and virginia opossums (didelphis virginiana kerr) in western tennessee. spotted fever group rickettsia were detected by amplification of a 617-bp segment of the citrate synthase gene by polymerase chain reaction.200111476343
sarcocystis greineri n. sp. (protozoa: sarcocystidae) in the virginia opossum (didelphis virginiana).sarcocysts were found in the skeletal muscles of road-killed and live-trapped opossums collected in north central florida. sarcocysts were spindle-shaped and macroscopic and had an average measurement of 3.8 mm by 154.6 microm. sarcocysts were only observed in skeletal muscle. sarcocysts have invaginations throughout the sarcocyst wall, which is approximately 1 microm thick. protrusions on the sarcocyst wall are stumpy and digitlike and contain fibrillar elements that extend from the interior po ...200111695370
sarcocystis neurona infections in raccoons (procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (didelphis virginiana), and experimental induction of neurologic disease in raccoons.equine protozoal myeloencephalitis (epm) is a serious neurologic disease of horses in the americas and sarcocystis neurona is the most common etiologic agent. the distribution of s. neurona infections follows the geographical distributions of its definitive hosts, opossums (didelphis virginiana, didelphis albiventris). recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of s. neurona. in the present report, raccoons (procyon lotor) were identified ...200111698157
comparative pathology and pathogenesis of naturally acquired and experimentally induced colonic spirochetosis.research in the past decade has led to the recognition of brachyspira (formerly serpulina) pilosicoli as the primary etiologic agent of colonic spirochetosis (cs), an emerging cause of colitis in humans and animals. attachment of spirochetes to the epithelial surface of the lower intestine is considered to be the hallmark of cs. however, because b. pilosicoli, b. aalborgi and unclassified flagellated bacteria are found singly or together in humans and non-human primates with cs lesions, attachme ...200111708743
risk factors associated with the presence of sarcocystis neurona sporocysts in opossums (didelphis virginiana).sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (epm) in horse in the americas. the only known definitive host for this parasite in the united states is the opossum (didelphis virginiana); however, despite the importance of the disease, the epidemiology of the parasite in the definitive host is poorly understood. to begin addressing these data gaps, potential risk factors were evaluated for their association with the presence of sporocysts of s. neurona in o ...200111777597
sarcocystis neurona infections in sea otter (enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (didelphis virginiana).although sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. here, sarcocysts from 2 naturally infected sea otters (enhydra lutris) were characterized biologically, ultrastructurally, and genetically. dna was extracted from frozen muscle of the first of these sea otters and was characterized as s. neurona by polymerase chain reation (pcr) amplification followed by restriction fragment length p ...200111780826
acute pulmonary sarcocystis falcatula-like infection in three victoria crowned pigeons (goura victoria) housed indoors.three free-roaming victoria crowned pigeons (goura victoria) housed in a completely enclosed tropical exhibit were found dead without antemortem signs of illness. the birds died within 9 days of each other. gross necropsy revealed moderate pulmonary edema in all three birds. histopathologic examination revealed pulmonary edema and pulmonary protozoal merozoites compatible with sarcocystis spp., toxoplasma gondii, or neospora spp. infection. immunohistochemical staining for t. gondii and neospora ...200112790430
the striped skunk (mephitis mephitis) is an intermediate host for sarcocystis neurona.striped skunks, initially negative for antibodies to sarcocystis neurona, formed sarcocysts in skeletal muscles after inoculation with s. neurona sporocysts collected from a naturally infected virginia opossum (didelphis virginiana). skunks developed antibodies to s. neurona by immunoblot and muscles containing sarcocysts were fed to laboratory-reared opossums which then shed sporulated sarcocystis sporocysts in their faeces. mean dimensions for sporocysts were 11.0 x 7.5 microm and each contain ...200111403777
viability of sarcocystis neurona sporocysts and dose titration in gamma-interferon knockout mice.gamma-interferon knockout mice have become the model animal used for studies on sarcocystis neurona. in order to determine the viability of s. neurona sporocysts and to evaluate the course of the disease in these mice, sporocysts were collected from opossums (didelphis virginiana), processed, and stored for varying periods of time. gamma-interferon knockout mice were then inoculated orally with different isolates at different doses. these animals were observed daily for clinical signs until they ...200111223202
the seroprevalence of antibodies to sarcocystis neurona in michigan equids.a cross-sectional study of serum antibodies to sarcocystis neurona (the etiologic agent of equine protozoal myeloencephalitis, epm) was performed on michigan equids. our objectives were to determine the seroprevalence of antibodies to s. neurona in michigan equids and to identify specific risk factors for seropositivity. a random, weighted sample of michigan horse farms (stratified by the state's opossum (didelphis virginiana) population and the number of equids on each operation) was selected. ...200111154784
scanning electron microscopy of turgida turgida (nematoda: spiruroidea), parasite of the virginia opossum, didelphis virginiana, from southern california.taxonomic characters for identification of turgida turgida rudolphi, 1819, a parasitic nematode of the virginia opossum didelphis virginiana, were studied by scanning electron microscopy. the distinguishing feature of the cephalic end is the presence of numerous denticles, structures associated with the internal tooth, and 2 spongelike areas on the inner side of each pseudolabia. the posterior end of male t. turgida differs from that in other species of physalopteridae by the number of caudal pa ...200111695400
mitochondrial genomes of a bandicoot and a brushtail possum confirm the monophyly of australidelphian marsupials.recent molecular analyses suggest that the position of bandicoots is the major difficulty in determining the root of the tree of extant marsupials. to resolve this, we analyse mitochondrial genome sequences of a bandicoot (isoodon macrourus) and a brushtail possum (trichosurus vulpecula) together with the previously available marsupial mitochondrial genomes, the virginia opossum (didelphis virginiana) and the wallaroo (macropus robustus). analyses of mitochondrial protein-coding and rna genes st ...200111454299
prevalence and site specificity of sarcocystis greineri sarcocysts in virginia opossum (didelphis virginiana) in florida.sarcocysts of sarcocystis greineri in the virginia opossum (didelphis virginiana) were observed for documenting sarcocyst prevalence, seasonal prevalence, and muscle specificity. characteristics of sarcocysts found in striated muscle were recorded, as were light microscopy measurements. overall prevalence of sarcocysts in striated muscle was 10.0% (24/240). no statistical difference (p = 0.156) in prevalence was detected between summer (13.1%; 16/122) and fall (6.7%; 8/118). sarcocysts were foun ...200212099438
molecular systematics of sciurognathi (rodentia): the mitochondrial cytochrome b and 12s rrna genes support the anomaluroidea (pedetidae and anomaluridae).nucleotide sequence data from the mitochondrial 12s rrna and cytochrome b genes were used to analyze phylogenetic relationships among sciurognath rodents. our sample taxa included representatives of 11 sciurognath and 3 hystricognath families with two marsupial species, didelphis virginiana and macropus robustus, as outgroups. the dataset was analyzed using both maximum-parsimony (weighted and unweighted) and likelihood methods. three suprafamilial groupings are strongly supported: geomyidae + h ...200211820843
the effects of western diamondback rattlesnake (crotalus atrox) venom on the production of antihemorrhagins and/or antibodies in the virginia opossum (didelphis virginiana).opossums are animals that are naturally resistant to the proteolytic effects of crotalid venoms. opossums possess proteinase inhibitors in their sera that bind to and neutralize hemorrhagic and other proteolytic activity in many snake venoms. the proteinase inhibitors are not antibodies since they have different molecular weights (60kda) and pi (4.2). the purpose of this study was to determine if opossums were capable of producing antibodies against venom and/or increasing the production of prot ...200211738236
comparison of the reservoir competence of medium-sized mammals and peromyscus leucopus for anaplasma phagocytophilum in connecticut.in the northeastern united states, anaplasma phagocytophilum, the agent of human granulocytic ehrlichiosis (hge), is transmitted by the tick vector ixodes scapularis. the white-footed mouse peromyscus leucopus is a competent reservoir for this agent, but the reservoir competence of non-peromyscus hosts of i. scapularis has not been studied. here, we report data confirming reservoir competence of medium-sized mammals for a. phagocytophilum. raccoons, virginia opossums, gray squirrels, and striped ...200212737542
sarcocystis neurona reacting antibodies in missouri feral domestic cats (felis domesticus) and their role as an intermediate host.sarcocystis neurona is the parasite associated with equine protozoal myeloencephalitis (epm). recently, cats (felis domesticus) have been implicated as a potential intermediate host in the life cycle of s. neurona. this study was initiated to determine whether cats have antibodies that react to s. neurona antigens similar to antibodies from horses with epm, and to evaluate the role of cats as intermediate hosts in the parasite's life cycle. nine feral cats were used for analysis. only one had an ...200211826870
seroprevalence of trypanosoma cruzi in raccoons from south carolina and georgia.trypanosoma cruzi, the causative agent of american trypanosomiasis or chagas' disease, is of both medical and veterinary importance as is evidenced by chronic phase myocarditis in humans and dogs. further, t. cruzi has been reported from over 20 species of wildlife reservoir hosts in the usa, with raccoons (procyon lotor) and opossums (didelphis virginiana) being the most common. whereas previous studies on t. cruzi in raccoons have included only culture and direct examination of blood, the indi ...200211838232
spontaneous squamous cell carcinoma of the tongue and multiple bronchioloalveolar carcinomas in a virginia opossum (didelphis virginiana).two primary tumours, squamous cell carcinoma of the tongue and multiple bronchioloalveolar carcinomas, were diagnosed in a virginia opossum (didelphis virginiana). two oral masses were located in the right ventrolateral surface of the tongue, near the frenulum, and the lungs contained multiple, widely distributed, nodular masses. microscopically, the oral masses were composed of invasive cords of pleomorphic, polyhedral cells, typical of squamous cells. the multiple pulmonary masses consisted of ...200211945013
experimental inoculation of north american opossums (didelphis virginiana) with mycobacterium bovis.eight north american opossums (didelphis virginiana) were inoculated with 1 x 10(5) colony forming units of mycobacterium bovis to investigate their potential as reservoir hosts for bovine tuberculosis in michigan. four animals received this dose orally and four were inoculated intramuscularly (i.m.). in each group, two animals were euthanized 1 mo postinoculation (pi) and two at 2 mo pi. four control animals were housed separately and sacrificed in the same manner as those inoculated. one of fo ...200212038125
sarcocystis meningoencephalitis in a northern gannet (morus bassanus).sarcocystis sp. schizonts were found in the cerebellum of a northern gannet (morus bassanus), exhibiting neurologic signs, found on the florida (usa) east coast. based upon molecular characterization of dna isolated from the brain of the gannet, this sarcocystis sp. appeared to be closely related, if not identical, to an unnamed sarcocystis sp. typified by isolates 1085 and 1086 collected from feces of a virginia opossum (didelphis virginiana) on the east coast of florida. because the life cycle ...200212038144
'candidatus mycoplasma haemodidelphidis' sp. nov., 'candidatus mycoplasma haemolamae' sp. nov. and mycoplasma haemocanis comb. nov., haemotrophic parasites from a naturally infected opossum (didelphis virginiana), alpaca (lama pacos) and dog (canis familiaris): phylogenetic and secondary structural relatedness of their 16s rrna genes to other mycoplasmas.the 16s rrna sequence of newly characterized haemotrophic bacteria in an opossum (didelphis virginiana) and alpaca (lama pacos) was determined. in addition, the 16s rrna sequence of a haemotrophic parasite in the dog (canis familiaris) was determined. sequence alignment and evolutionary analysis as well as secondary structural similarity and signature nucleotide sequence motifs of their 16s rrna genes, positioned these organisms in the genus mycoplasma. the highest scoring sequence similarities ...200212054227
porrorchis nickoli n. sp. (acanthocephala:: plagiorhynchidae) from mammals in southeastern mexico, first known occurrence of porrorchis in the western hemisphere.porrorchis nickoli n. sp. is described from the intestine of the gray four-eyed opossum philander opossum (type host), the virginia opossum didelphis virginiana, the common opossum didelphis marsupialis, and the white-nosed coati nasua narica. hosts were collected in southeastern mexico in the los tuxtlas region of the state of veracruz (type locality) and in the states of tabasco and chiapas. this new species is distinguished from other porrorchis species by its small proboscis (0.286-0.428 mm ...200212058721
experimental inoculation of domestic cats (felis domesticus) with sarcocystis neurona or s. neurona-like merozoites.sarcocystis neurona is the parasite most commonly associated with equine protozoal myeloencephalitis (epm). recently, cats (felis domesticus) have been demonstrated to be an experimental intermediate host in the life cycle of s. neurona. this study was performed to determine if cats experimentally inoculated with culture-derived s. neurona merozoites develop tissue sarcocysts infectious to opossums (didelphis virginiana), the definitive host of s. neurona. four cats were inoculated with s. neuro ...200212072209
establishment of besnoitia darlingi from opossums (didelphis virginiana) in experimental intermediate and definitive hosts, propagation in cell culture, and description of ultrastructural and genetic characteristics.besnoitia darlingi from naturally infected opossums (didelphis virginiana) from mississippi, usa, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. tachyzoites were successfully cultivated and mai ...200212076634
isolation of salmonella enterica and serologic reactivity to leptospira interrogans in opossums (didelphis virginiana) from yucatán, méxico.the presence of salmonella enterica and serologic evidence of infection by leptospira interrogans, were detected in the opossum didelphis virginiana in a semi-urban locality of the yucatán state, méxico. ninety-one opossums were captured during the period april 1996 and may 1998. from a total of 17 feces samples, four salmonella enterica subsp. enterica serotypes (sandiego, newport, anatum, and minnesota), and one salmonella enterica subsp. arizonae serovar o44:z4,z23:- were isolated. some oposs ...200212219118
the opossum didelphis virginiana as a synanthropic reservoir of trypanosoma cruzi in dzidzilché, yucatán, méxico.in méxico, the role of mammals in the transmission cycle of trypanosoma cruzi is poorly known. in the state of yucatán, an endemic area of chagas disease, both didelphis virginiana and d. marsupialis occur sympatrically. however, until now, only the former species had been found infected with t. cruzi. to evaluate the role of d. virginiana in a peridomestic transmission, nine periods of capture-recapture were performed around the village of dzidzilché, yucatán. the sex, age, reproductive status, ...200212219121
a retrospective study of 11 cases of lungworm (didelphostrongylus hayesi) infection in opossums (didelphis virginiana).a juvenile, female north american opossum (didelphis virginiana) died of verminous pneumonia caused by didelphostrongylus haysei despite aggressive treatment with oral fenbendazole, corticosteroids, and antibiotics. this prompted a retrospective study of lungworm infection in opossums, during which 19 additional necropsy reports from opossums were reviewed. including the subject of this report, a total of 11 (55%) of these cases included a diagnosis of lungworm infection. this diagnosis was cons ...200212398306
parastrongylus (=angiostrongylus) cantonensis now endemic in louisiana wildlife.parastrongylus (=angiostrongylus) cantonensis, a lung worm of rats, was first reported in the united states in 1987, with a probable introduction by infected rats from ships docking in new orleans, louisiana, during the mid-1980s. since then, it has been reported in nonhuman primates and a boy from new orleans, and in a horse from picayune, mississippi, a distance of 87 km from new orleans. parastrongylus cantonensis infection is herein reported in a lemur (varencia variegata rubra) from new ibe ...200212435151
prevalence of agglutinating antibodies to sarcocystis neurona in skunks (mephitis mephitis), raccoons (procyon lotor), and opossums (didelphis virginiana) from connecticut.equine protozoal myeloencephalitis is the most important protozoan disease of horses in north america and is usually caused by sarcocystis neurona. natural cases of encephalitis caused by s. neurona have been reported in skunks (mephitis mephitis) and raccoons (procyon lotor). opossums (didelphis spp.) are the only known definitive host. sera from 24 striped skunks, 12 raccoons, and 7 opossums (d. virginiana) from connecticut were examined for agglutinating antibodies to s. neurona using the s. ...200212435152
normal conjunctival flora in the north american opossum (didelphis virginiana) and raccoon (procyon lotor).we documented the normal conjunctival bacterial flora from 17 opossums (didelphis virginiana) and 10 raccoons (procyon lotor) trapped in manhattan, kansas (usa) from november 1999 to january 2000. both raccoons and opossums were free of apparent ocular disease. the inferior conjunctival sacs of each animal were swabbed for aerobic bacterial and mycoplasma culture and polymerase chain reaction (pcr) for mycoplasma and chlamydia detection. all conjunctival samples were positive for one or more spe ...200212528457
neurologic disease in gamma-interferon gene knockout mice caused by sarcocystis neurona sporocysts collected from opossums fed armadillo muscle.fifteen gamma-interferon gene knockout mice were each orally inoculated with 5 x 10(3) sarcocystis sporocysts derived from virginia opossums (didelphis virginiana) fed nine-banded armadillo (dasypus novemcinctus) muscle containing sarcocysts. three mice were inoculated with similarly obtained homogenates, but in which no sporocysts were detected. mouse m8 was pregnant when inoculated and gave birth during the trial. fifteen of 15 (100%) mice inoculated with sporocysts developed neurologic signs ...200211751001
host associations and seasonal occurrence of haemaphysalis leporispalustris, ixodes brunneus, i. cookei, i. dentatus, and i. texanus (acari: ixodidae) in southeastern missouri.hemaphysalis leporispalustris (packard), ixodes brunneus koch, ixodes cookei packard, ixodes dentatus marx, and ixodes texanus banks were collected during a 3-yr study of pathogen-tick-host interactions in southeastern missouri. h. leporispalustris was collected from the eastern cottontail rabbit, northern bobwhite, and carolina wren, and it was active all year. i. brunneus was collected by drag and from passerine birds during december, march, and april. i. cookei was collected from raccoons and ...200312597662
besnoitia oryctofelisi n. sp. (protozoa: apicomplexa) from domestic rabbits.a species of besnoitia from naturally infected rabbits from argentina was propagated experimentally in mice, gerbils, rabbits, cats, and cell cultures. cats fed tissue cysts from rabbits shed oocysts with a prepatent period of nine to 13 days. sporulated oocysts were infective to gerbils, rabbits, outbred swiss webster and interferon gamma gene knockout mice. bradyzoites were infective orally to gerbils and cats. tachyzoites were successfully cultivated and maintained in vitro in bovine monocyte ...200312879849
experimental aerosol inoculation of mycobacterium bovis in north american opossums (didelphis virginiana).the goal of this study was to evaluate the susceptibility of north american opossums (didelphis virginiana) to aerosol inoculation of mycobacterium bovis at two dose levels in order to gain information on disease pathogenesis, fecal shedding of the organism, and the potential role that opossums play in the spread of this disease in nature. six opossums received high dose (1 x 10(7) colony forming units (cfu) by aerosol inoculation, six opossums received low dose (1 x 10(3) cfu inoculation, and s ...200312910771
prevalence and tissue distribution of besnoitia darlingi cysts in the virginia opossum (didelphis virginiana) in michigan.specimens of virginia opossums (didelphis virginiana) in michigan were examined over 1 year to document the presence of besnoitia darlingi cysts. cyst morphology, prevalence, seasonal variation, and tissue sites of isolation were studied. histology and ultrastructural features of the detected cysts and bradyzoites were consistent with b. darlingi. in the opossums, b. darlingi had intracellular tissue cysts. tissue cysts had a mean diameter of 560 microm and were separated from the host tissue by ...200312944045
prevalence of antibodies to neospora caninum, sarcocystis neurona, and toxoplasma gondii in wild horses from central wyoming.sarcocystis neurona, neospora caninum, n. hughesi, and toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. the source of infection for n. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for s. neurona, n. caninum, and t. gondii, respectively. seroprevalence of these coccidians in 276 wild horses from central wyoming outside the known range of the opossum (didelphis virginiana) was determined. antibodies to t. gond ...200314533680
a serosurvey of leptospirosis in connecticut peridomestic wildlife.recently, leptospirosis has gained attention as a re-emerging infection in domestic dogs in the northeastern united states. in order to gain insight into the epizootiology of leptospirosis in this region, 109 small wild mammals (31 raccoons (procyon lotor), 30 skunks (mephitis mephitis), 28 opossums (didelphis virginiana), and 20 gray squirrels (sciurus carolinensis)) collected between february 27 and september 17, 2001 were tested for serologic evidence of exposure to five common leptospira ser ...200314733671
purification of sarcocystis neurona sporocysts from opossum (didelphis virginiana) using potassium bromide discontinuous density gradient centrifugation.this report describes a new, inexpensive procedure for the rapid and efficient purification of sarcocystis neurona sporocysts from opossum small intestine. s. neurona sporocysts were purified using a discontinuous potassium bromide density gradient. the procedure provides a source of sporocyst wall and sporozoites required for reliable biochemical characterization and for immunological studies directed at characterizing antigens responsible for immunological responses by the host. the examined i ...200312756543
electrical stimulation of the vagus nerve restores motility in an animal model of achalasia.esophageal peristalsis generally does not return to normal after surgical treatment of achalasia. direct electrical stimulation of the vagus nerve is known to stimulate antegrade peristalsis in the normal esophagus; however, it is not known whether electrical stimulation will induce return of peristalsis once an achalasia-like disorder has been established. the objective of this study was to perform quantitive and qualitative measurements of motility during electrical stimulation of the vagal ne ...200314592656
sarcocystis inghami n. sp. (sporozoa: sarcocystidae) from the skeletal muscles of the virginia opossum didelphis virginiana in michigan.this report describes the newly identified sarcocystis inghami n. sp. from the skeletal muscles of opossums (mammalia: didelphidae) that were collected from south central michigan (42 degrees 43'-42 degrees 79'n, 84 degrees 18'-84 degrees 86'w), usa. the new species is distinguished from all species described from north and south american opossums by the distinctive morphology of the villar protrusions on the cyst wall. sarcocysts of s. inghami are microscopic, up to 700 microm long and 110 micr ...200312975625
carpal ontogeny in monodelphis domestica and caluromys philander (marsupialia).carpal bones have experienced numerous changes during marsupial evolution, even though their diversity and development remain poorly studied. the aim of this work was to document adult form and the pattern of mesenchymal tissue condensation and formation of chondrification and ossification centers in the hand of two marsupials. two fundamental questions were asked: whether the loss of embryonic precursors was associated with the loss of adult elements, or whether there were developmental signs o ...200316351892
prevalence of and risk factors associated with the presence of sarcocystis neurona sporocysts in opossum (didelphis virginiana) from michigan: a retrospective study.from april 1996 to december 2002 the prevalence of sarcocystis neurona sporocysts in north american opossum (didelphis virginiana) in southern michigan was estimated. sporocysts of s. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. the frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). also, prevalence of s. neurona sporocysts in opossums in relation to factors s ...200415482884
viability of sarcocystis neurona sporocysts after long-term storage.the effect of long-term storage on the viability and infectivity of sarcocystis neurona sporocysts was investigated. s. neurona sporocysts were harvested from the small intestine of virginia opossums from 1996 to 2002 and stored at 4 degrees c. viability of sporocysts was assessed by propidium iodide (pi) exclusion assay, in vitro excystation and development in tissue cultures, and bioassay in gamma-interferon gene knockout (gamma-ifn-ko) mice. the rate of excystation was apparently unaffected b ...200415325051
concurrent presence of sarcocystis neurona sporocysts, besnoitia darlingi tissue cysts, and sarcocystis inghami sarcocysts in naturally infected opossums (didelphis virginiana).opossums (didelphis virginiana) are exposed to a wide range of coccidia through feeding on a variety of foods, including, but not limited to, carrion, insects, and nestling birds. abundant d. virginiana populations in urban and suburban areas can be important reservoirs of parasitic infection because of their profuse and prolonged excretion of the sporocysts of several species of sarcocystis, their omnivorous diet, and their relatively long life span. this report describes 2 adult female opossum ...200415305752
phylogenetic footprint analysis of igf2 in extant mammals.genomic imprinting results in monoallelic gene transcription that is directed by cis-acting regulatory elements epigenetically marked in a parent-of-origin-dependent manner. we performed phylogenetic sequence and epigenetic comparisons of igf2 between the nonimprinted platypus (ornithorhynchus anatinus) and imprinted opossum (didelphis virginiana), mouse (mus musculus), and human (homo sapiens) to determine if their divergent imprint status would reflect differences in the conservation of genomi ...200415342558
molecular characterization and evolution of x and y-borne atrx homologues in american marsupials.in eutherians, the sex-reversing atrx gene on the x has no homologue on the y chromosome. however, testis-specific and ubiquitously expressed x-borne genes have been identified in australian marsupials. we studied nucleotide sequence and chromosomal location of atrx homologues in two american marsupials, the opossums didelphis virginiana and monodelphis domestica. a pcr fragment of m. domestica atrx was used to probe southern blots and to screen male genomic libraries. southern analysis demonstr ...200415702418
prevalence of sarcocystis species sporocysts in northern virginia opossums (didelphis virginiana).a total of 206 virginia opossums ( didelphis virginiana) collected from the mid-michigan region, united states, during a period extending from 1996 to 2002 were sampled for the presence of sarcocystis spp sporocysts. all isolates were phenotypically identified as sarcocystis spp and genotyped to the species level by pcr-based techniques. the overall prevalence of sarcocystis spp in opossums was 18% (37/206). the prevalence of sarcocystis spp differed significantly with age ( p<0.001) and adult o ...200415205944
experimental talipes in the virginia opossum. 20055133035
comparative sequencing provides insights about the structure and conservation of marsupial and monotreme genomes.sequencing and comparative analyses of genomes from multiple vertebrates are providing insights about the genetic basis for biological diversity. to date, these efforts largely have focused on eutherian mammals, chicken, and fish. in this article, we describe the generation and study of genomic sequences from noneutherian mammals, a group of species occupying unusual phylogenetic positions. a large sequence data set (totaling >5 mb) was generated for the same orthologous region in three marsupia ...200515718282
dexamethasone treatment induces susceptibility of outbred webster mice to experimental infection with besnoitia darlingi isolated from opossums (didelphis virginiana).the sarcocystidae comprise a diverse, monophyletic apicomplexan parasite family, most of whose members form intracellular cysts in their intermediate hosts. the extent of pathology associated with such cyst formation can range widely. we currently lack experimental animal models for many of these infections. here we explored dexamethasone treatment as a means to render outbred mice susceptible to besnoitia darlingi infection and demonstrated that this approach allows viable parasites to be subse ...200515759157
helminths of the virginia opossum didelphis virginiana (mammalia: didelphidae) in mexico.the goal of this study was to provide further information about helminth parasites of virginia opossum didelphis virginiana kerr, 1792 from mexico. during routine faunal investigations between 1958 and 2001, 101 opossum were necropsied. nineteen taxa of helminths were collected, representing 13 genera from hosts in 27 localities from mexico. there are 58 new locality records, with 6 species recorded in mexico for the first time: brachylaima virginiana dickerson, 1930; cruzia americana mapleston, ...200515856909
serologic evidence of exposure of wild mammals to flaviviruses in the central and eastern united states.serosurveys were conducted to obtain flavivirus and west nile virus (wnv) seroprevalence data from mammals. sera from 513 small- and medium-sized mammals collected during late summer and fall 2003 from colorado, louisiana, new york, ohio, and pennsylvania were screened for flavivirus-specific antibodies. sera samples containing antibody to flaviviruses were screened for wnv-specific antibodies by epitope-blocking enzyme-linked immunosorbent assays and confirmed with plaque reduction neutralizati ...200515891139
serologic evidence of west nile virus infection in free-ranging mammals, slidell, louisiana, 2002.after an outbreak of west nile virus (wnv) infections in slidell, louisiana, in 2002, we detected neutralizing antibodies to wnv in 13 of 120 mammals, representing five of six species sampled. seroprevalence was measured in opossum, didelphis virginiana (75%, n = 8), raccoons, procyon lotor (60%, n = 5), black rats, rattus rattus (6%, n = 36), hispid cotton rats, sigmodon hispidus (4%, n = 24), and eastern gray squirrels, sciurus carolinensis (2%, n = 43).200516187899
isolation of mycobacterium avium subsp paratuberculosis (map) from feral cats on a dairy farm with map-infected cattle.paratuberculosis is an economically important disease of dairy cattle caused by mycobacterium avium subsp. paratuberculosis (map). the role of nonruminant, nondomestic animals in the epidemiology of paratuberculosis in cattle is unclear. to examine nonruminant, nondomestic animals for the presence of map, 25 feral cats, nine mice (species unknown), eight rabbits (sylvilagus floridanus), six raccoons (procyon lotor), and three opossums (didelphis virginiana) were collected from a mid-western dair ...200516244077
bartonella and rickettsia in fleas and lice from mammals in south carolina, u.s.a.species in the genera bartonella and rickettsia are vector-borne pathogens of humans and domestic animals. the natural reservoirs and enzootic transmission cycles of these bacteria are poorly known in south carolina. thirteen species of lice and fleas were collected from urban animals and screened for the presence of bartonella and rickettsia by pcr amplification using genus-specific primers. bartonella henselae was present in cat fleas (ctenocephalides felis) from virginia opossums (didelphis v ...200516599169
the role of feral mammals on wildlife infectious disease prevalence in two nature reserves within mexico city limits.wild and feral medium-sized mammals were live trapped at two natural protected areas within the mexico city limits to determine antibody prevalence for the most common infectious diseases (rabies, toxoplasmosis, and canine parvovirus) in dogs and cats. mammals were trapped during the dry (march-april) and rainy seasons (july-august) of 1996 and 1997. a total of 68 individuals were captured, representing 8 species: opossums (didelphis virginiana), ringtails (bassariscus astutus), spotted skunks ( ...200517312768
large mesozoic mammals fed on young dinosaurs.mesozoic mammals are commonly portrayed as shrew- or rat-sized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. the largest known mesozoic mammal represented by substantially complete remains is repenomamus robustus, a triconodont mammal from the lower cretaceous of liaoning, china. an adult individual of r. robustus was the size of a virginia opossum. here we report a new species of the genus, represented by a skeleton with most of the skull and p ...200515650737
efferent connections of the caudate nucleus in the virginia opossum.the efferents of the opossum's caudate nucleus were investigated by charting the the fiber degenerations produced by electrolytic lesions in various parts of this nucleus. by the aid of a modified fink-heimer procedure, degenerating fibers were traced from each of the lesions to the small globus pallidus in which they appeared to be distributed in an orderly dorsoventral pattern. fibers from all lesion sites in the caudate nucleus were found to terminate in the entopedunucular nucleus. in the su ...20051262560
studies on the energy metabolism of opossum (didelphis virginiana) erythrocytes--vi. de novo purine nucleotide biosynthesis is limited to the final steps of the pathway in vitro.1. high pressure liquid radiochromatography was used to show the incorporation of [14c] formate with z-compounds into atp and gtp in opossum erythrocytes. 2. the use of z-riboside with [14c] formate resulted in more extensive labeling of atp than the z-base/[14c] formate combination as substrates for nucleotide biosynthesis. 3. substantial accumulation of zmp and ztp, but no zdp was detected in the chromatograms. 4. atp was unstable in red cells metabolizing in the presence of z-compounds under ...20052253476
immunohistochemical localization of gastrin-releasing peptide, neuronal nitric oxide synthase and neurone-specific enolase in the uterus of the north american opossum, didelphis virginiana.the present study has demonstrated the immunohistochemical localization of gastrin-releasing peptide (grp), neuronal nitric oxide synthase (nnos) and neurone-specific enolase (nse) in the uterus of the north american opossum. although the presence of grp, nnos and nse has been reported recently in the uterus of eutherian species this is the first description of these peptides in a metatherian species. metatherian mammals are of interest because in these species it is the prolonged lactation phas ...200515996123
flea (pulex simulans) infestation in captive giant anteaters (myrmecophaga tridactyla).a pair of captive adult giant anteaters (myrmecophaga tridactyla) presented heavily infested with a flea species (pulex simulans) commonly found on virginia opossums (didelphis virginiana) and raccoons (procyon lotor) in the central united states. in this case, the flea was demonstrated to have completed its entire life cycle with the anteaters as the host. a single treatment of topical imidacloprid, coupled with removal and replacement of infested bedding, was rapidly effective at controlling t ...200617319150
lack of sarcocystis neurona antibody response in virginia opossums (didelphis virginiana) fed sarcocystis neurona-infected muscle tissue.serum was collected from laboratory-reared virginia opossums (didelphis virginiana) to determine whether experimentally infected opossums shedding sarcocystis neurona sporocysts develop serum antibodies to s. neurona merozoite antigens. three opossums were fed muscles from nine-banded armadillos (dasypus novemcinctus), and 5 were fed muscles from striped skunks (mephitis mephitis). serum was also collected from 26 automobile-killed opossums to determine whether antibodies to s. neurona were pres ...200616884017
imprinting of opossum igf2r in the absence of differential methylation and air.phylogenetic comparison of extant mammals with divergent imprint status is a powerful method for identifying critical components of imprint regulation at individual loci. the entire genomic region of igf2r in the imprinted marsupials, didelphis virginiana and monodelphis domestica, and the non-imprinted monotreme, ornithorhynchus anatinus, was isolated and sequenced. genetic and epigenetic comparisons of over 160 kb of sequence were then performed in five distinct mammalian species. surprisingly ...200617998818
genetic variation among isolates of sarcocystis neurona, the agent of protozoal myeloencephalitis, as revealed by amplified fragment length polymorphism markers.sarcocystis neurona causes serious neurological disease in horses and other vertebrates in the americas. based on epidemiological data, this parasite has recently emerged. here, the genetic diversity of sarcocystis neurona was evaluated using the amplified fragment length polymorphism (aflp) method. fifteen s. neurona taxa from different regions collected over the last 10 years were used; six isolates were from clinically diseased horses, eight isolates were from wild-caught opossums (didelphis ...200616714575
endemic infections of parastrongylus (=angiostrongylus) costaricensis in two species of nonhuman primates, raccoons, and an opossum from miami, florida.parastrongylus (=angiostrongylus) costaricensis was first reported in the united states from cotton rats, sigmodon hispidus, in texas in 1979. here, we report the findings of p. costaricensis in a siamang (hylobates syndactylus) from the miami metrozoo, in 2 ma's night monkeys (aotus nancymaae) from the dumond conservancy located at monkey jungle in miami, in 4 raccoons (procyon lotor) trapped near the metrozoo, and in an opossum (didelphis virginiana) trapped at the metrozoo. these records are ...200616729706
common procedures in hedgehogs, prairie dogs, exotic rodents, and companion marsupials.nondomesticated species are commonly being kept as companion animals. these include the african pygmy hedgehog (atelerix albi-ventris), the north american black-tailed prairie dog (cynomys lu-dovicianus), and exotic rodents such as the degu (octodon degus)and duprasi or fat-tailed gerbil (pachyuromys duprasi). common companion marsupials include the sugar glider (petaurus breviceps),bennett's or tammar (dama) wallabies (macropus rufogriseus rufo-griseus and macropus eugenii, respectively), the b ...200616759954
prevalence of agglutinating antibodies to toxoplasma gondii in striped skunks (mephitis mephitis), opossums (didelphis virginiana), and raccoons (procyon lotor) from connecticut.the prevalence of agglutinating antibodies to toxoplasma gondii was examined in striped skunks (mephitis mephitis), opossums (didelphis virginiana), and raccoons (procyon lotor) from 8 cities in connecticut. ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. these results suggest that t. gondii is prevalent in the environment, or prey items, or both, of these omnivores in connecticut.200616884022
serologic evidence of west nile virus exposure in north american mesopredators.sera from 936 mammalian mesopredators (virginia opossums, gray foxes, striped skunks, hooded skunks, raccoons, a bobcat, and a red fox) were collected during 2003 and 2004 in california, arizona, texas, louisiana, ohio, and wyoming and screened for flavivirus-specific antibodies by an epitope-blocking enzyme-linked immunosorbent assay (blocking elisa). serum samples positive for antibodies against flaviviruses were screened for west nile virus (wnv)-specific antibodies by blocking elisa and sele ...200717255248
genes flanking xist in mouse and human are separated on the x chromosome in american marsupials.x inactivation, the transcriptional silencing of one of the two x chromosomes in female mammals, achieves dosage compensation of x-linked genes relative to xy males. in eutherian mammals x inactivation is regulated by the x-inactive specific transcript (xist), a cis-acting non-coding rna that triggers silencing of the chromosome from which it is transcribed. marsupial mammals also undergo x inactivation but the mechanism is relatively poorly understood. we set out to analyse the x chromosome in ...200717333537
the unique paired retinal vascular pattern in marsupials: structural, functional and evolutionary perspectives based on observations in a range of species.in the few marsupial species studied to date that possess a retinal vasculature, the arterial and venous segments, down to the smallest calibre capillaries, have been shown to occur in pairs. it is a pattern seen in the marsupial central nervous system (cns) but not in other tissues in this group or in any tissues in eutherian mammals. the aim of the present study was to investigate the presence of retinal vessels in a range of non-eutherian mammalian species (marsupials and monotremes) and to d ...200717475712
observations on besnoitiosis in virginia opossum (didelphis virginiana) from michigan, usa.besnoitia tissue cysts were found in five naturally-infected adult opossums (didelphis virginiana) from michigan. details of the microscopy, histopathology, ultra-structure, and genetic features of the cysts were studied to identify their species-specific traits. the materials were differentiated phenotypically from cysts of other besnoitia spp. by difference in size, pattern of tissue distribution, morphology of pellicle and nucleus, number of micronemes and rhoptries, amount of lipids and amyl ...200717580564
salmonella enterica isolated from wildlife at two ohio rehabilitation centers.between may and september 2004, fecal samples from various wildlife species admitted to two rehabilitation centers in ohio were cultured for salmonella enterica and escherichia coli o157:h7. eight of 71 (11%) samples, including specimens from three opossums (didelphis virginiana), two gray squirrels (sciurus carolinensis), a woodchuck (marmota monax), a harris hawk (parabuteo unicinctus), and a screech owl (otus asio) tested positive for salmonella serovars braenderup, senftenberg, oranienburg, ...200717939349
ultrastructure characteristics of besnoitia darlingitachyzoites brumpt, 1913 (protozoa: sarcocystidae) of the michigan strain mibd1.tachyzoites of besnoitia darlingi brumpt, 1913 were redescribed based on new materials isolated from virginia opossums (didelphis virginiana, kerr) from michigan, u.s.a. tachyzoites of the mibd1 strain were propagated in bovine turbinate cell culture for more than two years. a comparison with previously described tachyzoites of the b. darlingi op1 strain from mississippi, usa revealed some morphological differences despite the remarkable genetic homogeneity between the two b. darlingi strains. m ...200718383798
the development of selected rubral connections in the north american opossum.we have employed axonal transport and degeneration techniques to study the development of selected rubral connections in the north american opossum. opossums were chosen for study because they are born in an immature state, 12 days after conception, and have a lengthy postnatal development. the results of our studies suggest that: (1) the red nucleus innervates the spinal cord early in development, but not as early as some areas of the brainstem; (2) rubrospinal development occurs postnatally in ...20073382514
the brainstem origin of monoaminergic projections to the spinal cord of the north american opossum: a study using fluorescent tracers and fluorescence histochemistry.the retrograde transport of fluorescent markers has been combined with the glyoxylic acid and falck-hillarp techniques to identify the origin of monoamine axons within the spinal cord of the north american opossum. catecholamine axons arise from neurons located within the ventrolateral medulla, dorsal to the superior olivary complex, within the dorsolateral and rostrolateral pons and within the periventricular nuclei of the hypothalamus. such neurons are most numerous within the dorsolateral pon ...20076129037
neutralization of lethality and proteolytic activities of malayan pit viper (calloselasma rhodostoma) venom with north american virginia opossum (didelphis virginiana) serum.malayan pit viper (calloselasma rhodostoma) envenomation is a major health problem in south east asia. during envenomation, venom components mainly affect the hemostatic system. the sera from the north american virginia opossums (didelphis virginiana) were able to neutralize the venom of the malayan pit viper. these natural inhibitors could be explored as potential therapeutics against envenomations of a variety of venomous snake species in different geographical habitats.200818617212
the development of a testosterone stimulation test in the virginia opossum (didelphis virginiana) and its use in evaluating deslorelin contraception.the aims of the present study were to examine the variability of testosterone secretion in the virginia opossum over a 24 h period and to develop a testosterone stimulation test that would provide an index of the prevailing testosterone biosynthetic capacity of the testes; the latter was used to clinically evaluate the efficacy of a gonadotrophin-releasing hormone agonist contraceptive. sexually-mature captive opossums (n = 12) located in africam safari (mexico) sampled every 12 h over 24 h cons ...200818577353
distribution of mycobacterium avium subspecies paratuberculosis in the lower florida keys.johne's disease, a fatal and contagious gastrointestinal infection caused by mycobacterium avium subsp. paratuberculosis (map), was first diagnosed in an endangered florida key deer (odocoileus virginianus clavium) in 1996 and later in six additional key deer deaths from 1998 to 2004. we investigated the geographic distribution of map in the lower florida keys from february 2005 through may 2006 via collection of blood and fecal pellets from 51 live-captured deer, collection of 550 fecal samples ...200818689642
detection of lawsonia intracellularis by real-time pcr in the feces of free-living animals from equine farms with documented occurrence of equine proliferative enteropathy.the objective of this study was to determine whether lawsonia intracellularis was present in the feces of free-living animals collected on two equine premises with documented occurrence of equine proliferative enteropathy (epe). fresh feces from black-tailed jackrabbits (lepus californicus, n=100), striped skunks (mephitis mephitis, n=22), feral cats (felis catus, n=14), brewer's blackbirds (euphagus cyanocephalus, n=10), virginian opossums (didelphis virginiana, n=9), raccoons (procyon lotor, n ...200818957657
evaluation of cruzia americana, turgida turgida, and didelphostrongylus hayesi infection in the virginia opossum (didelphis virginiana) and risk factors along the california coast.three nematodes, turgida turgida, cruzia americana, and didelphostrongylus hayesi, have been documented to cause morbidity and mortality in the virginia opossum (didelphis virginiana). the present study was designed to determine the frequency of infection of these nematodes in opossums at 2 study sites in california and to determine if there are risk factors associated with shedding of eggs or larvae in the feces. turgida turgida and c. americana adults were found in 84.4% (stomach; n = 45) and ...200818973414
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