RESUMEN
OBJECTIVE: Successful disease management requires effective surveillance. Slaughterhouse inspections provide opportunities to efficiently collect regular disease data from many animals across large areas. Toxoplasma is a cat-borne parasite that causes reproduction failure in sheep, although it is not visually detectable at slaughterhouses. Macroscopic sarcocystosis is a disease of sheep that is visually detectable at slaughter and is caused by parasites that share a similar biology with Toxoplasma. We investigated if sarcocystosis could act as a proximate measure for Toxoplasma exposure in sheep to facilitate its efficient surveillance at large scales. DESIGN/METHODS: We compared the presence of macroscopic sarcocystosis to Toxoplasma serostatus at the animal and farm levels. RESULTS: At the animal level, we found a weak association between Toxoplasma seropositivity and sarcocysts in the oesophagus (OR = 1.76 [95% CI: 1.17, 2.65; McFadden's R2 = 0.01]) but no association between Toxoplasma seropositivity and sarcocysts in skeletal muscles. At the farm level, the seroprevalence of Toxoplasma was strongly associated with oesophageal sarcocystosis prevalence (OR = 28.59 [95% CI: 13.07, 62.57; McFadden's R2 = 0.34]) but less strongly associated with sarcocystosis prevalence in skeletal muscles (OR = 7.91 [95% CI: 1.24, 50.39; McFadden's R2 = 0.02]). CONCLUSIONS: For Toxoplasma surveillance in sheep at the farm level, routine slaughter inspection and recording of macroscopic oesophageal sarcocystosis could be are liable and efficient proximate measure. The monitoring of oesophageal sarcocystosis may be a useful passive Toxoplasma surveillance tool for guiding the timing and location of other Toxoplasma detection methods to facilitate the management of Toxoplasma impacts within the sheep industry.
Asunto(s)
Enfermedades de los Gatos , Sarcocystis , Sarcocistosis/veterinaria , Enfermedades de las Ovejas , Toxoplasma , Animales , Gatos , Esófago , Estudios Seroepidemiológicos , OvinosRESUMEN
The full-genome sequences of strains chicken/Indonesia/Cilebut/010WJ/2015 and chicken/Indonesia/ITA/012WJ/1951, isolated in West Java, Indonesia, in 2015 and 1951, respectively, were examined. Chicken/Indonesia/Cilebut/010WJ/2015 (genotype VII) caused a 2015 disease outbreak in Indonesia, and chicken/Indonesia/ITA/012WJ/1951 (genotype VI) is used as a standard strain for challenge in Newcastle disease virus (NDV) vaccine trials.
RESUMEN
Infection with the cat-borne parasite Toxoplasma gondii has been detected in numerous Australian marsupials and can lead to severe disease (toxoplasmosis) in some cases. The seroprevalence of Toxoplasma on Kangaroo Island, South Australia has been reported to be higher than the South Australian mainland in macropods, cats, and sheep, suggesting an increased risk of infection on this island. However, Toxoplasma seroprevalence in small- and medium-sized terrestrial mammals was almost zero on the island and did not differ from that on the mainland. We surveyed Toxoplasma seroprevalence in koala (Phascolarctos cinereus) populations on the island and on the mainland and assessed their risk of infection and their role in the life cycle of Toxoplasma. All screened koalas from the island (n = 94) and the mainland (n = 63) were seronegative. This represents the largest Toxoplasma seroprevalence survey in this species and provided sufficient evidence to confidently demonstrate freedom from parasite exposure in both island and mainland populations at the time of the survey. Because koalas are extensively arboreal and predominately consume tree foliage, they appear to be at negligible risk of Toxoplasma infection. Furthermore, as koalas are rarely consumed by cats, we suggest that they have a minor role in the parasite's life cycle.
Asunto(s)
Phascolarctidae/parasitología , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/epidemiología , Pruebas de Aglutinación/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Femenino , Islas/epidemiología , Masculino , Estudios Seroepidemiológicos , Australia del Sur/epidemiología , Toxoplasma/inmunologíaRESUMEN
Neospora caninum naturally infects many mammal species, but has not previously been demonstrated in birds. We examined sera for N. caninum antibodies from 200 outdoor chickens and from 200 chickens confined indoors in the state of Bahia, Brazil. Seroprevalence was greater in outdoor chickens (23.5% versus 1.5%, P<0.001). PCR testing for N. caninum was positive in six of 10 seropositive chickens. Amplicons from two of these were sequenced and had 97-98% nucleotide identity with N. caninum. This finding extends the list of intermediate hosts of N. caninum to include birds and may have important epidemiological consequences.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Pollos/parasitología , Coccidiosis/transmisión , Neospora/fisiología , Crianza de Animales Domésticos/métodos , Animales , Secuencia de Bases , Enfermedades de las Aves/parasitología , Aves/parasitología , Brasil , Pollos/inmunología , ADN Protozoario/análisis , Reservorios de Enfermedades/parasitología , Técnica del Anticuerpo Fluorescente Indirecta , Datos de Secuencia Molecular , Neospora/genética , Neospora/inmunología , Estudios Seroepidemiológicos , Toxoplasma/inmunología , Toxoplasma/fisiologíaRESUMEN
Neospora caninum has recently been shown to be a cause of abortions of sheep in New Zealand. A commercially available enzyme-linked immunosorbent assay (ELISA) was validated for use in sheep with sera from experimentally infected sheep. A cut-off threshold was established that demonstrated sero-conversion between 7 and 14 days post-infection. Higher inocula led to earlier sero-conversion. This ELISA was applied to 640 sera collected from rams across New Zealand and 0.625% (+/-0.61%) (4/640) were shown to be serologically positive. The four positive sera were also demonstrated to be positive by indirect fluorescent antibody test (IFAT). The ELISA evaluated here lends itself more readily to large-scale investigations than IFAT. The low background of N. caninum infection in the New Zealand sheep population suggests that N. caninum abortions could be more easily diagnosed by serological means than in populations with higher background sero-prevalence.
Asunto(s)
Coccidiosis/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Neospora/aislamiento & purificación , Enfermedades de las Ovejas/diagnóstico , Enfermedades de las Ovejas/epidemiología , Animales , Anticuerpos Antiprotozoarios/sangre , Coccidiosis/diagnóstico , Coccidiosis/epidemiología , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Masculino , Nueva Zelanda/epidemiología , Ovinos , Enfermedades de las Ovejas/parasitología , Factores de TiempoRESUMEN
Whilst it is presumed that infection of pregnant cattle with Neospora caninum oocysts can provoke abortion and is the likely cause of epidemic abortion outbreaks, only two previous experiments have involved inoculation of pregnant cows with oocysts (and only one abortion was provoked in 22 pregnancies). Here, we describe the oral oocyst challenge of 18 cows synchronously bred and inoculated precisely at 70 (n=6), 120 (n=6) and 210 (n=6) days in pregnancy with a nominal dose of 40,000 oocysts. Only one abortion occurred (at the 120 days challenge) which could be definitively ascribed to N. caninum and no transplacental infection (TPI) was detected in any of the other 11 calves born in the 70 and 120 day challenge groups. In contrast, 4/5 live calves born to cattle challenged at 210 days were transplacentally infected. When cows which had transplacentally infected their calves in the first pregnancy were rebred, no TPI occurred. The results show that the timing of challenge influences clinical and parasitological outcomes and that cattle in late pregnancy are exquisitely sensitive to oocyst challenge leading to exogenous TPI and congenitally infected calves. However, cattle which were indisputably systemically infected in their first pregnancy did not induce endogenous TPI in their subsequent pregnancy. This confirms previous results with experimental tachyzoite challenge and suggests that post-natal infection does not lead to persisting infections which can recrudesce in pregnancy.
Asunto(s)
Enfermedades de los Bovinos/parasitología , Coccidiosis/transmisión , Coccidiosis/veterinaria , Transmisión Vertical de Enfermedad Infecciosa , Neospora/patogenicidad , Complicaciones Parasitarias del Embarazo , Aborto Veterinario/parasitología , Animales , Anticuerpos Antiprotozoarios/biosíntesis , Bovinos , Enfermedades de los Bovinos/inmunología , Coccidiosis/inmunología , Femenino , Interferón gamma/biosíntesis , Intercambio Materno-Fetal , Neospora/inmunología , Oocistos/inmunología , Embarazo , Complicaciones Parasitarias del Embarazo/inmunología , VirulenciaRESUMEN
CASE REPORT: A 17-day-old Bulldog puppy died soon after presentation for weakness and tachypnoea. Gross lesions included diffuse pulmonary oedema and a region of myocardial pallor that resembled an infarct. Inflammation was observed histopathologically in many organs, with numerous clusters of intracellular protozoa that stained positively using Neospora caninum immunohistochemistry. Myocarditis was severe and had associated necrosis of individual myocytes, but the tissue was not infarcted. The bitch had an antibody titre of 1â:â1600 for N. caninum. All six littermates were sold and reported to be healthy at 6 months of age. CONCLUSION: Unusual aspects of this case include the occurrence of clinical disease in only 1 of 7 neonatal puppies, widespread dissemination of the organism in multiple tissues, and regional pallor associated with myocarditis that gave a false gross appearance of infarction. This report also adds Bulldogs to the list of dog breeds shown to be susceptible to clinical neosporosis.
Asunto(s)
Coccidiosis/veterinaria , Enfermedades de los Perros/parasitología , Miocarditis/veterinaria , Neospora/aislamiento & purificación , Edema Pulmonar/veterinaria , Animales , Animales Recién Nacidos , Coccidiosis/parasitología , Perros , Femenino , Inflamación/parasitología , Inflamación/veterinaria , Masculino , Miocarditis/parasitología , Edema Pulmonar/parasitologíaRESUMEN
To investigate whether dogs shed Neospora caninum oocysts more than once, five dogs with a previous history of shedding oocysts were fed infected bovine tissues. Two of three dogs shed oocysts when they were re-exposed 18-20 months after the first challenge; two other dogs re-exposed earlier, only 8 months after the primary exposure, did not produce oocysts. These results suggest that dogs may become refractory to shedding N. caninum oocysts for a period approximately between 8 and 18 months after a primary infection; however, this possibility requires statistical validation by testing of more dogs. The development of a high antibody titer did not ensure that a dog would completely resist shedding oocysts after consuming an infected meal. Oocyst production was also compared between puppies and adult dogs with primary infections. Twelve puppies (three from the present study and nine from a previous study) shed significantly more oocysts (mean: 166,400) compared with five adult dogs following primary exposure (mean: 2900), indicating that a dog's age can influence N. caninum oocyst production (P=0.02).
Asunto(s)
Coccidiosis/veterinaria , Enfermedades de los Perros/parasitología , Neospora/fisiología , Factores de Edad , Animales , Animales Recién Nacidos , Anticuerpos Antiprotozoarios/sangre , Bovinos , Enfermedades de los Bovinos/parasitología , Coccidiosis/sangre , Coccidiosis/inmunología , Coccidiosis/parasitología , ADN Protozoario/química , ADN Protozoario/genética , Enfermedades de los Perros/inmunología , Perros , Heces/parasitología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Masculino , Carne/parasitología , Neospora/genética , Neospora/inmunología , Oocistos , Recuento de Huevos de Parásitos/veterinaria , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
The avidity (functional affinity) of specific antibodies are being used to estimate duration of bovine Neospora caninum infection. Here, we report for the first time the avidity pattern in cattle orally inoculated with N. caninum oocysts. In all, 16 pregnant cows and 7 calves were administered N. caninum oocysts. In the cows, the avidity increased during the early course of infection. In all but one, the avidity was < or = 35 during the first 6 weeks after infection and no cow had an avidity value >50 until week 9. The calves were sampled either week 6 (n = 3) or week 9 (n = 9) after infection, and by then had avidities between 2 and 17. The results are in agreement with results from previous investigations of naturally infected cattle, and calves that were experimentally infected with tachyzoites. They further validate the ability of the N. caninum iscom avidity ELISA to accurately assess the duration of infection.
Asunto(s)
Anticuerpos Antiprotozoarios/inmunología , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/parasitología , Coccidiosis/veterinaria , Inmunoglobulina G/inmunología , Neospora/inmunología , Animales , Animales Recién Nacidos , Anticuerpos Antiprotozoarios/sangre , Afinidad de Anticuerpos/inmunología , Portador Sano/inmunología , Portador Sano/parasitología , Bovinos , Coccidiosis/inmunología , Coccidiosis/parasitología , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Inmunoglobulina G/sangre , Masculino , Oocistos/inmunología , EmbarazoRESUMEN
During a canine distemper virus (CDV) outbreak in raccoons (Procyon lotor) from Cook County, Illinois, a juvenile female suffering from seizures was killed and necropsied. Gross and histologic findings of necrotizing encephalitis and proliferative bronchopneumonia were attributed to CDV infection and considered the cause of clinical signs. A section of cerebellum stained immunohistochemically for Neospora caninum revealed an approximately 40 microm diameter, round to oval cyst with a 2- to 3-microm-thick wall and filled with 1-2 microm diameter, round to oval bradyzoites. Polymerase chain reaction (PCR) results were positive for N. caninum using DNA extracted from the brain. Specific PCR for the closely related organisms Toxoplasma gondii and Hammondia heydorni yielded negative results. This case report provides histologic, immunohistochemical, and molecular evidence that raccoons are a naturally occurring intermediate host of N. caninum.
Asunto(s)
Coccidiosis/veterinaria , Virus del Moquillo Canino , Moquillo/complicaciones , Neospora/aislamiento & purificación , Mapaches/parasitología , Animales , Cerebelo/parasitología , Coccidiosis/complicaciones , ADN Protozoario/aislamiento & purificación , Femenino , Inmunohistoquímica/veterinaria , Neospora/genética , Neospora/inmunología , Reacción en Cadena de la Polimerasa/veterinaria , Mapaches/virologíaRESUMEN
Toxoplasma gondii is a protozoal parasite with worldwide distribution that is able to infect a wide variety of mammals and birds. Our main goal was to screen for T. gondii antibody titers in a previously untested species, the spotted hyena ( Crocuta crocuta); however, this goal first required us to investigate serological procedures that could be suitable for hyenas. Cats are the closest domestic relations of hyenas, so T. gondii antibody titers were first compared in 26 feral cats with specific or nonspecific fluorophore-labeled secondary reagents, i.e., anti-cat IgG or protein A. Substitution of anti-cat IgG with protein A caused a statistically significant drop in titer measurements in cats (P = 0.01) with a reduction of the geometric mean titer equivalent to 1 doubling-dilution. The same procedures were then applied to captive spotted hyenas. Titers measured in 9 of 10 hyenas were identical whether anti-cat IgG or protein A was used as the secondary reagent: 5 had titers <1:16, 2 had titers of 1:16, and 2 had titers of 1:32. One hyena had maximum titers of 1:64 or 1:32 when anti-cat IgG or protein A was used, respectively. The use of protein A as the secondary reagent in serologic assays can be applied to a range of mammalian species and seems unlikely to affect test specificity; however, the use of protein A may reduce test sensitivity, as suggested in the present study using cats. Despite a control program, some exposure to T. gondii had occurred in the Zoo's spotted hyenas.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedades de los Gatos/parasitología , Hyaenidae/parasitología , Toxoplasma/inmunología , Toxoplasmosis Animal/parasitología , Animales , Enfermedades de los Gatos/inmunología , Gatos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Especificidad del Huésped , Sueros Inmunes , Inmunoglobulina G , Sensibilidad y Especificidad , Proteína Estafilocócica A , Toxoplasmosis Animal/inmunologíaRESUMEN
The ultrastructure of tachyzoites, bradyzoites and tissue cysts of the NC-1, NC-5 and NC-Liverpool strains of Neospora caninum are reviewed and compared with those of the VEG and ME-49 strains of Toxoplasma gondii. While each stage of N. caninum and T. gondii shared many ultrastructural characteristics, each parasite stage also had certain features or organelles that could be used to distinguish the two parasites. Some of the most prominent ultrastructural differences occurred in the number, appearance and location of rhoptries, looped-back rhoptries, micronemes, dense granules, small dense granules and micropores. The tissue cysts of both parasites were also basically similar, being surrounded by a cyst wall and not compartmentalised by septa. The cyst wall of N. caninum was irregular and substantially thicker, 0.5-4 microm, than those of T. gondii which were smooth and 0.5 microm thick.
Asunto(s)
Coccidiosis/veterinaria , Neospora/ultraestructura , Toxoplasma/ultraestructura , Toxoplasmosis Animal/parasitología , Animales , Bovinos , Coccidiosis/parasitología , Enfermedades de los Perros/parasitología , Perros , Ratones , Microscopía Electrónica , Neospora/crecimiento & desarrollo , Toxoplasma/crecimiento & desarrolloRESUMEN
Neospora caninum is a recently identified apicomplexan protozoan parasite that is closely related to Toxoplasma gondii. Neospora caninum is of significant economic importance as it causes neurological disease and abortion in numerous animals. Antibodies to BAG1/hsp30 (also known as BAG5), a T. gondii bradyzoite-specific protein, have been demonstrated to react with N. caninum tissue cysts in vivo. Bradyzoite differentiation of N. caninum in vitro was investigated using culture conditions previously utilised for T. gondii in vitro bradyzoite development. Utilising the NC-Liverpool isolate of N. caninum, cyst-like structures developed within 3-4 days of culture of this parasite in human fibroblasts. In addition, an antigen reacting with mAb 74.1.8 (anti-BAG1) and rabbit anti-recombinant BAGI was demonstrable by immunofluorescence, fluorescence-activated cell sorter, and immunoblot analyses. Expression of this antigen was increased by stress conditions, similar to that which has been described for T. gondii bradyzoite induction. Cyst-wall formation in vitro, as assayed by lectin binding, did not occur as readily for N. caninum as it does for T. gondii.
Asunto(s)
Neospora/crecimiento & desarrollo , Neospora/ultraestructura , Animales , Anticuerpos Monoclonales/inmunología , Antígenos de Protozoos/análisis , Antígenos de Protozoos/inmunología , Células Cultivadas , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Proteínas del Choque Térmico HSP30 , Proteínas de Choque Térmico/inmunología , Humanos , Immunoblotting , Proteínas de la Membrana/inmunología , Microscopía Electrónica , Neospora/inmunologíaRESUMEN
Dogs were investigated to determine if they are definitive hosts of Neospora caninum. Four dogs were fed N. caninum tissue cysts in infected mouse tissue, and two negative control dogs were fed uninfected mouse tissue. Dog faeces were examined daily for 30 days using a sucrose flotation technique. Three challenged dogs shed spherical to subspherical unsporulated oocysts, measuring 10 to 11 microns in diameter. Oocysts sporulated within 3 days and contained two sporocysts, each with four sporozoites. Outbred, inbred, and gamma-interferon knockout mice were inoculated with canine faecal extracts and monitored for evidence of neosporosis using a variety of morphologic, immunohistologic, serologic, and genetic analyses. Mice that received faeces from each dog observed to shed oocysts were demonstrated to have neosporosis by two or more techniques. One mouse was demonstrated to be infected with N. caninum by immunohistochemistry, ultrastructural analysis, and a species-specific PCR test. No evidence of neosporosis was observed in control animals. Based on this study, dogs are a definitive host of Neospora caninum.
Asunto(s)
Coccidiosis/veterinaria , Vectores de Enfermedades , Enfermedades de los Perros/parasitología , Neospora/aislamiento & purificación , Animales , Anticuerpos Monoclonales , Anticuerpos Antiprotozoarios , Especificidad de Anticuerpos , Encéfalo/parasitología , Células Cultivadas/parasitología , Coccidiosis/patología , ADN Protozoario/análisis , Enfermedades de los Perros/patología , Perros , Heces/parasitología , Técnica del Anticuerpo Fluorescente Indirecta , Interacciones Huésped-Parásitos , Inmunohistoquímica , Estadios del Ciclo de Vida , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Neospora/inmunología , Reacción en Cadena de la PolimerasaRESUMEN
Neospora caninum is a protozoan parasite of animals, which before 1984 was misidentified as Toxoplasma gondii. Infection by this parasite is a major cause of abortion in cattle and causes paralysis in dogs. Since the original description of N. caninum in 1988, considerable progress has been made in the understanding of its life cycle, biology, genetics and diagnosis. In this article, the authors redescribe the parasite, distinguish it from related coccidia, and provide accession numbers to its type specimens deposited in museums.
Asunto(s)
Coccidios/clasificación , Neospora/clasificación , Neospora/citología , Animales , Bancos de Muestras Biológicas , Coccidios/citología , Coccidios/fisiología , Coccidiosis/parasitología , Coccidiosis/patología , Perros/parasitología , Zorros/parasitología , Microscopía , Museos , Neospora/genética , Neospora/fisiología , Filogenia , Especificidad de la EspecieRESUMEN
Compressive lumbar myelopathy is a recognized iatrogenic complication of injecting water-in-oil vaccines into paravertebral sites of laboratory animals and chickens. Herein, we report the histologic and ultrastructural features of a similar complication in a herd of cattle. Iatrogenic posterior paresis developed over 34 days in 56 of 610 cows (9.2%) following injection of a commercial bacterin 11-34 days earlier into M. longissimus lumborum. The bacterin was composed of inactivated Escherichia coli and Campylobacter fetus ssp. venerealis in a proprietary adjuvant. Tissues were collected for histopathology from 9 affected cattle that died or were euthanized after clinical signs lasting 6-38 days. A range of tissues, including the injection site lesion and lumbar spinal nerve roots, was obtained for ultrastructural examination from a cow with paresis of 31 days duration. There was locally extensive pyogranulomatous myositis with fibrosis and necrosis in right M. longissimus lumborum. Extension of the lesion into the vertebral canal via spinal nerve foramina resulted in focal pyogranulomatous inflammation in epidural fat and in adjacent dura mater. There was axonal degeneration in dorsal, lateral, and ventral columns and chromatolysis of spinal motor neurons in lumbar spinal cord, secondary to compression. A distinctive histologic and ultrastructural feature of pyogranulomata was the presence of osmiophilic material at the center of inflammatory foci, surrounded by macrophages and giant cells that contained intracytoplasmic lipid droplets. Ultrastructural examination of entrapped spinal nerves revealed axonal degeneration and loss of myelinated and unmyelinated fibers, segmental demyelination with remyelination, axonal spheroid formation, and early axonal regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Adyuvantes Inmunológicos/efectos adversos , Enfermedades de los Bovinos/etiología , Enfermedad Iatrogénica/veterinaria , Radiculopatía/veterinaria , Compresión de la Médula Espinal/veterinaria , Adyuvantes Inmunológicos/administración & dosificación , Animales , Vacunas Bacterianas/administración & dosificación , Bovinos , Enfermedades de los Bovinos/patología , Femenino , Inyecciones Intramusculares , Región Lumbosacra , Microscopía Electrónica , Paresia/etiología , Paresia/patología , Paresia/veterinaria , Embarazo , Radiculopatía/etiología , Radiculopatía/patología , Compresión de la Médula Espinal/etiología , Compresión de la Médula Espinal/patología , Raíces Nerviosas Espinales/patologíaRESUMEN
A Holstein dairy farm suffered an abortion outbreak due to neosporosis. Abortion losses were > 18%. Cows with the highest Neospora antibody titers were at the greatest risk of aborting. Mummified fetuses were found after the 43rd day of the outbreak. The epidemic curve was suggestive of a point source exposure, which is consistent with the hypothesis that Neospora can be spread by a definitive host.
Asunto(s)
Aborto Veterinario/parasitología , Enfermedades de los Bovinos , Coccidiosis/veterinaria , Neospora , Complicaciones Parasitarias del Embarazo/veterinaria , Aborto Veterinario/epidemiología , Animales , Anticuerpos Antiprotozoarios/sangre , California/epidemiología , Bovinos , Coccidiosis/embriología , Coccidiosis/epidemiología , Estudios de Cohortes , Brotes de Enfermedades , Femenino , Feto/parasitología , Incidencia , Embarazo , Complicaciones Parasitarias del Embarazo/epidemiologíaRESUMEN
Pregnant ewes inoculated with cultured Neospora caninum tachyzoites in 1995, 1996, or 1995 and 1996 aborted or delivered weak or clinically normal lambs in 1996. Nine of 11 ewes in the study had previously produced infected lambs or fetuses after being experimentally infected in 1995. Fetuses and lambs produced in 1996 showed histologic lesions and zoites indicative of Neospora. Serologic responses and production of infected fetuses/lambs indicated systemic neosporosis in the ewes during gestation, although tachyzoites could not be cultured from maternal tissues. The repetitive infection of fetuses, and resulting clinical and histopathologic findings in the present study are similar to those reported in naturally infected cattle, adding to the already established similarities of neosporosis between sheep and cattle.
Asunto(s)
Aborto Habitual/veterinaria , Aborto Veterinario/parasitología , Coccidiosis/veterinaria , Neospora/fisiología , Enfermedades de las Ovejas/parasitología , Aborto Habitual/parasitología , Aborto Veterinario/fisiopatología , Animales , Animales Recién Nacidos , Anticuerpos Antiprotozoarios/sangre , Encéfalo/embriología , Encéfalo/parasitología , Chlorocebus aethiops , Coccidiosis/complicaciones , Coccidiosis/transmisión , Femenino , Feto/parasitología , Feto/patología , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Corazón/parasitología , Transmisión Vertical de Enfermedad Infecciosa/veterinaria , Embarazo , Ovinos , Enfermedades de las Ovejas/transmisión , Células VeroRESUMEN
Three pregnant cows were each orally challenged at 10 weeks of gestation with 600 sporulated oocysts of Neospora caninum. The number of oocysts was limited by those available. In concurrent bioassays, one oocyst per os infected each of two gerbils. Challenged cattle developed Neospora-specific antibody, cell proliferation and gamma-interferon responses. N. caninum specific PCR demonstrated persisting infection in the brains of cows 4 months after calving. Abortion was not induced and there was no evidence of transplacental infection in the healthy calves born at full-term. This experiment suggests that the dose threshold for induction of abortion exceeds 600 oocysts.
Asunto(s)
Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/parasitología , Coccidiosis/inmunología , Coccidiosis/veterinaria , Neospora/inmunología , Oocistos/inmunología , Complicaciones Infecciosas del Embarazo/inmunología , Complicaciones Infecciosas del Embarazo/veterinaria , Animales , Anticuerpos Antiprotozoarios/inmunología , Anticuerpos Antiprotozoarios/aislamiento & purificación , Bioensayo , Encéfalo/parasitología , Bovinos , Enfermedades de los Bovinos/transmisión , Coccidiosis/parasitología , Coccidiosis/transmisión , ADN Protozoario/aislamiento & purificación , Femenino , Feto/inmunología , Gerbillinae/parasitología , Transmisión Vertical de Enfermedad Infecciosa , Intercambio Materno-Fetal , Oocistos/citología , Reacción en Cadena de la Polimerasa , Embarazo , Complicaciones Infecciosas del Embarazo/parasitologíaRESUMEN
Neospora caninum was isolated from the brain of an adult dog in Brazil. Cerebral tissue from the dog was inoculated into Mongolian gerbils. Gerbils were euthanized 3-4 months later and bradyzoite-containing tissue cysts were observed in their brains. N. caninum (designated NC-Bahia) was isolated in cell culture after inoculation with tissue cysts from the gerbils. The identity of the parasite was confirmed by immunohistochemical examination and polymerase chain reaction (PCR). Gerbils may be a useful alternative to immunosuppressed mice for isolation of N. caninum and for production of encysted bradyzoites.