Neosporosis in Mexican Dairy Herds: Lesions and Immunohistochemical Detection of Neospora caninum in Fetuses (original) (raw)
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Veterinary Parasitology, 2001
Neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. In this study, the role of N. caninum was investigated in groups of aborted cattle and dairy herds from the west of France. Good correlation was found between parasite DNA detection in fetuses and serologic statuses of dams. In groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropostive for N. caninum, and significant relationship between prevalence of Neospora antibodies and frequency of abortions was found. Neospora-associated abortions were observed all the year round, with a peak in summer. Higher ratios of seropositive abortions were found before the 6th month of gestation. In 12 herds studied in the field, serologic prevalence ranged 6-47%. No difference in age was found between seropositive and seronegative cows. Results indicate that N. caninum is an important and stable cause of abortion in cattle in France.
Neospora caninum infections in bovine foetuses and dairy cows with abortions in Argentina
International Journal for Parasitology, 1999
Antibodies to Neospora caninum were measured in bovine foetuses, dairy cows and beef cows in Argentina using the IFAT, the N. caninum agglutination test, and the recombinant NCDG1 and NCDG2 ELISA. Serum antibodies (IFAT titre 1:80) were found in 20 of 82 (24.4%) dairy cow foetuses and one of 22 (4.5%) beef cow foetuses. Microscopic lesions suggestive of neosporosis were seen in brains of seven of eight foetuses with IFAT titres of 1:80. Antibodies (IFAT) were found in 122 of 189 (64.5%) dairy cows that aborted. Serum antibody titres (IFAT) of 189 dairy cows that aborted were: <1:25 (67 cows), 1:25 (four cows), 1:50 (16 cows), 1:200 (seven cows), 1:r800 (95 cows). Of the 87 sera with IFAT titres of 1:50, 57 had no antibodies in 1:40 dilution and 30 had titres of 1:40 in the N. caninum agglutination test. Thus, sera from at least 56 dairy cows which had aborted were seronegative both in the N. caninum agglutination test and the IFAT. The distribution of positive and negative sera was similar when measured by ELISA, except that, depending on cut-o titre, the ELISA indicated a greater number of seropositive cows that were negative by the IFAT and N. caninum agglutination test. These results suggest that transplacental transmission of N. caninum in dairy cows in Argentina is frequent.
Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina
Veterinary Parasitology, 2002
The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution ≥1:200 and ≥1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or ≤ to 50%) of seropositive dogs. Additionally, the seroprevalence in beef and dairy cattle cohabiting in the same farm with these dogs was compared. Microscopic studies were performed in 188 aborted fetuses and/or their placentas. Formalin-fixed fetal tissues with microscopic lesions compatible with N. caninum were processed by immunohistochemistry (IHC). The seroprevalence in cows without reproductive diseases was 4.7% (19/400) for beef cattle and 16.6% (174/1048) for dairy cattle. The seroprevalence of N. caninum in dairy cattle was higher (P < 0.05) in farms grouped according to the percentage (> or ≤ to 50%) of seropositive dogs. The analysis of 966 serum samples from aborted cows, demonstrated positive 18.9% (41/216) and 43.1% (323/750) from beef and dairy herds, respectively. Microscopic lesions compatible with N. caninum were observed in 43 of 188 (22.8%) fetuses and/or placentas evaluated. The protozoan was identified in 29 of 43 (67.4%) aborted specimens, being the largest number of positive results : S 0 3 0 4 -4 0 1 7 ( 0 2 ) 0 0 1 2 9 -2 304 D.P. Moore et al. / Veterinary Parasitology 107 (2002) [303][304][305][306][307][308][309][310][311][312][313][314][315][316] in dairy fetuses. The results obtained demonstrate a high association between neosporosis and dairy herds, however, our data also reveals that N. caninum is an important risk factor for reproductive losses in the extensively farmed beef cattle in the Humid Pampas of Argentina.
Microbial pathogenesis, 2015
Neosporosis is a parasitic disease cause by Neospora caninum, a parasite of great importance in livestock. This study aimed to evaluate the presence of antibody against N. caninum in dairy cattle with history of abortion, as well as to identify associated risk factors for neosporosis. Animals suspected of neosporosis (n = 130) after clinical examination were randomly selected. Sera samples from 29 farms were submitted to indirect immunofluorescence technique (IFA) in order to detect antibodies against N. caninum, and animals were considered positive if ≥IFA 1:200. An epidemiological questionnaire was used to verify probable risk factors for neosporosis and their cause-effect relation. Serological results showed that 43.8% of the animals were seropositives for N. caninum. The univariate statistical analysis found a significant relation between neoporosis and age. The number of pregnancies and the number of years that the farms had been producing milk were found as associated risk fac...
Objectives. To determine Neospora caninum seroprevalence in nonvaccinated dairy cattle from the Northern plains of Antioquia. Materials and methods. A cross-sectional study was conducted to determine the prevalence of neosporosis in a major dairy area of Colombia. Blood samples were collected from 1003 dairy cattle in 29 herds located in the municipality of San Pedro de los Milagros, in Antioquia. N. caninum antibody levels were measured by an enzymatic immunoassay (ELISA) and the results classified as positive or negative. Results. Seropositive cattle were observed in all herds, with a prevalence ranging from 7 to 97% and a mean (±S.E) of 37.1% (±4.2). The distribution of seropositive animals by age groups of <1, 1-2, 2-3 and ≥3 years old was 25.5, 30.3, 46.1 and 39.1%, respectively. Conclusions. There is a high seroprevalence of N. caninum in the main dairy cattle area of Antioquia. The large variation among herds suggests the presence of mayor risk factors whose identification would be essential to establish control programs. Considering that any seropositive cow has a greater risk to abort than uninfected mates, future studies should address the epidemiology of abortions that can be attributed to neosporosis and the type of control strategies that could be implemented. RESUMEN Objetivos. Determinar la seroprevalencia de Neospora caninum en ganado lechero sin vacunar del altiplano Norte de Antioquia. Materiales y métodos. Se realizó un estudio transversal para determinar la prevalencia de neosporosis en bovinos de la principal zona lechera antioqueña. En Mayo-Junio del 2014 se recolectaron muestras de sangre de 1003 bovinos en 29 hatos ubicados en el municipio de San Pedro de los Milagros, en Antioquia. Los niveles de anticuerpos de N. caninum se midieron mediante un kit de inmunoensayo enzimático (ELISA) y los resultados se clasificaron como positivos o negativos. Resultados. Se observaron bovinos seropositivos en todos los hatos, con una prevalencia entre el 7 y 97%, y una media (±SE) del 37.1% (±4.2). La distribución de los animales seropositivos por grupos
Veterinary Parasitology, 2002
Neospora caninum was isolated from the brain of an aborted 4-month-old fetus from a dairy cow herd with endemic neosporosis in Porto, Portugal. The fetal brain homogenate was inoculated interperitoneally first into outbred Swiss Webster mice given dexamethasone and then the peritoneal exudates from these mice was co-inoculated with mouse sarcoma cells in the peritoneal cavity of mice given dexamethasone. N. caninum tachyzoites were seen in peritoneal exudate of the second passage. Tachyzoites from the peritoneal exudate reacted positively with anti-N. caninum antibodies and not with anti-Toxoplasma gondii antibodies and contained N. caninum specific DNA. This Portuguese isolate of N. caninum has been successfully maintained in cell culture. The dam of the aborted fetus had an antibody titer of 1:10240 in the Neospora agglutination test (NAT). Antibodies to N. caninum were found in 76 of 106 cows from this herd in titers of 1:40 in 31, 1:80 in 22, ≥1:160 or more in 23 in the Neospora agglutination test. This is the first isolation of a viable N. caninum-like parasite from any host in Portugal.
The objective of this study was to report the presence of Neospora caninum-associated abortion in bovines at a farm in the northeast region of São Paulo State. In January 2010, it was sent to the Department of Pathology, UNESP-Jaboticabal, a bovine fetus with an estimated age of seven months, which was natural of a dairy farm with 300 animals and an average daily production of 3,000 liters of milk, nearly 20 liters per cow. The animals were vaccinated against rabies, foot and mouth disease, carbuncle, brucellosis, leptospirosis, bovine herpes virus type I and bovine viral diarrhea virus. The herd consisted of purebred Holstein animals, Jersey, and mostly by crossbred animals 7-8 (gir x holstein). During necropsy, samples of the serosanguineous liquid present at the thoracic cavity and the heart of the fetus were collected for the detection of anti-Neospora caninum antibodies through Indirect Immunofluorescence Assay (IFA). Fragments of brain, cerebellum, tongue, liver, heart and kidneys were collected for the execution of histopathology (HP), immunohistochemistry (IHC) and Polymerase Chain Reaction. In order that IFA could be performed, the owner was requested blood samples without anticoagulants of the mother and other cows in the farm, with or without a history of abortion. At necropsy, it was verified a severe autolysis of the fetus. The serology of the fetus was 1:25, while the serology of the mother was 1:3,200. At HP, it was observed discrete multifocal non-suppurative encephalomyelitis characterized by gliosis and mononuclear inflammatory infiltration associated with cellular debris. DNA amplification of N. caninum was positive in fragments of brain, tongue, cerebellum, heart and kidneys. At IHC, it has been observed immunoreactivity to a cyst located in the tongue. The owner reported that his herd showed endemic episodes of abortion, while 27.69% (18/65) of the 65 animals sampled were seropositive. Although it has not been a significant difference (p>0.05), a higher seropositivity was observed in animals with a history of abortion (10/26) 38.46%, in comparison with animals without previous abortion (8/39) 20.51%. These findings show that the abortion under study was provoked by the protozoan N. caninum, while this is the first report concerning cattle in the northeast region of São Paulo State.
Neospora-associated Abortion Episode over a 1Year Period in a Dairy Herd in North-east Spain
Journal of Veterinary Medicine Series B-infectious Diseases and Veterinary Public Health, 2004
This report describes a retrospective study based on serological screening, performed on a Neospora-associated abortion episode over a 12-month period in a dairy herd in north-east Spain. During the 1-year study period, the overall abortion rate for the herd was 23.2% (38 abortions of 164 diagnosed pregnancies). The data analysed were those derived from blood samples collected from the whole herd (n ¼ 237) and from diagnosed pregnancies. Antibodies to Neospora caninum were found in 35.4% of the cattle with 44% of seropositive pregnant animals aborting over 1-year period. Based on the odds ratio, the risk of abortion was 12.2 times higher (P < 0.0001) in the Neospora-seropositive animals than in seronegative animals and significantly higher during the second term of gestation (P < 0.01) than during the first and third terms. Abortions were not found to be associated with parity status or season of pregnancy, and the common risk factors associated with pregnancy loss in the geographical area of the study. Age-related differences in N. caninum seroprevalence were not statistically significant, indicating vertical transmission as the main route of infection. Indeed, a high percentage of congenitally infected offspring was observed (90.6%) and the farm had been free of dogs for the last 7 years. Our results suggest that, when a dairy herd shows an increased incidence of abortions due to Neosporosis, maternal serology can be a good indicator of the abortion risk in individual cows, and that the effects of factors normally related to abortion, such as parity and pregnancy season, may be masked.
Iranian Journal of …, 2009
Background: The objective of the study was to evaluate the presence of Neospora caninum organisms in the brain of aborted fetuses and placentas of full-term calves born of seropositive cows. Methods: During 2006-2007, 12 brains of aborted calves from Neospora seropositive cattle and 7 placentas from seropositive dams giving birth to full-term calves, from four dairy cattle farms located around Tehran province, Iran were examined by Nested-PCR and histopathology techniques. Result: The Nested-PCR demonstrated that all of 12 aborted fetal brain samples and 5 of 7 placentas were infected by N. caninum. Mild to severe placentitis was observed in 5 placentas. Severe hyperemia and perivascular and perineuronal edema revealed in all fetal brain. In 3 out of 12 brains, scattered foci of hemorrhages, neuropilar necrosis and gliosis were present. In addition, nonpurulent encephalitis with severe lymphohistiocytic perivascular cuffing in one case and a small tissue cyst like Neospora caninum cyst in other calf were observed. Conclusion: Our results confirmed the molecular and histopathologic findings of other studies about Neospora caninum infection and it seems to support the hypothesis that Neospora infection is associated with bovine abortion in Iran.