Incidence and transplacental transmission of Neospora caninum in primiparous females from Bos indicus slaughtered in Presidente Pradente, São Paulo, Brazil

To produce an epidemiological map of neosporosis in Brazil and identify the types of transmission of this disease, the present study evaluated the occurrence of Neospora caninum in Nelore cattle (Bos indicus) in Presidente Prudent, west region of São Paulo state; its vertical transmission; and the early stage in which fetuses are infected. To achieve this, serum samples from 518 slaughtered pregnant heifers and their fetuses were tested by ELISA technique and fetal brain tissues subjected to PCR. One hundred and three heifers (19.88%) had antibodies to N. caninum, as well as 38 (36.8%) of fetuses from 4 months of gestation. The conventional PCR failed to detect N. caninum DNA. These findings show that neosporosis occurs in the area studied and that it may be transmitted the transplacental route, althought N. caninum had not detected in brain tissue from non-aborted fetuses. The use of nested PCR it would be applied to increase the sensitivy of test.

Freqüência de anticorpos anti-Neospora caninum em soros de caprinos do estado de São Paulo e sua relação com o manejo dos animais

Com o objetivo de se avaliar a freqüência de caprinos leiteiros soropositivos para Neospora caninum, no estado de São Paulo, e se verificarem possíveis associações com idade, sexo e problemas reprodutivos, nos capris, e, também, presença de cães, nas propriedades, foram obtidos soros de 923 caprinos de ambos os sexos e idade acima de 3 meses. Os animais eram provenientes de 17 propriedades de diferentes municípios. Para o diagnóstico, foi utilizado o teste de aglutinação para Neospora (NATe25), e, em todos os capris, aplicou-se um inquérito a partir do qual se obtiveram informações epidemiológicas e de esfera reprodutiva. Todos os resultados estatísticos foram discutidos no nível de 5% de significância. Assim, chegou-se à conclusão de que a freqüência percentual de positividade para N. caninum foi de 19,77%, e, em apenas uma propriedade, não houve registro de animal soropositivo, o que revela difusão do agente, no Estado. Não foram verificadas diferenças significativas entre freqüências de positividade quanto ao sexo, idade ou problemas reprodutivos. Porém, ressalta-se que a presença de cães, nos capris, foi associada a uma maior freqüência de caprinos soropositivos a N. caninum. A representação geográfica da distribuição de caprinos soropositivos para o protozoário, em mapa coroplético em hachuras, pode implicar em um ganho considerável para estudos da epidemiologia geográfica, na elaboração de um planejamento de controle da enfermidade.

Detection and molecular analysis of Toxoplasma gondii and Neospora caninum from dogs with neurological disorders

Introduction: Toxoplasma gondii and Neospora caninum are related Apicomplexa parasites responsible for systemic diseases in many species of animals, including dogs. Methods: This study aimed to determine the occurrence of T. gondii and N. caninum infections in 50 dogs with neurological signs that were admitted to the Veterinary Hospital of Universidade Estadual Paulista, City of Botucatu, Brazil. All animals were screened for antibodies using an immunofluorescent antibody test for both parasites. Tissues of positive animals were bioassayed in mice (T. gondii) and gerbils (N. caninum), and DNA was analyzed using the polymerase chain reaction (PCR). Positive samples for T. gondii by PCR were typed using restriction fragment length polymorphism-PCR for 11 markers: SAG1, SAG2 (5'-3'-SAG2 and alt.SAG2), SAG3, Btub, GRA6, L358, c22-8, c29-6, PK1 and Apico, and CS3 marker for virulence analysis. Results: Specific antibodies were detected in 11/50 (22%; 95% confidence interval (CI95%), 12.8-35.3%) animals for T. gondii and 7/50 (14%; CI95%, 7.02-26.3%) for N. caninum. In the bioassay and PCR, 7/11 (63.6%; CI95%, 34.9-84.8%) samples were positive for T. gondii and 3/7 (42.9%; CI95% I, 15.7-75.5%) samples were positive for N. caninum. Three different genotypes were identified, but only 1 was unique. Conclusions: These data confirm the presence of T. gondii and N. caninum in dogs from Brazil, indicating the importance of this host as a sentinel of T. gondii for human beings, and the genotypic variation of this parasite in Brazil.

Serological profile of Toxoplasma gondii and Neospora caninum infection in commercial sheep from São Paulo State, Brazil

Neosporosis and toxoplasmosis are two important infections in young and adult sheep, leading to low production and abortion. This study aimed to determine the frequency of antibodies to Toxoplasma gondii and Neospora caninum in sheep from the eastern region of São Paulo State, Brazil. Serum samples (382) were collected from the sheep and assayed for T. gondii through modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT), and for N. caninum antibodies, through IFAT, with cut-off titers equal to 16 (T. gondii) and 25 (N. caninum). All frozen samples were sent to the Center for Zoonoses Research (NUPEZO), Department of Veterinary Hygiene and Public Health (DHSVP), FMVZ, UNESP, for serological tests. A total of 71/382(18.6%) samples reacted to T. gondii, especially at titers 16 (28; 39.4%), 64(15; 21.1%), 256 (21; 29.6%) and 1024 (6; 8.5%) by MAT, and 16(34: 47.9%), 64 (18; 25.4%), 256 (14; 19.7%) and 1024 (5; 7%) by IFAT. As regards N. caninum, 49/382 (12.8%) samples reacted at titers 25 (17; 34.7%), 50 (11; 22.5%), 100 (11; 22.5%), and >= 200 (10; 20.4%). These animals presented infection but no clinical signs. Six and ten animals had high titers for toxoplasmosis and neosporosis. No significant association was observed between antibodies for both parasites (P = 0.535) according to Fisher's exact test, and no correlation was found between T. gondii (MAT) and N. caninum antibody titers (r = -0.0068; P=0.895), T. gondii (IFAT) and N. caninum antibody titers (r = -0.0025; P = 0.961). Thus, T. gondii and N. caninum infections were observed in farms located in São Paulo State, where sheep play an important economical role for the national and regional business. (C) 2010 Elsevier By. All rights reserved.

Neospora caninum infection dynamics in dairy cattle

Neospora caninum is considered in many countries as one of the key abortion agents in cattle. This study aims to investigate the parasite behavior in dairy cattle in the municipality of Avar,, SP, Brazil, where abortions frequently occur. An ELISA was performed to compare two samplings on a total of 615 animals; tests were performed in the same herds with a gap of 3 years. An increase in the percentage of reactive animals was observed, ranging from 21.6% at the first sampling to 38.9% at the second sampling. of the 176 animals tested at both samplings, 61.93% retained a non-reactive status, 15.9% retained a reactive status, 19.88% switched from non-reactive to reactive and 2.27% switched from reactive to non-reactive. of the 100 animals with reproductive disturbances, 50% presented anti-Neospora antibodies, thereby indicating the presence of the protozoa. When comparing cows and their respective female offspring, a predominance of horizontal infection was observed. Moreover, considering the significant percentage of animals that switched from non-reactive to reactive and the abundant presence of dogs among the herds, the N. caninum transmission may be attributed to presence of carnivores.

Serological survey of Neospora caninum in small ruminants from Pernambuco State, Brazil

A infecção por Neospora caninum é uma importante causa de abortos em bovinos, assim como mortalidade neonatal em caprinos e ovinos. Uma pesquisa sorológica de anticorpos anti-N. caninum foi realizada no município de Ibimirim (PE, Brasil). Os resultados ao teste de imunofluorescência revelaram que 26,6% (85/319) dos caprinos e 64,2% (52/81) dos ovinos foram positivos. A reatividade à sorologia foi associada com a idade nos caprinos (p < 0,01) e ovinos (p > 0,05), com maior ocorrência nos animais mais velhos. Estes resultados indicam exposição a N. caninum entre pequenos ruminantes na área estudada.

Toxoplasma gondii and Neospora caninum serological status of different canine populations from Uberlândia, Minas Gerais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seroprevalence of Toxoplasma gondii and Neospora caninum in captive maned wolves (Chrysocyon brachyurus) from southeastern and midwestern regions of Brazil

The main purpose of the present study was to investigate the occurrence of antibodies against T gondii and N. caninum in captive maned wolves from Brazil, considering that little information is available at the literature about infections by these parasites in this wild animal. Serum samples were obtained from 59 maned wolves originated from six zoos and from one ecological reserve of the southeastern and midwestern regions of Brazil. To detect IgG antibodies against T gondii, an ELISA protocol was used and the results were expressed as ELISA reactivity indexes (131). Serology for N. caninum was carried out by indirect fluorescent antibody test (IFAT) and cut-off titers were established at 1:25 dilution. From the total of the analyzed samples, 44 (74.6%) were seropositive for T gondii and only 5 (8.5%) for N. caninum. Seropositivity for T gondii ranged from 0 to 100% in the seven different origin locals, with rates over 50% among the six zoos, whereas no positivity was found in the samples from ecological reserve. For N. caninum, seroprevalence varied from 0 to 50% in the different locals, with the highest rates also detected in zoos. Seroprevalence for T gondii was strongly related with age, with rates significantly higher among adult wolves (91.7%) when compared to newborn or young animals. Seropositive samples for N. caninum were found predominantly in adult wolves. For both parasites, seroprevalence did not show a significant distinction in relation to gender. Although seroprevalence for T gondii was significantly higher when compared to N. caninum in the Brazilian captive maned wolves tested, these findings reflect the great exposure of this species to T gondii and, in lower extension, to N. caninum. Also, the present study demonstrated for the first time the presence of antibodies to N. caninum in wild life from South America. (C) 2004 Elsevier B.V. All rights reserved.

Serological responses to Neospora caninum in experimentally and naturally infected water buffaloes (Bubalus bubalis)

The water buffalo (Bubalus bubalis) is an important natural host for Neospora caninum. Serologic responses to N. caninum were studied in experimentally and naturally infected water buffaloes in Brazil. Antibodies were assayed by the indirect fluorescent antibody test (IFAT) using a cut off value of 1:25. Six buffaloes were each inoculated subcutaneously with 5 x 106 live culture-derived tachyzoites of the cattle Illinois strain of N. caninum, and two calves were kept as uninoculated controls. Post-inoculation (p.i.) blood samples were collected weekly for 8 weeks and then monthly until 1 year p.i. All inoculated buffaloes developed IFAT titers of 1:100 or more between 7 and 11 days p.i. and the titers remained elevated until 7 weeks p.i. Antibody titers peaked to 1:1600 in 1, 1:800 in 3 and 1:400 in 2, usually by 3 weeks p.i. Antibody titers declined to 1:25 or 1:50 in all the six buffaloes by 12 months p.i. IFAT titers to N. caninum remained at an undetectable level (< 1:25) in both control uninoculated buffaloes. To follow the dynamics of N. caninum antibodies, sera from 29 buffaloes and their calves were collected for 1 year and assayed for N. caninum antibodies; 23 of 29 calves were seropositive (IFAT of 1:100 or more) at 1-2 day of age. of these 23 calves, 17 remained seropositive during the study, while six became seronegative at four (two calves), six (one calf) seven (two calves) and eight (one calf) months of age. These findings suggest a high rate of neonatal transmission of N. caninum in buffaloes. Published by Elsevier B.V.

Seroprevalence of Neospora caninum in dairy cattle in Bahia, Brazil

Sera collected from 447 dairy cattle on 14 dairy farms were tested for Neospora caninum antibodies by use of an immunofluorescent antibody technique. Positive reactions with titres greater than or equal to 1:200 were found in 63 (14.09%) of animals. Neospora positive sera were also tested for Toxoplasma gondii antibodies by using a commercial latex agglutination test. Antibodies to T. gondii were detected in 3 (4.76%) of 63 N. caninum positive sera. These results indicate that N. caninum infection is widespread among dairy cattle in Bahia state. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Detection of IgG antibodies to Neospora caninum and Toxoplasma gondii in dogs examined in a veterinary hospital from Brazil

A total of 163 dogs with neuromuscular, respiratory and/or gastrointestinal disorders, was admitted at the Veterinary Hospital, Federal University of Uberlandia, Brazil, and submitted to serology for Toxoplasma gondii and Neospora caninum. Assays for T gondii included indirect haemagglutination (IHA), indirect fluorescent antibody (IFAT-Tg), immunoenzymatic (ELISA), and immunoblotting (IB-Tg). Assays for N, caninum included IFAT-Nc and immunoprecipitation (IP-Nc). Based on concordant results by three serological tests (IHA, IFAT-Tg and ELISA) for T gondii, and divergent results further confirmed by IB-Tg for reactivity to TgSAG1, the 163 sera were divided into two groups: 59 (36%) Tg-seropositive samples and 104 (64%) Tg-seronegative samples. Antibodies to Neospora were detected in 11 (6.7%) out of 163 analyzed dog sera, with 5 (3.1 %) samples reactive to both parasites (Tg+/Nc+), and 6 (3.7%) reactive only to Neospora (Tg-/Nc+). Antibodies only to T: gondii were found in 54 (33%) samples. Among the 11 Neospora-positive sera analyzed by IB-Tg, the five sera Tg+/Nc+ showed strong reactivity to Toxoplasma antigens, especially to TgSAG1 (p30). No reactivity was observed to TgSAG1 in the six samples Tg-/Nc+. By TP-Nc, two highly immunodominant antigens (29 and 35 kDa proteins) were recognized by all 11 IFAT-Nc positive sera. Our results suggest that the infection by N, caninum can be concomitantly present in dogs from this area, although less common, and therefore should be considered in the differential clinical diagnosis with T. gondii in dogs presenting neuromuscular, respiratory and/or gastrointestinal disorders. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Antibodies to Neospora caninum and Toxoplasma gondii in domestic cats from Brazil

The occurrence of antibodies to Neospora caninum and Toxoplasmagondii was determined in 400 domestic cats (Siamese, Persian, and undetermined breeds) from the Municipality of Aracatuba, São Paulo, Brazil, through the indirect fluorescence antibody test (IFAT). of the 400 cats, 100 were seropositive to T. gondii (25%, titer >= 64) and 98 to N. caninum (24.5%, titer >= 16). The rate of seropositive cats for T. gondii was correlated with age (chi(2)=35.7; p < 0.001), with a higher number of infected animals at older ages. of the 219 cats younger than 1-year-old, 13.2% were seropositive for T. gondii, while 39.2% were positive in the 181 older animals. The presence of N. caninum was also correlated with age (divided by(2)=8.8; p < 0.01), with 18.7% (41/219) and 31.5% (57/181) of positive animals at ages below and above 12-month, respectively. An association between the occurrences of both protozoa in the felines was also observed (chi(2)=19.6; p < 0.001).