Detection of Toxoplasma gondii by PCR and mouse bioassay in commercial cuts of pork from experimentally infected pigs

The distribution of T. gondii in commercial cuts of pork (ham, tenderloin, spareribs and arm picnic) by PCR and bioassay from experimentally infected pigs, was evaluated. Eighteen mixed breed pigs were divided into two groups (G). The G1 animals (n=10) were infected with 4 x10(4) oocysts of the T. gondii VEG strain and the G2 animals (n=8) were used as control. Pigs of both groups were slaughtered at 59th day after infection, and meat samples were collected for bioassay and PCR. All animals from G1 were positive by at least one or both tests, and all control animals were negative. T. gondii was identified in pork by mouse bioassay and PCR in 27/40 (67.5 percent) and in 9/40 (22.5 percent) of the evaluated samples, respectively. There were no statistical differences in the distribution of tissue cysts from commercial cuts of pork by bioassay (P>0.05). However, statistical differences were observed when mouse bioassay and PCR were compared (P<0.01).

Avaliou-se a presença de T. gondii em cortes comerciais de carne suína (pernil, lombo, costela e paleta), por meio do bioensaio e PCR, em animais experimentalmente inoculados. Dois grupos (G) foram formados. Os animais do G1 (n=10) foram inoculados com 4 x10(4) oocistos da cepa VEG e os do G2 (n=8) permaneceram como grupo-controle, não inoculado. Todos os animais foram abatidos no dia 59 após a infecção, quando foram colhidas as amostras de carne para a realização das provas de bioensaio e da PCR. Todos os suínos do G1 apresentaram-se positivos a pelo menos um dos testes de diagnóstico ou a ambos, e os do grupo-controle permaneceram negativos. Não houve diferenças significativas em relação aos tipos de cortes comerciais e à presença do parasita no bioensaio (P>0,05). O bioensaio foi capaz de detectar T. gondii em 27/40 (67,5 por cento) amostras e a PCR em 9/40 (22,5 por cento). O estudo mostrou diferença entre o bioensaio e a PCR (P<0,01).

Dairy cow abortion associated with Neospora caninum and other infectious agents

Trinta e cinco vacas de rebanhos leiteiros da região Norte do estado do Paraná, com histórico de abortamento, foram pesquisadas sorologicamente para verificar a presença de anticorpos contra Neospora caninum, Toxoplasma gondii, Leptospira spp., Brucella abortus, BHV-1 e BVDV. Vinte e uma vacas apresentaram títulos sorológicos compatíveis com infecção. Todas elas, soropositivas para N. caninum, foram também soropositivas para outros agentes infecciosos, sugerindo a possibilidade de associação desses agentes nos problemas reprodutivos de bovinos, no estado do Paraná.

Occurrence of antibodies to Neospora caninum and Toxoplasma gondii in dairy cattle from the northern region of the Paraná State, Brazil

Foram analisadas, por meio da imunofluorescência indireta, 385 amostras de soros de vacas, pertencentes a 90 propriedades leiteiras de 12 municípios da região Norte do estado do Paraná. Foram observados 45 (12%) sororeagentes ao Neospora caninum e 102 (26%) ao Toxoplasma gondii. Apenas quatro animais apresentaram títulos de anticorpos para ambos os coccídios. Não foi observada diferença significativa na associação entre a sorologia do N. caninum e as variáveis relacionadas ao manejo, produção de leite, problemas reprodutivos, alimentação, presença de cães, gatos e roedores. Os resultados sugerem que neosporose e toxoplasmose estão disseminadas nos rebanhos leiteiros da região Norte do estado do Paraná, e a freqüência simultânea de anticorpos anti-N. caninum e anti-T. gondii, demonstra sua ocorrência independente em vacas leiteiras.

Vaccination of pigs with Toxoplasma gondii antigens incorporated in immunostimulating complexes (iscoms)

Immunity to Toxoplasma gondii was studied in pigs, after vaccination with T. gondii antigens incorporated into immunostimulating complexes. Nine pigs (group 1 - G1) were inoculated subcutaneously with T. gondii iscoms (LIV-5 sample) and three doses were given at 21 and 13 day-intervals. The results were compared in other three groups of nine pigs each: animals in group 2 (G2) were immunized with the LIV-5 antigens without Quil A, animals in group 3 (G3) were inoculated with tachyzoites of RH T. gondii isolate, and animals in group 4 (G4) received no vaccination. Four animals were neither vaccinated nor challenged with T. gondii (group 5 - G5). Thirty days after vaccination, pigs were challenged orally with 5´10(4) oocysts at AS-28 T. gondii isolate. Euthanasia was carried out 47 days after challenge and specimens of the heart, muscle, brain, liver, tongue and retina were inoculated into mice. Three out of nine pigs from G2 and one out of nine pigs from G4 showed hypertermia after the challenge. Antibody response was analysed by indirect fluorescent antibody test. The first iscom immunization (G1) induced low antibody levels, the second and third produced high antibody levels, similarly to the RH isolate infection (G3). Western blotting analysis indicated that the antibody response in animals in G1, after challenge, was more intense than in animals in the non-vaccinated group. T. gondii was not isolated by bioassays from tissues of iscom vaccinated pigs, while recovery was obtained from four animals in G4, one in G2 and one in G3.

Freqüência de anticorpos contra Babesia bigemina, B. bovis e Anaplasma marginale em rebanhos leiteiros da regiäo de Londrina, Paraná / Frequency of antibodies against Babesia bigemina, B. bovis and Anaplasma marginale in dairy farms of Parana State, Brazil

Sera collected from 417 dairy cows from Londrina, PR, Brazil, were analysed by the indirect fluorescent antibody test (IFAT) for the presence of anitbody against Babesia bigemina, Babesia bovis e Anaplasma marginale. All samples were tested diluted 1:80 using rabbit anti-bovine IgG FITC conjugate diluted 1:100. Among the samples, 289 (67.30 per cent), 251 (60.19 per cent) and 281 (67.38 per cent) showed reactivity to B. bigemina, B. bovis and A. marginale, respectively. Although the number of reactive animals as relatively high, considerable percentages of negative animals (30.70 per cent, B. bigemina, 39.18 per cent, B. bovis and 32.62 per cent, A. marginale) were susceptible, characterizing the situation as enzootically instable

Levantamento soroepidemiológico da toxoplasmose em ovinos na regiäo de Londrina, Paraná / Epidemiological study of ovine toxoplasmosis in Londrina region, Parana State, Brazil

Three hundred and seventy serum samples collected from ovine herds in Londrina, Parana State, were tested by indirect immunofluorescence for Toxoplasma gondii. The overal percentage of reagents (>=1:64) was 47.83 per cent. There were no significant differences amongst age groups. The percentage of reagents was: 48.55 per cent amongst ewes, 36.84 per cent amongst rams, 47.37 per cent amongst ram lambs and 48.31 per cent amongst lambs. Is was concluded that T. gondii infection is highly pervalent in ovine herds of Londrina region