ISOLATION AND GENOTYPING OF Toxoplasma gondii IN SERONEGATIVE URBAN RATS AND PRESENCE OF ANTIBODIES IN COMMUNICATING DOGS IN BRAZIL.

The role of rodents in the epidemiology of toxoplasmosis was investigated in Londrina, Paraná State, Brazil. One hundred and eighty-one Rattus rattus and one Mus musculus were caught in 37 places. Blood and tissues were collected and submitted to the indirect fluorescence antibody test (IFAT) and the bioassay. Serum samples from 61 contacting dogs were also collected. Sixteen rats (8.8%) were positive for Toxoplasma gondii, but just two of them were positive by serology and bioassay test. Antibodies were found in nine (4.9%) rats. Tissues of nine rats bioassayed were positive and four isolates were obtained. Restriction fragment length polymorphism (RFLP) analysis was performed using 12 markers (SAG1, SAG2, SAG2-alt, C22-8, C29-2, L358, PK1, BTUB, GRA6, SAG3, Apico, CS3). Genotyping revealed that the four strains isolated from this study have been isolated before in cats and chickens from Brazil. None of the isolates was identified like clonal archetypal T-types I, II, and III. The rats presented lower serologic Toxoplasma gondii prevalence (8.8%) compared to contacting dogs (70.5%).

Soroprevalência da Leishmaniose Tegumentar Americana (LTA) canina e fauna de Flebotomíneos (Diptera: Psychodidae) em Bela Vista do Paraíso, Paraná / Seroprevalence of Cutaneous Leishmaniasis (LC) in dogs and identification of vectors (Diptera: Psychodidae) in Bela Vista do Paraíso, Parana state

O trabalho teve como objetivo determinar a soroprevalência da Leishmaniose Tegumentar Americana (LTA) canina no município de Bela Vista do Paraíso, Paraná, comparar as técnicas de imunofluorescência indireta (IFI) e ensaio imunoenzimático (ELISA) e identificar as espécies de flebotomíneos presentes, possivelmente envolvidas no ciclo do parasito. Amostras de sangue de 489 cães foram submetidas à pesquisa de anticorpos anti-Leishmania sp. pela IFI e ELISA. Foram consideradas positivas as amostras que apresentaram título ≥ 40 na IFI e densidade ótica ≥ 0.174 no ELISA. Entre as amostras analisadas, 222 (45,4%) foram reagentes pela IFI e 189 (38,7%) pelo ELISA. Comparando-se os testes foram encontradas 176 amostras positivas (36,0%) e 254 negativas (51,9%) para ambas as técnicas. A sensibilidade do ELISA foi de 79,3% e a especificidade foi de 95,1%. O coeficiente global do teste foi de 87,0% com coeficiente Kappa de 0,75. A análise das variáveis para cães com sorologia positiva pela IFI demonstrou diferença significativa em relação à ausência de matas e ausência de convívio com outras espécies animais. Em cães sororeagentes pelo ELISA as variáveis que apresentaram diferença significativa foram o tipo de mata ciliar existente no ambiente, a ausência de lixo, o esgoto a céu aberto e lançado diretamente em rios ou córregos e do lixo lançado em terreno baldio, queimado ou enterrado. O resultado obtido com a captura dos flebotomíneos foi a predominância do Lutzomyia whitmani com 79,9% das espécies coletadas. Os resultados demonstraram que a LTA está amplamente disseminada na população canina do município de Bela Vista do Paraíso, e que tanto a IFI como o ELISA podem ser utilizados para o diagnóstico. Deste modo o cão apresenta-se como um elo entre o ciclo silvestre e o peridomiciliar da LTA, podendo tornar-se um sinalizador do agente no ecossistema da doença nesse ecossistema.

The aim of this study was to determine the seroprevalence of Cutaneous Leishmaniasis (CL) in dogs of Bela Vista do Paraiso, Parana state, compare the IFA and ELISA techniques and identify the vectors possibly involved in the cycle of the parasite. Were collected blood samples from 489 dogs that were subjected to detection of anti-Leishmania sp. by IFA and by ELISA. Were considered positive samples ≥40 titers in IFA and for ELISA ≥ 0.174 optical density. Among the samples analyzed, 222 (45.4%) were positive by IFA and 189 (38.7%) by ELISA. Comparing the tests were found 176 positive samples (36.0%) and 254 negative (51.9%) for both techniques. The sensitivity of ELISA was 79.3% and specificity was 95.1%. The global coefficient of the test was 87.0% with kappa coefficient of 0.75. Analysis of variables for dogs with positive serology by IFA showed significant differences regarding the absence of forests and lack of contact with other animal species. Positive sera by ELISA in dogs variables that showed significant differences were the type of riparian vegetation existing in the environment, the lack of garbage, open sewers and released directly into rivers or streams and garbage thrown on wasteland, burned or buried. The result obtained with the capture of sandflies was the predominance of Lutzomyia whitmani with 79.9% of the species collected. The result obtained with the capture of sandflies was the predominance of Lutzomyia whitmani with 79.9% of the species collected. The results showed that the LTA is widespread in the canine population of Bela Vista do Paraiso, and both the IFI and ELISA can be used for diagnosis. So the dog appears as a link between wild and peridomestic cycle of CL may become an amplifier of disease in this ecosystem.

Eimeria tenella: utilization of a nasal vaccine with sporozoite antigens incorporated into Iscom as protection for broiler breeders against a homologous challenge.

The aim of this study was to evaluate a nasal vaccine using antigens derived from sporozoites of Eimeria tenella incorporated into Iscom to protect broiler chicks. Forty-five one-day-old chickens (Cobb), unvaccinated against coccidiosis, were used in this experiment. The birds were maintained in separated battery cages and divided into three groups: G1 (n=15), G2 (n=15), and G3 (n=15). G1 received 50 microg of sporozoites+Iscom vaccine, G2 received Iscom without antigens, and G3 received only PBS. The treatments were administered by nasal route on days 0, 7, and 21 of the experiment. On the 28th day, all birds were challenged with 105 sporulated oocysts of E. tenella. On the challenge day, three birds from each group were euthanized to evaluate lymphocyte proliferation. Lesion scores were obtained from five birds from each group, 7 days after challenge. The remaining animals were euthanized on the 50th day. The mean lymphocyte proliferation responses were significantly different (P=0.03); G1 was 2.3-2.6 times more elevated than G2, and G3 (P<0.001). 83% of the birds from G1 showed an IgY antibody reaction by ELISA at challenge. The means for oocysts shedding were 16,890+/-20,511, 48,080+/-50,047, and 65,020+/-74,461, for G1, G2 and G3 birds, respectively. There was no significant difference (P>0.17) in oocysts shedding between groups. However, the G1 and G2 chicks demonstrated reduction in percentage of oocyst shedding when compared to control birds (G3) by 74.02% and 26.05%, respectively. The average lesion scores were G1=0.4, G2=1, and G3=2. This study demonstrated that the lowest lesion score and oocyst shedding were observed in the birds from the group that received antigens derived from sporozoite with an Iscom adjuvant (G1). These results suggest that this vaccine can induce protection against avian coccidiosis.

Evaluation of IFA, MAT, ELISAs and immunoblotting for the detection of anti-Toxoplasma gondii antibodies in paired serum and aqueous humour samples from experimentally infected pigs.

The study evaluated the efficiency of diagnostic laboratory methods to detect anti-Toxoplasma gondii antibodies in paired serum and aqueous humour samples from experimentally infected pigs. 18-mixed breed pigs were used during the experiment; these were divided into two groups, G1 (infected group, n=10) and G2 (uninfected group, n=8). Infection was performed with 4 x 10(4) VEG strain oocysts at day 0 by the oral route in G1 animals. All pigs were euthanized at day 60, when retina, aqueous humour, and blood samples were collected. Anti-T. gondii antibody levels were assessed in serum (s) and aqueous humour (ah) by indirect immunofluorescence assay (IFA), modified agglutination test (MAT), m-ELISA (using crude membranes from T. gondii tachyzoites as antigen) and r-ELISA (using rhoptries from T. gondii tachyzoites as antigen). Polymerase chain reactions (PCR) of samples from the retina were performed by using Tox4 and Tox5 primers. Antibody titers of G1 animals ranged from 128 to 1024 and from 16 to 256 in serum and aqueous humour, respectively. There were differences in the correlation coefficients between IFA(s) x IFA (ah) (r=0.62, P=0.05), MAT(s) x MAT (ah) (r=0.97, P<0.0001); however, there was no significant difference between r-ELISA(s) x r-ELISA (ah) (r= 0.14, P=0.7). Antibodies present in serum and aqueous humour recognized similar antigens. Samples of retina were positive by PCR in 30% (3/10) of infected pigs. G2 animals remained without antibody levels and were PCR negative throughout the experiment. These results suggest that the use of a combination of tests and immunoblotting for paired aqueous humour and serum samples could improve the sensitivity and specificity for the diagnosis of ocular toxoplasmosis.

Protective activity against oocyst shedding in cats vaccinated with crude rhoptry proteins of the Toxoplasma gondii by the intranasal route.

This study evaluated a vaccine made from crude rhoptry proteins of Toxoplasma gondii with Quil-A, which was administered to cats by the intranasal route. Eleven short-hair domestic cats were divided into four groups: G1 (n=3) received three doses (200 microg/dose) of the rhoptry vaccine with Quil-A (20 microg); G2 (n=3) received PBS with Quil-A (20 microg); G3 (n=3) and G4 (n=2) received only PBS. Treatments were administered at days 0, 21, and 42 by the intranasal route. Challenge was done to G1, G2, and G3 animals with 600 cysts of the VEG strain on day 51 (challenge day); G4 animals were unchallenged. The anti-T. gondii IgG and IgA antibody levels from sera were measured by indirect enzyme-linked immunosorbent assay (ELISA). At challenge, two animals from G1 revealed antibody levels for both IgG and IgA; oocysts were not detected in feces of these two cats. There were no differences in hematological values between groups throughout the experiment (p>0.10). Preventable fractions were 67% in G1 and 0% in G2 and G3. Comparatively, G1 animals shed 89.3% and 90.8% less oocysts than G3 and G4, respectively. Two out of three cats were protected against T. gondii oocyst shedding when the rhoptry vaccine was administered by the intranasal route. This is the first study using crude rhoptry proteins as vaccine by the intranasal route in cats to evaluate protection against oocysts shedding.

Toxoplasma gondii in fresh pork sausage and seroprevalence in butchers from factories in Londrina, Paraná State, Brazil.

The aims of this study were to verify the presence of Toxoplasma gondii cysts in fresh pork sausage and the presence of antibodies against T. gondii in serum of workers from factories with Municipal Inspection Service, in Londrina, PR, Brazil. 149 samples of sausage were collected from eight factories and blood samples from 47 workers. We also took information about the practices that were adopted in the factories and the workers' habits that could influence the prevalence of toxoplasmosis. After bioassay in mice, 13 (8.7%) sausage samples were positive, in one of them T. gondii was isolated and in the other 12 the mice seroconverted. Of 47 workers, 36 (76.6%) worked in sausage production and 11 (23.4%) were involved in other functions; 59.5% (28/47), 55.5% (20/36) and 72.7% (8/11), respectively, had T. gondii antibodies. There were no significant differences in the variables of industries' practices and workers' habits related to T. gondii infection. We concluded that fresh pork sausage could be important in the transmission of toxoplasmosis.

Toxoplasma gondii in fresh pork sausage and seroprevalence in butchers from factories in Londrina, Paraná State, Brazil

Os objetivos deste estudo foram verificar a presença de cistos de Toxoplasma gondii em lingüiça de origem suína tipo frescal e de anticorpos anti-T. gondii no soro de trabalhadores de indústrias produtoras, com Serviço de Inspeção Municipal (SIM) de Londrina, PR. Buscou-se ainda, obter informações relativas às práticas adotadas nestas indústrias e aos hábitos dos trabalhadores, que pudessem influenciar na prevalência desta parasitose. Foram coletadas 149 amostras de lingüiça em oito indústrias produtoras e 47 amostras de sangue de todos os trabalhadores destes locais. Após a realização do bioensaio em camundongos, obteve-se 13 (8,72%) amostras de lingüiça positivas, sendo que em uma o parasita foi isolado e nas outras 12 os camundongos soroconverteram. Dos 47 trabalhadores, 36 (76,6%) atuavam na produção de lingüiça e 11 (23,4%) exerciam outras funções; os percentuais de soropositivos ao T. gondii foram, respectivamente, 59,5% (28/47), 55,5% (20/36) e 72,7% (8/11). Não houve diferença significativa entre nenhuma das variáveis relacionadas às indústrias e aos trabalhadores. Os resultados permitem inferir que lingüiças tipo frescal possuem importância na cadeia epidemiológica da toxoplasmose no Município de Londrina-PR.