Zoonoses ocupacionais: inquérito soro-epidemiológico em estudantes de Medicina Veterinária e análise de risco para leptospirose, brucelose e toxoplasmose

Pós-graduação em Doenças Tropicais - FMB

Avaliação da infecção de ratos Fischer com dua amostras geneticamente distintas de Toxoplasma gondii: cinética de anticorpos, reisolamento em camundongos e reação em cadeia pela polimerase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevalence of antibodies against Toxoplasma gondii and Neospora caninum in dogs

Toxoplasmosis and neosporosis are parasitic diseases of global importance. The present study had the objective to determine the influence of age, sex and breed in the prevalence of antibodies against both diseases in dogs from Brotas city, São Paulo State, Brazil. Blood samples of 342 dogs were collected, and the age, sex and breed of each animal were recorded. The serological diagnosis for toxoplasmosis and neosporosis were performed using the immunofluorescent antibody test (IFAT). The Fischer's test was used to calculate the association probability of the variables, with a = 5%. For toxoplasmosis the prevalence of antibodies was 26.9% (CI 95% 22.4-31.8%), and for neosporosis 4.97% (CI 95% 3.1-7.8%). The statistical analysis revealed a higher risk of infection for T. gondii in dogs with more than five years.

Diagnostic tests for hepatitis C: Recent trends in electrochemical immunosensor and genosensor analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bartonella clarridgeiae and Bartonella vinsonii subsp berkhoffii exposure in captive wild canids in Brazil

Wild canids are potential hosts for numerous species of Bartonella, yet little research has been done to quantify their infection rates in South America. We sought to investigate Bartonella seroprevalence in captive wild canids from 19 zoos in São Paulo and Mato Grosso states, Brazil. Blood samples were collected from 97 wild canids belonging to four different native species and three European wolves (Canis lupus). Indirect immunofluorescent antibody testing was performed to detect the presence of B. henselae, B. vinsonii subsp. berkhoffii, B. clarridgeiae, and B. rochalimae. Overall, Bartonella antibodies were detected in 11 of the canids, including five (12·8%) of 39 crab-eating foxes (Cerdocyon thous), three (11·1%) of 27 bush dogs (Speothos venaticus), two (8·7%) of 23 maned wolves (Chrysocyon brachyurus) and one (12·5%) of eight hoary foxes (Lycalopex vetulus), with titres ranging from 1:64 to 1:512. Knowing that many species of canids make excellent reservoir hosts for Bartonella, and that there is zoonotic potential for all Bartonella spp. tested for, it will be important to conduct further research in non-captive wild canids to gain an accurate understanding of Bartonella infection in free-ranging wild canids in South America.

Coinfection by toxoplasma gondii and leishmania spp. in domestic cats (Felis catus) in State of Mato Grosso do Sul

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção de co-infecções por Leishmania (l.) chagasi, Trypanosoma evansi, Toxoplasma gondii e Neospora caninum em cães

Co-infections by Leishmania (L.) chagasi, Trypanosoma evansi, Toxoplasma gondii and Neospora caninum in dogs were investigated. Amastigotes forms of Leishmania spp. were detected by cytopathological analysis of lymph nodes in 46,42% (39/84) of dogs. In a male dog, adult, without defined breed, from rural area and positive for Leishmania, were observed flagellated forms of T. evansi in blood smear. By immunofluorescence antibody test, 5,95% (5/84) of dogs were considered reactive to T. gondii, with titer equal to or higher than 1:64, while 3,57% (3/84) were reactive to N. caninum, with titer ≥1:50. Among the animals with visceral leishmaniasis, one showed positive serological response to T. gondii and two for N. caninum. All dogs reactive to N. caninum were from rural area and the predominance of infection by T. gondii was in dogs from urban area. A young male dog from the rural area and seropositive for T. gondii showed Ehrlichia spp. morulae in the cytology and positive reaction for canine distemper virus. Thus, further studies are needed to assess the epidemiology of these infections in canine population, especially with respect to the reservoirs of Trypanosoma spp. in rural areas.

Participação de gambás e cães domiciliados como reservatórios de Leishmania infantum e Trypanosoma cruzi georreferenciados nos municípios da Regional de Saúde de Três Lagoas - MS

Pós-graduação em Doenças Tropicais - FMB

Rabies neutralizing antibody detection by indirect immunperoxidase serum neutralization assay performed on chicken embryo related cell line

The aim of this study was to evaluate the indirect immunoperoxidase virus neutralization (IPVN) and mouse neutralization test (MNT) to detect antibodies against rabies virus from vaccinated dogs and cattle. The IPVN was set up for the ability to measure 0.5 International Units/ml (IU) of antibody required by the World Health Organization and the Office International des Epizooties as the minimum response for proof of rabies immunization. IPVN was developed and standardized in chicken embryo related (CER) cell line when 141 dog and 110 cattle sera were applied by serial five-fold dilutions (1:5, 1:25, 1:125) as well as the positive and negative reference controls, all added in four adjacent wells, of 96-well microplates. A 50 µl amount of CVS32 strain dilution containing 50-200 TCID50/ml was mixed to each serum dilution, and after 90 min 50 µl of 3 x 10(5) cells/mlcell suspension added to each well. After five days of incubation, the monolayers were fixed and the IPVN test performed. The correlation coefficient between the MNT and IPVN performed in CER cells was r = 0.9949 for dog sera (n = 100) and r = 0.9307 for cattle sera (n = 99), as well as good specificity (94.7%), sensitivity (87.5%), and agreement (96.6%) were also obtained. IPVN technique can adequately identify vaccinated and unvaccinated animals, even from low-responding vaccinated animals, with the advantage of low cost and faster then MNT standard test.

Toxocariasis: Serological diagnosis by indirect antibody competition elisa

Toxocariasis is caused by infection of man by Toxocara canis and Toxocara, cati larvae, the common roundworm of dogs and cats. Because larvae are difficult to detect in tissues, diagnosis is mostly based on serology. Non specific reactions are observed mainly due to cross-reactivity with Ascaris sp antigens. This investigation aimed at developing and evaluating an indirect antibody competition ELISA (IACE) employing a specific rabbit IgG anti-Toxocara canis excretory-secretory antigens as the competition antibody. in order to improve indirect ELISA specificity performed for toxocariasis diagnosis. For that, the rabbit IgG was previously absorbed by Ascaris suum adult antigens. Sensitivity and specificity of IACE were first evaluated in 28 serum samples of mice experimentally infected with T. canis embryonated eggs. Adopting cut-off value established in this population before infection, sensitivity and specificity were 100% after 20 days post-inoculation. For human population IACE was evaluated using sera from 440 patients with clinical signs of toxocariasis and the cut-off value was established with 60 serum samples from apparently healthy individuals. Using as reference test the indirect ELISA performed by Adolfo Lutz Institute, sensitivity was 60.2%, specificity was 98% and concordance was 77.3%. Repeatability of IACE was evaluated by the inter-reactions variation coefficient (2.4%).

A double antibody sandwich ELISA for rapid diagnosis of virus infection and to measure the humoral response against infectious bursal disease on clinical material

A double antibody sandwich ELISA (DAS-ELISA) was developed and employed for simultaneous direct detection of infectious bursal disease virus (IBDV) from bursal samples and to measure the humoral response, using the same basic immunoreagents, the purified and non-purified antigen, capture antibody and chicken hyperimmune sera were prepared, and standardized for this purpose, the DAS-ELISA was applied to both 80 bursal suspensions and 224 corresponding serum samples from vaccinated and non-vaccinated commercial hocks, Bursae samples were collected at 2 weeks of age, and submitted to histological examination, virus isolation in specific pathogen-free chickens embryos, and the DAS-ELISA technique, Serum titres obtained in indirect ELISA and serum neutralization test were compared with those in DAS-ELISA, the agreement was 80% between DAS-ELISA, and the conventional techniques, with high sensitivity (87%) and specificity (90%).

Comparative evaluation of an indirect ELISA test for diagnosis of swine cysticercosis employing antigen from Taenia solium and Taenia crassiceps metacestodes

Taenia solium cysticercosis is still a serious public health problem in several countries where poverty and lack of hygiene favor transmission. Because pigs are the primary intermediate hosts, prevalence of porcine cysticercosis is a reliable indicator of active transmission zones. Serological diagnostic methods are important tools for epidemiological studies since they can be applied to living animals on a large scale. Four antigen preparations (cyst fluid and crude) from T. solium and T. crassiceps metacestodes were compared for swine cysticercosis diagnosis by indirect ELISA (IE). Twenty-eight serum samples from swine naturally and experimentally infected by cysticerci of T. solium and 56 serum samples from swine reared in commercial herds were tested. Best results of overall sensitivity were obtained by the use of cyst fluid and crude antigen of T. crassiceps metacestode (100 and 96.4%, respectively). Using homologous antigen preparations we have observed higher specificity percentage (98.2% for cyst fluid and 96.4% for crude metacestode T. solium antigen). We concluded that sensitivity is of far more importance than specificity for identification of endemic areas in order to prevent transmission to man. We conclude, therefore, that IE performed with cyst fluid antigen of T. crassiceps metacestode is a better tool for that purpose. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Near-infrared Raman spectroscopy to detect anti-Toxoplasma gondii antibody in blood sera of domestic cats: quantitative analysis based on partial least-squares multivariate statistics

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of an indirect ELISA method for the detection of chicken antibodies against infectious bronchitis virus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Experimental infection of Newcastle disease virus in pigeons (Columba livia): Humoral antibody response, contact transmission and viral genome shedding

The aim of this study was to evaluate the humoral antibody response, the genome viral excretion and the contact transmission of pathogenic chicken origin Newcastle disease virus (NDV) from experimentally infected pigeons (Columba livia) to in-contact pigeon. The antibody response to infection was assessed by the hemagglutination inhibition (HI) test and the genome viral excretion was detected by RT-PCR. Viral strain induced high antibody levels, both in inoculated and in sentinel birds. The pathogenic viral strain for chickens was unable to produce clinical signs of the disease in experimentally infected pigeons, although it induced the Immoral antibody response and produced NDV genome shedding. NDV genome was detected intermittently throughout the experimental period, from 5 days post-infection (dpi) to 24 dpi. Therefore, viral genome shedding occurred for 20 days. The viral genome was detected in all birds, between I I and 13 dpi. Furthermore, the high infectivity of the virus was confirmed, as all non-inoculated sentinel pigeons showed antibody levels as high as those of inoculated birds. (C) 2007 Elsevier B.V. All rights reserved.