Prevalence of Toxoplasma gondii infection in free-range chickens reared in Rio Bonito, Rio de Janeiro

Submitted by Sandra Infurna ([email protected]) on 2017-05-04T17:02:42Z No. of bitstreams: 1 maria_amendoeira_etal_IOC_2012.pdf: 94960 bytes, checksum: 7cfbf2150d39a73bd2efb7ba11274198 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-05-04T17:09:52Z (GMT) No. of bitstreams: 1 maria_amendoeira_etal_IOC_2012.pdf: 94960 bytes, checksum: 7cfbf2150d39a73bd2efb7ba11274198 (MD5)Made available in DSpace on 2017-05-04T17:09:52Z (GMT). No. of bitstreams: 1 maria_amendoeira_etal_IOC_2012.pdf: 94960 bytes, checksum: 7cfbf2150d39a73bd2efb7ba11274198 (MD5) Previous issue date: 2012Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Universidade Federal Fluminense. Niterói, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ. Brasil.The prevalence of T. gondii infection was investigated in free-range chickens for human consumption in the county of Rio Bonito, Rio de Janeiro, Brazil. Thus, a search for antibodies to T. gondii by indirect fluorescent antibody test was done in the serum of 220 chickens from twenty two farms. Titres equal or greater than 16 were considered positive. The prevalence of toxoplasmic infection found in chickens was 27.6% (61/220). There were positive cases in eighteen (77.2%) farms. The more frequent titre was 16 (12.5%) and the highest was 4096 (0.4%). The high prevalence of T. gondii in chickens and the high percentage of farms with positive cases indicate environmental contamination in the studied area showing the possibility of human and animal infection

Sensitivity and specificity of serological tests, histopathology and immunohistochemistry for detection of Toxoplasma gondii infection in domestic chickens

Since free-range chickens are important for the epidemiology of toxoplasmosis, this study evaluated the sensitivity and specificity of different laboratory techniques for the diagnosis of Toxoplasma gondii in these animals. Serum samples from 135 adult domestic chickens were tested for anti-T. gondii antibodies by the indirect fluorescent antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), modified agglutination test (MAT), and indirect hemagglutination test (IHAT). Tissue samples from all animals were analyzed by histopathology, immunohistochemistry and mouse bioassay (gold standard). Fifty-four chickens were positive for T. gondii in the bioassay. The sensitivity and specificity of the different tests were, respectively, 85% and 56% for ELISA; 80% and 52% for IFAT; 76% and 68% for MAT; 61% and 80% for IHAT; 7% and 98% for immunohistochemistry, and 6% and 98% for histopathology. The MAT was the most effective method for the diagnosis of T. gondii infection in chickens, followed by ELISA. Histopathology and immunohistochemistry are useful tools for the diagnosis of T. gondii infection in chickens due to their specificity. (C) 2014 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Predominance of atypical genotypes of Toxoplasma gondii in free-roaming chickens in St. Kitts, West Indies

BACKGROUND: Toxoplasma gondii is a worldwide protozoan parasite of felids which can infect almost all warm-blooded animals, including humans. Free-roaming chickens are good indicators of environmental contamination with T. gondii oocysts because they feed from the ground. Previous research has demonstrated a high seroprevalence of T. gondii in domestic animals on St. Kitts but little is known about the genotypes circulating in the environment. METHODS: Hearts and brains from 81 free-roaming chickens in St. Kitts were digested and inoculated into 243 Swiss Webster mice in a bioassay. DNA was extracted from digested chicken tissues and the brains of all mice, and screened for T. gondii. Positive samples were genotyped using restriction fragment length polymorphism. Chicken sera were also screened for T. gondii antibodies using a modified agglutination test (MAT). RESULTS: Overall, 41% (33 out of 81) of chickens were positive for T. gondii either by serology and/or by PCR. Antibodies to T. gondii were detected by MAT in 32% (26 out of 81) of chickens, and T. gondii DNA was detected in mouse brains representing 26% (21 out of 81) of chickens. Genotyping of 21 DNA isolates, using polymorphisms at 10 loci, including SAG1, SAG2 (5′-3′ SAG2 and alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, revealed that 7 were ToxoDB genotype #141, 6 were #1 (Type II), 3 were #13, 3 were #265, one was #264 and one was #2 (Type III). Genotypes #13 and #141 appear to be more virulent. CONCLUSIONS: The results of this study highlight the greater genetic diversity of T. gondii circulating in the Caribbean region, with potentially different degrees of virulence to humans