Biological and genetic characterisation of Toxoplasma gondii isolates from chickens (Gallus domesticus) from São Paulo, Brazil: unexpected findings

Dubey, J. P.; Graham, Douglas H.; Blackston, C. R.; Lehmann, Tovi; Gennari, Solange Maria; Ragozo, Alessandra Mara Alves; Nishi, Sandra Mayumi; Shen, S. K.; Kwok, O. C. H.; Hill, Dolores E.; Thulliez, P.

doi:10.1016/s0020-7519(01)00364-2

Cited by 258 publications

(138 citation statements)

References 35 publications

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“…Three virulent strains (CH4, CH5 and CH10) in mice were type I and one (CH11) was type I or II. Our results are in agreement with those by Dubey et al (2002Dubey et al ( , 2003a, who observed a predominance of T. gondii isolates as being type I in chickens obtained in the States of São Paulo and Rio de Janeiro. On the other hand, other reports have revealed that T. gondii isolates from chickens obtained in Argentina (Dubey et al, 2003c), Egypt (Dubey et al, 2003d) and the US (Dubey et al, 2003e) were mostly type III, suggesting a different epidemiological prevalence of T. gondii genotypes in Brazil, as compared to other countries.…”

Section: Discussionsupporting

confidence: 93%

“…T. gondii was isolated from 11 out of 28 free range chickens and 53.6 % showed T. gondii antibodies (IFAT ≥ 1:16). Dubey et al (2002), investigating T. gondii seroprevalence in free range chickens in São Paulo, Brazil, through Modified Agglutination Test (MAT), reported a rate of 39.02 % and Silva et al (2003), in a similar investigation, reported a T. gondii seroprevalence of 64 % for the State of Rio de Janeiro. According to Dubey & Beattie (1988), chickens do not produce T. gondii antibodies at levels that can be detected by routine tests, which might explain the fact that, in the present work, T. gondii was isolated from two serologically negative chickens.…”

Section: Discussionmentioning

confidence: 99%

“…Howe et al (1997) developed a typing system for T. gondii strains based on analysis of restriction fragments of the gene SAG2, amplified by nested-PCR, which allows a differentiation among strain genotypes of the three clonal lineages, previously described by Howe & Sibley (1995). In Brazil, this method was used for analyzing T. gondii isolates from São Paulo (Dubey et al, 2002), Rio de Janeiro (Dubey et al, 2003a) and Paraná (Dubey et al, 2003b), which showed to be predominantly type I. Ferreira et al (2006), using a multilocus PCR-RFLP, demonstrated that Brazilian strains present recombinant genotypes with typical alleles of the strains types I, II, and III in the majority of the loci.…”

Section: Introductionmentioning

confidence: 99%

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Characterization ofToxoplasma gondiifrom domestic animals from Minas Gerais, Brazil

Brandão

Ferreira²,

Melo³

et al. 2006

Parasite

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Summary :In an attempt to isolate and characterize Toxoplasma gondii from the State of Minas Gerais, Brazil, musculature samples from 72 pigs, 25 dogs, 28 free-range chickens and 50 chickens produced in industrialized farms were collected. Antibodies to T. gondii have not been detected in pigs, but were found in nine (40.9 %) out of 22 dogs, and in 15 (53.6 %) of 28 free range chickens. T. gondii was not isolated from pigs and industrialized chickens, but from eight dogs and 11 free range chickens. In order to determine T. gondii virulence, female BALB/c mice were inoculated with 10 3 , 10 2 , 10 1 and 10 0 tachyzoites of the 19 isolates. The strains RH (virulent) and ME49 (non-virulent) were used as references. Isolates were divided into three groups according to the virulence phenotype: five isolates were classified into virulent in mice, one into non-virulent and 13 into intermediate virulent. Nested-PCR of T. gondii SAG2 locus amplified DNA from 21 out of 22 DNA samples directly extracted from heart of free range chickens. These samples were genotyped through a PCR-RFLP assay. Seventeen (80.9 %) were classified into type I; one (4.8 %) into type III and three (14.3 %) into type I or II. Résumé

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Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterization ofToxoplasma gondiifrom domestic animals from Minas Gerais, Brazil

Brandão

Ferreira²,

Melo³

et al. 2006

Parasite

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“…Espírito Santo of the strains prevalent in the environment, as FR chickens become infected mostly by feeding from soil contaminated with oocysts (Ruiz and Frenkel, 1980). In the last 12 years we and others have determined prevalence of T. gondii in FR chickens from different regions of Brazil (Peixoto and Lopes, 1990;Garcia et al, 2000;Dubey et al, 2002;da Silva et al, 2003;Dubey et al, 2003a,b;Brandão et al, 2006;Dubey et al, 2006Dubey et al, , 2007Aigner et al, 2010;de Oliveira et al, 2009;Soares et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Seroprevalence and isolation of Toxoplasma gondii from free-range chickens from Espírito Santo state, southeastern Brazil

Beltrame

Pena

Ton

et al. 2012

Veterinary Parasitology

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“…In Brazil, the frequency of seropositive chickens T. gondii by MAT (1:5) ranged from 39% (São Paulo) to 100% (Alagoas) (Dubey et al 2002, De Oliveira et al 2009). …”

Section: Resultsmentioning

confidence: 99%

Serologic and molecular diagnostic and bioassay in mice for detection of Toxoplasma gondii in free ranges chickens from Pantanal of Mato Grosso do Sul

et al. 2012

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The aim of this study was to investigate the occurrence of Toxoplasma gondii and compare the results obtained in the Modiϐied Agglutination Test (MAT), Polimerase Chain Reaction (PCR) and bioassay in mice. In order to accomplish this, 40 free-range chickens from eight farms in neighboring areas to the Pantanal in Nhecolândia, Mato Grosso do Sul, were euthanized and blood samples, brain and heart were collected. The occurrence of anti-T. gondii antibodies found in chickens was 67.5% (27 samples), considering as a cutoff point the dilution 1:5. Among the samples analyzed, 7 (25.9%) were positive in the dilution 1:5, 3 (11.1%) in 1:10, 2 (7.4%) in 1:20, 3 (11.1%) in 1:320, 1 ( 3.7%) in 1:640, 3 (11.1%) in 1:1280, 2 (7.4%) in 1:2560, 4 (14.8%) in 1:5120 and 2 (7.4%) in 1:10.240. From the mixture of tissue samples (brain and heart) from the chickens analyzed, 16 (40%) presented electrophoretic bands compatible with T. gondii by PCR (gene B1). In the comparison of techniques, 59.26% positivity in PCR was revealed among animals that were seropositive in MAT (cutoff 1:5). From 141 inoculated mice, six (4.44%) died of acute toxoplasmosis between 15 and 23 days after inoculation. Surviving mice were sacriϐiced at 74 days after inoculation, and a total of 28 cysts were found in the brains of 10 distinct groups. From the seropositive hens, 27 bioassays were performed and 11 (40.7%) isolates were obtained. A greater number of isolations happened in mice that were inoculated with tissues from chickens that had high titers for anti-T. gondii antibodies. Chronic infection in mice was observed in nine groups (33.3%) from ϐive different properties. Among the surviving mice, 25.6% were positive for T. gondii in MAT (1:25). From mice positive in PCR, 87.5% were also positive in MAT. Among the PCR-negative mice, 5.2% were positive for T. gondii in MAT. It can be concluded through this study that the occurrence of infecton by T. gondii in the rural properties studied was high, that PCR directed to gene B1 does not conϐirm the viability of the parasite, but it can be used as a screening method for the selection of chickens infected by T. gondii, that the animals with titer greater than 10 must be prioritized for the selection of animals for bioassay, since for them, the chances of isolating the parasite are greater and that seroconversion in experimentally infected mice is not a good indicator for isolating the agent.

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Biological and genetic characterisation of Toxoplasma gondii isolates from chickens (Gallus domesticus) from São Paulo, Brazil: unexpected findings

Cited by 258 publications

References 35 publications

Characterization ofToxoplasma gondiifrom domestic animals from Minas Gerais, Brazil

Characterization ofToxoplasma gondiifrom domestic animals from Minas Gerais, Brazil

Seroprevalence and isolation of Toxoplasma gondii from free-range chickens from Espírito Santo state, southeastern Brazil

Serologic and molecular diagnostic and bioassay in mice for detection of Toxoplasma gondii in free ranges chickens from Pantanal of Mato Grosso do Sul

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