Characterization of Toxoplasma Gondii Isolates in Free-Range Chickens From Amazon, Brazil

Abstract

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 50 free-range chickens (Gallus domesticus) from Amazon, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT) and found in 33 (66%) chickens with titers of 1:5 in 3, 1:10 in 2, 1:20 in 1, 1:40 in 1, 1:80 in 2, 1:160 in 5, 1:200 in 9, 1:400 in 5, 1:800 in 2, 1:1,600 in 2, and 1:3,200 or higher in 1. Hearts and brains of 33 seropositive chickens were bioassayed individually in mice. Tissues from 17 seronegative chickens were pooled and fed to 2 T. gondii-free cats. Feces of cats were examined for oocysts, but none was found. Toxoplasma gondii was isolated from 24 chickens with MAT titers of 1:5 or higher. Genotyping of these 24 T. gondii isolates by polymorphisms at the SAG2 locus indicated that 14 were type I, and 10 were type III; the absence of type II strains from Brazil was confirmed. Fifty percent of the infected mice died of toxoplasmosis, irrespective of the genotype.

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

“…The relative frequency of animals positive for T. gondii of all farms valued between 40 and 100%. The results of this study showed a high frequency of animals positive for T. gondii by MAT, which agrees with other ϐin-dings in surveys conducted in Brazil (Dubey et al 2006a, 2007a, De Oliveira et al 2009). …”

Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon

“…According to Dubey et al (5) , domestic chickens are a good indicator of environmental contamination with T. gondii oocysts, such that they are used as sentinel animals in many studies around the world. In the present study, the results obtained for chickens provide information on the state of environmental contamination and warn about the care that must be taken in preparing the meat of such animals for human consumption.…”

“…Cavalcante et al (3) ( 4) found a prevalence of 73.3% in humans, 87.3% in cats and 37.5% in pigs on 71 farms in the municipality of Monte Negro, Rondônia, in the western Amazon region. From the same area, T. gondii was isolated in free-range chickens and, based on restriction fragment length polymorphism (RFLP), 24 isolates were genotyped (5) , and seven different genotypes were found (6) , thus confi rming the high diversity of T. gondii isolates in Brazil (7) (8) . Furthermore, the pathogenicity of Brazilian strains, based on mouse bioassays, suggested that they carry a higher virulence than isolates from other regions of the world (7) .…”

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

“…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).…”