Molecular and Biologic Characteristics of Toxoplasma Gondii Isolates From Wildlife in the United States

Abstract

Toxoplasma gondii isolates can be grouped into 3 genetic lineages. Type I isolates are considered more virulent in outbred mice and have been isolated predominantly from clinical cases of human toxoplasmosis, whereas types II and III isolates are considered less virulent for mice and are found in humans and food animals. Little is known of genotypes of T. gondii isolates from wild animals. In the present report, genotypes of isolates of T. gondii from wildlife in the United States are described. Sera from wildlife were tested for antibodies to T. gondii with the modified agglutination test, and tissues from animals with titers of 1:25 (seropositive) were bioassayed in mice. Toxoplasma gondii was isolated from the hearts of 21 of 34 seropositive white-tailed deer (Odocoileus virginianus) from Mississippi and from 7 of 29 raccoons (Procyon lotor); 5 of 6 bobcats (Lynx rufus); and the gray fox (Urocyon cinereoargenteus), red fox (Vulpes vulpes), and coyote (Canis latrans) from Georgia. Toxoplasma gondii was also isolated from 7 of 10 seropositive black bears (Ursus americanus) from Pennsylvania by bioassay in cats. All 3 genotypes of T. gondii based on the SAG2 locus were circulating among wildlife.

Inquérito sorológico para toxoplasmose e leptospirose em mamíferos selvagens neotropicais do Zoológico de Aracaju, Sergipe

“…Os títulos corresponderam à maior diluição que apresentou aglutinação. Os animais com título e"25 foram considerados como submetidos a uma infecção passada pelo T. gondii (Silva et al 2001, Dubey et al 2004). Soros controles positivos e negativos foram incluídos em cada teste.…”

Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

“…During an initial survey of wildlife from Georgia and Mississippi, viable T. gondii was isolated from white-tailed deer, raccoons, bobcats, foxes and coyotes and only preliminary genotyping was performed on these samples (Dubey et al, 2004a). Details of these isolates are given in Supplementary Tables S2 and S3.…”

“…Red foxes are present throughout the country and infection in this host indicates T. gondii infection in local small mammals and birds. Viable T. gondii was isolated from a red fox from Georgia (Dubey et al, 2004a) and one of four red foxes from Kansas (Smith and Frenkel, 1995); the isolate from Georgia was Type II based on SAG2 and the isolates from Kansas were not genotyped. Here, we isolated viable T. gondii from two seropositive red foxes from Alaska; these isolates were Type II (with a type I allele at the Apico locus).…”

Toxoplasma in Animals, Food, and Humans: An Old Parasite of New Concern

“…EFSA data estimate that > 50% of the game meat eaten in Europe contains T. gondii cysts (Anonymous, 2007(Anonymous, , 2009a. Meat from black bear and deer hunted in the United States had a percentage of positivity ranging from 9.8% to 70% (Dubey et al, 2004a(Dubey et al, , 2008cLindsay et al, 1991).…”