Location: Animal Parasitic Diseases LaboratoryTitle: Toxoplasmosis in geese and detection of two new atypical Toxoplasma gondii strains from naturally infected Canada geese (Branta canadensis)
|VERMA, SHIV - Non ARS Employee|
|CALERO-BERNAL, R - Non ARS Employee|
|CERQUEIRA-CEZAR, CAMILA - Non ARS Employee|
|JIANG, T - University Of Tennessee|
|SU, C - University Of Tennessee|
Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2016
Publication Date: 6/30/2016
Citation: Verma, S.K., Calero-Bernal, R., Cerqueira-Cezar, C.K., Kwok, O.C., Dudley, M.R., Jiang, T., Su, C., Hill, D.E., Dubey, J.P. 2016. Toxoplasmosis in geese and detection of two new atypical Toxoplasma gondii strains from naturally infected Canada geese (Branta canadensis). Parasitology Research. 15(5):1767-72.
Interpretive Summary: Wild birds are important in the epidemiology of toxoplasmosis because they can serve as reservoir hosts, and vectors of zoonotic pathogens including Toxoplasma gondii. Canada goose (Branta canadensis) is the most widespread geese in North America. Little is known concerning T. gondii infection in both migratory, and local resident populations of Canada geese. Here, we evaluated the seroprevalence, isolation, and genetic characterization of viable T. gondii isolates from a migratory population of Canada geese. Antibodies against T. gondii were detected in 12 of 169 Canada geese using the modified agglutination test (MAT, cutoff 1:25). The hearts of 12 seropositive geese were bioassayed in mice for isolation of T. gondii. Viable parasites were isolated from eight. One isolate was obtained from a seropositive goose by both bioassays in mice, and in a cat; the cat fed infected heart excreted T. gondii oocysts. Additionally, one isolate was obtained from a pool of four seronegative (<1:25) geese by bioassay in a cat. The T. gondii isolates were further propagated in cell culture, and DNA extracted from cell culture-derived tachyzoites were characterized using 10 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) genetic markers (SAG1, 5' and 3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed five different genotypes. ToxoDB PCR-RFLP genotype #1 (type II) in one isolate, genotype #2 (type III) in four isolates, genotype #4 in two isolates, and two new genotypes (ToxoDB PCR-RFLP genotype #266 in one isolate and #267 in one isolate) were identified. These results indicate genetic diversity of T. gondii strains in the Canada geese, and this migratory bird might provide a mechanism of T. gondii transmission at great distances from where an infection was acquired.
Technical Abstract: The protozoan Toxoplasma gondii infects virtually all warm-blooded animals, including birds, humans, livestock, and marine mammals. The consumption of raw or undercooked meat infected with T. gondii is considered an important source of infection in humans. Canada goose (Branta canadensis), the most widespread goose in North America, is found in every contiguous US states and Canadian provinces at one time of the year or another. Their populations increased 4.5 folds from 1.26 million in 1970 to 5.69 million in 2012. Canada geese are wild, hunted for their meat for human consumption. Geese can serve as a reservoir host and vector host of T. gondii, infecting other hosts in new ecosystems along the flyway. Little is known of T. gondii infection in Canada geese. In this study, we report the serology, isolation, and genetic characterization of T. gondii from Canada geese. Additionally, we reviewed worldwide surveys of T. gondii infections in different species of geese.