RESUMO
Stray dogs are considered as sentinels in the epidemiology of Toxoplasma gondii because they are carnivores and eat a variety of foods, including garbage. In the present study, tissues and sera of 249 stray dogs (Canis familiaris) from Grenada, West Indies were examined for T. gondii infection. Sera were examined for antibodies to T. gondii by the modified agglutination test (MAT); 89 (35.7%) of 249 were seropositive with titers of 25 in seven dogs, 50 in 22 dogs, 100 in 22 dogs, 200 or higher in 38 dogs. Hearts of 76 seropositive dogs were bioassayed in mice. Viable T. gondii was isolated from 12 dogs; these isolates were designated TgDogGr1 to TgDogGr12. These isolates were further propagated in cell culture and DNA isolated from cell culture derived tachyzoites of 12 isolates was genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed six genotypes, including ToxoDB PCR-RFLP #1, #2, #3, #7, #13 and #224, with 1, 6, 1, 2, 1 and 1 isolates, respectively. The result supports previous findings that T. gondii population genetics is highly diverse in Grenada.
Assuntos
Doenças do Cão/parasitologia , Genótipo , Polimorfismo de Fragmento de Restrição , Toxoplasma/genética , Toxoplasmose Animal/parasitologia , Animais , Anticorpos Antiprotozoários , Doenças do Cão/epidemiologia , Cães , Feminino , Variação Genética , Granada/epidemiologia , Masculino , Reação em Cadeia da Polimerase/veterinária , Toxoplasmose Animal/epidemiologiaRESUMO
Nothing is known of the genetic diversity of Toxoplasma gondii circulating in wildlife in Mexico. In the present study, a mouse virulent T. gondii strain was isolated from the heart of a wild puma (Felis concolor). The puma was found roaming in outskirt of Durango City, Mexico and tranquilized for moving to a zoo. The puma died during translocation and a necropsy examination was performed. The puma had an antibody titer for T. gondii of 200 by the modified agglutination test. Its heart and brain tissue were bioassayed into 2 outbred Swiss Webster (SW) and 1 gamma interferon gene knockout (KO) mouse. The KO mouse and the 2 SW mice that became infected after inoculation with homogenate of puma heart died of acute toxoplasmosis 12, 19 and 20 days p.i. respectively and tachyzoites were found in lungs of all 3 mice. None of the 4 SW and 1 KO mouse inoculated with digest of the puma brain became infected with T. gondii. Tachyzoites from the lungs of mice were propagated in cell cultures. Tachyzoites from cell culture were inoculated into 5 SW; the mice died or had to be killed 14 days p.i. and a cat fed tissues of these mice shed T. gondii oocysts. Results of mortality and infectivity of tachyzoites and oocysts in SW mice indicated that the puma T. gondii strain (designated TgPumaMe1) was virulent for outbred mice. DNA isolated from culture-derived tachyzoites was characterized using 11 PCR-RFLP markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed a new genotype (ToxoDB PCR-RFLP #222). Isolation of atypical genotype T. gondii from wild puma indicates that mouse virulent strains are circulating in wildlife in Mexico.
Assuntos
Coração/parasitologia , Puma , Toxoplasma/classificação , Toxoplasma/genética , Toxoplasmose Animal/parasitologia , Animais , Anticorpos Antiprotozoários , Evolução Fatal , Feminino , Variação Genética , Interferon gama/genética , México/epidemiologia , Camundongos , Camundongos Knockout , Toxoplasma/patogenicidade , Toxoplasmose Animal/epidemiologia , VirulênciaRESUMO
There is a lack of information concerning the prevalence of Toxoplasma gondii infection in wild birds in Mexico. In the present study, serum samples and tissues from 653 birds from Durango State, Mexico, were evaluated for T. gondii infection. Antibodies to T. gondii (modified agglutination test, titer 1â¶25 or higher) were found in 17 (2.6%) of the 653 birds, including 1 of 2 curve-billed thrashers (Toxostoma curvirostre), 2 (1 Anas platyrhynchos, 1 Anas diazi) of 4 ducks, 1 of 2 eagles (Aquila sp.), 5 (27.8%) of 18 great-tailed grackles (Quiscalus mexicanus), 7 (1.3%) of 521 rock pigeons (Columba livia), and 1 (14.3%) of 7 quail (Coturnix coturnix). The seroprevalence of T. gondii infection in birds captured in a park outside the city zoo (11.6%, 8/69) was significantly higher than that found in birds from other regions (1.5%, 9/584, OR â=â 8.38; 95% CI: 2.82-24.77; P â=â 0.0001). Brains and hearts of 23 birds (17 seropositive, 6 seronegative) were bioassayed in mice for the isolation of T. gondii . Viable T. gondii was isolated from 1 of 7 seropositive pigeons. The DNA obtained from the T. gondii isolate from the pigeon was genotyped using the PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and revealed an atypical genotype. This is the first report of T. gondii infection in great-tailed grackles, the Mexican duck, and curved-billed thrashers and the first survey of wild birds in Mexico.