RESUMO
The abundance of Toxoplasma gondii with or without sulfamethoxazole (SMX) treatment was evaluated with quantitative competitive polymerase chain reaction in various organs of wild-type C57BL/6 mice, a susceptible immunocompetent host, after peroral infection with a cyst-forming Fukaya strain of T. gondii. SMX affected different organs in three ways: T. gondii was reduced independently of SMX (skin and kidney); T. gondii was not eradicated with continuous treatment (brain, heart, and lung); and T. gondii was eradicated with continuous treatment (tongue, skeletal muscle, and small intestine). The SMX concentrations in the brains, hearts, and lungs were higher in infected mice than in uninfected mice. These results indicate that even in an immunocompetent host, chemotherapy is necessary to reduce the parasite load and thus reduce the risk of recurrent disease.
Assuntos
Coccidiostáticos/uso terapêutico , Imunocompetência , Sulfametoxazol/uso terapêutico , Toxoplasma/efeitos dos fármacos , Toxoplasmose Animal/tratamento farmacológico , Toxoplasmose Animal/parasitologia , Animais , Encéfalo/metabolismo , Encéfalo/parasitologia , Coccidiostáticos/farmacocinética , Coccidiostáticos/farmacologia , DNA de Protozoário , Modelos Animais de Doenças , Coração/parasitologia , Pulmão/metabolismo , Pulmão/parasitologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Carga Parasitária , Reação em Cadeia da Polimerase em Tempo Real , Sulfametoxazol/farmacocinética , Sulfametoxazol/farmacologia , Toxoplasma/genética , Toxoplasma/crescimento & desenvolvimentoRESUMO
A rapid, accurate, environmentally friendly and cost-effective microwave extraction technique was developed for the extraction of spiked and incurred salinomycin from chicken tissues (kidney, liver, muscle, ovarian yolk and fat). Extraction of salinomycin from various tissues was achieved by irradiating the sample in absolute ethanol and 2-propanol (15 + 2) for 9 sec. in a common household microwave oven. The extract was analysed without further cleanup by HPLC on a C18 column (5 microns) and detected at 592 nm via post-column reaction with 4-dimethylaminobenzaldehyde (DMABA) in a heated reactor coil at 86 degrees C. Recoveries of salinomycin from spiked tissues at 30 ng/g level ranged between 87 and 100%. The limit of quantitation was found to be 10 ng/g. The developed method was applied for the analysis of incurred tissues and ovarian yolk of laying chickens given sodium salinomycin in feed at different levels for 14 consecutive days followed by withdrawal periods. Residues were detected in all tissues and ovarian yolk at 0 withdrawal time but declined during the withdrawal period. Highest residue were found in fat and ovarian yolk.