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Abstract
This study investigated the cultivation of T. gondii in ten cell lines using different initial concentration of cells and tachyzoites, detection of infection by three methods, including histology, western blot and nestedPCR, and the prevalence of Toxoplasma gondii in pigs and cattle from USA and Peru. Toxoplasma gondii tachyzoites were cultivated in different cell lines at initial concentrations of 10 3 , 10 4 , and 10 5 tachyzoites, per 10 4 , and 10 5 cells individually. There was a significant difference (p<0.05) among cell lines regarding the propagation of tachyzoites. Most of the cell lines had an aggressive overgrowth that did not allow the propagation of tachyzoites. MRC-5 was the best cell line in which T. gondii grew providing a regular supply of viable tachyzoites. The detection of T. gondii was determined by histology, western blot and nested-PCR in mice experimentally inoculated intraperitoneally and orally with 10, 10 2 , 10 3 , and 2x10 5 tachyzoites. No significant difference (p>0.05) was observed among these three techniques in detecting T. gondii in mice intraperitoneally infected. A significant difference (p<0.05) was observed between different methods of inoculation and among the initial concentration of tachyzoites used. Infection was found in 50% of the mice inoculated i.p. and in 30% of the mice inoculated orally among the three techniques. The prevalence of antibodies to T. gondii in pigs and cattle from Peru and USA was determined by western blot. Sera of 137 pigs and 253 cattle were collected at a slaughterhouse in Lima, Peru. Sera of 152 pigs and 23 cattle were collected from a slaughterhouse in Georgia, USA. Immunoglobulin G (IgG) antibodies to T. gondii were detected in 27.7% of pigs and in 51.4% of cattle from Peru; in 16.4% of pigs and in 26% of cattle from USA.