Serological profile of chronically infected mice with the cystogenic ME-49 strain of Toxoplasma gondii before and after specific treatment

Abstract

This study evaluated the serological profile after experimental specific therapy
of BALB / c mice infected with the cystogenic strain ME-49. Forty-five animals
were inoculated individually, intraperitoneally with ten cysts of strain ME-49. Mice
were divided into three groups of fifteen animals each, and a control group with
five non-infected and non-treated animals. The infected animals and controls were
simultaneously monitored daily for twenty days. After this period, they were divided
into two groups: A and B and subjected to specific treatment regimens as follows: group A: pyrimethamine plus folic acid, group B: pyrimethamine, folinic acid and
sulfadiazine for ten consecutive days. From the fifth day of treatment on, one mouse
of each group was anesthetized and blood was collected by cardiac puncture; the
serum was analyzed by the indirect immunofluorescence test. Treated animals
showed a significant decrease in the titers of IgG antibodies, compared to the
infected and untreated group. There was no significant difference among samples
with different treatment regimes, showing that early treatment reduces rapidly the
levels of IgG anti T. gondii and suggesting a possible cure of the infection.