Parasitemia and parasitic loads in acute infection and after anti-gamma-interferon treatment in a toxoplasmic mouse model.
Toxoplasma gondii infection was induced in Swiss-Webster mice by intraperitoneal inoculation of avirulent Beverley strain cysts. We studied parasitemia and parasitic loads first in acute toxoplasmosis, then in the chronic stage of the disease. In the latter stage a group of mice received weekly administration of a rabbit antiserum directed against mouse gamma-interferon. Parasitemia, sequentially determined by amplification of the B1 gene using polymerase chain reaction, persisted for more than 1 month in acute toxoplasmosis. Brain and lung parasitic loads, assessed by a tissue-culture method, were significantly increased in mice treated with anti-interferon. Moreover, this increase was prevented by concomitant administration of pyrimethamine and sulfadiazine, suggesting that early prophylaxis would be suitable. Surprisingly, the anti-interferon treatment induced neither abnormal clinical signs nor a significant rise in the parasitemia level. Such a model seems to be particularly appropriate for the comparison of different strains of Toxoplasma gondii in a moderately immunodeficient state.
Miédougé
M
M
Department of Parasitology and Mycology, Centre Hospitalier Universitaire, Hôpital de Rangueil, Toulorese, France.
Bessières
M H
MH
Cassaing
S
S
Swierczynski
B
B
Séguéla
J P
JP
D000208:Acute Disease; D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D000906:Antibodies / Q000627:therapeutic use*; D001921:Brain / Q000469:parasitology; D002908:Chronic Disease; D004359:Drug Therapy, Combination; D005260:Female; D017125:Genes, Protozoan; D007371:Interferon-gamma / Q000276:immunology*; D008168:Lung / Q000469:parasitology; D051379:Mice; D018512:Parasitemia / Q000276:immunology / Q000469:parasitology* / Q000628:therapy; D016133:Polymerase Chain Reaction; D011739:Pyrimethamine / Q000627:therapeutic use; D013411:Sulfadiazine / Q000627:therapeutic use; D014124:Toxoplasmosis, Animal / Q000276:immunology / Q000469:parasitology* / Q000628:therapy
D000890:Anti-Infective Agents; D000906:Antibodies; D013411:Sulfadiazine; D007371:Interferon-gamma; D011739:Pyrimethamine