title: Experimental amebiasis. I. Pathogenicity of axenically cultured Entamoeba histolytica in the brain of the newborn mouse.
abstract: Axenically cultured Entamoeba histolytica inoculated intracerebrally into newborn Swiss mice invaded the cerebrum and produced multiple abscesses containing viable trophozoites. As few as 20 amebae of a virulent strain (HM-1:IMSS) occasionally produced fatal disease, 200 killed about 75% of animals and higher doses regularly killed all animals. In contrast, avirulent strains (HK-9 and HB-301:NIH) failed to produce acute brain disease in comparable time periods even when mice were inoculated with as many as 20,000 amebae. Two other strains (1295 and H-458:CDC) were of intermediate virulence. High doses of avirulent amebae often produced hydrocephalus as a late manifestation. In newborn, 3 week-old, and 6-week-old mice resistance to infection increased with age, and older animals often responded late to virulent strains by developing hydrocephalus.
mesh_terms: D000562:Amebiasis / Q000469:parasitology*; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000473:pathology; D001922:Brain Abscess / Q000469:parasitology* / Q000473:pathology; D004195:Disease Models, Animal; D004748:Entamoeba histolytica / Q000472:pathogenicity*; D004749:Entamoebiasis / Q000469:parasitology* / Q000473:pathology; D005856:Germ-Free Life; D006849:Hydrocephalus / Q000209:etiology; D051379:Mice; D014774:Virulence