Figure 1.

Representative photomicrographs of co-culture of mice and rats samples on Acanthamoeba castellanii. Pictures (a–d) show positive samples by co-culture as indicated by the visible infected amoebas with Marseillevirus. These samples include NALT from aerosol inoculated mice and spleen from rats after IV inoculation with Marseillevirus. The arrows indicate viral factories and N indicate the nucleus of amoeba. Pictures (e,f) show negative samples by amoebal co-culture: the amoebas are not infected and do not contain viral factories.