title: Leishmania infantum and Toxoplasma gondii: Mixed infection of macrophages in vitro and in vivo.
abstract: Although macrophages have a microbicidal role in the immune system they themselves can be infected by pathogens. Often a simultaneous infection by more than one microbe may occur in a single cell. This is the first report of coinfection of macrophages with Toxoplasma gondii and Leishmania infantum, in vitro and in vivo. L. infantum does not cause severe disease in mice but T. gondii, RH strain, is lethal. Cell culture studies using THP-1 macrophages dually infected in vitro revealed that 4.3% harbored both parasites 24h after infection. When mice were infected with both parasites on the same day 7.3% of the infected cells carried both parasites 7 days later. Yet, if mice were first infected with L. infantum and then with Toxoplasma (5 days post-infection) 18.7% of the macrophages hosted either parasite but concomitant infection could not be found and mice, already harboring L. infantum, survived Toxoplasma's lethal effect.
authors.affiliation: Laboratory of Clinical Bacteriology Parasitology Zoonoses and Geographical Medicine, Faculty of Medicine, University of Crete, Crete, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Christodoulou
authors.forename: Ippokratis
authors.initials: I
authors.lastname: Messaritakis
authors.forename: Eleni
authors.initials: E
authors.lastname: Svirinaki
authors.forename: Christos
authors.initials: C
authors.lastname: Tsatsanis
authors.forename: Maria
authors.initials: M
authors.lastname: Antoniou
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D005455:Fluorescent Antibody Technique; D006801:Humans; D018314:Leishmania infantum / Q000502:physiology*; D007898:Leishmaniasis, Visceral / Q000150:complications*; D008264:Macrophages / Q000469:parasitology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018613:Microscopy, Confocal; D013154:Spleen / Q000166:cytology / Q000469:parasitology; D014122:Toxoplasma / Q000502:physiology*; D014123:Toxoplasmosis / Q000150:complications*; D014709:Vero Cells