title: Infection of macrophage-like cells by Legionella species that have not been associated with disease.
abstract: We assessed the ability of Legionella species that have not been associated with disease to infect macrophage-like U937 cells. Two of fourteen species tested exhibited a 50% infective dose that was within I log unit of that of virulent L. pneumophila. Indeed, intracellular CFU of L. jamestowniensis and L. parisiensis increased 100-fold over a 72-h period. These data indicate that additional legionellae can flourish within phagocytes and therefore, can, if given the opportunity, cause disease.
authors.affiliation: Department of Microbiology-Immunology, Northwestern University, Chicago, Illinois 60611, USA.
authors.forename: W A
authors.initials: WA
authors.lastname: O'Connell
authors.forename: L
authors.initials: L
authors.lastname: Dhand
authors.forename: N P
authors.initials: NP
authors.lastname: Cianciotto
mesh_terms: D002460:Cell Line; D006801:Humans; D007875:Legionella / Q000502:physiology*; D008264:Macrophages / Q000382:microbiology*