Intracellular growth of Legionella pneumophila within Acanthamoeba castellanii Neff.
AUTOR(ES)
Holden, E P
RESUMO
Acanthamoeba castellanii Neff supports the intracellular growth of Legionella pneumophila. When acanthamoebae were exposed to L. pneumophila for 1 h and then washed free of unassociated bacteria and placed in liquid culture, levels of viable amoeba-associated legionellae and legionellae free in the culture medium increased by three to four orders of magnitude in 48 to 72 h. However, most of the legionellae remained amoeba-associated and could be cultured only after disruption of the amoebae. Furthermore, legionella viability declined rapidly in amoeba culture medium alone or when bacteria and amoebae were separated by a microporous membrane. Therefore, direct amoeba-legionella contact is required for this growth. Infected acanthamoebae treated with cold acetone to permeabilize them to fluorescent-labeled anti-L. pneumophila antibody appeared to contain far more legionellae than amoebae fixed with glutaraldehyde so as to prevent antibody penetration. Electron micrographs of infected A. castellanii showed numerous bacteria, including some dividing forms, within vacuoles in the cytoplasm. These results together show that A. castellanii is able to provide an intracellular niche for the growth of L. pneumophila.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=263250Documentos Relacionados
- Isolation and characterization of a cycloheximide-resistant mutant of Acanthamoeba castellanii Neff.
- A quantitative model of intracellular growth of Legionella pneumophila in Acanthamoeba castellanii.
- The Legionella pneumophila rpoS Gene Is Required for Growth within Acanthamoeba castellanii
- Growth of Legionella pneumophila in Acanthamoeba castellanii enhances invasion.
- Intracellular Growth in Acanthamoeba castellanii Affects Monocyte Entry Mechanisms and Enhances Virulence of Legionella pneumophila