Intrapulmonary Hartmannella vermiformis: a potential niche for Legionella pneumophila replication in a murine model of legionellosis.
AUTOR(ES)
Brieland, J
RESUMO
The potential role of inhaled protozoa as a niche for intrapulmonary replication of Legionella pneumophila was investigated in vivo with mutant strains of L. pneumophila which have reduced virulence for the amoeba Hartmannella vermiformis. L. pneumophila AA488 and AA502 were derived from wild-type strain AA100 after transposon mutagenesis. These mutants have reduced virulence for H. vermiformis but are fully virulent for mononuclear phagocytic cells. A/J mice, which are susceptible to replicative L. pneumophila lung infections, were inoculated intratracheally with L. pneumophila AA100, AA488, or AA502 (10[6] bacteria per mouse) or were coinoculated with one of the L. pneumophila strains (10[6] bacteria per mouse) and uninfected H. vermiformis (10[6] amoebae per mouse). The effect of coinoculation with H. vermiformis on intrapulmonary growth of each L. pneumophila strain was subsequently assessed. In agreement with our previous studies, coinoculation with H. vermiformis significantly enhanced intrapulmonary growth of the parent L. pneumophila strain (AA100). In contrast, intrapulmonary growth of L. pneumophila AA488 or AA502 was not significantly enhanced by coinoculation of mice with H. vermiformis. These studies demonstrate that L. pneumophila virulence for amoebae is required for maximal intrapulmonary growth of the bacteria in mice coinoculated with H. vermiformis and support the hypothesis that inhaled amoebae may potentiate intrapulmonary growth of L. pneumophila by providing a niche for bacterial replication.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=175705Documentos Relacionados
- Coinoculation with Hartmannella vermiformis enhances replicative Legionella pneumophila lung infection in a murine model of Legionnaires' disease.
- The role of Legionella pneumophila-infected Hartmannella vermiformis as an infectious particle in a murine model of Legionnaire's disease.
- Formalin-killed versus heat-killed Legionella pneumophila serogroup 1 antigen in the indirect immunofluorescence assay for legionellosis.
- Intracellular Proliferation of Legionella pneumophila in Hartmannella vermiformis in Aquatic Biofilms Grown on Plasticized Polyvinyl Chloride
- Protein expression by the protozoan Hartmannella vermiformis upon contact with its bacterial parasite Legionella pneumophila.