Chlamydia psittaci genetic variants differ in virulence by modulation of host immunity.

ABSTRACT:

Background

Psittacosis is a zoonosis caused by Chlamydia psittaci and is characterized by severe pneumonia and systemic infection. We sought to determine the basis of the 1000-fold difference in lethal dose of 2 C. psittaci 6BC strains in mice.

Methods

Genomes of the strains were sequenced. Mice were infected intraperitoneally and the growth kinetics, immune responses, and pathology were compared.

Results

The 2 strains differed by the presence of a 7.5-kb plasmid in the attenuated strain and 7 nonsynonomous single-nucleotide polymorphisms between the chromosomes, including a serine/threonine protein kinase gene pkn5. The plasmid was cured from the attenuated strain, but it remained nonlethal. Strains did not differ in growth kinetics in vitro or in vivo. Infection wit

SUBMITTER: Miyairi I 

PROVIDER: S-EPMC3203387 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature