A Francisella tularensis Pathogenicity Island Required for Intramacrophage Growth
AUTOR(ES)
Nano, Francis E.
FONTE
American Society for Microbiology
RESUMO
Francisella tularensis is a gram-negative, facultative intracellular pathogen that causes the highly infectious zoonotic disease tularemia. We have discovered a ca. 30-kb pathogenicity island of F. tularensis (FPI) that includes four large open reading frames (ORFs) of 2.5 to 3.9 kb and 13 ORFs of 1.5 kb or smaller. Previously, two small genes located near the center of the FPI were shown to be needed for intramacrophage growth. In this work we show that two of the large ORFs, located toward the ends of the FPI, are needed for virulence. Although most genes in the FPI encode proteins with amino acid sequences that are highly conserved between high- and low-virulence strains, one of the FPI genes is present in highly virulent type A F. tularensis, absent in moderately virulent type B F. tularensis, and altered in F. tularensis subsp. novicida, which is highly virulent for mice but avirulent for humans. The G+C content of a 17.7-kb stretch of the FPI is 26.6%, which is 6.6% below the average G+C content of the F. tularensis genome. This extremely low G+C content suggests that the DNA was imported from a microbe with a very low G+C-containing chromosome.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=516616Documentos Relacionados
- MglA regulates transcription of virulence factors necessary for Francisella tularensis intraamoebae and intramacrophage survival
- Growth of Francisella tularensis LVS in macrophages: the acidic intracellular compartment provides essential iron required for growth.
- Identification of a pathogenicity island required for Salmonella survival in host cells.
- Survival and Growth of Francisella tularensis in Acanthamoeba castellanii
- Francisella tularensis Bacteremia