• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Scientific Publications by FDA Staff

  • Print
  • Share
  • E-mail
-

Search Publications



Fields



Centers











Starting Date


Ending Date


Order by

Entry Details

J Bacteriol 2004 Oct;186(19):6430-6

A Francisella tularensis pathogenicity island required for intramacrophage growth.

Nano FE, Zhang N, Cowley SC, Klose KE, Cheung KK, Roberts MJ, Ludu JS, Letendre GW, Meierovics AI, Stephens G, Elkins KL

Abstract

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.


Category: Journal Article, Peer
PubMed ID: #15375123
Includes FDA Authors from Scientific Area(s): Biologics
Entry Created: 2011-10-04 Entry Last Modified: 2012-08-29
Feedback
-
-