Transcript Francisella tularensis - University of Louisville

Francisella tularensis
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Gram negative
Small, pleomorphic coccobacillus
Encapsulated
non-motile
causes tularemia
– also called glandular fever, rabbit fever, tick
fever, and deer fly fever
V. Mosley F2013
Modified by DYH
Table 1 Overall features of the genome of F.
tularensis strain SCHU S4
Size
1,892,819 bp
G+C content (%)
32.9
CDS
1,804
Coding percentage
79.4
Unique genes
302
Pseudogenes or gene fragments
201
IS elements
74
ISFtu1 (IS630 family)
50
ISFtu2 (IS5 family)
16
ISFtu3 (ISHpaI-IS1016 family)
3
ISFtu4 (IS982 family)
1
ISFtu5 (IS4 family)
1
rRNAs
3 operons
tRNAs
38
Other stable RNAs
7
Subspecies (Human isolate)
http://www.nature.com/ng/journal/v37/n2/full/ng1499.html
• Infects
– through the bite of infected insects (ex. ticks
and deerflies)
– by handling infected sick or dead animals (ex.
rabbits, rodents, and hares)
– by eating or drinking contaminated food or
water
– by inhaling airborne bacteria
(A) buffered charcoal yeast extract; (B) chocolate agar medium;
(C) sheep’s blood agar; (D) cysteine heart agar.
http://www.ppdictionary.com/bacteria/gnbac/tularensis.htm
Francisella tularensis
V. Mosley F2013
Modified by DYH
• Virulence factors not well
studied
• hemolytic agents
–
may facilitate degradation of the phagosome
• NlyA (hemolysin activity )
• ATP binding cassette (ABC)
proteins
–
may be linked to the secretion of virulence factors
• type IV pili
–
–
bind to the exterior of a host cell
thus become phagocytosed
• IglC (23-kD protein )
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phagosomal breakout and intracellular replication
Down regulates immune response to increase
growth time
• AcpA
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inhibts the respiratory burst
Down regulates immune response to increase
growth time
• No natural resistance to
antibiotics used to treat the
diesease
Tularemia. Number of reported cases - United States and U.S. territories, 2007
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5653a1.htm