[Francisella tularensis--feature of pathogen, pathogenesis, diagnostics]

Francisella tularensis belongs to the Francisellaceae family. There are four known subspecies of Francisella tularensis: tularensis, holarctica, mediasiatica and novicida. Fully virulent strains possess a capsule, which protects F. tularensis from bactericidal action of serum. The main virulen factors of F. tularensis are 23-kDa cytoplasmatic protein and LPS. F tularensis mechanism of pathogenecity is very unique. F. lularensis affect macrophages using a cytochalasin B intensive pathway. Bacteria live within macrophage in a phagosome. Acidification of the phagosome and acquisition of iron is essential for growth of F. tularensis. An acid pH promotes the release of iron from host-cell transferrin. An acid phosphatase function protein, AcpA, has been identified in F. tularensis. AcpA is capable of inhibiting the respiratory burst. A laboratory diagnostics of tularemia is based on classical microbiology and molecular biology techniques: PCR, nested-PCR, PCR-ELISA, Real-Time - PCR, ALFP, ERIC-PCR, PFGE, LR-REP-PCR and microarray techniques.