Abstract
Francisella tularensis live vaccine strain (LVS), taken directly from lyophilized vials, did not appear to have a capsule and had low virulence for Balb/c mice. When this strain was subcultured on Chamberlain's synthetic medium (pH 6.5), it became extensively capsulated (1-5 micron in diameter) and its virulence for Balb/c mice increased about 1000-fold. We conclude that the virulence of the attenuated vaccine strain, F. tularensis LVS, may still be influenced by growth conditions.
MeSH terms
-
Amino Acids / chemistry
-
Animals
-
Bacterial Capsules / immunology
-
Bacterial Capsules / ultrastructure
-
Bacterial Vaccines / immunology*
-
Buffers
-
Culture Media
-
Francisella tularensis / cytology
-
Francisella tularensis / immunology*
-
Francisella tularensis / pathogenicity
-
Freeze Drying
-
Hydrogen-Ion Concentration
-
Mice
-
Mice, Inbred BALB C
-
Microscopy, Electron
-
Tularemia / prevention & control
-
Vaccines, Attenuated / immunology
-
Virulence / immunology
Substances
-
Amino Acids
-
Bacterial Vaccines
-
Buffers
-
Culture Media
-
Vaccines, Attenuated