Construction of a shuttle vector for use in Francisella tularensis.

The characterisation of virulence factors of Francisella tularensis has been hampered by the lack of genetic system for the bacterium. In this study, a shuttle vector was constructed that can replicate autonomously in F. tularensis and Escherichia coli. To obtain this vector, the p15A replication origin of F. coli plasmid pACYC184 was introduced into a plasmid derivative of plasmid pFNL2OO, a plasmid which only can replicate in F. tularensis. The resulting shuttle vector, designated pKK2O2, harboured resistance genes for chloramphenicol and tetracycline. This vector might be used as a basis for the studies of virulence factors of F. tularensis.