Transformation of Haemophilus influenzae

Although Haemophilus influenzae genes may be transferred by plasmidmediated conjugation, this process is not discussed further below, as it has received little attention and is rarely used for strain construction. Conjugative plasmids are common in H. influenzae , as in other bacteria (1 -3 ). The F plasmid of Escherichia coli can conjugate into H. influenzae cells (4 ) (and into many other cell types), and can then transfer by conjugation from one H. influenzae strain to another. As in E. coli , efficient transfer of chromosomal genes requires a region of homology between the plasmid and the chromosome. A method for F-mediated conjugation into H. influenzae is described by Deich and Green (4 ).