Interaction of bacteriophage T7 with Hind-endonuclease-producing Haemophilus influenzae Rd cells

In order to test the influence of the restriction endonucleases of Haemophilus species on in vivo DNA restriction of phage T7 and its close relative T3 as well as to determine whether the anti-DNA restriction effect of the T7 and T3 ocr+ gene is also expressed in Haemophilus cells, we studied the interaction of T7 and T3 with Haemophilus influenzae serotypes Rd and Rc and Haemophilus parainfluenzae. The results show that T7 and T3 are unable to infect these bacterial species because they do not absorb to the cells.