Table 3. Growth of different T4-related phages on cell lawns of E. coli DH10B expressing either CT596GmrSD or CT596GmrSD and IPI*.

Phage	Phage has IPI*	pHERD20Ta	pHERD20T + CT596GmrSD	pHERD20T + CT596GmrSD + IPI* (see Fig. 7)
T4	Yes	+	+	+
T4ip1HA35	No	+	−	+
T4eG192	Yes	+	+	+
T4eG506	No	+	−	+
RB15	No	+	+	+
T2b	No	+	−	+
RB49 (no 5hmC)	No	+	+	+
T4ip1KAI−	No	+	−	+
a.A control of host (DH10B) containing the expression vector alone. Cultures were induced with 0.4% arabinose. A series of spots containing 102, 104, 105 and 108 phage particles were examined for growth after overnight incubation. −, indicates no phage growth; +, indicates EOP (efficiency of phage plating) >0.6; +/− indicates EOP < 0.6.
b.The co-expression of IPI* prevented restriction of phages normally sensitive to GmrSD, e.g., T2.