Endemic bacteriophages: a cautionary tale for evaluation of bacteriophage therapy and other interventions for infection control in animals

Table 1 E. coli strains used to assess the virulence of the three isolates of the rogue phage as determined by the microplate virulence assay

Strain No.	Serotype	*E. coli*O157 Phage Type	Strain description	Minimum Phage MOI¹
Strain No.	Serotype	*E. coli*O157 Phage Type	Strain description	LRCSh151d1	LRCSh158d1	LRCSh166d1
EC19990293	O157:H7	PT21	Phage type reference strain	0.00001	0.000001	0.000001
EC19990295	O157:H7	PT4	Phage type reference strain	0.00001	0.00001	0.000001
EC19990296	O157:H7	PT23	Phage type reference strain	0.000001	0.000001	0.00001
EC19990298	O157:H7	PT14	Phage type reference strain	0.00001	0.000001	0.000001
EC19990299	O157:H7	PT14	Phage type reference strain	0.01	0.00001	0.001
EC19990300	O157:H7	PT2	Phage type reference strain	0.0001	0.0001	0.00001
EC20010992	O7:H21	NA²	Non-pathogenic E. coli	>10	>10	>10
EC19990779	O173:HUN	NA	Non-pathogenic E. coli	>10	>10	>10
EC20030480	O157:H7	PT4	Challenge strain LRC.E318N	0.000001	0.000001	0.000001
EC20030479	O157:H7	PT1	Challenge strain LRC.E319	>10	>10	>10
EC20030478	O157:NM	PT87	Challenge Strain LRC.E32511N	10	10	10
EC20030477	O157:H7	PT87	Challenge Strain LRC.H4420nal	0.000001	0.00001	0.000001
EC20030481	O157:H7	PT14	Challenge Strain LRC.R508N	0.00001	0.00001	0.000001
EC19940312	O157:H7	PT8	Challenge Strain LCDC.CO281–31nal	0.000001	0.0001	0.01

¹ MOI: Multiplicity of Infection required for complete lysis of 1 CFU of the tested strains by the listed phages. Phages were identified as virulent for a bacterial strain when the MOI was ≤10. ² NA: not applicable. Description: Table (Microsoft Word).