TABLE 1.

Host range of PY100^a

Organism	Source	Strain properties	No. of strains tested	No. of PY100-sensitive strains
Y. enterocolitica	RKI, IP	Serogroup O:3	10	9
Y. enterocolitica	RKI, IP	Serogroup O:5,27	5	5
Y. enterocolitica	RKI, IP	Serogroup O:9	9	8
Y. enterocolitica	RKI, IP	Serogroup O:8	6	4
Y. enterocolitica	RKI, IP	Biogroup 1A, various serogroups, NT	20	15
Y. pseudotuberculosis	RKI, IP	Serogroups I to VII	10	10
Y. pestis		KIM, EV76	2	2
Y. intermedia	RKI, IP	Various serogroups, NT	10	6
Y. kristensenii	RKI, IP	Various serogroups, NT	10	6
Y. frederiksenii	RKI, IP	Various serogroups, NT	10	4
Y. mollaretii	RKI, IP	Various serogroups, NT	10	3
Y. rohdei	RKI		1	0

^aTests were performed by spotting 20 μl of phage suspensions containing approximately 10⁸, 10⁶, or 10³ PFU/ml on lawns of test bacteria (100 μl of overnight culture mixed with 3 ml of LB soft agar). Plaques were determined after overnight incubation at 37°C. Abbreviations: RKI, strain collection of the Robert Koch Institute; IP, strains from the Institute Pasteur, Paris, France. NT, strains not typeable with standard sera.