TABLE 3.

C. diphtheriae strains within the ET 215 complex isolated in the United States from 1973 to 1996

Strain designationa	Yr	Biotypeb	Toxigenicity status	Ribotype	ET
PR101	1996	M	+	M1a	221
PR20	1996	M	+	M1a	222
PR130	1996	M	+	M1a	229
E5340	1979	M	−	M1a	219
E7798	1980	M	−	M1a	220
PR109	1996	G	+	M11d	227
PR110	1996	M	+	M11b	228
PR115	1996	M	+	M11b	228
G4218	1978	G	+	M11a	34
E5449	1979	G	+	M11a	40
C5276	1973	M	+	M11c	217
C4943	1973	G	+	M11a	215
D7643	1979	G	+	M11a	215
E8277	1980	G	+	M11a	215
C5214	1973	M	−	M7a	216

^aAll strains except G4218, which was collected in Colorado, were collected in South Dakota. 

^bM, mitis; G, gravis.