TABLE 1.

Frequency of VREF strains, van genotypes, ampicillin and aminoglycoside susceptibilities, and detection periods

Pattern	No. of isolates	Genotype	MIC (μg/ml)			Detection period
			Ampicillin	Gentamicin	Streptomycin
A	122	vanA	16	>1,024	32	June 1992–December 1994
B	92	vanB	64	>2,048	>2,048	January 1994–November 1996
C	10	vanA	128	>2,048	>2,048	March 1995a and November 1996–February 1997
D	92	vanA	128	>2,048	>2,048	November 1995–June 1997

^aTwo isolates.