TABLE 1.

MIC range, MIC₅₀, MIC₉₀, and resistance rates of 156 streptococcal isolates from neutropenic patients in Germany, 1996 to 1999

Species (no. of isolates)	Antibiotica	MIC (mg/liter)			% Ib	% Rb
		Range	50%	90%
All (156)	Pencillin G	≤0.06–8	≤0.06	≤0.06	2.6	0.6
	Amoxicillin	≤0.125–8	≤0.125	≤0.25	3.2	1.3
	Erythromycin	≤0.25–≥32	≤0.25	4	2.6	16
	Clindamycin	≤0.25–≥32	≤0.25	≤0.25	0	5.8
	Vancomycinc	0.25–≥32	≤0.25	0.5	0	0.6
	Teicoplaninc	0.25–16	≤0.25	≤0.25	0	0.6
	Ciprofloxacind	0.25–32	0.5	2	7.7	1.9
	Q-De	0.25–4	0.5	1	6.4	1.3
S. oralis (41)	Penicillin	≤0.06–2	≤0.06	0.25	14.6	0.0
	Amoxicillin	≤0.125–8	0.25	0.25	7.3	2.4
	Erythromycin	≤0.25–≥32	≤0.25	4	4.9	29.3
	Clindamycin	≤0.25–≥32	≤0.25	≤0.25	0	7.3
	Vancomycinc	0.25–1	1	1	0	0
	Teicoplaninc	0.25–0.5	≤0.25	≤0.25	0	0
	Ciprofloxacind	0.25–32	2	4	24.4	4.9
	Q-D	0.25–4	1	1	4.9	0
S. pneumoniae (41)	Penicillin G	≤0.06–0.25	≤0.06	≤0.06	4.9	0.0
	Amoxicillin	≤0.125	≤0.125	≤0.125	0.0	0.0
	Erythromycin	≤0.25–4	≤0.25	≤0.25	2.4	2.4
	Clindamycin	≤0.25	≤0.25	≤0.25	0.0	0.0
	Vancomycinc	0.25–0.5	≤0.25	≤0.25	0.0	0.0
	Teicoplaninc	≤0.25	≤0.25	≤0.25	0.0	0.0
	Ciprofloxacind	0.25–2	0.5	1	0.0	0.0
	Q-D	0.25–4	0.5	1	0.0	0.0
S. agalactiae (18)	Penicillin G	≤0.06	≤0.06	0.125	0.0	0.0
	Amoxicillin	≤0.125–0.5	≤0.25	≤0.25	0.0	0.0
	Erythromycin	≤0.25–≥32	≤0.25	4	5.6	11.1
	Clindamycin	≤0.25–≥32	≤0.25	≤0.5	0.0	5.6
	Vancomycinc	≤0.25–0.5	0.5	0.5	0.0	0.0
	Teicoplaninc	≤0.25	≤0.25	≤0.25	0.0	0.0
	Ciprofloxacind	0.25–2	2	2	0	0.0
	Q-D	0.25–0.5	0.25	0.5	0.0	0.0
S. mitis (14)	Penicillin	≤0.06–8	≤0.06	≤0.06	0	7.1
	Amoxicillin	≤0.125–8	≤0.125	0.5	7.1	7.1
	Erythromycin	≤0.25–≥32	≤0.25	8	0.0	21.4
	Clindamycin	≤0.25–≥32	≤0.25	≤0.25	0.0	7.1
	Vancomycinc	0.25–1	0.5	0.5	0.0	0.0
	Teicoplaninc	0.25	≤0.25	≤0.25	0.0	0.0
	Ciprofloxacind	0.25–2	1	2	0.0	0.0
	Q-D	0.25–4	1	2	14.3	0.0

^aFor data on HLGR, see the text. 

^bThe following breakpoints for intermediate resistance (I) and resistance (R) according to NCCLS (13) were used: penicillin G (for S. pneumoniae), 0.1 to 1 and ≥2 mg/liter; penicillin G (for Streptococcus spp. other than S. pneumoniae), 0.25 to 2 and ≥4 mg/liter; amoxicillin (S. pneumoniae), 4 and ≥8 mg/liter; amoxicillin (for Streptococcus spp. other than S. pneumoniae), 0.5 to 4 and ≥8 mg/liter; erythromycin, 0.5 and ≥1 mg/liter; clindamycin, 0.5 and ≥1 mg/liter; ofloxacin, 4 and ≥8 mg/liter; quinupristin-dalfopristin, 2 and ≥4 mg/liter. 

^cAll strains with vancomycin or teicoplanin MICs of ≤1 mg/liter were deemed to be susceptible. 

^dOfloxacin breakpoints were used for ciprofloxacin because ciprofloxacin breakpoints are not available. 

^eQ-D, quinupristin-dalfopristin.