TABLE 3.

Antimicrobial susceptibilities of 102 erythromycin-resistant S. pneumoniae strains

Antibiotic	MIC (μg/ml)a			No. (%) of strains
	50%	90%	Range	Susceptible	Intermediate	Resistant
Penicillinb	2	4	<0.03->8	25 (24.5)	7 (6.9)	70 (68.6)
Amoxicillin-clavulanic acid	<2/1	>8/4	<2/1-8/4	68 (66.7)	5 (4.9)	29 (28.4)
Cefotaxime	1	2	<0.06->2	64 (62.7)	32 (31.4)	6 (5.9)
Tetracycline	≥8	≥8	<0.5->8	25 (24.5)	1 (1.0)	76 (74.5)
Chloramphenicol	4	8	<2->16	68 (66.7)	0 (0)	34 (33.3)
Levofloxacin	1	1	<0.5-1	102 (100.0)	0 (0)	0 (0)
Gatifloxacin	<0.5	<0.5	<0.5	102 (100.0)	0 (0)	0 (0)
Moxifloxacin	<0.25	<0.25	<0.25-1	102 (100.0)	0 (0)	0 (0)
Erythromycin	>2	>2	>2	0 (0)	0 (0)	102 (100.0)
Azithromycin	>2	>2	>2	0 (0)	0 (0)	102 (100.0)
Linezolid	1	1	0.5-2	102 (100.0)	0 (0)	0 (0)
Clindamycin	>2	>2	<0.06->2	31 (30.4)	2 (2.0)	69 (67.6)
Vancomycin	<0.5	<0.5	<0.5-1	102 (100.0)	0 (0)	0 (0)
SXTc	>4/76	>4/76	<0.5/9.5-4/76	23 (22.6)	18 (17.6)	61 (59.8)
Meropenem	0.5	1	<0.25-1	34 (33.3)	33 (32.4)	35 (34.3)

^a50% and 90%, MIC₅₀ and MIC₉₀, respectively.

^bSusceptible, intermediate, and resistant MIC breakpoints for penicillin were ≤0.06, 0.12-1, and ≥2 mg/liter, respectively.

^cSXT, trimethoprim-sulfamethoxazole.