TABLE 2.

Susceptibility of 91 H. influenzae isolates from sterile sites in relation to noncapsulated and capsulated strains^a

Antibiotic	Noncapsulated strains (n = 67)						Capsulated strains (n = 24)
	MIC50	MIC90	Range	S (%)	I (%)	R (%)	MIC50	MIC90	Range	S (%)	I (%)	R (%)
Ampicillin	0.25	>4	0.12->4	56 (83.6)	0	11 (16.4)	0.5	>4	0.25->4	13 (54.2)	0	11 (45.8)
Amoxicillin-clavulanic acid	≤0.5	1	≤0.5-1	67 (100)	0	0	≤0.5	≤0.5	≤0.5-1	24 (100)	0	0
Cefuroxime	0.5	1	0.25-2	67 (100)	0	0	0.5	1	0.25-2	24 (100)	0	0
Cefotaxime	≤0.03	0.06	≤0.03-0.12	67 (100)	0	0	≤0.03	0.06	≤0.03-0.06	24 (100)	0	0
Cefixime	≤0.25	≤0.25	≤0.25	67 (100)	0	0	≤0.25	≤0.25	≤0.25	24 (100)	0	0
Cefepime	0.12	0.5	≤0.06-0.5	67 (100)	0	0	0.12	0.5	≤0.06-0.5	24 (100)	0	0
Meropenem	≤0.12	≤0.12	≤0.12-0.5	67 (100)	0	0	≤0.12	≤0.12	≤0.12	24 (100)	0	0
Clarithromycin	8	16	1->16	51 (76.1)	13 (19.4)	3 (4.5)	4	8	2-16	22 (91.7)	2 (8.3)	0
Tetracycline	0.5	0.5	≤0.25->4	64 (95.5)	1 (1.5)	2 (3)	0.5	>4	≤0.25->4	20 (83.3)	3 (12.5)	1 (4.2)
Ciprofloxacin	≤0.06	≤0.06	≤0.06	67 (100)	0	0	≤0.06	≤0.06	≤0.06	24 (100)	0	0
Levofloxacin	≤0.25	≤0.25	≤0.25	67 (100)	0	0	≤0.25	≤0.25	≤0.25	24 (100)	0	0
Cotrimoxazole	≤0.5	>2	≤0.5->2	43 (64.2)	6 (9)	18 (26.9)	>2	>2	≤0.5->2	4 (16.7)	6 (25)	14 (58.3)
Chloramphenicol	≤2	≤2	≤2->4	66 (98.5)	1 (1.5)	0	≤2	>4	≤2->4	19 (79.2)	3 (12.5)	2 (8.3)
Rifampin	≤0.5	1	≤0.5-2	65 (97)	2 (3)	0	≤0.5	≤0.5	≤0.5-1	24 (100)	0	0

^aMIC₅₀, MIC₉₀, and range values are expressed in micrograms per milliliter. S, susceptible; I, intermediate; R, resistant.