TABLE 2.

Antimicrobial susceptibilities of S. pneumoniae, H. influenzae, and M. catarrhalis collected during the 2005-2006 respiratory season in the United States

Organism, antimicrobial, and phenotype	MIC (μg/ml)				% of isolates that werea:
	Range	Modef	50%	90%	S	I	R
S. pneumoniaeb
Faropenem
All	≤0.004-2	0.008	0.015	0.5
Penicillin susceptible	≤0.004-0.06	0.008	0.008	0.015
Penicillin intermediate	0.008-0.5	0.03	0.06	0.25
Penicillin resistant	0.12-2	1	1	2
Amoxicillin-clavulanate
All	≤0.12-16	≤0.12	≤0.12	2	92.2	1.4	6.4
Penicillin susceptible	≤0.12-0.25	≤0.12	≤0.12	≤0.12	100	0	0
Penicillin intermediate	≤0.12-2	≤0.12	≤0.12	1	100	0	0
Penicillin resistant	0.5-16	8	2	8	51.4	8.5	40.1
Cefdinir
All	≤0.06->8	≤0.06	0.12	8	76.8	4.0	19.2
Penicillin susceptible	≤0.06-1	≤0.06	≤0.06	0.12	99.9	0.1	0
Penicillin intermediate	≤0.06->8	0.12	0.25	2	67.5	17.7	14.8
Penicillin resistant	2->8	8	8	>8	0	0	100
Cefuroxime
All	≤0.5-32	≤0.5	≤0.5	8	78.2	3.1	18.7
Penicillin susceptible	≤0.5-2	≤0.5	≤0.5	≤0.5	99.9	0.1	0
Penicillin intermediate	≤0.5-16	≤0.5	≤0.5	4	74.0	13.3	12.7
Penicillin resistant	2-32	8	8	16	0	0.8	99.2
Meropenem
All	≤0.004-4	0.015	0.015	0.5	83.2	7.3	9.5
Penicillin susceptible	≤0.004-0.06	0.015	0.015	0.015	100	0	0
Penicillin intermediate	0.015-0.5	0.03	0.06	0.25	93.2	6.8	0
Penicillin resistant	0.25-4	1	1	1	4.5	36.0	59.5
Penicillin
All	≤0.03->4	≤0.03	≤0.03	2	62.1	21.9	16.0
Penicillin susceptible	≤0.03-0.06	≤0.03	≤0.03	≤0.03	100	0	0
Penicillin intermediate	0.12-1	0.12	0.25	1	0	100	0
Penicillin resistant	2->4	4	4	4	0	0	100
Azithromycin
All	≤0.12->16	≤0.12	≤0.12	>16	65.5	0.5	34.0
Penicillin susceptible	≤0.12->16	≤0.12	≤0.12	4	87.9	0.8	11.3
Penicillin intermediate	≤0.12->16	≤0.12	4	>16	35.5	0	64.5
Penicillin resistant	≤0.12->16	32	32	>16	19.4	0	80.6
Telithromycin
All	≤0.12->16	≤0.12	≤0.12	0.5	99.4	0.5	0.1
Penicillin susceptible	≤0.12->16	≤0.12	≤0.12	≤0.12	99.8	0.1	0.1
Penicillin intermediate	≤0.12-1	≤0.12	≤0.12	0.5	100	0	0
Penicillin resistant	≤0.12-2	≤0.12	0.5	1	97.2	2.8	0
Levofloxacin
All	0.25->8	1	1	1	99.2	0.2	0.6
Penicillin susceptible	0.25->8	1	1	1	99.7	0.1	0.2
Penicillin intermediate	0.5->8	1	1	1	98.8	0.3	0.9
Penicillin resistant	0.5->8	1	1	1	98.0	0.4	1.6
SXT
All	≤0.06->8	0.25	0.25	8	69.0	7.5	23.5
Penicillin susceptible	≤0.06->8	0.25	0.25	1	89.1	5.8	5.1
Penicillin intermediate	≤0.06->8	0.25	1	8	49.7	13.0	37.3
Penicillin resistant	0.25->8	8	8	>8	17.4	6.5	76.1
H. influenzaec
Faropenem
All	0.008-4	0.25	0.5	1
β-Lactamase positive	0.06-4	0.25	0.25	1
β-Lactamase negative	0.008-4	0.25	0.5	1
Amoxicillin-clavulanate
All	≤0.12-8	0.5	0.5	1	99.6
β-Lactamase positive	0.25-4	0.5	0.5	2	99.4
β-Lactamase negative	≤0.12-8	0.5	0.5	1	100
Cefdinir
All	≤0.06-4	0.25	0.25	1	94.8
β-Lactamase positive	≤0.06-4	0.25	0.25	1	94.4
β-Lactamase negative	≤0.06-4	0.25	0.25	1	95.0
Cefuroxime
All	≤0.5-32	≤0.5	1	2	97.6	2.1	0.3
β-Lactamase positive	≤0.5-16	≤0.5	1	2	96.3	3.0	0.7
β-Lactamase negative	≤0.5-32	≤0.5	1	2	98.0	1.8	0.2
Meropenem
All	≤0.004-8	0.03	0.03	0.12	99.7
β-Lactamase positive	0.008-0.25	0.03	0.03	0.06	100
β-Lactamase negative	≤0.004-8	0.03	0.06	0.12	99.6
Ampicillin
All	≤0.12->16	0.25	0.25	>16	71.9	0.5	27.6
β-Lactamase positive	2->16	>16	>16	>16	0	0.4	99.6
β-Lactamase negative	≤0.12-4	0.25	0.25	0.5	99.0	0.6	0.4
Azithromycin
All	≤0.12->16	1	1	2	98.7
β-Lactamase positive	≤0.12-16	1	1	2	98.1
β-Lactamase negative	≤0.12->16	1	1	2	98.9
Telithromycin
All	≤0.12->16	2	2	4	96.4	2.9	0.7
β-Lactamase positive	≤0.12-16	2	2	4	97.0	2.2	0.8
β-Lactamase negative	≤0.12->16	2	2	4	96.1	3.2	0.7
Levofloxacin
All	≤0.06->8	≤0.06	≤0.06	≤0.06	99.9
β-Lactamase positive	≤0.06-0.12	≤0.06	≤0.06	≤0.06	100
β-Lactamase negative	≤0.06->8	≤0.06	≤0.06	≤0.06	99.7
SXT
All	≤0.06->8	0.25	0.5	8	64.9	16.8	18.3
β-Lactamase positive	≤0.06->8	0.12	0.5	8	63.7	14.1	22.2
β-Lactamase negative	≤0.06->8	0.25	0.5	8	65.4	17.9	16.7
M. catarrhalisd,e
Faropenem	0.03-1	0.5	0.25	0.5
Amoxicillin-clavulanate	≤0.12-1	≤0.12	≤0.12	0.25
Cefdinir	≤0.06-1	0.25	0.25	0.5
Cefuroxime	≤0.5-8	2	1	2
Meropenem	≤0.004-0.12	≤0.004	≤0.004	0.008
Ampicillin	0.25->16	4	4	16
Azithromycin	≤0.12-4	≤0.12	≤0.12	≤0.12
Telithromycin	≤0.12-4	≤0.12	≤0.12	≤0.12
Levofloxacin	≤0.06-0.25	≤0.06	≤0.06	≤0.06
SXT	≤0.06-4	0.25	0.25	0.5

^aPercentages of isolates that were susceptible (S), intermediate (I), and resistant (R) according to CLSI breakpoints. Breakpoints are not available for faropenem.

^bOf the 1,543 isolates of S. pneumoniae, 958 were penicillin susceptible, 338 were penicillin intermediate, and 247 were penicillin resistant.

^cOf the 987 isolates of H. influenzae, 270 were β-lactamase positive, and 717 were β-lactamase negative.

^dCLSI breakpoints are not available for M. catarrhalis.

^eA total of 489 isolates of M. catarrhalis were tested.

^fMode, modal MIC.