Table 3. Antimicrobial susceptibility of erythromycin-resistant isolates, by genotype, year 6 (2005–2006) of the PROTEKT US surveillance study*.

Genotype	Amoxicillin−clavulanate							Levofloxacin							Telithromycin
	Susceptibility, %				MIC, μg/mL			Susceptibility, %				MIC, μg/mL			Susceptibility, %				MIC, μg/mL
	S	I	R		MIC50	MIC90		S	I	R		MIC50	MIC90		S	I	R		MIC50	MIC90
erm(B)†	96.2	0.9	2.9		0.12	2		98.2	0.2	1.6		1	1		99.1	0.7	0.2		0.03	0.12
mef(A)‡	92.1	3.7	4.2		0.25	2		98.9	0.1	1.0		1	1		99.6	0.4	0		0.25	0.5
erm(B) + mef(A)§	9.7	9.9	80.3		>8	>8		98.8	0.2	1.0		1	1		99.1	0.5	0.3		1	1

   *PROTEKT US, Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin, United States; S, susceptible; I, intermediate; R, resistant.
   †n = 448.
   ‡n = 1,282.
   §n = 575.