Volume 15, Number 8—August 2009
Research
Increase in Pneumococcus Macrolide Resistance, United States
Stephen G. Jenkins
and David J. Farrell
and David J. FarrellTable 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.
