TABLE 3.
Prevalence of MDR phenotypes in S. pneumoniae isolated from patients in different age groups in the United States from 2000 to 2002
| Patient age (yr) | No. of isolates tested | No. (%) of isolates with an MDR phenotypea | % of MDR isolates with the most prevalent MDR phenotypeb | No. (%) of MDR isolates that included levofloxacin resistance | % of all isolates that were MDR and resistant to levofloxacin |
|---|---|---|---|---|---|
| <2 | 1,080 | 283 (26.1) | 75.3 | 0 (0) | 0 |
| 2-4 | 797 | 192 (24.1) | 70.8 | 1 (0.5) | 0.1 |
| 5-10 | 611 | 84 (13.7) | 71.4 | 1 (1.2) | 0.2 |
| 11-17 | 346 | 41 (11.9) | 70.3 | 0 (0) | 0 |
| 18-64 | 6,339 | 767 (12.1) | 74.6 | 25 (3.3) | 0.4 |
| >64 | 4,627 | 573 (12.4) | 76.6 | 22 (3.8) | 0.5 |
a
Resistance to three or more of the following antimicrobial agents: penicillin, ceftriaxone, azithromycin, SXT, and levofloxacin (19).
b
The most prevalent MDR phenotype consisted of resistance to penicillin, azithromycin, and SXT. For all age groups, this phenotype included ceftriaxone-intermediate isolates five to seven times more frequently than ceftriaxone-susceptible isolates.