Table 1.

In vitro activities of 32 antimicrobial agents for 1,531 isolates of S. pneumoniae

AntimicrobialAll strains (n = 1,531)Penicillin-susceptible strains (n = 1,008)Pencillin-intermediate strains (n = 194)Pencillin-resistant strains (n = 329)
MIC50MIC90MIC range% I% R% I + RMIC50MIC90MIC range% I% R% I + RMIC50MIC90MIC range% I% R% I + RMIC50MIC90MIC range% I% R% I + R
Penicillin 0.03 2≤0.004–4 12.7 21.5 34.20.015 0.03 ≤0.004–0.06 0.51 0.12–1 2 42–4
Amoxicillina 0.015 2 ≤0.004–8 4.2 2.2 6.3 0.0150.03 ≤0.004–0.06 0.0 0.0 0.0 0.25 10.03–2 0.0 0.0 0.0 2 4 0.5–8 19.510.0 29.5
Amoxicillin-clavulanateb 0.015 2≤0.004–8 4.6 1.7 6.3 0.015 0.03≤0.004–0.12 0.0 0.0 0.0 0.25 1 0.015–20.0 0.0 0.0 2 4 0.5–8 21.3 7.929.2
Cefuroximec 0.03 8≤0.015–32 2.0 25.3 27.3 0.03 0.12≤0.015–2 0.1 0.0 0.1 1 4 0.12–3213.9 32.0 45.9 8 16 1–32 0.6 99.199.7
Ceftriaxone 0.03 2 ≤0.008–8 10.314.4 24.7 0.03 0.06 ≤0.008–0.5 0.0 0.00.0 0.25 1 0.03–4 23.7 2.6 26.3 24 0.5–8 33.7 65.7 99.4
Cefpodoxime 0.034 ≤0.015–32 2.0 25.7 27.7 0.03 0.06≤0.015–2 0.5 0.1 0.6 0.5 2 0.03–1611.9 34.0 45.9 4 8 1–32 0.6 99.4100.0
Cefixime 0.25 32 ≤0.06–>1280.25 0.5 ≤0.06–16 4 160.25–64 32 64 4–>128
Cefprozil 0.25 16 ≤0.03–64 1.324.8 26.1 0.12 0.25 ≤0.03–16 0.0 0.10.1 2 8 0.12–16 9.3 26.3 35.6 1632 4–64 0.6 99.4 100.0
Cefaclor 0.5 64≤0.06–>128 2.9 29.5 32.4 0.5 1≤0.06–64 1.2 0.2 1.4 4 64 0.25–6416.5 62.4 78.9 64 >128 8–>128 0.0100.0 100.0
Loracarbef 1 128 ≤0.06–>1282.7 29.3 32.0 1 2 ≤0.06–128 0.8 0.10.9 8 64 0.25–128 17.5 60.8 78.4 128>128 16–>128 0.0 100.0 100.0
Cefditoren0.015 0.5 ≤0.008–4 0.015 0.03≤0.008–0.5 0.12 0.5 ≤0.008–20.5 2 0.12–4
Cefdinir 0.068 ≤0.008–>8 1.4 25.8 27.2 0.06 0.12≤0.008–0.5 0.0 0.0 0.0 0.5 4 0.03–810.8 34.5 45.4 4 6 0.5–>8 0.0 99.799.7
Clarithromycin 0.06 8 ≤0.03–>64 0.925.2 26.1 ≤0.03 0.06 ≤0.03–>64 0.6 5.35.9 0.06 >64 ≤0.03–>64 1.0 41.8 42.84 >64 ≤0.03–>64 1.8 76.3 78.1
Erythromycin 0.06 8 ≤0.03–>64 0.5 25.726.2 0.06 0.12 ≤0.03–>64 0.5 5.6 6.10.06 >64 ≤0.03–>64 0.5 42.3 42.8 4>64 ≤0.03–>64 0.3 77.8 78.1
Azithromycin0.12 16 ≤0.03–>64 0.5 25.7 26.2 0.120.25 ≤0.03–>64 0.4 5.7 6.1 0.25 >64≤0.03–>64 0.0 42.8 42.8 8 >640.06–>64 0.9 77.2 78.1
Clindamycin 0.060.12 ≤0.008–>8 0.3 8.9 9.2 0.06 0.12≤0.008–>8 0.2 1.3 1.5 0.12 >8 0.03–>80.5 19.6 20.1 0.12 >8 0.03–>8 0.325.8 26.1
Tetracycline 0.12 16 ≤0.03–640.3 16.3 16.6 0.12 0.12 ≤0.03–32 0.23.1 3.3 0.12 32 0.06–64 0.5 31.4 31.90.25 32 0.06–64 0.3 48.0 48.3
Chloramphenicol 4 4 ≤0.5–>16 8.3 8.32 4 ≤0.5–>16 1.0 1.0 4 8≤0.5–>16 13.4 13.9 4 16 1–>1627.7 27.7
TMP-SMX 0.25 8 ≤0.03–32 5.630.3 35.9 0.25 1 ≤0.03–32 5.6 7.613.2 0.5 8 ≤0.03–16 9.3 39.2 48.5 816 0.25–32 3.3 94.5 97.9
Rifampin ≤0.12≤0.12 ≤0.12–>4 0.0 0.1 0.1 ≤0.12≤0.12 ≤0.12–0.25 0.0 0.0 0.0 ≤0.12≤0.12 ≤0.12–0.25 0.0 0.0 0.0 ≤0.12≤0.12 ≤0.12–>4 0.0 0.3 0.3
Vancomycin0.5 0.5 ≤0.015–0.5 0.0 0.0 0.0 0.50.5 ≤0.015–0.5 0.0 0.0 0.0 0.5 0.50.06–0.5 0.0 0.0 0.0 0.5 0.5 0.25–0.50.0 0.0 0.0
Quinupristin-dalfopristin 0.250.5 ≤0.008–2 0.1 0.0 0.1 0.25 0.5≤0.008–2 0.1 0.0 0.1 0.25 0.5 0.06–10.0 0.0 0.0 0.25 0.5 0.12–1 0.0 0.00.0
Ofloxacin 2 2 0.12–>64 5.0 0.65.6 2 2 0.12–32 5.8 0.3 6.1 2 20.25–>64 4.6 1.0 5.7 2 2 1–16 2.71.2 4.0
Ciprofloxacin 1 1 0.06–>641 2 0.06–32 1 10.12–>64 1 1 0.25–16
Levofloxacin 1 1 0.12–64 0.4 0.30.7 1 1 0.12–16 0.3 0.2 0.5 1 10.25–64 0.0 1.0 1.0 1 1 0.5–8 0.90.3 1.2
Gatifloxacind 0.250.25 0.015–16 0.1 0.3 0.4 0.25 0.250.015–4 0.0 0.2 0.2 0.25 0.25 0.06–160.0 1.0 1.0 0.25 0.25 0.12–2 0.6 0.00.6
Gemifloxacin 0.015 0.03 ≤0.008–20.015 0.03 ≤0.008–0.25 0.0150.03 ≤0.008–2 0.015 0.03≤0.008–0.25
Sitafloxacin 0.03 0.06≤0.008–2 0.03 0.06 ≤0.008–0.250.03 0.06 ≤0.008–2 0.030.06 0.015–0.25
Moxifloxacind 0.12 0.12≤0.008–8 0.1 0.1 0.3 0.12 0.12 ≤0.008–20.2 0.0 0.2 0.12 0.12 0.03–8 0.0 1.01.0 0.12 0.12 0.06–1 0.0 0.0 0.0
ABT773 ≤0.008 0.06 ≤0.008–4 ≤0.0080.015 ≤0.008–0.5 ≤0.008 0.06≤0.008–1 0.03 0.25 ≤0.008–4
Telithromycin 0.015 0.12 ≤0.004–20.015 0.015 ≤0.004–1 0.0150.12 ≤0.004–0.5 0.06 0.5 0.008–2
Linezolid 1 2 ≤0.004–2 12 ≤0.004–2 1 2 0.25–21 2 0.25–2
  • a Percents I and R based on NCCLS 2000 breakpoints of 4 and ≥8 μg/ml, respectively. Percents I and R based on 1999 breakpoints of 1 and ≥2 μg/ml are 10.6 and 13.6%, respectively.

  • b Percents I and R based on NCCLS 2000 breakpoints of 4 and ≥8 μg/ml, respectively. Percents I and R based on 1999 breakpoints of 1 and ≥2 μg/ml are 10.8 and 13.4%, respectively.

  • c Percents I and R based on NCCLS 2000 breakpoints of 2 and ≥4 μg/ml, respectively. Percents I and R based on 1999 breakpoints of 1 and ≥2 μg/ml are 1.8 and 27.3%, respectively.

  • d Susceptibility breakpoints were adopted by the NCCLS in 2000 and will be published in 2001 documents. Breakpoints are ≤1, 2, ≥4 μg/ml (S, I, R, respectively).