Table 1.

Susceptibility of S. pneumoniae to 26 antimicrobial agents

Antimicrobial agent and phenotype (no. of isolates)aMIC (μg/ml)Percentb
Range50%90%SIR
Amoxicillin
 All (1,274)≤0.06–16≤0.062.080.58.111.5
 Pen S (818)≤0.06–1≤0.06≤0.0399.90.10.0
 Pen I (218)≤0.06–40.251.083.911.94.1
 Pen R (238)0.5–162.04.010.531.957.6
Amoxicillin-clavulanate
 All (1,269)≤0.03–16≤0.032.077.711.311.0
 Pen S (816)≤0.03–1≤0.03≤0.0399.90.10.0
 Pen I (217)≤0.03–40.251.077.918.93.2
 Pen R (236)0.5–162.04.00.842.856.4
Penicillin
 All (1,276)0.008–>80.032.064.317.118.7
 Pen S (820)0.008–0.060.030.03100.00.00.0
 Pen I (218)0.12–10.251.00.0100.00.0
 Pen R (238)2–>82.04.00.00.0100.0
Cephalothinc
 All (1,276)≤0.03–>640.258.0
 Pen S (820)≤0.03–80.120.25
 Pen I (218)0.06–161.04.0
 Pen R (238)1–>648.032
Cefaclorc
 All (1,275)0.03–>320.5>32
 Pen S (820)0.03–>320.51.0
 Pen I (218)0.25–>324.0>32
 Pen R (237)1–>32>32>32
Loracarbefc
 All (1,273)0.06–>321.0>32
 Pen S (817)0.06–>321.02.0
 Pen I (218)0.25–>324.0>32
 Pen R (238)1–>32>32>32
Cefuroxime
 All (1,275)≤0.03–>32≤0.034.072.13.424.5
 Pen S (820)≤0.03–8≤0.030.2599.10.40.5
 Pen I (218)≤0.03–321.04.046.818.334.9
 Pen R (237)0.25–>324.0161.70.098.3
Cefprozilc
 All (1,274)0.03–>320.258.0
 Pen S (818)0.03–80.120.5
 Pen I (218)0.06–321.04.0
 Pen R (238)0.5–>328.032
Cefpodoximec
 All (1,274)≤0.015–>320.032.0
 Pen S (818)≤0.015–20.030.06
 Pen I (218)0.03–320.52.0
 Pen R (238)0.06–>322.08.0
Cefiximec
 All (1,275)≤0.25–>8≤0.25>8
 Pen S (819)≤0.25–>8≤0.250.5
 Pen I (218)≤0.25–>84.0>8
 Pen R (238)1–>8>8>8
Ceftibutenc
 All (1,275)≤0.25–>84.0>8
 Pen S (819)≤0.25–>84.0>8
 Pen I (218)≤0.25–>8>8>8
 Pen R (238)8–>8>8>8
Cefotaxime
 All (1,276)≤0.015–320.031.079.913.66.5
 Pen S (820)≤0.015–1≤0.0150.0699.90.10.0
 Pen I (218)≤0.015–80.251.085.311.03.7
 Pen R (238)0.06–321.04.05.962.631.5
Ceftriaxone
 All (1,274)≤0.015–>320.031.080.712.96.4
 Pen S (818)≤0.015–1≤0.0150.0699.90.10.0
 Pen I (218)≤0.015–40.251.085.811.03.2
 Pen R (238)0.03–>321.04.010.158.431.5
Erythromycin
 All (1,276)≤0.03–>640.068.076.40.323.3
 Pen S (820)≤0.03–>640.060.0693.50.16.3
 Pen I (218)≤0.03–>640.06>6461.90.937.2
 Pen R (238)≤0.03–>644.0>6430.70.468.9
Azithromycin
 All (1,275)0.06–>640.121677.00.222.8
 Pen S (820)0.06–>640.120.2593.70.06.3
 Pen I (218)0.06–>640.12>6464.20.535.3
 Pen R (237)0.06–>648.0>6431.20.468.4
Clarithromycin
 All (1,275)≤0.03–>64≤0.038.076.70.522.7
 Pen S (820)≤0.03–>64≤0.030.0693.70.46.0
 Pen I (218)≤0.03–>64≤0.03>6461.91.836.2
 Pen R (237)≤0.03–>642.0>6431.60.068.4
Clindamycin
 All (1,276)≤0.015–>320.060.1293.60.26.3
 Pen S (820)≤0.015–>320.060.1298.80.11.1
 Pen I (218)0.03–>320.06>3286.70.013.3
 Pen R (238)0.03–>320.06>3281.90.417.6
Grepafloxacin
 All (1,275)0.004–80.120.2599.80.00.2
 Pen S (820)0.004–20.120.2599.90.00.1
 Pen I (218)0.015–80.120.2599.50.00.5
 Pen R (237)0.06–40.120.1299.60.00.4
Sparfloxacin
 All (1,276)0.015–>80.250.2599.60.20.2
 Pen S (820)0.015–10.250.2599.80.20.0
 Pen I (218)0.06–>80.250.2599.50.00.5
 Pen R (238)0.06–20.250.2599.20.00.8
Levofloxacin
 All (1,276)0.008–>80.51.099.80.10.2
 Pen S (820)0.008–20.51.0100.00.00.0
 Pen I (218)0.5–>80.51.099.50.00.5
 Pen R (238)0.25–80.51.099.20.40.4
Ciprofloxacind
 All (1,275)0.004–>80.51.0
 Pen S (820)0.004–40.51.0
 Pen I (218)0.015–>80.51.0
 Pen R (237)0.12–>80.51.0
Ofloxacin
 All (1,275)0.008–>81.02.099.60.20.2
 Pen S (820)0.008–41.02.099.80.20.0
 Pen I (218)0.008–>81.02.099.50.00.5
 Pen R (237)0.25–>81.02.099.20.40.4
Rifampin
 All (1,276)≤0.015–>160.030.0399.80.00.2
 Pen S (820)≤0.015–>160.030.0399.80.00.2
 Pen I (218)≤0.015–0.250.030.03100.00.00.0
 Pen R (238)≤0.015–40.030.0399.60.00.4
Tetracycline
 All (1,273)≤0.5–>4≤0.5>483.10.316.6
 Pen S (819)≤0.5–>4≤0.5≤0.596.00.23.8
 Pen I (218)≤0.5–>4≤0.5>472.00.927.1
 Pen R (236)≤0.5–>4>4>448.70.051.3
SXT
 All (1,268)≤0.125–>40.25>488.10.011.9
 Pen S (817)≤0.125–>4≤0.1251.096.70.03.3
 Pen I (216)≤0.125–>41.0>486.60.013.4
 Pen R (235)≤0.125–>44.0>459.60.040.4
Vancomycin
 All (1,275)0.12–0.50.250.25100.00.00.0
 Pen S (820)0.12–0.50.250.25100.00.00.0
 Pen I (217)0.12–0.50.250.25100.00.00.0
 Pen R (238)0.25–0.50.250.25100.00.00.0
  • a Analysis by all isolates, penicillin-susceptible isolates (Pen S) isolates, penicillin-intermediate (Pen I) isolates, and penicillin-resistant (Pen R) isolates.

  • b Percent susceptible (S), intermediate (I), and resistant (R) according to NCCLS breakpoints.

  • c Breakpoints are not available for most oral cephalosporins and are being established or revised by NCCLS.

  • d NCCLS breakpoints not available for the fluoroquinolone ciprofloxacin.