TABLE 1.
Results of MIC testing of 354 ciprofloxacin-susceptible and -resistant strains
| Organism (no. of strains)a and antimicrobial agent | MIC (μg/ml)b for strains
|
|||||
|---|---|---|---|---|---|---|
| Ciprofloxacin susceptible (≤1.0 μg/ml)
|
Ciprofloxacin resistant (≥2.0 μg/ml)
|
|||||
| Range | 50% | 90% | Range | 50% | 90% | |
| Pseudomonas aeruginosa (10/10) | ||||||
| Clinafloxacin | 0.06–0.125 | 0.125 | 0.125 | 1.0–8.0 | 2.0 | 4.0 |
| Ciprofloxacin | 0.06–0.25 | 0.25 | 0.25 | 4.0–32.0 | 8.0 | 32.0 |
| Levofloxacin | 0.25–1.0 | 0.5 | 1.0 | 8.0–>32.0 | 16.0 | 32.0 |
| Sparfloxacin | 0.25–1.0 | 1.0 | 1.0 | 8.0–>32.0 | 16.0 | >32.0 |
| Trovafloxacin | 0.25–0.5 | 0.5 | 0.5 | 4.0–>32.0 | 16.0 | >32.0 |
| Piperacillin | 4.0–8.0 | 4.0 | 8.0 | 2.0–>128.0 | 128.0 | >128.0 |
| Piperacillin-tazobactam | 4.0 | 4.0 | 4.0 | 2.0–>128.0 | 128.0 | >128.0 |
| Trimethoprim-sulfamethoxazole | 8.0–16.0 | 8.0 | 16.0 | 1.0–>16.0 | 16.0 | >16.0 |
| Ceftazidime | 1.0–2.0 | 2.0 | 2.0 | 1.0–>128.0 | >128.0 | >128.0 |
| Imipenem | 1.0–2.0 | 1.0 | 2.0 | 0.25–128.0 | 16.0 | 32.0 |
| Stenotrophomonas maltophilia (0/10) | ||||||
| Clinafloxacin | 0.5–2.0 | 1.0 | 1.0 | |||
| Ciprofloxacin | 4.0–16.0 | 16.0 | 16.0 | |||
| Levofloxacin | 2.0–8.0 | 4.0 | 4.0 | |||
| Sparfloxacin | 0.5–4.0 | 2.0 | 4.0 | |||
| Trovafloxacin | 1.0–4.0 | 2.0 | 4.0 | |||
| Piperacillin | 16.0–>128.0 | 128.0 | >128.0 | |||
| Piperacillin-tazobactam | 16.0–>128.0 | 128.0 | >128.0 | |||
| Trimethoprim-sulfamethoxazole | 4.0–>16.0 | 16.0 | >16.0 | |||
| Ceftazidime | 4.0–>128.0 | 16.0 | 128.0 | |||
| Imipenem | >128.0 | >128.0 | >128.0 | |||
| Acinetobacter spp. (10/10) | ||||||
| Clinafloxacin | ≤0.008–0.125 | 0.06 | 0.125 | 0.125–8.0 | 4.0 | 4.0 |
| Ciprofloxacin | 0.125–1.0 | 0.25 | 0.5 | 4.0–>32.0 | >32.0 | >32.0 |
| Levofloxacin | 0.03–0.5 | 0.25 | 0.5 | 1.0–16.0 | 16.0 | 16.0 |
| Sparfloxacin | ≤0.008–0.125 | 0.06 | 0.06 | 0.25–16.0 | 8.0 | 16.0 |
| Trovafloxacin | ≤0.008–0.06 | 0.03 | 0.06 | 0.25–16.0 | 8.0 | 16.0 |
| Piperacillin | 1.0–64.0 | 8.0 | 16.0 | 1.0–>128.0 | 32.0 | >128.0 |
| Piperacillin-tazobactam | ≤0.06–16.0 | ≤0.06 | 4.0 | ≤0.06–>128.0 | 32.0 | >128.0 |
| Trimethoprim-sulfamethoxazole | 0.125–1.0 | 0.25 | 0.5 | 1.0–>16.0 | 8.0 | 16.0 |
| Ceftazidime | 2.0–64.0 | 4.0 | 8.0 | 1.0–>128.0 | 32.0 | >128.0 |
| Imipenem | 0.06–0.5 | 0.25 | 0.5 | 0.25–1.0 | 0.5 | 1.0 |
| Burkholderia cepacia (2/12) | ||||||
| Clinafloxacin | 0.25–0.5 | 0.25 | 1.0–4.0 | 2.0 | 4.0 | |
| Ciprofloxacin | 1.0 | 1.0 | 2.0–32.0 | 8.0 | 16.0 | |
| Levofloxacin | 2.0 | 2.0 | 4.0–16.0 | 8.0 | 16.0 | |
| Sparfloxacin | 0.5–1.0 | 0.5 | 2.0–16.0 | 8.0 | 16.0 | |
| Trovafloxacin | 1.0 | 1.0 | 2.0–16.0 | 8.0 | 16.0 | |
| Piperacillin | 4.0 | 4.0 | 4.0–64.0 | 32.0 | 64.0 | |
| Piperacillin-tazobactam | 1.0–2.0 | 1.0 | 2.0–64.0 | 32.0 | 64.0 | |
| Trimethoprim-sulfamethoxazole | 1.0–2.0 | 1.0 | 1.0–16.0 | 4.0 | 16.0 | |
| Ceftazidime | 2.0 | 2.0 | 2.0–8.0 | 4.0 | 8.0 | |
| Imipenem | 2.0–8.0 | 2.0 | 4.0–>128.0 | 16.0 | 128.0 | |
| Chryseobacterium and Myroides spp. (7/15)c | ||||||
| Clinafloxacin | 0.03–0.25 | 0.125 | 0.125–4.0 | 0.5 | 4.0 | |
| Ciprofloxacin | 0.125–1.0 | 1.0 | 2.0–>32.0 | 2.0 | >32.0 | |
| Levofloxacin | 0.25–1.0 | 0.5 | 0.5–32.0 | 2.0 | 16.0 | |
| Sparfloxacin | 0.06–0.25 | 0.125 | 0.06–8.0 | 0.5 | 4.0 | |
| Trovafloxacin | 0.06–0.125 | 0.06 | 0.06–4.0 | 0.25 | 4.0 | |
| Piperacillin | 4.0–64.0 | 16.0 | 16.0–128.0 | 32.0 | 64.0 | |
| Piperacillin-tazobactam | 4.0–64.0 | 16.0 | 0.5–128.0 | 16.0 | 64.0 | |
| Trimethoprim-sulfamethoxazole | 0.25–>16.0 | >16.0 | 4.0–>16.0 | 16.0 | >16.0 | |
| Ceftazidime | 4.0–>128.0 | 128.0 | 32.0–>128.0 | 128.0 | >128.0 | |
| Imipenem | 0.25–32.0 | 4.0 | 4.0–64.0 | 16.0 | 32.0 | |
| Escherichia coli (10/10) | ||||||
| Clinafloxacin | ≤0.008–0.016 | ≤0.008 | 0.016 | 0.25–8.0 | 1.0 | 4.0 |
| Ciprofloxacin | 0.016–0.03 | 0.016 | 0.016 | 2.0–>32.0 | 32.0 | >32.0 |
| Levofloxacin | 0.03–0.06 | 0.03 | 0.06 | 2.0–>32.0 | 16.0 | >32.0 |
| Sparfloxacin | 0.016–0.03 | 0.03 | 0.03 | 2.0–>32.0 | 16.0 | >32.0 |
| Trovafloxacin | 0.016–0.03 | 0.03 | 0.03 | 2.0–>32.0 | 16.0 | >32.0 |
| Piperacillin | 1.0–>128.0 | 2.0 | 64.0 | 1.0–>128.0 | 16.0 | >128.0 |
| Piperacillin-tazobactam | 1.0–2.0 | 2.0 | 2.0 | 1.0–16.0 | 4.0 | 16.0 |
| Trimethoprim-sulfamethoxazole | 0.125–>16.0 | 0.5 | >16.0 | 0.25–>16.0 | 4.0 | >16.0 |
| Ceftazidime | 0.25 | 0.25 | 0.25 | 0.125–128.0 | 0.25 | 64.0 |
| Imipenem | 0.125–0.25 | 0.125 | 0.25 | 0.06–0.5 | 0.125 | 0.25 |
| Klebsiella spp. (10/10)d | ||||||
| Clinafloxacin | 0.016–0.06 | 0.016 | 0.03 | 1.0–8.0 | 1.0 | 8.0 |
| Ciprofloxacin | 0.016–0.125 | 0.03 | 0.06 | 4.0–>32.0 | 8.0 | >32.0 |
| Levofloxacin | 0.06–0.5 | 0.06 | 0.125 | 4.0–>32.0 | 16.0 | 32.0 |
| Sparfloxacin | 0.03–0.5 | 0.06 | 0.125 | 4.0–>32.0 | 8.0 | >32.0 |
| Trovafloxacin | 0.06–0.5 | 0.06 | 0.25 | 2.0–>32.0 | 8.0 | >32.0 |
| Piperacillin | 4.0–>128.0 | 8.0 | >128.0 | 4.0–>128.0 | >128.0 | >128.0 |
| Piperacillin-tazobactam | 2.0–>128.0 | 4.0 | 8.0 | 2.0–>128.0 | 4.0 | >128.0 |
| Trimethoprim-sulfamethoxazole | 0.25–>16.0 | 1.0 | >16.0 | 2.0–>16.0 | >16.0 | >16.0 |
| Ceftazidime | ≤0.06–1.0 | 0.25 | 0.5 | 0.25–>128.0 | 1.0 | 128.0 |
| Imipenem | 0.125–0.25 | 0.125 | 0.25 | 0.06–0.25 | 0.125 | 0.25 |
| Enterobacter spp. (16/12)e | ||||||
| Clinafloxacin | ≤0.008–0.125 | 0.016 | 0.03 | 0.5–4.0 | 1.0 | 4.0 |
| Ciprofloxacin | ≤0.008–0.25 | 0.016 | 0.125 | 4.0–>32.0 | 8.0 | >32.0 |
| Levofloxacin | 0.03–0.5 | 0.06 | 0.25 | 4.0–>32.0 | 8.0 | 32.0 |
| Sparfloxacin | 0.03–0.5 | 0.03 | 0.5 | 2.0–>32.0 | 8.0 | >32.0 |
| Trovafloxacin | 0.03–0.5 | 0.06 | 0.125 | 4.0–>32.0 | 16.0 | >32.0 |
| Piperacillin | 2.0–>128.0 | 4.0 | 64.0 | 2.0–128.0 | 64.0 | 64.0 |
| Piperacillin-tazobactam | 2.0–64.0 | 4.0 | 32.0 | 2.0–64.0 | 16.0 | 64.0 |
| Trimethoprim-sulfamethoxazole | 0.25–>16.0 | 0.5 | 1.0 | 0.5–>16.0 | 1.0 | >16.0 |
| Ceftazidime | 0.25–64.0 | 0.5 | 64.0 | 0.5–128.0 | 8.0 | 128.0 |
| Imipenem | 0.125–0.5 | 0.25 | 0.5 | 0.125–1.0 | 0.25 | 1.0 |
| Citrobacter spp. (13/7)f | ||||||
| Clinafloxacin | ≤0.008–0.25 | 0.016 | 0.03 | 0.5–2.0 | 1.0 | |
| Ciprofloxacin | ≤0.008–1.0 | 0.016 | 0.125 | 2.0–32.0 | 4.0 | |
| Levofloxacin | 0.03–2.0 | 0.06 | 0.25 | 4.0–16.0 | 8.0 | |
| Sparfloxacin | 0.016–2.0 | 0.06 | 0.25 | 4.0–>32.0 | 16.0 | |
| Trovafloxacin | 0.03–2.0 | 0.06 | 0.5 | 4.0–32.0 | 16.0 | |
| Piperacillin | 2.0–>128.0 | 4.0 | >128.0 | 8.0–>128.0 | >128.0 | |
| Piperacillin-tazobactam | 2.0–16.0 | 2.0 | 8.0 | 8.0–>128.0 | 32.0 | |
| Trimethoprim-sulfamethoxazole | 0.25–>16.0 | 0.5 | >16.0 | 0.125–>16.0 | 4.0 | |
| Ceftazidime | ≤0.006–32.0 | 0.5 | 1.0 | 1.0–>128.0 | 64.0 | |
| Imipenem | 0.125–0.5 | 0.25 | 0.5 | 0.125–0.5 | 0.25 | |
| Serratia spp. (12/12)g | ||||||
| Clinafloxacin | 0.016–0.125 | 0.03 | 0.125 | 0.5–4.0 | 1.0 | 2.0 |
| Ciprofloxacin | 0.03–0.125 | 0.125 | 0.125 | 2.0–>32.0 | 4.0 | 8.0 |
| Levofloxacin | 0.06–0.5 | 0.25 | 0.25 | 2.0–32.0 | 8.0 | 8.0 |
| Sparfloxacin | 0.06–1.0 | 0.25 | 1.0 | 2.0–>32.0 | 8.0 | 16.0 |
| Trovafloxacin | 0.125–1.0 | 0.25 | 1.0 | 4.0–>32.0 | 8.0 | 16.0 |
| Piperacillin | 2.0–>128.0 | 4.0 | 4.0 | 2.0–>128.0 | 8.0 | 128.0 |
| Piperacillin-tazobactam | 2.0–>128.0 | 2.0 | 4.0 | 2.0–>128.0 | 8.0 | 128.0 |
| Trimethoprim-sulfamethoxazole | 0.5–2.0 | 1.0 | 2.0 | 1.0–>16.0 | 8.0 | 16.0 |
| Ceftazidime | 0.25–4.0 | 0.5 | 0.5 | 0.25–2.0 | 0.5 | 1.0 |
| Imipenem | 0.5–4.0 | 1.0 | 1.0 | 0.25–2.0 | 1.0 | 2.0 |
| Morganella and Providencia spp. (10/13)h | ||||||
| Clinafloxacin | 0.016–0.125 | 0.06 | 0.06 | 0.5–8.0 | 1.0 | 2.0 |
| Ciprofloxacin | 0.03–0.25 | 0.06 | 0.125 | 2.0–>32.0 | 8.0 | >32.0 |
| Levofloxacin | 0.125–1.0 | 0.25 | 0.25 | 2.0–>32.0 | 8.0 | 32.0 |
| Sparfloxacin | 0.125–1.0 | 0.25 | 1.0 | 0.5–>32.0 | 16.0 | 16.0 |
| Trovafloxacin | 0.125–1.0 | 0.25 | 0.5 | 0.5–>32.0 | 16.0 | 32.0 |
| Piperacillin | 1.0–8.0 | 1.0 | 4.0 | 1.0–>128.0 | 4.0 | 128.0 |
| Piperacillin-tazobactam | 0.5–8.0 | 1.0 | 2.0 | 1.0–64.0 | 4.0 | 16.0 |
| Trimethoprim-sulfamethoxazole | 0.25–>16.0 | 0.5 | >16.0 | 0.25–>16.0 | >16.0 | >16.0 |
| Ceftazidime | 0.125–1.0 | 0.25 | 0.5 | 0.25–>128.0 | 0.5 | 64.0 |
| Imipenem | 1.0–4.0 | 2.0 | 4.0 | 0.5–2.0 | 1.0 | 2.0 |
| Staphylococcus spp. (25/15)i | ||||||
| Clinafloxacin | 0.03–0.125 | 0.03 | 0.06 | 0.06–4.0 | 1.0 | 2.0 |
| Ciprofloxacin | 0.25–1.0 | 0.5 | 1.0 | 2.0–>32.0 | 32.0 | >32.0 |
| Levofloxacin | 0.125–1.0 | 0.25 | 0.5 | 0.25–>32.0 | 8.0 | 32.0 |
| Sparfloxacin | 0.06–0.25 | 0.125 | 0.25 | 0.125–16.0 | 8.0 | 16.0 |
| Trovafloxacin | 0.016–0.125 | 0.06 | 0.06 | 0.06–8.0 | 2.0 | 8.0 |
| Piperacillin | 0.5–>128.0 | 2.0 | 128.0 | 2.0–>128.0 | 128.0 | >128.0 |
| Piperacillin-tazobactam | ≤0.06–64.0 | 1.0 | 8.0 | 1.0–128.0 | 64.0 | 128.0 |
| Trimethoprim-sulfamethoxazole | ≤0.06–>16.0 | 0.125 | 16.0 | ≤0.06–>16.0 | 2.0 | >16.0 |
| Ceftazidime | 4.0–>128.0 | 16.0 | 64.0 | 8.0–>128.0 | >128.0 | >128.0 |
| Imipenem | ≤0.016–64.0 | ≤0.016 | 32.0 | ≤0.016–32.0 | 4.0 | 32.0 |
| Streptococcus pneumoniae (16/44)j | ||||||
| Clinafloxacin | 0.03–0.125 | 0.06 | 0.06 | 0.06–0.25 | 0.125 | 0.25 |
| Ciprofloxacin | 0.5–1.0 | 1.0 | 1.0 | 2.0–8.0 | 2.0 | 4.0 |
| Levofloxacin | 0.5–1.0 | 1.0 | 1.0 | 1.0–2.0 | 2.0 | 2.0 |
| Sparfloxacin | 0.125–0.25 | 0.25 | 0.25 | 0.125–0.5 | 0.5 | 0.5 |
| Trovafloxacin | 0.06–0.125 | 0.06 | 0.125 | 0.06–0.25 | 0.25 | 0.25 |
| Piperacillin | ≤0.06–4.0 | 1.0 | 2.0 | ≤0.06–8.0 | 1.0 | 8.0 |
| Piperacillin-tazobactam | ≤0.06–4.0 | 0.5 | 2.0 | ≤0.06–8.0 | 0.5 | 4.0 |
| Trimethoprim-sulfamethoxazole | 0.125–>16.0 | 2.0 | 8.0 | 0.125–>16.0 | 1.0 | 8.0 |
| Ceftazidime | 0.25–64.0 | 1.0 | 16.0 | 0.125–64.0 | 2.0 | 16.0 |
| Imipenem | ≤0.016–0.25 | ≤0.016 | 0.125 | ≤0.016–0.5 | 0.03 | 0.5 |
| Enterococcus faecalis (0/13)k | ||||||
| Clinafloxacin | 0.25–8.0 | 4.0 | 4.0 | |||
| Ciprofloxacin | 2.0–>32.0 | >32.0 | >32.0 | |||
| Levofloxacin | 2.0–>32.0 | 32.0 | >32.0 | |||
| Sparfloxacin | 1.0–>32.0 | 32.0 | >32.0 | |||
| Trovafloxacin | 0.5–32.0 | 4.0 | 16.0 | |||
| Piperacillin | 2.0–32.0 | 8.0 | 16.0 | |||
| Piperacillin-tazobactam | 1.0–32.0 | 8.0 | 16.0 | |||
| Trimethoprim-sulfamethoxazole | 0.125–>16.0 | 8.0 | >16.0 | |||
| Ceftazidime | 16.0–>128.0 | >128.0 | >128.0 | |||
| Imipenem | 0.5–16.0 | 2.0 | 4.0 | |||
| Enterococcus faecium (2/18)l | ||||||
| Clinafloxacin | 0.125–0.25 | 0.125 | 0.25–16.0 | 8.0 | 8.0 | |
| Ciprofloxacin | 1.0 | 1.0 | 2.0–>32.0 | >32.0 | >32.0 | |
| Levofloxacin | 2.0 | 2.0 | 4.0–>32.0 | >32.0 | >32.0 | |
| Sparfloxacin | 1.0 | 1.0 | 1.0–>32.0 | 32.0 | >32.0 | |
| Trovafloxacin | 0.5 | 0.5 | 0.5–16.0 | 16.0 | 16.0 | |
| Piperacillin | 8.0–64.0 | 8.0 | 8.0–>128.0 | >128.0 | >128.0 | |
| Piperacillin-tazobactam | 8.0–32.0 | 8.0 | 8.0–>128.0 | >128.0 | >128.0 | |
| Trimethoprim-sulfamethoxazole | 2.0–16.0 | 2.0 | 0.125–>16.0 | 4.0 | >16.0 | |
| Ceftazidime | >128.0 | >128.0 | >128.0 | >128.0 | >128.0 | |
| Imipenem | 2.0–16.0 | 2.0 | 2.0–>128.0 | 128.0 | >128.0 | |
The number of ciprofloxacin-susceptible strains is shown before the slash, and the number of ciprofloxacin-resistant strains is shown after the slash.
50% and 90%, MICs for 50 and 90% of isolates tested, respectively.
The ciprofloxacin-susceptible strains are Chryseobacterium meningosepticum (three strains) and Myroides odoratus (four strains). The ciprofloxacin-resistant strains are C. meningosepticum (seven strains), M. odoratus (seven strains), and Chryseobacterium indologenes or Chryseobacterium gleum (one strain).
The ciprofloxacin-susceptible strains are Klebsiella pneumoniae (five strains) and Klebsiella oxytoca (five strains). The ciprofloxacin-resistant strains are K. pneumoniae (seven strains) and K. oxytoca (three strains).
The ciprofloxacin-susceptible strains are Enterobacter cloacae (eight strains) and Enterobacter aerogenes (eight strains). The ciprofloxacin-resistant strains are E. cloacae (eight strains) and E. aerogenes (four strains).
The ciprofloxacin-susceptible strains are Citrobacter freundii (eight strains) and Citrobacter diversus (five strains). The ciprofloxacin-resistant strains are C. freundii (seven strains).
The ciprofloxacin-susceptible strains are Serratia marcescens (11 strains) and Serratia liquefaciens (1 strain). The ciprofloxacin-resistant strains are S. marcescens (12 strains).
The ciprofloxacin-susceptible strains are Morganella morganii (six strains), Providencia stuartii (three strains), and Providencia rettgeri (one strain). The ciprofloxacin-resistant strains are M. morganii (three strains), P. stuartii (nine strains), and Providencia rettgeri (one strain).
The ciprofloxacin-susceptible strains are methicillin-susceptible Staphylococcus aureus (9 strains), methicillin-susceptible coagulase-negative staphylococci (10 strains), methicillin-resistant S. aureus (2 strains), and methicillin-resistant coagulase-negative staphylococci (4 strains). The ciprofloxacin-resistant strains are methicillin-susceptible S. aureus (one strain), methicillin-resistant S. aureus (eight strains), and methicillin-resistant coagulase-negative staphylococci (six strains).
Twenty strains each of penicillin-susceptible, -intermediate-resistant, and -resistant strains.
Three vancomycin-resistant strains.
The two ciprofloxacin-susceptible strains were also vancomycin susceptible. Of the ciprofloxacin-resistant strains, eight were vancomycin susceptible.