Volume 10, Number 10—October 2004
Research
Fluoroquinolone Resistance in Penicillin-resistant Streptococcus pneumoniae Clones, Spain
, Luz Balsalobre*, Carmen Ardanuy†, Asunción Fenoll*, Emilio Pérez-Trallero‡, Josefina Liñares†, and the Spanish Pneumococcal Infection Study Network G03/103
Table 1
In vitro activity of 13 antimicrobial drugs against 75 ciprofloxacin-resistant Streptococcus pneumoniae isolatesa
| Drug | MIC50 (μg/mL) | MIC90 (μg/mL) | MIC range (μg/mL) | Susceptible breakpoints | %S | %I | %R | %I+R |
|---|---|---|---|---|---|---|---|---|
| Penicillin | 1 | 2 | 0.03–8 | ≤ 0.06 | 26.7 | 48.0 | 25.3 | 73.3 |
| Amoxicillin | 1 | 4 | 0.06–16 | ≤ 2 | 80.0 | 12.0 | 8.0 | 20.0b |
| Cefotaxime | 0.5 | 1 | 0.03–8 | ≤ 1 | 92.1 | 5.3 | 2.6 | 7.9b |
| ≤ 0.5 | 56.1 | 36.0 | 7.9 | 43.9c | ||||
| Erythromycin | 128 | 128 | 0.06–>256 | ≤ 0.25 | 29.3 | 0.0 | 70.7 | 70.7 |
| Clindamycin | 128 | 128 | 0.06–>256 | ≤ 0.25 | 37.3 | 0.0 | 62.7 | 62.7 |
| Tetracycline | 32 | 64 | 0.12–64 | ≤ 2 | 30.7 | 2.7 | 66.6 | 69.3 |
| Chloramphenicol | 2 | 16 | 2–32 | ≤ 4 | 56.0 | 44.0 | 44.0 | |
| Cotrimoxazole | >4/76 | >4/76 | 0.5/9.5–>4/76 | ≤ 0.5/9.5 | 32.0 | 4.0 | 64.0 | 68.0 |
| Ciprofloxacind | 32 | 64 | 4–128 | NA | NA | NA | NA | |
| Levofloxacin | 16 | 32 | 1–64 | ≤ 2 | 16.0 | 2.7 | 81.3 | 84.0 |
| Gatifloxacin | 4 | 8 | 0.5–16 | ≤ 1 | 17.3 | 2.7 | 80.0 | 82.7 |
| Moxifloxacin | 2 | 4 | 0.12–8 | ≤ 1 | 20.0 | 37.3 | 42.7 | 80.0 |
| Gemifloxacin | 0.12 | 0.5 | 0.06–2 | ≤ 0.12 | 50.7 | 28.0 | 21.3 | 49.3 |
aS, susceptible; I, intermediate; and R, resistant, according to National Committee for Clinical Laboratory Standards (NCCLS) 2004 interpretative criteria; NA, not available.
bNCCLS 2004 nonmeningitis criteria.
cNCCLS 2004 meningitis criteria.
dCiprofloxacin resistance defined as >4 μg/mL by Chen et al. (4).
1Spanish Pneumococcal Infection Study Network—general coordination: Román Pallarés; participants and centers: Ernesto García (Centro de Investigaciones Biológicas, Madrid); Julio Casal, Asuncion Fenoll, Adela G. de la Campa (Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid); Emilio Bouza, (Hospital Gregorio Marañon, Madrid); Fernando Baquero (Hospital Ramón y Cajal, Madrid); Francisco Soriano, José Prieto (Fundación Jiménez Díaz y Hospital Clínico, Madrid); Román Pallarés, Josefina Liñares (Hospital Universitari de Bellvitge, Barcelona); Javier Garau, Javier Martínez Lacasa (Hospital Mutua de Terrassa, Barcelona); Cristina Latorre (Hospital Sant Joan de Deu, Barcelona); Emilio Pérez-Trallero, Alberto González (Hospital Donostia, San Sebastian); Juan García de Lomas (Hospital Clínico, Valencia); and Ana Fleites (Hospital Central de Asturias).