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Document Details : Title: Surveillance of antibiotic resistance in clinical isolates of Streptococcus Pneumoniae collected in Belgium during winter 2000-2001 Author(s): VANHOOF R, CARPENTIER M, CARTUYVELS R, DAMÉE S, FAGNART O, GARRINO MG, GLUPCZYNSKI Y, GORDTS B, GOVAERTS D, MAGERMAN K, MANS I, SURMONT I, VAN BOSSUYT E, VAN DE VYVERE M, VAN LANDUYT H, VAN NIMMEN L, VAN NOYEN R Journal: Acta Clinica Belgica Volume: 58 Issue: 2 Date: 2003 Pages: 117-125 DOI: 10.2143/ACB.58.2.1002737 Abstract : A total of 314 isolates of Streptococcus pneumoniae collected by 10 different laboratories were tested for their susceptibility by using a microdilution technique following NCCLS recommendations. The following antibiotics were included: penicillin, ampicillin, amoxicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, levofloxacin, erythromycin, clarithromycin, azithromycin, miocamycin, clindamycin and tetracycline. The insusceptibility rate (IR) to penicillin was 21.0% [10.8% intermediate (≥ 0.12 - 1 μg/mL) and 10.2 % high-level (≥2 μg/mL)], to cefotaxime 7.3 % [3.5 % intermediate (≥ 1μg/mL) and 3.8 % high-level (≥2 μg/mL)], to imipenem 3.8 % [3.8 % intermediate (≥ 0.25 – 0.5 μg/mL) and 0 % high-level (≥1 μg/mL)], to ciprofloxacin 11.2 % [8.3 % intermediate (2 μg/mL) and 3.9 % high-level (≥4 μg/mL)], to erythromycin 30.3 % [3.5 % intermediate (0.5 μg/mL) and 26.8 % high-level (≥1 μg/mL)] and to tetracycline 38.5 % [0.9 % intermediate (4μg/mL) and 37.6 % high-level (≥8 μg/mL)]. No decreased susceptibility was found for gemifloxacin (≥0.5 μg/mL). This compound was the most active with MIC50, MIC90 and an IR of 0.015 μg/mL, 0.03 μg/mL and 0 % respectively, followed by amoxicillin/clavulanate, amoxicillin and imipenem (MIC50, MIC90 and IR: 0.015 μg/mL, 1 μg/mL, 1.6 %/ 0.015 μg/mL, 1 μg/mL, 1.9 %/ 0.008 μg/mL, 0.12 μg/mL, 3.8 % respectively). Compared to the 1999 surveillance, penicillin and tetracycline-insusceptibility increased with 4.9 % and 15.6% respectively, while cefotaxime, erythromycin and ciprofloxacin insusceptibility decreased with 5.4 %, 5.8 % and 4.4 % respectively. MICs of all ß-lactams rose with those of penicillin for penicillin-insusceptible isolates. Imipenem, cefotaxime, amoxicillin and amoxicillin/clavulanate were generally 4, 2, 1 and 1 doubling dilutions respectively more potent than penicillin on these isolates while ampicillin, cefuroxime and cefaclor were generally 1, 2 and 4 dilutions respectively less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin/clavulanate (92.4 %), amoxicillin (90.9 %) and imipenem (81.8 %). Erythromycin-tetracycline insusceptibility was the most common resistance phenotype (14.3 %). Three- and fourfold resistance was found in 12.4 %and 1.6 % respectively of the isolates. Most penicillin-insusceptible isolates were of capsular types 14 (22.7 %), 23 (21.2 %), 6 (18.2 %), 9 (13.6 %) and 19 (12.1 %). |
