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Document Details : Title: In vitro study of the antimicrobial activity of various antibiotics against clinical isolates of streptococcus pneumoniae from Belgium collected during winter 1998-1999 Author(s): VANHOOF R, CARPENTIER M, FAGNART O, GARRINO MG, GLUPCZYNSKY Y, GORDTS B, GOVAERTS D, MAGERMAN K, MANS Y, NYSSEN HJ, SURMONT I, SCHWAM V, VAN DE VYVERE M, VAN LANDUYT H, VAN NIMMEN L, VAN NOYEN R Journal: Acta Clinica Belgica Volume: 55 Issue: 6 Date: 2000 Pages: 312-322 DOI: 10.2143/ACB.55.6.1002918 Abstract : A total of 205 isolates of Streptococcus pneumoniae obtained from 10 different centres were included in this study. The susceptibilities to penicillin, ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefaclor, cefuroxime, cefotaxime, imipenem, ciprofloxacin, gemifloxacin, grepafloxacin, levofloxacin, trovafloxacin, erythromycin, clarithromycin, miocamycin, clindamycin and tetracycline were determined by a microdilution technique following NCCLS recommendations. Decreased susceptibility to penicillin was 16.1% [6.8% intermediate (0.12 - 1 μg/ mL) and 9.3% high-level (≥2 μg/mL)], cefotaxime insusceptibility (≥1 μg/mL) 12.7 %, ciprofloxacine insusceptibilty (≥2 μg/mL) 15.6 % with 1.5 % of high level resistance (≥4 μg/mL), erythromycin insusceptibility (≥0.5 μg/mL) 36.1 % and tetracycline insusceptibility (≥4 μg/mL) 22.9 %. Decreased susceptibility to cefotaxime was found in 78.8 % of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (≥0.5 μg/mL) and trovafloxacin (≥1 μg/mL). Compared to the 1996-1997 surveillance, penicillin, cefotaxime and erythromycin insusceptibility rose by 3.8 %, 5.2 % and 5.0 % respectively, while tetracycline insusceptibility decreased with 8.2 %. MICs of all ß-lactams rose with those of penicillin for penicillin-insusceptible isolates. Amoxicillin ± clavulanate, cefotaxime and imipenem were generally 1, 1 and 5 doubling dilutions respectively more potent than penicillin on these isolates. Penicillin, ampicillin and cefuroxime were equally active while cefaclor was generally 5 dilutions less potent. Most penicillin-insusceptible isolates remained fully susceptible to amoxicillin ± clavulanate and imipenem. The penicillin-insusceptible isolates were 36.4 %, 27.3 % and 3.0 % co-insusceptible to erythromycin, erythromycin plus tetracycline and tetracycline respectively. A subpopulation of 52 isolates obtained from children aged ≤ 3 years was also studied. Compared to the other isolates we found a statistically significant increase in insusceptibility for penicillin, cefaclor, cefuroxime, erythromycin, clarithromycin and tetracycline while a significant decrease was found for ciprofloxacin. |
