In vitro study on the antimicrobial activity of various antibiotics against clinical isolates of Streptococcus pneumoniae from Belgium collected during winter 1998-1999.
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 microgram/mL) and 9.3% high-level (> or = 2 micrograms/mL)], cefotaxime insusceptibility (> or = 1 microgram/mL) 12.7%, ciprofloxacine insusceptibility (> or = 2 micrograms/mL) 15.6% with 1.5% of high level resistance (> or = 4 micrograms/mL), erythromycin insusceptibility (> or = 0.5 microgram/mL) 36.1% and tetracycline insusceptibility (> or = 4 micrograms/mL) 22.9%. Decreased susceptibility to cefotaxime was found in 78.8% of the penicillin-insusceptible isolates. No decreased susceptibility was found for gemifloxacin (> or = 0.5 microgram/mL) and trovafloxacin (> or = 1 microgram/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 beta-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 < or = 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.
Vanhoof
R
R
Pasteurinstituut-Brussel, Eenheid Antibiotica-Onderzoek, Engelandstraat 642, B-1180 Brussel.
Carpentier
M
M
Fagnart
O
O
Garrino
M G
MG
Glupczynski
Y
Y
Gordts
B
B
Govaerts
D
D
Magerman
K
K
Mans
Y
Y
Nyssen
H J
HJ
Surmont
I
I
Schwam
V
V
Van De Vyvere
M
M
Van Landuyt
H
H
Van Nimmen
L
L
Van Noyen
R
R
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001530:Belgium; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents