[In vitro activity of meropenem and seven other beta-lactam antibiotics against K.pneumoniae and enterobacteriaceae producing beta-lactamases with extended spectrum].
Meropenem is a broad antibacterial spectrum carbapenem with a good activity on betalactam resistant Gram-negative bacilli. 120 non repetitive strains isolated from clinical samples from 1989 to 1992 were selected: 60 K. pneumoniae, 7 E. coli, 2 E. aerogenes and 1 S. marcescens with extended spectrum betalactamases (23 CTX-1, 18 SHV-2, 5 SHV-3, 16 SHV-4, 4 SHV-5, 3 CTX-1 + SHV-4, 1 CAZ-1), 10 K. pneumoniae with broad spectrum TEM-1 enzyme, and 40 K. pneumoniae with only SHV-1 chromosomal betalactamase. Determination of Minimal inhibitory concentrations (MIC) was done by agar dilution method for meropenem and 7 other betalactams (amoxicillin + clavulanic acid 2 mg/l, piperacillin + tazobactam 4 mg/l, cefoxitin, cefotetan, cefotaxime, ceftazidime, imipenem). All antibiotics except amoxicillin + clavulanic acid are active against strains with constitutive penicillinase. For strains with TEM-1 penicillinase, cephamycins, third generation cephalosporins and carbapenems are active. For strains with different extended spectrum betalactamases only cephamycins and carbapenems are efficious. There is no difference according to the period of isolation: 1989-90 or 1991-92. Meropenem has the best in vitro activity (MIC50 = 0.03 mg/l) for all strains independently of the nature of betalactamase.
Cavallo
J D
JD
Laboratoire de Biologie Médicale, HIA Bégin, St-Mandé, France.
Fabre
R
R
Crenn
Y
Y
Meyran
M
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology; D004926:Escherichia coli / Q000187:drug effects; D066298:In Vitro Techniques; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology; D000077731:Meropenem; D013845:Thienamycins / Q000494:pharmacology*; D001618:beta-Lactamases / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D013845:Thienamycins; D001618:beta-Lactamases; D000077731:Meropenem
Activité in vitro du méropénème et de sept autres bêtalactamines vis-à-vis de K.pneumoniae et d'entérobactéries produisant des bêtalactamases à spectre élargi.