In vitro comparative assessment of beta-lactamase inhibitors and their penicillin combinations against selected enterobacteria.
A comparative in vitro assessment of the inhibitory activity of clavulanate, sulbactam and tazobactam against the most frequent beta-lactamases found in enterobacteria isolated in Greek hospitals, has been performed. Tazobactam and clavulanate were potent inhibitors of TEM-1, SHV-1, SHV-2 and SHV-5 while sulbactam was less effective. In addition, tazobactam exerted a moderate inhibitory activity against AmpC-type beta-lactamases. In contrast with clavulanate, tazobactam could not cause significant induction of chromosomal cephalosporinases. Potentiation of the activity of penicillins (amoxycillin, ampicillin, ticarcillin and piperacillin), when combined with the inhibitors, has also been evaluated using a sample of recently isolated enterobacteria with beta-lactamase-mediated resistance. The results showed that the most effective among the commercially available combinations, is piperacillin/tazobactam followed by ticarcillin/clavulanate.
Tzouvelekis
L S
LS
Department of Bacteriology, Hellenic Pasteur Institute, Vass. Sofias Ave. 127, Athens 11521, Greece.
Zissis
N P
NP
Gazouli
M
M
Tzelepi
E
E
Legakis
N J
NJ