Bactericidal activity of three beta-lactams alone or in combination with a beta-lactamase inhibitor and two aminoglycosides against Klebsiella pneumoniae harboring extended-spectrum beta-lactamases.

OBJECTIVE: To study the bactericidal activity of beta-lactam antibiotics (imipenem, cefepime, cefpirome) alone or in combination with a beta-lactamase inhibitor (sulbactam) in the presence or absence of aminoglycoside (amikacin or isepamicin) against Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases (ESBLs). METHODS: We characterized 10 strains by means of analytic isoelectric focusing and pulsed-field gel electrophoresis. The ESBLs produced by these strains were derived from either TEM (TEM-1, TEM-2) or SHV-1.