Version 2000:: the new β-lactamases of gram-negative bacteria at the dawn of the new millennium

beta-lactamases of Gram-negative bacteria are evolving dynamically. New developments include the production of enzymes with novel substrate profiles, reduced susceptibility to beta-lactamase inhibitors, and the simultaneous production of multiple types of beta-lactamases. The changes represent evolutionary upgrades which provide modern pathogens with a greater potential to resist beta-lactam antibiotics and cause formidable therapeutic, infection control, and diagnostic challenges. This review is a clinically oriented outline of recent developments in the beta-lactamase production of Gram-negative bacteria. (C) 2000 Editions scientifiques et medicales Elsevier SAS.