title: The evolution of resistance to cephalosporins.
abstract: The expression of resistance to cephalosporins is highly varied and due to various mechanisms. The greatest disadvantage of the cephalosporins is that they are inactivated by the array of beta-lactamases produced by bacteria. The high levels of chromosomal enzymes produced by these organisms are a major cause of cephalosporin resistance. Plasmid-mediated beta-lactamases (PMBLs) have also been implicated as causes of resistance, and other cephalosporinases have been described. Point mutations of specific amino acids of well-recognized PMBLs (e.g., TEM-1 and SHV-1) have also produced enzymes capable of attacking a wider spectrum of beta-lactam agents. The availability of newer beta-lactams may be conducive to the development of such beta-lactamases, in which chromosomal and newer plasmid derivatives that may or may not contain the AmpC gene are selected. The occurrence of such enzymes is likely to continue to increase.
authors.affiliation: Department of Medical Microbiology, Faculty of Medical Sciences, The University of the West Indies, Kingston, Jamaica.
authors.forename: F
authors.initials: F
authors.lastname: Moosdeen
mesh_terms: D001419:Bacteria / Q000201:enzymology; D018550:Cephalosporin Resistance; D001618:beta-Lactamases
chemical_list: D001618:beta-Lactamases