title: Mechanisms of beta-lactam resistance in Haemophilus influenzae.
abstract: Haemophilus influenzae has become increasingly resistant to beta-lactam antibiotics. Three major mechanisms, both enzymatic and non-enzymatic, are involved. Enzymatic resistance is mainly due to production of a TEM-1 plasmid-mediated beta-lactamase, and in some cases to a new enzyme ROB-1. Of the non-enzymatic mechanisms, decreased permeability due to alteration of outer membrane proteins seems to be rare in comparison to decreased affinity of penicillin-binding proteins for beta-lactam antibiotics. Enzymatic resistance is present in about 10-20% of clinical isolates, while non-enzymatic resistance is present only in 2-4%.
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000378:metabolism; D002463:Cell Membrane Permeability; D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000201:enzymology; D006602:Hexosyltransferases; D006801:Humans; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D001618:beta-Lactamases