title: Analysis of the beta-lactam resistance phenotypes of Escherichia coli. An 8-year survey conducted in Greece.
abstract: There have been few studies, outside of France, on the resistance of Escherichi coli to beta-lactams by means of resistance phenotypes. In the present 8-year study from a tertiary Greek hospital, a statistically significant decrease in wild-type strains was noted, with a parallel increase in strains producing penicillinase. Of the total 6,089 isolates analyzed, 62.47% had no acquired resistance mechanisms while 35.70% produced penicillinase, 0.61% cefalosporinase and 0.94% extended-spectrum beta-lactamase. No overexpression of chromosomal cephalosporinase or synthesis of inhibitor-resistant enzymes was found. A shift in the pattern of penicillinase production was noted as, in the early years of the study, intermediate- and high-level penicillinase predominated whereas, in later years, low-level penicillinase prevailed.
authors.affiliation: Department of Clinical Bacteriology, Parasitology, Zoonoses and Geographical Medicine, University Hospital of Heraklion, Heraklion, Greece. ineonakis@gmail.com
authors.forename: Ioannis K
authors.initials: IK
authors.lastname: Neonakis
authors.forename: Stavroula
authors.initials: S
authors.lastname: Baritaki
authors.forename: Alexandros
authors.initials: A
authors.lastname: Georgiladakis
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002510:Cephalosporinase / Q000096:biosynthesis; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology*; D006115:Greece; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests; D010405:Penicillinase / Q000096:biosynthesis; D010641:Phenotype; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D002510:Cephalosporinase; D010405:Penicillinase; D001618:beta-Lactamases