title: PER-1- and OXA-10-like beta-lactamases in ceftazidime-resistant Pseudomonas aeruginosa isolates from intensive care unit patients in Istanbul, Turkey.
abstract: The presence of PER-1- and OXA-10-like beta-lactamases was investigated by PCR in 49 ceftazidime-resistant Pseudomonas aeruginosa isolates from patients hospitalised in the 24-bed general intensive care unit of the Istanbul Faculty of Medicine during a 12-month period between February 1999 and February 2000. The clonal relatedness of the isolates was investigated by random amplified polymorphic DNA (RAPD) analysis, and the sequences of the PER-1 and OXA genes from all isolates were determined. The rates of resistance of the isolates to imipenem, aztreonam and cefepime were 98%, 92% and 96%, respectively, and to piperacillin and piperacillin-tazobactam were 41% and 37%, respectively. Using the double-disk synergy test, 37% (18/49) of the isolates were identified as extended-spectrum beta-lactamase producers. The PER-1 gene was identified in 86% (42/49) and the OXA-10 gene in 55% (27/49) of the ceftazidime-resistant isolates. Of isolates carrying the PER-1 gene, 48% (20/42) also carried the OXA-10 gene. The respective nucleotide sequences were identical for each isolate. Sixteen RAPD patterns were detected among the PER-1-positive isolates, but 60% (25/42) of the PER-1-positive isolates belonged to two distinct patterns, while the remainder exhibited a wide clonal diversity. The results indicated that the prevalence of PER-1- and OXA-10-like beta-lactamases remains high among ceftazidime-resistant P. aeruginosa isolates in Turkey.
authors.affiliation: Department of Microbiology and Clinical Microbiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. aktaszerrin@yahoo.com
authors.forename: Z
authors.initials: Z
authors.lastname: Aktaş
authors.forename: L
authors.initials: L
authors.lastname: Poirel
authors.forename: M
authors.initials: M
authors.lastname: Salcioğlu
authors.forename: P E
authors.initials: PE
authors.lastname: Ozcan
authors.forename: K
authors.initials: K
authors.lastname: Midilli
authors.forename: C
authors.initials: C
authors.lastname: Bal
authors.forename: O
authors.initials: O
authors.lastname: Anğ
authors.forename: P
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology*; D018550:Cephalosporin Resistance / Q000502:physiology*; D006801:Humans; D007362:Intensive Care Units; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology; D014421:Turkey; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002442:Ceftazidime; C425107:beta-lactamase OXA-10; C108863:beta-lactamase PER-1; D001618:beta-Lactamases