title: Molecular characterization of extended-spectrum beta-lactamases produced by nosocomial isolates of Enterobacteriaceae from an Italian nationwide survey.
abstract: Extended-spectrum beta-lactamases (ESBLs) are widespread in hospital settings worldwide. The present investigation was undertaken to assess the distribution and prevalence of ESBLs belonging to the TEM and SHV families in 448 ESBL-producing clinical isolates of Enterobacteriaceae collected from 10 different Italian hospitals. The natures of TEM and SHV determinants were identified by direct sequencing of PCR-amplified genes. TEM-52 and SHV-12 were the most common variants, and they were found in most hospitals and in several different species. Other less frequent variants included TEM-5, TEM-12, TEM-15, TEM-19, TEM-20, TEM-24, TEM-26, TEM-43, TEM-60, TEM-72, TEM-87, SHV-2a, SHV-5, and SHV-11. Proteus mirabilis was the most common producer of TEM-type ESBLs, while Klebsiella pneumoniae was the most common producer of SHV-type ESBLs. The distribution of TEM- and SHV-type ESBL variants in Enterobacteriaceae from Italian hospitals exhibited notable differences from those from other geographical settings.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biomediche, Università di L'Aquila, L'Aquila, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Perilli
authors.forename: Emanuela
authors.initials: E
authors.lastname: Dell'Amico
authors.forename: Bernardetta
authors.initials: B
authors.lastname: Segatore
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: de Massis
authors.forename: Ciro
authors.initials: C
authors.lastname: Bianchi
authors.forename: Francesco
authors.initials: F
authors.lastname: Luzzaro
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Rossolini
authors.forename: Antonio
authors.initials: A
authors.lastname: Toniolo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nicoletti
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Amicosante
mesh_terms: D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D007558:Italy / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics*
chemical_list: D001618:beta-Lactamases