title: Nosocomial spread of colistin-only-sensitive sequence type 235 Pseudomonas aeruginosa isolates producing the extended-spectrum beta-lactamases GES-1 and GES-5 in Spain.
abstract: The mechanisms responsible for the increasing prevalence of colistin-only-sensitive (COS) Pseudomonas aeruginosa isolates in a Spanish hospital were investigated. Pulsed-field gel electrophoresis revealed that 24 (50%) of the studied isolates belonged to the same clone, identified as the internationally spread sequence type 235 (ST235) through multilocus sequence typing. In addition to several mutational resistance mechanisms, an integron containing seven resistance determinants was detected. Remarkably, the extended-spectrum beta-lactamase GES-1 and its Gly170Ser carbapenem-hydrolyzing derivative GES-5 were first documented to be encoded in a single integron. This work is the first to describe GES enzymes in Spain and adds them to the growing list of beta-lactamases of concern (PER, VIM, and OXA) detected in ST235 clone isolates.
authors.affiliation: Servicio de Microbiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Viedma
authors.forename: Carlos
authors.initials: C
authors.lastname: Juan
authors.forename: Joshi
authors.initials: J
authors.lastname: Acosta
authors.forename: Laura
authors.initials: L
authors.lastname: Zamorano
authors.forename: Joaquín R
authors.initials: JR
authors.lastname: Otero
authors.forename: Francisca
authors.initials: F
authors.lastname: Sanz
authors.forename: Fernando
authors.initials: F
authors.lastname: Chaves
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliver
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D003091:Colistin / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology*; D006801:Humans; D008969:Molecular Sequence Data; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; C405902:GES-1 beta-lactamase; D001618:beta-Lactamases; D003091:Colistin