title: Sequential outbreaks in a Spanish hospital caused by multiresistant OXA-58-producing Acinetobacter baumannii ST92.
abstract: The aim of this study was to assess the epidemiology and molecular basis of the infection and dissemination of multidrug-resistant Acinetobacter baumannii (MDRAB) in three sequential outbreaks at the intensive care units (ICUs) of a tertiary university hospital in Granada, Spain, between 2009 and 2011. Strains from all patients infected and/or colonized by MDRAB during outbreak periods were characterized using PFGE and multilocus sequence typing (MLST). The first outbreak appeared in the summer of 2009 involving 38 ICU patients: 25 from a Traumatology-Rehabilitation hospital (TRH) and 13 from a Medical-Surgery hospital (MSH). Between 2010 and 2011, outbreaks were limited to the MSH-ICU, affecting 9 and 11 patients, respectively. Two PFGE types were detected. In the 2009 outbreak, two clones were identified: profile 1 strains were isolated at the TRH, whilst profile 2 was isolated at the MSH. Only one clone was identified in the 2010 and 2011 outbreaks: the profile 2 clone detected at the MSH in 2009. After MLST analysis, a single sequence type (ST92) was identified. This suggested that an endemic strain could evolve and cause localized outbreaks in vulnerable patients. Multiplex PCR for OXA group enzymes yielded a positive result for blaOXA-58-like and blaOXA-51-like genes, and gene sequencing showed the presence of blaOXA-58. However, the absence of ISAba1 upstream of the blaOXA-51-like gene suggested the absence of OXA-51 expression. The susceptibility pattern was not an appropriate method for MDRAB surveillance, as several susceptibility patterns were identified in a single clone. Consequently, molecular methods of characterization are recommended for epidemiological surveillance of MDRAB.
authors.affiliation: Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain.
authors.forename: Jorge Julio Cabrera
authors.initials: JJC
authors.lastname: Alvargonzalez
authors.affiliation: Antibiotic Laboratory, Department of Bacteriology, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Ana Vindel
authors.initials: AV
authors.lastname: Hernando
authors.affiliation: Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain.
authors.forename: Maria Dolores Rojo
authors.initials: MDR
authors.lastname: Martín
authors.affiliation: Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain.
authors.forename: Consuelo Miranda
authors.initials: CM
authors.lastname: Casas
authors.affiliation: Antibiotic Laboratory, Department of Bacteriology, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Jesús Oteo
authors.initials: JO
authors.lastname: Iglesias
authors.affiliation: Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain.
authors.forename: Mari Fe Bautista
authors.initials: MFB
authors.lastname: Marín
authors.affiliation: Antibiotic Laboratory, Department of Bacteriology, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Maria Luisa Azañedo
authors.initials: MLA
authors.lastname: Alvarez
authors.affiliation: Antibiotic Laboratory, Department of Bacteriology, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Veronica Bautista
authors.initials: VB
authors.lastname: Sanchez
authors.affiliation: Department of Microbiology, University Hospital Virgen de las Nieves, Granada, Spain.
authors.forename: Jose Maria Navarro
authors.initials: JMN
authors.lastname: Marí
mesh_terms: D000151:Acinetobacter Infections / Q000235:genetics / Q000378:metabolism*; D040981:Acinetobacter baumannii / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D024901:Drug Resistance, Multiple, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases; C534889:beta-lactamase OXA-58, Acinetobacter baumannii