title: Investigation of Extensively Drug-Resistant blaOXA-23-Producing Acinetobacter baumannii Spread in a Greek Hospital.
abstract: A rapid increase was observed in the incidence of extensively drug-resistant Acinetobacter baumannii (XDR Aba) isolates in a Greek hospital during 2014. To investigate the causes of this rise, the antimicrobial resistance profiles of all carbapenem-resistant (CARB-R) Aba isolates recovered during 2014-2015 were determined. Selected XDR Aba isolates (n = 13) were characterized by molecular methods. XDR Aba (48 isolates) represented 21.4% of the 224 CARB-R Aba recovered during the study period. The 13 selected XDR Aba isolates were positive for the blaOXA-23, the intrinsic blaOXA-51, and the adeB gene of the AdeABC efflux pump, and all belonged to the 3LST ST101, corresponding to the international clone II. Three bloodstream isolates possessed two amino acid substitutions (A138T+A226V) in the deduced amino acid sequences of the pmrB gene, which may be implicated in colistin resistance. This study demonstrates that this clone still evolves by obtaining an ever-increasing arsenal of antibiotic resistance mechanisms. The clinical characteristics of the intensive care unit (ICU) patients with XDR Aba were reviewed retrospectively. Infected ICU patients with XDR Aba displayed higher death rates compared with infected ICU patients susceptible to colistin and tigecycline CARB-R Aba, although there were no statistically significant differences. Conclusively, continuous surveillance and molecular characterization of XDR Aba, combined with strict infection control measures are mandatory for combating nosocomial infections caused by this organism.
authors.affiliation: 1 Department of Microbiology, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens, Greece .
authors.forename: Angeliki
authors.initials: A
authors.lastname: Mavroidi
authors.affiliation: 2 Intensive Care Unit, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens Greece .
authors.forename: Maria
authors.initials: M
authors.lastname: Katsiari
authors.affiliation: 1 Department of Microbiology, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens, Greece .
authors.forename: Eleftheria
authors.initials: E
authors.lastname: Palla
authors.affiliation: 1 Department of Microbiology, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens, Greece .
authors.forename: Sofia
authors.initials: S
authors.lastname: Likousi
authors.affiliation: 1 Department of Microbiology, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens, Greece .
authors.forename: Zoi
authors.initials: Z
authors.lastname: Roussou
authors.affiliation: 2 Intensive Care Unit, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens Greece .
authors.forename: Charikleia
authors.initials: C
authors.lastname: Nikolaou
authors.affiliation: 1 Department of Microbiology, General Hospital of Nea Ionia , "Konstantopouleio-Patission," Athens, Greece .
authors.forename: Evangelia D
authors.initials: ED
authors.lastname: Platsouka
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015780:Carbapenems / Q000494:pharmacology; D002999:Clone Cells; D003091:Colistin / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006115:Greece / Q000453:epidemiology; D006761:Hospitals; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D009154:Mutation; D012189:Retrospective Studies; D016019:Survival Analysis; D000078304:Tigecycline; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: C445684:AdeB protein, Acinetobacter baumannii; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D026901:Membrane Transport Proteins; C409039:PmrB protein, bacteria; D014157:Transcription Factors; D000078304:Tigecycline; D001618:beta-Lactamases; C000599728:beta-lactamase OXA-23, Acinetobacter baumannii; C577373:beta-lactamase OXA-51, Acinetobacter baumannii; D008911:Minocycline; D003091:Colistin
keywords: Acinetobacter baumannii; carbapenemases; genotyping; resistance mechanisms