title: In Vitro Activity of Tigecycline Against Acinetobacter baumannii: Global Epidemiology and Resistance Mechanisms.
abstract: Acinetobacter baumannii is a pathogen of increasing concern, commonly causing outbreaks in the hospital environment. Of particular concern, A. baumannii strains exhibiting resistance to carbapenems, which were previously considered the treatment of choice for infected patients, have dramatically increased worldwide, leaving a few antibacterial choices. Tigecycline, a broad-spectrum modified minocycline derivative, isconsidered as a last resort drug against multidrug-resistant A. baumannii. Though, resistance to tigecycline has emerged and is growing notably following increasing tigecycline usage. Comparative evaluation of the tigecycline resistance rates reported worldwide is challenging due to the absence of official interpretative criteria for in vitro susceptibility testing and the discrepancies among the different susceptibility methodologies used, with broth microdilution being considered the reference method. Tigecycline resistance is mainly associated with resistance-nodulation-cell division (RND)-type transporters, mainly the AdeABC, AdeFGH and AdeIJK efflux pumps, but other resistance mechanisms have also been implicated. Tigecycline is still an attractive choice for A. baumannii, but further investigations are warranted so that treatment of MDR Α. baumannii could be guided by validated in vitro data.
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, 11527, Greece.|Department of Biopathology, Aretaieio Hospital, University of Athens, Athens, Greece.
authors.forename: Spyros
authors.initials: S
authors.lastname: Pournaras
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, 11527, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Koumaki
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, 11527, Greece.
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Gennimata
authors.affiliation: Department of Biopathology, Aretaieio Hospital, University of Athens, Athens, Greece.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kouskouni
authors.affiliation: Department of Microbiology, Medical School, University of Athens, Athens, 11527, Greece. atsakris@med.uoa.gr.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Tsakris
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology; D040981:Acinetobacter baumannii / Q000378:metabolism*; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008911:Minocycline / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000078304:Tigecycline
chemical_list: D000078304:Tigecycline; D008911:Minocycline
keywords: Acinetobacter baumannii; MIC; Resistance; Resistance mechanisms; Susceptibility methods; Tigecycline