title: Antibiotic trends of Klebsiella pneumoniae and Acinetobacter baumannii resistance indicators in an intensive care unit of Southern Italy, 2008-2013.
abstract: BACKGROUND
  The overuse of antimicrobials is one of the main factors responsible for the development and spread of antimicrobial resistance, together with other causes, such as intra- and inter-hospital spread of resistant microorganisms and infection control policies and practices. The objective of the present study is to report the trends of Klebsiella pneumoniae and Acinetobacter baumannii antimicrobial resistance indicators in an Italian intensive care unit (ICU) during a six-year period, from 2008 to 2013.
  
  
  METHODS
  Susceptibility data and annual antibiotic consumptions in the ICU were retrospectively obtained from the clinical laboratory and the pharmacy. Trends over time of resistance rates (RRs) and of incidence densities of resistant isolates were determined by linear regression.
  
  
  RESULTS
  Isolation density of A. baumannii increased significantly from 2008 (20.4 per 1,000 patient-days) to 2013 (58.1 per 1,000 patient-days) and of K. pneumoniae from 2010 (22.3 per 1,000 patient-days) to 2013 (55.9 per 1,000 patient-days). RRs of third-generation cephalosporins (3GCs)-resistant K. pneumoniae (from 2010: 41.9 %, to 2012: 87.0 %), of carbapenem-resistant K. pneumoniae (from 2008: 0 %, to 2013: 59.2 %), and of carbapenem-resistant A. baumannii (from 2008: 87.5 %, to 2013: 96.6 %) showed significant increasing trends. Carbapenems was the main antibiotic class consumed (24.9 % of the total antimicrobial usage density), followed by 3GCs (21.0 %), fluoroquinolones (20.6 %), aminoglycosides (17.3 %), penicillins (15.1 %) and glycopeptides (1.1 %). Carbapenems consumption decreased from 2008 to 2012 and then increased in 2013. Glycopeptides consumption decreased from 2008 to 2011 and then increased in 2013. Aminoglycosides consumption decreased from 2008 to 2010 and increased from 2012 to 2013. Finally, 3GC, penicillins and fluoroquinolones consumptions decreased from 2012 to 2013.
  
  
  CONCLUSIONS
  RRs of carbapenem-resistant A. baumannii and of carbapenem- and 3GC-resistant K. pneumoniae were higher than those for Europe. Our findings highlight the necessity to implement an integrated system for monitoring not only consumption of antibiotics and resistance profiles but also the clonality of alert microorganisms in the ICU for effective infection control.
authors.affiliation: Department of Medical and Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Agodi
authors.affiliation: Department of Medical and Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Barchitta
authors.affiliation: Department of Medical and Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Quattrocchi
authors.affiliation: Department of Medical and Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, Via S. Sofia 87, 95123 Catania, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Maugeri
authors.affiliation: Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Via S. Sofia, 78, 95123 Catania, Italy.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Aldisio
authors.affiliation: Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Via S. Sofia, 78, 95123 Catania, Italy.
authors.forename: Anna Elisa
authors.initials: AE
authors.lastname: Marchese
authors.affiliation: Azienda Ospedaliero-Universitaria 'Policlinico-Vittorio Emanuele', Via S. Sofia, 78, 95123 Catania, Italy.
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Mattaliano
authors.affiliation: Department of Microbiology, Medical School, University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Tsakris
keywords: Antimicrobial resistance; Antimicrobial usage density; Resistance rates