title: Antimicrobial use, incidence, etiology and resistance patterns in bacteria causing ventilator-associated pneumonia in a clinical-surgical intensive care unit.
abstract: BACKGROUND
  Antimicrobial resistance is an increasing threat in hospitalized patients, and inappropriate empirical antimicrobial therapy is known to adversely affect outcomes in ventilator-associated pneumonia (VAP). The aim of this study was to evaluate antimicrobial usage, incidence, etiology, and antimicrobial resistance trends for prominent nosocomial pathogens causing ventilator-associated pneumonia in a clinical-surgical intensive care unit (ICU).
  
  
  METHODS
  Gram-negative bacilli and Staphylococcus aureus causing VAP, as well as their antimicrobial resistance patterns and data on consumption (defined daily dose [DDD] per 1,000 patient days) of glycopeptides, extended-spectrum cephalosporins, and carbapenems in the unit were evaluated in two different periods (A and B).
  
  
  RESULTS
  Antimicrobial use was high, mainly of broad-spectrum cephalosporins, with a significant increase in the consumption of glycopeptides (p < 0.0001) and carbapenems (p < 0.007) in period B. For Acinetobacter baumannii and members of the Enterobacteriaceae family, 5.27- and 3.06-fold increases in VAPs, respectively, were noted, and a significant increase in resistance rates was found for imipenem-resistant A. baumannii (p = 0.003) and third-generation cephalosporins-resistant Enterobacteriaceae (p = 0.01) isolates in this same period.
  
  
  CONCLUSIONS
  Our results suggest that there is a link between antibiotics usage at institutional levels and resistant bacteria. The use of carbapenems was related to the high rate of resistance in A. baumannii and therefore a high consumption of imipenem/meropenem could play a major role in selective pressure exerted by antibiotics in A. baumannii strains.
authors.affiliation: Laboratório de Microbiologia, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, MG, Brasil. moreira.mr@hotmail.com
authors.forename: Michel Rodrigues
authors.initials: MR
authors.lastname: Moreira
authors.forename: Munick Paula
authors.initials: MP
authors.lastname: Guimarães
authors.forename: Aurélia Aparecida de Araújo
authors.initials: AA
authors.lastname: Rodrigues
authors.forename: Paulo Pinto
authors.initials: PP
authors.lastname: Gontijo Filho
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003422:Critical Care; D003430:Cross-Sectional Studies; D024901:Drug Resistance, Multiple, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D006801:Humans; D057970:Inappropriate Prescribing / Q000009:adverse effects; D015994:Incidence; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D053717:Pneumonia, Ventilator-Associated / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents