title: Methicillin-resistant Staphylococcus species in a cardiac surgical intensive care unit: a 5-year experience.
abstract: OBJECTIVE
  Methicillin-resistant Staphylococcus is a growing problem in intensive care units (ICUs). The aim of this study was to describe the epidemiology of methicillin-resistant Staphylococcus isolates in a cardiac surgical ICU over a 5-year period and to determine the risk factors and outcome of this condition.
  
  
  METHODS
  During the period from January 1998 to July 2003, the clinical data of all adult patients who underwent cardiac surgery in a university hospital were prospectively recorded in a database; the perioperative clinical variables and microbiologic data were studied by means of univariate and multivariate analysis in order to identify risk factors for the development of methicillin resistance and in-hospital death.
  
  
  RESULTS
  Methicillin-resistant Staphylococcus species strains were isolated in 118 of 6,423 patients operated on during the study period (7.6 cases per 1,000 days of ICU stay), with a constant prevalence rate throughout the years. Methicillin-resistant Staphylococcus species have been the most frequently isolated microorganisms in the authors' ICU; 75% of Staphylococcus aureus and 95% of coagulase-negative staphylococci were methicillin resistant. In-hospital mortality in methicillin-resistant Staphylococcus-positive patients was 50.0% (59/118), whereas it was 1.7% (108/6305) in other patients (p < 0.0001). On multivariate analysis, methicillin-resistant Staphylococcus species isolation was the single risk factor with the strongest association with in-hospital death (odds ratio, 8.5; 95% confidence interval 4.9-14.7). In the present series, there were no isolates of vancomycin-resistant species (Enterococcus species or Staphylococcus species).
  
  
  CONCLUSIONS
  Staphylococcus species represent the most frequently isolated microorganisms in the authors' ICU. In-hospital mortality in cardiac surgical patients is strongly correlated to the isolation of methicillin-resistant Staphylococcus.
authors.affiliation: Department of Cardiovascular Anesthesia, Vita-Salute University of Milan, IRCCS San Raffaele Hospital, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zangrillo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Landoni
authors.forename: Luca
authors.initials: L
authors.lastname: Fumagalli
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bove
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Bellotti
authors.forename: Ornella
authors.initials: O
authors.lastname: Sottocorna
authors.forename: Andrea
authors.initials: A
authors.lastname: Roberti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Marino
mesh_terms: D000328:Adult; D000368:Aged; D019072:Antibiotic Prophylaxis; D006348:Cardiac Surgical Procedures; D003428:Cross Infection / Q000382:microbiology*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013210:Staphylococcus / Q000187:drug effects / Q000302:isolation & purification*