title: Are laboratory-based antibiograms reliable to guide the selection of empirical antimicrobial treatment in patients with hospital-acquired infections?
abstract: OBJECTIVE
  Antibiograms are often taken into account to define a rational selection of an empirical antimicrobial therapy for treating patients with hospital-acquired infections. In this study, we performed a paired comparison between the antibiogram constructed with laboratory-based data and that formed with data subjected to prior clinical validation.
  
  
  METHODS
  Between 2003 and 2005, the laboratory of microbiology printed in duplicate every individual susceptibility report corresponding to hospitalized patients and the copy was sent to the department of infection control. Every individual report was assessed in real time at the bedside of the patient by a multidisciplinary team for clinical significance and appropriateness of the specimen, as well as for the type, source and origin of the infection. Cumulative resistance rates were estimated in parallel at the laboratory with the whole data, and at the infection control department with data subjected to prior clinical validation. These rates were designated as 'laboratory-based' and 'clinically based', respectively.
  
  
  RESULTS
  A total of 2305 individual susceptibility reports were assessed. Only 1429 (62.0%) were considered as clinically significant by the multidisciplinary team. Escherichia coli, Enterobacter cloacae, Citrobacter freundii group, Klebsiella species and Proteus mirabilis resistant to broad-spectrum cephalosporins, as well as methicillin-resistant Staphylococcus aureus, were significantly more frequent in the clinically based rates (P < or = 0.03).
  
  
  CONCLUSIONS
  Laboratory-based data underestimate the frequency of several major resistant organisms in patients with hospital-acquired infection. Previous clinical validation of the individual susceptibility reports seems to be a suitable strategy to get more reliable data.
authors.affiliation: Department of Infection Control, Hospital San Martín, Perón 450 (3100) Paraná, Entre Ríos, Argentina. cbantar@arnet.com.ar
authors.forename: Carlos
authors.initials: C
authors.lastname: Bantar
authors.forename: Gabriela
authors.initials: G
authors.lastname: Alcazar
authors.forename: Diego
authors.initials: D
authors.lastname: Franco
authors.forename: Francisco
authors.initials: F
authors.lastname: Salamone
authors.forename: Eduardo
authors.initials: E
authors.lastname: Vesco
authors.forename: Teodoro
authors.initials: T
authors.lastname: Stieben
authors.forename: Florencia
authors.initials: F
authors.lastname: Obaid
authors.forename: Alejandro
authors.initials: A
authors.lastname: Fiorillo
authors.forename: Mariano
authors.initials: M
authors.lastname: Izaguirre
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Oliva
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D003428:Cross Infection / Q000188:drug therapy*; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents