title: Automated identification and susceptibility determination directly from blood cultures facilitates early targeted antibiotic therapy.
abstract: BACKGROUND
  The increasing prevalence of antibiotic resistance is challenging established empirical treatments, making early identification and susceptibility determination more important. To avoid time-consuming overnight cultures, a previously published method for the rapid identification and susceptibility testing of blood cultures was instituted at Molde Hospital. The time saved compared to the standard method, and how often the results could have led to a change in the empirical antibiotic treatment compared to Gram stain from cultures, were evaluated.
  
  
  METHODS
  All positive blood cultures with Gram-negative bacilli obtained between March and December 2010 were included in the study (n = 69). Accuracy and turn-around times were compared to those of the standard methods. The empirical antibiotic treatment was recorded when consulting the clinician about the results.
  
  
  RESULTS
  Correct identification was obtained in 66/69 (95.7%) of the isolates. Correct susceptibility determination was obtained in 758/759 (99.9%) of the tests. Oral reports to the clinician were given on average 11 h 22 min earlier for identification, and 10 h 51 min earlier for susceptibility determination, compared to the standard methods. With optimal handling we could have managed 17 h 26 min and 16 h 14 min, respectively. In 14/69 cases the empirical treatment included no effective or appropriate antibiotics. 7 of these 14 would not have been changed to working antibiotic treatment based on Gram stain alone.
  
  
  CONCLUSIONS
  The rapid method was found to be accurate and showed the potential for the initiation of effective antibiotic treatment more than 16 h earlier for 10% of the patients in this small sample.
authors: Laboratory of Medical Microbiology, Molde Hospital, Molde, and Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway. einar.nilsen@unn.no
authors: Einar
authors: E
authors: Nilsen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology*; D015373:Bacterial Typing Techniques / Q000379:methods*; D024881:Drug Resistance, Bacterial; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents