title: Rapid identification of pneumococci, enterococci, beta-haemolytic streptococci and S. aureus from positive blood cultures enabling early reports.
abstract: BACKGROUND
  The aim of this study was to evaluate diagnostic tests in order to introduce a diagnostic strategy to identify the most common gram-positive bacteria (pneumococci, enterococci, β-haemolytic streptococci and S. aureus) found in blood cultures within 6 hours after signalling growth.
  
  
  METHODS
  The tube coagulase test was optimized and several latex agglutination tests were compared and evaluated before a validation period of 11 months was performed on consecutive positive blood culture patient samples from Kalmar County Hospital, Sweden.
  
  
  RESULTS
  During the validation period 150 (91%) of a total of 166 gram-positive cocci (119 in clusters, 45 in chains or pairs and 2 undefined morphology) were correctly identified as S. aureus, CoNS, Pneumococci, Enterococci or group A streptococci (GAS), group B streptococci (GBS), group G streptococci (GGS) within 6 hours with a minimal increase in work-load and costs. The remaining samples (9%) were correctly identified during the next day. No samples were incorrectly grouped with this diagnostic strategy and no patient came to risk by early reporting.
  
  
  CONCLUSIONS
  A simple strategy gives reliable and cost-effective reporting of >90% of the most common gram-positive cocci within 6 hours after a blood cultures become positive. The high specificity of the tests used makes preliminary reports reliable. The reports can be used to indicate the focus of infection and not the least, support faster administration of proper antimicrobial treatment for patients with serious bacterial infections.
authors.forename: Marie C
authors.initials: MC
authors.lastname: Larsson
authors.forename: Ewa
authors.initials: E
authors.lastname: Karlsson
authors.forename: Hanna
authors.initials: H
authors.lastname: Woksepp
authors.forename: Kerstin
authors.initials: K
authors.lastname: Frölander
authors.forename: Agneta
authors.initials: A
authors.lastname: Mårtensson
authors.forename: Foad
authors.initials: F
authors.lastname: Rashed
authors.forename: Wistedt
authors.initials: W
authors.lastname: Annika
authors.forename: Thomas
authors.initials: T
authors.lastname: Schön
authors.affiliation: Division of Clinical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, SE 581 85, Sweden. lena.serrander@lio.se.
authors.forename: Lena
authors.initials: L
authors.lastname: Serrander
mesh_terms: D000818:Animals; D016470:Bacteremia / Q000097:blood / Q000175:diagnosis / Q000382:microbiology*; D015373:Bacterial Typing Techniques / Q000379:methods*; D006094:Gram-Positive Bacteria / Q000145:classification* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000097:blood / Q000175:diagnosis / Q000382:microbiology*; D006736:Horses; D006801:Humans; D007841:Latex Fixation Tests; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013548:Sweden