title: Use of Directigen and acridine orange for rapid identification of human blood culture isolates.
abstract: Of 7,871 blood cultures from hospital patients, 22 yielded growth of Streptococcus pneumoniae or Haemophilus influenzae type b. The identities of 19 (86%) of these 22 strains could be verified after 18 to 24 h of incubation by application of the Directigen meningitis test kit to the unheated, uncentrifuged supernatant from the cultures; thus, the turnaround time for these cultures was halved. Growth in 16 (72%) of the Directigen-positive cultures was detected by visual inspection, and that in 3 (14%) of the cultures was detected by acridine orange staining. Growth in the three remaining bottles (14%) was detected by blind subculturing after 18 to 24 h or incubation and, therefore, was delayed by 24 h. The systematic application the acridine orange stain was helpful in 40 (44%) of 91 cases for which macroscopic inspection failed to reveal growth after 24 h of incubation.
mesh_terms: D000165:Acridine Orange; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D011933:Reagent Kits, Diagnostic; D018805:Sepsis / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
chemical_list: D011933:Reagent Kits, Diagnostic; D000165:Acridine Orange