Acridine orange staining as a replacement for subculturing of false-positive blood cultures with the BACTEC NR 660

Abstract

Despite the customization of growth index thresholds within individual laboratories, use of the BACTEC NR 660 automated blood culture system results in a number of false-positive cultures. The results of Gram staining, acridine orange staining, and subculturing to agar media were evaluated on 210 false-positive blood cultures over a 6-month period. Inclusion of acridine orange staining in the routine workup of false-positive blood cultures can eliminate the need for subculturing.