Clinical laboratory comparison of a slide blood culture system with a conventional broth system

Abstract

The recovery of bacteria and fungi from [human] blood cultures was compared in conventional tryptic soy broth (TSB) bottles and in TSB bottles with an agar coated slide attachment. A total of 2662 sets of blood cultures, including 413 that were positive (15.5%), were evaluated. Significantly more gram-positive and gram-negative bacteria wer recovered in the slide culture bottles than in conventional bottles (299 vs. 253 isolates). Growth of gram-positive organisms and fungi was detected in the slide culture bottles 24-48 h earlier than in the TSB bottles. Of the isolates in the slide culture system, 76% were detected on the agar slide. In comparison, only 40% of the isolates in the TSB bottles were detected initially by blind subculturing. The incidences of contamination were 2.7% (71 cultures) for the slide culture system and 1.5% (39 cultures) for the TSB bottles.