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

Abstract

The recovery of bacteria and fungi from blood cultures was compared in conventional tryptic soy broth (TSB) bottles and in TSB bottles with an agarcoated slide attachment. A total of 2,662 sets of blood cultures, including 413 that were positive (15.5%), were evaluated. Significantly more gram-positive and gram-negative bacteria were recovered in the slide culture bottles than in conventional bottles (299 versus 253 isolates). Growth of gram-positive organisms and fungi was detected in the slide culture bottles 24 to 48 h earlier than in the TSB bottles. In addition, 76% of the isolates in the slide culture system 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.