Comparative evaluation of the BCB Roche and Oxoid Signal blood culture systems

The agar-slide blood culture system BCB Roche was compared with the Oxoid Signal blood culture system using 2,266 paired blood cultures. A total of 271 (12%) paired sets were culture-positive, including 222 (9.8%) yielding pathogens associated with septicemia and 50 (2.2%) yielding likely contaminants. In the recovery of the total 235 isolates considered as pathogens, the BCB Roche system yielded 202 (85.9%), the Oxoid Signal 211 (89.8%); 178 (75.7%) were cultured by both systems. There was no statistically significant difference between the two systems in their sensitivity, contamination-rate and detection time, except for gram-positive organisms, which were detected earlier by the Oxoid Signal system. Both systems performed well and were easy to handle.