CLINICAL COMPARISON OF THE ISOLATOR AND BACT ALERT AEROBIC BLOOD CULTURE SYSTEMS/

The performance characteristics of the Isolator (Wampole Laboratories, Cranbury, N,J.) and the BacT/Alert (Organon Teknika Corporation, Durh am, N.C.) aerobic blood culture systems were compared for 6,009 blood culture sets obtained from patients with suspected bloodstream infecti ons. The BacT/Alert aerobic bottle [BTA(O-2)] was continuously agitate d while it was incubated in 5% CO2 at 36 degrees C; culture plates pre pared from the Isolator tube [I(O-2)] were incubated in 5% CO2 at 37 d egrees C. From 394 blood cultures, 416 clinically significant isolates of bacteria and yeasts were recovered. The overall yields for BTA(O-2 ) and I(O-2) were not significantly different (319 versus 336; P = 0.2 0). I(O-2) recovered significantly more staphylococcus (P < 0.05) and yeast isolates (P < 0.01). BTA(O-2) recovered significantly more aerob ic and facultatively anaerobic gram-negative bacilli (P < 0.05), In bl ood culture sets which produced growth of the same organisms in both t he BTA(O-2) and I(O-2) systems, the BTA(O-2) system detected growth so oner, but more rapid identification was possible with the I(O-2) syste m by virtue of earlier isolation of colonies on solid media.