Clinical comparison of bact/alert and isolator aerobic blood culture systems in a hospital setting

ABSTRACT

The BacT/Alcrt [BTA] [Bio Merieux, Durham, NC] and Isolator [ISO] [Wampole Laboratories, Cranbury, NJ] blood culture systems were evaluated for their ability to detect aerobic and facultatively anaerobic microorganisms in blood of adult patients. 8-10 ml of blood was inoculated into each of the aerobic BTA bottle and the ISO tube for every patient enrolled in the study. Out of 2,114 samples, 179 isolates were recovered from 89 patients. BTA detected 73.18% of the isolates, while ISO detected 78.77% of the isolates, with 51.96% detected by both. There was no statistically significant difference in the total recovery of isolates between the two systems, but BTA significantly detected more Gram negative rods, while ISO significantly detected more Gram positive cocci and yeasts. RTA detected Staphylococcus aureus, Streptococci and Gram positive rods significantly sooner than ISO, while the latter detected yeasts significantly sooner than BTA