CONTROLLED CLINICAL COMPARISON OF ISOLATOR AND BACTEC-9240 AEROBIC-F RESIN BOTTLE FOR DETECTION OF BLOOD-STREAM INFECTIONS

A controlled clinical comparison was carried out with the BACTEC 9240 Aerobic/F resin bottle and the Isolator system with adult patients sus pected of having bloodstream infections, A total of 10,500 paired spec imens were collected, of which 1,122 from 520 patients were positive. There were 68 false-positive BACTEC bottles; 259 positive cultures tha t were excluded from analysis because the bottle, the Isolator, or bot h failed to meet the minimum volume criterion of 8 mi of blood; and 20 7 positive cultures that were excluded because the isolates were found to be clinically insignificant or of indeterminate clinical significa nce on the basis of patient assessment, A total of 656 positive cultur es from 258 patients formed the basis of the analysis, Significantly m ore Staphylococcus aureus isolates (P = 0.03), Staphylococcus epidermi dis isolates (P = 0.03), members of the family Enterobacteriaceae (P = 0.03), and Pseudomonas aeruginosa isolates (P = 0.04) were recovered from the resin bottle, and there was no category of organism that was recovered significantly more frequently from the Isolator system, With patients receiving antibiotics at the time of blood culture, S. aureu s, S. epidermidis, and gram-negative bacilli were recovered significan tly more frequently from the resin bottle, No significant differences between systems were found with cultures from patients not receiving a ntibiotics at the time of blood culture, Only 12 clinically significan t organisms were recovered from the bottle on terminal subcultures, an d only 1 of these had not been previously isolated from another blood culture set (10 of the 12) or from the companion Isolator (1 of 12), T he Aerobic/F resin bottle continuously monitored in the BACTEC 9240 in strument proved to be superior to the Isolator in overall yield of org anisms causing bloodstream infections in adults and required less tech nician time for specimen processing and examination than the Isolator system.