COMPARATIVE-EVALUATION OF BACTEC AEROBIC PLUS F AND SEPTI-CHEK RELEASE BLOOD CULTURE MEDIA/

The BACTEC 9240 (Becton Dickinson, Sparks, Md,) automated blood cultur e system is based on the continuous monitoring of CO, production by me ans of a fluorescent sensor attached to the bottom of culture vials, W e compared the performance of the BACTEC aerobic Plus/F medium to that of the Septi-Chek Release medium (Becton Dickinson, Sparks, Md.), a m anual biphasic blood culture system, Sets consisting of BACTEC aerobic Plus/F and Septi-Chek Release vials inoculated with similar volumes ( 7 +/- 2 mi) were evaluated, In the laboratory, systems were equipped a nd analyzed according to the manufacturer's recommendations. The BACTE C and Septi-Chek vials were incubated at 35 degrees C for 5 days. A to tal of 6,116 compliant sets were obtained from 1,972 adult patients (3 .1 cultures per patient), Of these, 731 (12%) were culture positive, i ncluding 612 (10%) that yielded at least one pathogen, and 143 (2%) we re considered to be contaminated, Of the 672 pathogenic organisms dete cted, 524 were isolated from the BACTEC aerobic Plus/F medium and 574 were isolated from the Septi-Chek Release medium, 428 organisms grew i n both media, 96 organisms grew only in the BACTEC aerobic Plus/F medi um, and 146 organisms grew only in the Septi-Chek Release medium (P = 0.001), Haemophilus spp, were isolated more often (P = 0.03) from the BACTEC aerobic Plus/F medium; however, more Streptococcus anginosus or ganisms (P = 0.02), members of the Enterobacteriaceae family (P < 0.03 ), and gram-negative anaerobes (P = 0.03) were isolated from the Septi -Chek Release medium, Pathogenic organisms were detected significantly earlier (P < 0.0001) with the BACTEC aerobic Plus/F medium in conjunc tion with the BACTEC 9240 instrument than with the Septi-Chek Release medium.