Akm. Zaidi et al., CONTROLLED COMPARISON OF BIOMERIEUX VITAL AND BACTEC NR-660 SYSTEMS FOR DETECTION OF BACTEREMIA AND FUNGEMIA IN PEDIATRIC-PATIENTS, Journal of clinical microbiology, 35(8), 1997, pp. 2007-2012
The bioMerieux VITAL automated blood culture system measures a decreas
e in fluorescence to detect the presence of microorganisms in blood, T
o assess the performance of VITAL with AER aerobic medium versus that
of the nonradiometric BACTEC NR-660 PEDS PLUS medium for the detection
of sepsis in children, a total of 12,146 blood specimens were collect
ed at three university medical centers and inoculated into AER and PED
S PLUS bottles that were weighed before and after filling, The sample
volumes were considered adequate in 6,276 bottle pairs, The total yiel
d of isolates was 629, of which 489 (78%) were judged to be the cause
of true infections, Staphylococci (P < 0.001) and yeasts (P < 0.05) we
re detected more often in PEDS PLUS bottles, as were all microorganism
s combined (P < 0.001), The improved detection in the PEDS PLUS medium
was most marked for patients on antimicrobial therapy (P < 0.001), bu
t remained statistically Significant even for patients not on therapy
(P < 0.025), There were 431 episodes of sepsis, including 407 consider
ed adequate for analysis, Of the 363 unimicrobial episodes, 278 were d
etected by both bottles, 64 were detected by PEDS PLUS bottles only, a
nd 21 were detected by AER bottles only (P < 0.01), No false-negative
cultures were detected by terminal subculture of the PEDS PLUS bottles
when the companion AER bottle was positive, However, there were 14 fa
lse-negative cultures (7 yeasts, 5 staphylococci, 1 Enterococcus faeca
lis, and 1 Enterobacter sp,) on terminal subculture of the AER bottles
when the companion PEDS PLUS bottle was positive, When both systems w
ere positive, the VITAL system detected bacteria earlier than did the
BACTEC system by a mean of 1.6 h, Also, false-positive signals were le
ss common with the VITAL system, We conclude that the VITAL system wit
h AER medium must be modified to improve the detection of clinically i
mportant staphylococci and yeasts if it is to perform comparably to th
e BACTEC NR-660 nonradiometric system with PEDS PLUS medium for a pedi
atric population.