Comparison of the Fully Automated FilmArray BCID Assay to a 4-Hour Culture Test Coupled to Mass Spectrometry for Day 0 Identification of Microorganisms in Positive Blood Cultures

Table 1

Number of pathogens detected in the 153 blood specimen bottles by the three techniques that were compared in this study. The MALDI-TOF MS technique was taken as the gold standard.

	Reference technique (MALDI-TOF MS)	MALDI-TOF; MS at day 0; (% according to reference)	FilmArray; BCID assay (% according to reference)	P value^1
All pathogens	150	117 (78.0)	137 (91.3)	< 0.01
Gram positive bacteria detected by the FilmArray BCID panel	85	70 (82.4)	82 (96.5)	< 0.01
(i) Staphylococcus aureus	23	22 (95.7)	22 (95.7)^2
(ii) Coagulase negative staphylococci^3	42	36 (85.7)	41 (97.6)^4
(iii) Streptococcus pneumoniae	3	2 (66.7)	3 (100)
(iv) Streptococcus agalactiae	0	0	0
(v) Streptococcus pyogenes	0	0	0
(vi) Streptococcus spp.^5	5	4 (80.0)	4 (80.0)
(vii) Enterococcus spp.^6	11	5 (45.5)	11 (100)
(viii) Listeria monocytogenes	1	1 (100)	1 (100)
Gram negative bacteria detected by the FilmArray BCID panel	52	45 (86.5)	52 (100)	<0.05
(i) Acinetobacter baumannii	0	0	0
(ii) Haemophilus influenzae	1	0	1 (100)
(iii) Neisseria meningitidis	0	0	0
(iv) Pseudomonas aeruginosa	0	0	0
(v) Enterobacteriaceae	51	45 (88.2)	51 (100)
(a) Enterobacter cloacae complex	3	3 (100)	3 (100)
(b) Escherichia coli	34	31 (91.2)	34 (100)
(c) Klebsiella oxytoca	2	0	2 (100)
(d) Klebsiella pneumoniae	9	8 (88.9)	9 (100)
(e) Proteus spp.	1	1 (100)	1 (100)
(f) Serratia marcescens	2	2 (100)	2 (100)
Yeasts detected by the FilmArray BCID panel	3	0	3 (100)	NS
(i) Candida albicans	2	0	2 (100)
(ii) Candida glabrata	0	0	0
(iii) Candida krusei	1	0	1 (100)
(iv) Candida parapsilosis	0	0	0
(v) Candida tropicalis	0	0	0
Microorganisms absent from the FilmArray BCID panel but detected by MALDI-TOF MS	10	2 (20.0)	0	NS
(i) Gemella haemolysans	1	0	0
(ii) Gemella spp.	1	0	0
(iii) Corynebacterium amycolatum	2	0	0
(iv) Acinetobacter ursingii	1	0	0
(v) Clostridium perfringens	1	0	0
(vi) Clostridium ramosum	1	1 (100)	0
(vii) Bacteroides ovatum	1	1 (100)	0
(viii) Propionibacterium spp.	1	0	0
(ix) Fusarium spp.	1	0	0

two-tailed Fisher exact test was used. NS: not significant at the level of 5%.
²Four strains of S. aureus were positive for the mecA gene.
³The 42 strains of coagulase negative staphylococci included 35 strains of S. epidermidis, 3 strains of S. capitis, 2 strains of S. hominis, and 1 strain of S. caprae, S. haemolyticus, and S. warneri, each.
⁴Thirty-five strains of coagulase negative staphylococci were positive for the mecA gene.
⁵The 5 strains of Streptococcus spp. included 2 strains of S. gallolyticus, 2 strains of S. mitis/oralis, and 1 strain of S. parasanguinis.
⁶The 11 strains of Enterococcus spp. included 6 strains of E. faecalis, 3 strains of E. faecium, 1 strain of E. gallinarum, and 1 strain of E. hirae.