TABLE 1.

Rapid identification of bacteria in 400 blood cultures using smudge plate preparation and MALDI-TOF MS system

Organism	No. of isolates	No. with correct IDa (%)			No. with discordant ID	No. with no ID
		Species level	Genus level	Combined
Total	400	343 (85.8)	15 (3.7)	358 (89.5)	8	34
Gram-positive organisms	248	197 (79.4)	13 (5.2)	210 (84.7)	7	31
Staphylococcus aureus	58	56 (96.6)	0	56 (96.6)	1	1
CoNSb	95	76 (80.0)	0	76 (80.0)	2	17
Enterococcus faecalis	18	18 (100)	0	18 (100)	0	0
E. faecium	7	6 (85.7)	0	6 (85.7)	0	1
Streptococcus pneumoniae	7	7 (100)	0	7 (100)	0	0
S. viridans group	9	4 (44.4)	0	4 (44.4)	1	4
S. anginosus group	7	3 (42.9)	0	3 (42.9)	1	3
S. bovis group	3	3 (100)	0	3 (100)	0	0
S. pyogenes	2	1 (50.0)	0	1 (50.0)	0	1
S. agalactiae	5	5 (100)	0	5 (100)	0	0
S. dysgalactiae	2	1 (50.0)	0	1 (50.0)	0	1
S. suis	1	1 (100)	0	1 (100)	0	0
Bacillus species	21	9 (42.9)	10 (47.6)	19 (90.5)	1	1
Paenibacillus species	4	0	3 (75.0)	3 (75.0)	0	1
Listeria monocytogenes	2	1 (50.0)	0	1 (50.0)	1	0
Corynebacterium species	1	0	0	0	0	1
Lactobacillus casei	1	1 (100)	0	1 (100)	0	0
Dermabacter hominis	1	1 (100)	0	1 (100)	0	0
Microbacterium flavescens	1	1 (100)	0	1 (100)	0	0
Gram-negative organisms	152	146 (96.1)	2 (1.3)	148 (97.4)	1	3
Enterobacteriaceae	133	130 (97.7)	2 (1.5)	132 (99.2)	0	1
Escherichia coli	78	78 (100)	0	78 (100)	0	0
Klebsiella species	25	25 (100)	0	25 (100)	0	0
Enterobacter species	10	10 (100)	0	10 (100)	0	0
Proteus species	10	10 (100)	0	10 (100)	0	0
Serratia marcescens	7	7 (100)	0	7 (100)	0	0
Raoultella ornithinolytica	1	0	1 (100)	1 (100)	0	0
Salmonella species (nontyphi)	1	0	1 (100)	1 (100)	0	0
Pseudomonas aeruginosa	10	10 (100)	0	10 (100)	0	0
Stenotrophomonas maltophilia	2	2 (100)	0	2 (100)	0	0
Campylobacter jejuni	1	0	0	0	0	1
Moraxella atlantae	1	0	0	0	0	0
M. osloensis	1	1 (100)	0	1 (100)	0	1
Brevundimonas vesicularis	1	0	0	0	0	1
Sphingobacterium species	1	0	0	0	0	1
Anaerobic organisms
Clostridium clostridioforme	1	1 (100)	0	1 (100)	0	0
C. ramosum	1	1 (100)	0	1 (100)	0	0
Propionibacterium acnes	1	1 (100)	0	1 (100)	0	0
Bacteroides fragilis	2	2 (100)	0	2 (100)	0	0
B. thetaiotaomicron	1	1 (100)	0	1 (100)	0	0

^aID, identification.

^bCoNS, coagulase-negative Staphylococcus.