Research Article

Performances and Reliability of Bruker Microflex LT and VITEK MS MALDI-TOF Mass Spectrometry Systems for the Identification of Clinical Microorganisms

Table 4

High-confidence identifications by VITEK MS and Bruker Microflex LT MS systems.

Microorganism groups # of
isolates
Correct IdentificationMisidentificationNo-identification
SpeciesGenus only
VITEKBrukerVITEKBrukerVITEKBrukerVITEKBruker
SpeciesSpecies Complex

Nonfermentatives (16 species)
Achromobacter xylosoxidans6426
Acinetobacter baumannii1941921922
(F × 2)
2
(F × 2)
Acinetobacter guillouiae111
Acinetobacter johnsonii111
Acinetobacter lwoffii111
Acinetobacter radioresistens111
Aeromonas hydrophila3321 (C)
Aeromonas sobria111
(F)
Alcaligenes faecalis222
Burkholderia cepacia222 (C × 2)
Comamonas aquatica111 (D)
Delftia acidovorans333
Elizabethkingia meningoseptica111
Pseudomonas aeruginosa1251241251 (C)
Pseudomonas fluorescens111
Stenotrophomonas maltophilia131313
Total356151 (42.4%)201 (56.4%)350 (98.4%)3 (0.8%)2 (0.6%)2
(0.6%)
3
(0.8%)

Enterobacteriaceae (23 species)
Chryseobacterium indologenes111
Citrobacter braakii333
Citrobacter freundii5325
Citrobacter sedlakii111
Citrobacter youngae2211 (C)
Enterobacter aerogenes444
Enterobacter asburiae2211 (C)
Enterobacter cancerogenous111
Enterobacter cloacae111192 (C × 2)
Escherichia coli123123123
Klebsiella oxytoca555
Klebsiella pneumonia646464
Kluyvera cryocrescens11
(G)
1 (G)
Morganella morganii121212
Proteus mirabilis282828
Providencia rettgeri333
Providencia stuartii111
Raoultella ornithinolytica3213
Raoultella planticola111
Salmonella spp.151515
Serratia liquefaciens111
Serratia marcescens212121
Shigella boydii11 (N/A)1
(N/A)
Total309270 (87.4%)22 (7.1%)288 (93.3%)15 (4.9%)19 (6.1%)1 (0.3%)1
(0.3%)
1
(0.3%)
1
(0.3%)

Staphylococci (10 species)
Staphylococcus aureus525252
Staphylococcus capitis888
Staphylococcus caprae111
Staphylococcus epidermidis6868652
(C × 2)
1 (F)
Staphylococcus haemolyticus545454
Staphylococcus hominis828282
Staphylococcus lugdunensis111
Staphylococcus pettenkoferi111 (C)
Staphylococcus sciuri222
Staphylococcus simulans4341 (D)
Total273271 (99.3%)270 (98.9%)2 (0.7%)2
(0.7%)
1
(0.4%)

Streptococci (11 species)
Leuconostoc mesenteroides11 (F)1
(F)
Streptococcus agalactiae999
Streptococcus anginosus111
Streptococcus dysgalactiae333
Streptococcus gallolyticus111
Streptococcus mitis111 (C)
Streptococcus oralis111
Streptococcus parasanguinis111
Streptococcus pneumonia444
Streptococcus pyogenes666
Streptococcus salivarius111
Total2926 (89.7%)2 (6.9%)27 (93.2%)1 (3.4%)1
(3.4%)
1
(3.4%)

Enterococci and other Gr(+) cocci (5 species)
Aerococcus viridans444
Enterococcus avium444
Enterococcus faecalis545454
Enterococcus faecium848484
Enterococcus gallinarum141414
Total160160 (100%)160 (100%)

Coryneforms and other Gr(+) bacilli (14 species)
Actinomyces naeslundii11 (F)1
(F)
Bacillus cereus111
Bacillus simplex111
Corynebacterium amycolatum444
Corynebacterium appendicis11 (E)1 (E)
Corynebacterium coyleae111 (D)
Corynebacterium glaucum11
(G)
1 (G)
Corynebacterium jeikeium222
Corynebacterium mucifaciens331 (D)2
(F)
Corynebacterium striatum101010
Corynebacterium urealyticum111
Corynebacterium ureicelerivorans21 (E)2 (E, F)1
(F)
Lactobacillus paracasei111
Listeria monocytogenes111
Total3015 (50.0%)6 (20.0%)25 (83.4%)2 (6.7%)4 (13.3%)2 (6.7%)5
(16.6%)
1
(3.3%)

HACEK and other Gr(−) cocci (8 species)
Haemophilus haemolyticus111
Haemophilus influenza333
Haemophilus parahaemolyticus222
Haemophilus parainfluenzae111
Legionella pneumophila777
Moraxella catarrhalis111
Neisseria meningitides111
Pasteurella multocida222
Total1818 (100%)18 (100%)

Anaerobes (2 species)
Clostridium perfringens111
Clostridium sporogenes111
Total22 (100%)2 (100%)

Others (4 species)
Bergeyella zoohelcum111
Myroides odoratimimus111 (C)
Rhodococcus equi111
Wautersiella falsenii11 (G)1 (G)
Total43 (75.0%)2 (50.0%)1 (C) (25.0%)1 (G)
(25.0%)
1 (G) (25.0%)

Total (bacteria)1,181916 (77.6%)231 (19.6%)1,142 (96.7%)19 (1.6%)28 (2.4%)5 (0.4%)4
(0.3%)
10
(0.8%)
7
(0.6%)

Fungi (14 species)
Aspergillus brasiliensis111 (F)
Candida albicans4343412 (C × 2)
Candida dubliniensis111
Candida glabrata444444
Candida kefyr111111
Candida krusei444
Candida lusitaniae222
Candida norvegensis111
Candida orthopsilosis222 (D × 2)
Candida parapsilosis1414131 (C)
Candida tropicalis3231132
Cryptococcus neoformans111
Meyerozyma caribbica11 (E)1 (E)
Trichosporon asahii333
Total (fungi)160155 (96.9%)1 (0.6%)156 (97.5%)3 (1.9%)4 (2.5%)1
(0.6%)

TOTAL (bacteria + fungi)1,3411,071 (79.9%)232 (17.3%)1,298 (96.8%)22 (1.6%)32 (2.4%)5 (0.4%)4
(0.3%)
11 (0.8%)7
(0.5%)
1,303 (97.2%)