Research Article
Performances and Reliability of Bruker Microflex LT and VITEK MS MALDI-TOF Mass Spectrometry Systems for the Identification of Clinical Microorganisms
Table 3
Summary of high-confidence identifications by VITEK MS and Bruker Microflex LT MS systems.
| | Microorganism groups | Number of isolates | Species content | Correct Identification | Misidentification | No-identification | | Species | Genus only | | | | | | VITEK | Bruker | VITEK | Bruker | VITEK | Bruker | VITEK | Bruker |
| | Nonfermentatives | 356 (30.1%) | 16 | 352 (98.8%) | 350 (98.4%) | — | 3 (0.8%) | 2 (0.6%) | — | 2 (0.6%) | 3 (0.8%) | | Enterobacteriaceae | 309 (26.2%) | 23 | 292 (94.5%) | 288 (93.2%) | 15 (4.9%) | 19 (6.2%) | 1 (0.3%) | 1 (0.3%) | 1 (0.3%) | 1 (0.3%) | | Staphylococci | 273 (23.1%) | 10 | 271 (99.3%) | 270 (98.9%) | 2 (0.7%) | — | — | 2 (0.7%) | — | 1 (0.4%) | | Streptococci | 29 (2.5%) | 11 | 28 (96.6%) | 27 (93.2%) | — | 1 (3.4%) | — | 1 (3.4%) | 1 (3.4%) | — | | Enterococci and other Gr(+) cocci | 160 (13.6%) | 5 | 160 (100.0%) | 160 (100.0%) | — | — | — | — | — | — | | Coryneforms and other Gr(+) bacilli | 30 (2.5%) | 14 | 21 (70.00%) | 25 (83.3%) | 2 (6.7%) | 4 (13.4%) | 2 (6.7%) | — | 5 (16.6%) | 1 (3.3%) | HACEK and
other Gr(−) cocci | 18 (1.5%) | 8 | 18 (100.0%) | 18 (100.0%) | — | — | — | — | — | — | | Anaerobes | 2 (0.2%) | 2 | 2 (100.0%) | 2 (100.0%) | — | — | — | — | — | — | | Others | 4 (0.3%) | 4 | 3 (75.0%) | 2 (50.0%) | — | 1 (25.0%) | — | — | 1 (25.0%) | 1 (25.0%) | | TOTAL (bacteria) | 1,181 | 93 | 1,147 (97.1%) | 1,142 (96.7%) | 19 (1.6%) | 28 (2.4%) | 5 (0.4%) | 4 (0.3%) | 10 (0.9%) | 7 (0.6%) | | Fungi | 160 | 14 | 156 (97.5%) | 156 (97.5%) | 3 (1.9%) | 4 (2.5%) | — | — | 1 (0.6%) | — | | TOTAL (bacteria + fungi) | 1,341 | 107 | 1,303 (97.2%) | 1,298 (96.8%) | 22 (1.6%) | 32 (2.4%) | 5 (0.4%) | 4 (0.3%) | 11 (0.8%) | 7 (0.5%) |
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