Table 2. Comparison of the results between the conventional method and MALDI-TOF in 110 specimens with colony counts of ≥105 CFU/mL.
| Conventional identification (N of isolates) | Coincidence (%) | MALDI-TOF MS identification (N of isolates) | |
|---|---|---|---|
| Species level | Genus level | ||
| Escherichia coli (53) | 98.1 | 98.1 | Escherichia coli (52) |
| No reliable identification (1) | |||
| Klebsiella pneumoniae (11) | 100 | 100 | Klebsiella pneumoniae (11) |
| Klebsiella oxytoca (1) | 100 | 100 | Klebsiella oxytoca (1) |
| Enterobacter cloacae (2) | 0 | 100 | Enterobacter cloacae/asburiae (2) |
| Enterobacter aerogenes (1) | 100 | 100 | Enterobacter aerogenes (1) |
| Citrobacter koseri (1) | 100 | 100 | Citrobacter koseri (1) |
| Proteus vulgaris (1) | 0 | 100 | Proteus vulgaris/penneri (1) |
| Serratia marcescens (1) | 100 | 100 | Serratia marcescens (1) |
| Pseudomonas aeruginosa (4) | 75.0 | 75.0 | Pseudomonas aeruginosa (3) |
| No reliable identification (1) | |||
| Stenotrophomonas maltophilia (1) | 0 | 0 | Insufficient peak (1) |
| Total gram-negative bacteria (76) | 92.1 | 96.1 | |
| Enterococcus faecalis (5) | 60.0 | 60.0 | Enterococcus faecalis (3) |
| No reliable identification (2) | |||
| Enterococcus faecium (2) | 0 | 0 | No reliable identification (2) |
| Streptococcus agalactiae (2) | 50.0 | 50.0 | Streptococcus agalactiae (1) |
| Insufficient peak (1) | |||
| Total gram-positive cocci (9) | 44.4 | 44.4 | |
| Candida albicans (4) | 50.0 | 50.0 | Candida albicans (2) |
| No reliable identification (1) | |||
| Insufficient peak (1) | |||
| Candida glabrata (8) | 25.0 | 25.0 | Candida glabrata (2) |
| No reliable identification (4) | |||
| Insufficient peak (2) | |||
| Candida haemulonii (1) | 0 | 0 | No reliable identification (1) |
| Candida tropicalis (7) | 14.3 | 57.1 | Candida tropicalis (1) |
| Candida glabrata (1) | |||
| Candida lusitaniae (1) | |||
| Cryptococcus albidus (1) | |||
| No reliable identification (3) | |||
| Trichosporon asahii (1) | 0 | 0 | No reliable identification (1) |
| Others (4) | 0 | 0 | No reliable identification (4) |
| Total yeast (25) | 20.0 | 32.0 | |
| Total (110) | 71.8 | 76.4 | |
Abbreviations: MALDI-TOF MS, matrix-assisted laser desorption ionization time-of-flight mass spectrometry; CFU, colony-forming unit.