Table 1.
Comparison of the sensitivities of Vitek 2 and MALDI-TOF MS in the identification of Gram negative bacteria to the species and genus levels
| Organism (n) | Number (%) of isolates with Correct identification to the species level: | Number (%) of isolates with Correct identification to the genus level: | ||||
|---|---|---|---|---|---|---|
| Vitek 2 | MALDI-TOF MS | P value | Vitek 2 | MALDI-TOF MS | P value | |
| E coli (55) | 48 (87.3) | 55 (100.0) | 0.006 | 48 (87.3) | 55 (100.0) | 0.006 |
| Klebsiella pneumoniae (33) | 32 (97.0) | 33 (100.0) | 0.314 | 32 (97.0) | 33 (100.0) | 0.314 |
| Klebsiella oxytoca (4) | 3 (75.0) | 4 (100.0) | 0.285 | 4 (100.0) | 4 (100.0) | |
| Pseudomonas aeruginosa (14) | 14 (100.0) | 14 (100.0) | 14 (100.0) | 14 (100.0) | ||
| Pseudomonas mendocina (1) | 0 (0.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Pseudomonas pseudoalcaligenes (1) | 0 (0.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Acinetobacter baumannii (18) | 18 (100.0) | 18 (100.0) | 18 (100.0) | 18 (100.0) | ||
| Acinetobacter genomospecies 13BJ/14TU (1) | 0 (0.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Acinetobacter ursingii (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Citrobacter freundii (6) | 5 (83.3) | 6 (100.0) | 0.296 | 6 (100.0) | 6 (100.0) | |
| Citrobacter koseri (3) | 3 (100.0) | 3 (100.0) | 3 (100.0) | 3 (100.0) | ||
| Enterobacter cloacae (12) | 8 (66.7) | 12 (100.0) | 0.028 | 9 (75.0) | 12 (100.0) | 0.064 |
| Enterobacter aerogenes (5) | 5 (100.0) | 5 (100.0) | 5 (100.0) | 5 (100.0) | ||
| Enterobacter gergoviae (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Haemophilus influenzae (4) | 3 (75.0) | 4 (100.0) | 0.285 | 3 (75.0) | 4 (100.0) | |
| Morganella morganii (8) | 7 (87.5) | 8 (100.0) | 0.302 | 8 (100.0) | 8 (100.0) | |
| Proteus mirabilis (7) | 7 (100.0) | 7 (100.0) | 7 (100.0) | 7 (100.0) | ||
| Proteus penneri/vulgaris (7) | 6 (85.7) | 7 (100.0) | 0.299 | 7 (100.0) | 7 (100.0) | |
| Providencia rettgeri (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Stenotrophomonas maltophilia (10) | 7 (70.0) | 10 (100.0) | 0.06 | 7 (70.0) | 10 (100.0) | 0.06 |
| Serratia marcescens (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Vibrio alginolyticus (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Elizabethkingia meningoseptica (1) | 1 (100.0) | 1 (100.0) | 1 (100.0) | 1 (100.0) | ||
| Total (195) | 172 (88.2) | 195 (100.0) | 0.000 | 180 (92.3) | 195 (100.0) | 0.000 |