Table 1 Discrepancies and error in the conventional identification method (Vitek 2) and MALDI-TOF for the identification of 507 Gram-negative bacteria
Final identification (no of isolates) | No of isolates | ||||||
|---|---|---|---|---|---|---|---|
Conventional identification method (Vitek 2) | VITEK MS identification | Bruker MS identification | 16S rRNA sequence result (number of discrepant organisms sequenced) | ||||
No ID | Mis-ID | No ID | Mis - ID | No ID | Mis-ID | Â | |
Escherichia coli (181) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Klebsiella pneumoniae (71) | 0 | 0 | 0 | 0 | 0 | 1 (score <1.7) | K. pneumoniae (1) |
Klebsiella oxytoca (2) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Pseudomonas aeruginosa (66) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Acinetobacter baumannii (39) | 0 | 0 | 0 | 0 | 0 | 1 (Acinetobacter genomospecies 13TU)*, 3 (score <1.7) | A. baumannii (4) |
Acinetobacter lwoffii (2) | 0 | 0 | 0 | 0 | 0 | 1 (score <1.7) | A. lwoffii (1) |
Salmonella spp. (29) | 0 | 0 | 0 | 0 | 0 | 1 (score <1.7) | Salmonella spp. (1) |
Enterobacter cloacae (14) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Enterobacter aerogenes (7) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Enterobacter asburiae (5) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Pantoea agglomerans (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Proteus mirabilis (17) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Stenotrophomonas maltophilia (18) | 0 | 0 | 0 | 0 | 0 | 1 (score <1.7) | S. maltophilia (1) |
Serratia marcescens (15) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Citrobacter koseri (9) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Citrobacter freundii (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Morganella morganii (7) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Achromobacter xylosoxidans (5) | 0 | 0 | 0 | 0 | 0 | 2 (Acinetobacter spp.) | A. xylosoxidans (2) |
Providencia rettgeri (4) | 0 | 2 (Providencia stuartii) | 0 | 2 (P. stuartii) | 0 | 1 (score <1.7) | P. rettgeri (2) |
Burkholderia cepacia (2) | 0 | 0 | 0 | 0 | 0 | 1 (score <1.7) | B. cepacia (1) |
Sphingomonas paucimobilis (2) | 0 | 0 | 0 | 0 | 0 | 2 (score <1.7) | S. paucimobilis (2) |
Aeromonas hydrophila/caviae (2) | 0 | 0 | 0 | 0 | 0 | 2 (Aeromonas jandaei) | A. hydrophila/caviae (2) |
Ralstonia solanacearum (1) | 0 | 1(Ralstonia pickettii) | 0 | 1 (R. pickettii) | 0 | 1 (Ralstonia insidiosa) | R. solanacearum (1) |
Chryseobacterium indologenes (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Plesiomonas shigelloides (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Vibrio parahaemolyticus (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Campylobacter jejuni (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Bordetella pertussis (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Bordetella parapertussis (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |
Yersinia enterocolitica (1) | 0 | 0 | 0 | 0 | 0 | 0 | Â |