Table 1

Identification results by Biotyper and Vitek-MS using recommended cutoff values (n = 181)

Conventional bacterial identification (no. of strains)No. (%) of strains identified with the BiotyperMALDI-TOF identification (no. of strains)No. (%) of strains identified with the Vitek-MSMALDI-TOF identification (no. of strains)
Species levelGenus level onlyNot identifiedSpecies levelGenus level onlyNot identified
Gram-positive bacteria
    Enterococcus avium (1)100Enterococcus avium (1)100Enterococcus avium (1)
    Enterococcus casseliflavus (1)100Enterococcus casseliflavus (1)100Enterococcus casseliflavus (1)
    Enterococcus faecalis (5)500Enterococcus faecalis (5)500Enterococcus faecalis (5)
    Enterococcus faecium (5)500Enterococcus faecium (5)500Enterococcus faecium (5)
    Staphylococcus aureus (16)1510Staphylococcus aureus (15) and Staphylococcus aureus (1)a1402Staphylococcus aureus (14) and not identified (2)
    Staphylococcus epidermidis (10)370Staphylococcus epidermidis (3) and Staphylococcus epidermidis (7)a604Staphylococcus epidermidis (6), not identified (3), and wrong identification (1)
    Staphylococcus capitis (1)100Staphylococcus capitis (1)010Staphylococcus capitis (1)b and Staphylococcus caprae (1)b
    Staphylococcus hominis (1)100Staphylococcus hominis (1)100Staphylococcus hominis (1)
    Streptococcus agalactiae (4)400Streptococcus agalactiae (4)400Streptococcus agalactiae (4)
    Streptococcus anginosus (1)010Streptococcus constellatus (1)100Streptococcus constellatus (1)
    Streptococcus bovis (1)010Streptococcus gallolyticus (1)010Streptococcus gallolyticus (1)
    Streptococcus pyogenes (2)200Streptococcus pyogenes (2)200Streptococcus pyogenes (2)
    Streptococcus sanguinis (5)230Streptococcus sanguinis (2) and Streptococcus sanguinis (3)a500Streptococcus sanguinis (5)
    Listeria monocytogenes (1)100Listeria monocytogenes (1)100Listeria monocytogenes (1)
    Micrococcus luteus (1)100Micrococcus luteus (1)100Micrococcus luteus/lylae (1)
    Propionibacterium acnes (4)310Propionibacterium acnes (3) and Propionibacterium acnes (1)a400Propionibacterium acnes (4)
    Bacillus cereus/thuringiensis (9)720Bacillus cereus (7) and Bacillus weihenstephanensis (2)a090Bacillus mycoides (9)b, Bacillus cereus (9)b, and Bacillus thuringiensis (9)b
    Bacillus circulans (1)001Not identified (1)001Not identified (1)
    Bacillus flexus (1)100Bacillus flexus (1)010Bacillus megaterium (1)
    Bacillus horneckiae (2)002Not identified (2)002Not identified (2)
    Paenibacillus urinalis (1)100Paenibacillus urinalis (1)001Not identified (1)
    Paenibacillus illinoisensis (1)010Paenibacillus illinoisensis (1)a010Paenibacillus pabuli (1)b and Paenibacillus spp. (1)b
    Bacillus megaterium (1)010Bacillus flexus (1)001Not identified (1)
    Subtotal (75)54 (72.0)18 (24.0)3 (4.0)51 (68.0)13 (17.3)11 (14.7)
Gram-negative bacteria
    Acinetobacter baumannii (6)420Acinetobacter baumannii (4) and, Acinetobacter baumannii (2)a600Acinetobacter baumannii (6)
    Acinetobacter junii (1)100Acinetobacter junii (1)010Acinetobacter junii (1)a
    Aeromonas hydrophila (1)010Aeromonas caviae (1)010Aeromonas sobria (1)
    Brevundimonas diminuta (1)001Not identified (1)001Not identified (1)
    Citrobacter freundii (4)400Citrobacter freundii (4)310Citrobacter freundii (3) and Citrobacter youngae (1)
    Escherichia coli (53)5300Escherichia coli (53)5300Escherichia coli (53)
    Enterobacter aerogenes (4)400Enterobacter aerogenes (4)400Enterobacter aerogenes (4)
    Enterobacter cloacae (1)010Enterobacter asburiae (1)010Enterobacter cloacae (1) and Enterobacter asburiae (1)b
    Enterobacter kobei (2)110Enterobacter asburiae (1) and Enterobacter kobei (1)020Enterobacter cloacae (2) and Enterobacter asburiae (2)b
    Klebsiella pneumoniae (16)1600Klebsiella pneumonia (16)1600Klebsiella pneumonia (16)
    Proteus mirabilis (4)400Proteus mirabilis (4)400Proteus mirabilis (4)
    Pseudomonas aeruginosa (3)300Pseudomonas aeruginosa (3)300Pseudomonas aeruginosa (3)
    Pseudomonas putida (3)210Pseudomonas putida (2) and Pseudomonas putida (1)a300Pseudomonas putida (3)
    Salmonella enteritidis (3)030Salmonella spp. (3)a030Salmonella spp. (3)a
    Serratia marcescens (1)100Serratia marcescens (1)100Serratia marcescens (1)
    Stenotrophomonas maltophilia (2)110Stenotrophomonas maltophilia (1) and Stenotrophomonas maltophilia (1)a200Stenotrophomonas maltophilia (2)
    Vibrio vulnificus (1)010Vibrio vulnificus (1)a001Not identified (1)
    Subtotal (106)94 (88.7)11 (10.4)1 (0.9)95 (89.6)9 (8.5)2 (1.9)
Total (181)148 (81.8)29 (16.0)4 (2.2)146 (80.7)22 (12.2)13 (7.2)
  • a Identifications at genus confidence level only (Bruker Score < 2.0 or Vitek-MS confidence < 90.0).

  • b More than one identification generated at the same confidence level.