Skip to main content

Advertisement

Table 2 Discrepancies and error in the conventional identification method (Vitek 2) and MALDI-TOF for the identification of 267 Gram-positive bacteria

From: Real-time comparative evaluation of bioMerieux VITEK MS versus Bruker Microflex MS, two matrix-assisted laser desorption-ionization time-of-flight mass spectrometry systems, for identification of clinically significant bacteria

Final identification (no of isolates) Number of isolates
Conventional identification method (Vitek 2) VITEK MS identification Bruker MS identification 16S rRNA sequence results (number of discrepant organism sequenced)
No ID Mis-ID No ID Mis-ID No ID Mis-ID  
Staphylococcus aureus (53) 0 0 0 0 0 0  
Staphylococcus epidermidis (34) 0 1 (Staphylococcus capitis) 0 1 (S. capitis) 0 0 S. epidermidis (2)
Staphylococcus haemolyticus (11) 0 0 0 0 0 0  
S. capitis (11) 0 0 0 0 0 0  
Staphylococcus hominis (7) 0 0 0 0 0 0  
Staphylococcus lugdunensis (4) 0 0 0 0 0 0  
Staphylococcus caprae (1) 0 0 0 0 0 1 (Staphylococcus auricularis) S. caprae (1)
Staphylococcus warneri (2) 0 0 0 S.auricularis 0 1 (S. epidermidis) S. warneri (1)
Streptococcus agalactiae (46) 0 0 0 1 (Nocardia asteroides) 0 1 (Alloiococcus otitis), 1 (Lactobacillus sakei) S. agalactiae (3)
Rothia mucilaginosa (1) 0 0 0 0 0 0  
Enterococcus faecalis (29) 0 0 0 0 0 0  
Enterococcus faecium (6) 0 0 0 0 0 0  
Enterococcus raffinosus (3) 0 0 0 0 0 0  
Enterococcus avium (1) 0 0 0 0 0 0  
Streptococcus pyogenes (7) 0 0 0 0 0 0  
Micrococcus luteus/lylae (6) 0 2 (Kocuria kristinae) 0 0 0 3 (1 Clostridium beijeriuckii, 2 Propionibacterium acnes) M. luteus (5)
Rhodococcus equi (1) NA NA NA NA 0 0 R. equi (1)
Streptococcus parasanguis (3) 0 0 0 0 0 1 (Alloiococcus otitis) S. parasanguis (1)
Streptococcus salivarius (1) 0 0 0 0 0 0  
Streptococcus lutetiensis (1) 0 1 (Streptococcus infantarius) 0 1 (Streptococcus infantarius) 0 0 S. lutetiensis (1)
Streptococcus dysagalactiae (2) 0 0 0 0 0 0  
Streptococcus mitis/oralis (26) 0 3 (Streptococcus constellatus), 1 (Streptococcus peroris), 1 (Streptococcus pluranimalium), 1 (Streptococcus pentosaceus),1 (Streptococcus sanguis), 1 (Streptococcus thoraltensis) 0 1 (S. constellatus) 0 18 (Streptococcus pneumoniae) S. mitis / oralis (26)
Streptococcus anginosus (2) 0 0 0 0 0 0  
Streptococcus gallolyticus (1) 0 0 0 0 0 1 (Propionibacterium acnes) S. gallolyticus (1)
Granulicatella adiacens (2) 0 2 (S. sanguinis, S. thoraltensis) 0 0 0 2 (S. pneumoniae, Streptococcus oralis) G. adiacens (2)
S. pneumoniae (5) 0 0 0 0 0 0  
Streptococcus mutans (1) 0 0 0 0 0 1 (P. acnes) S. mutans (1)
  1. No ID = no identification in spite of its presence in database; Mis - ID = misidentification; NA = not present in database