Table 4.
Identification Discrepancies between the Conventional Protocols and MALDI-TOF MS Devices and Concordance between VITEK-MS and Microflex LT
| Strains | VITEK-MS | Microflex LT | N /SubT /Total | ||||
| Bacillus spp. |
Bacillus subtilis /
Bacillus amyloliquefaciens (L2R) |
M2 | Bacillus subtilis (L1R) | 29 | 47 | 100 | |
|
Bacillus thuringiensis / Bacillus cereus /
Bacillus mycoides (L2R) |
M2 | Bacillus cereus (L1R) | 13 | ||||
| Bacillus thuringiensis (L1R) | 1 | ||||||
| Bacillus pumilus (L1R) | M2 | Bacillus altitudinis (L1R) | 1 | ||||
| UNIDENTIFIED | F | Bacillus flexus (L1R) | 1 | ||||
| D | UNIDENTIFIED | F | Paenibacillus chitinolyticus (L2R) | 1 | |||
| D | Lysinibacillus fusiformis (L1R) | F | UNRELIABLE IDENTIFICATION | 1 | |||
| Corynebacterium spp. | Corynebacterium striatum (L1R) | M1 | Corynebacterium striatum (L1R) | 4 | 18 | ||
| Corynebacterium jeikeium (L1R) | M1 | Corynebacterium jeikeium (L1R) | 4 | ||||
| Corynebacterium tuberculostearicum (L1R) | M1 | Corynebacterium tuberculostearicum (L1R) | 1 | ||||
| D | Actinomyces neuii (L1R) | M1 | Actinomyces neuii (L1R) | 1 | |||
| D | Arthrobacter cumminsii (L1R) | M2 | Arthrobacter cumminsii (L2R) | 2 | |||
| Corynebacterium striatum (L1R) | M2 | Corynebacterium striatum (L2R) | 1 | ||||
| Corynebacterium amycolatum / xerosis (L2R) | M2 | Corynebacterium amycolatum (L1R) | 1 | ||||
| D | Propionibacterium acnes (L1R) | M2 | Propionibacterium acnes (L2R) | 1 | |||
| UNIDENTIFIED | F | Corynebacterium resistens (L1R) | 1 | ||||
| D | Paenibacillus durus (L1R) | F | UNRELIABLE IDENTIFICATION | 1 | |||
| D | Propionibacterium acnes (L1R) | F | UNRELIABLE IDENTIFICATION | 1 | |||
| Staphylococcus spp. | Staphylococcus hominis (L1R) | M1 | Staphylococcus hominis (L1R) | 1 | 8 | ||
| Staphylococcus epidermidis (L1R) | M1 | Staphylococcus epidermidis (L1R) | 1 | ||||
| Staphylococcus saccharolyticus (L1R) | M1 | Staphylococcus saccharolyticus (L1R) | 1 | ||||
| Staphylococcus simulans (L1R) | M1 | Staphylococcus simulans (L1R) | 1 | ||||
| Staphylococcus carnosus (L1R) | M2 | Staphylococcus condimenti (L2R) | 1 | ||||
| Staphylococcus auricularis (L1R) | M2 | Staphylococcus pettenkoferi (L1R) | 2 | ||||
| Staphylococcus simulans (L1R) | F | UNRELIABLE IDENTIFICATION | 1 | ||||
| Streptococcus spp. | Streptococcus gordonii (L1R) | M1 | Streptococcus gordonii (L1R) | 1 | 5 | ||
| D | Gemella morbillorum (L1R) | M1 | Gemella morbillorum (L1R) | 1 | |||
| D | Weissella confusa (L1R) | M1 | Weissella confusa (L1R) | 1 | |||
| D | Actinomyces europaeus (L1R) | M2 | Actinomyces europaeus (L2R) | 1 | |||
| Streptococcus mitis / oralis (L2R) | M2 | Streptococcus mitis (L1R) | 1 | ||||
| Peptostreptococcus sp. | D | Staphylococcus saccharolyticus (L1R) | M1 | Staphylococcus saccharolyticus (L1R) | 1 | 1 | |
| Glucose non-fermenting
Gram-negative rods |
Delftia acidovorans (L1R) | M1 | Delftia acidovorans (L1R) | 1 | 10 | ||
| Pseudomonas oryzihabitans (L1R) | M1 | Pseudomonas oryzihabitans (L1R) | 1 | ||||
| Ralstonia insidiosa (L1R) | M2 | Ralstonia insidiosa (L2R) | 1 | ||||
| Acinetobacter junii (L1R) | M2 | Acinetobacter junii (L2R) | 1 | ||||
| Sphingomonas paucimobilis (L1R) | M2 | Sphingomonas pseudosanguinis (L1R) | 1 | ||||
| D | Paenibacillus sp. (L2R) | M2 | Paenibacillus lautus (L2R) | 1 | |||
| Brevundimonas vesicularis (L1R) | M2 | Brevundimonas sp. (L2R) | 1 | ||||
| Pseudomonas aeruginosa (L1R) | M2 | Pseudomonas nitroreducens (L1R) | 1 | ||||
| Pseudomonas fluorescens (L1R) | M2 | Pseudomonas corrugata (L2R) | 1 | ||||
| D | Mycobacterium kansasii (L1R) | S | Herbaspirillum huttiense (L2R) | 1 | |||
| Gram-positive rods | Propionibacterium granulosum (L1R) | M1 | Propionibacterium granulosum (L1R) | 1 | 5 | ||
| Lactobacillus casei / paracasei (L2R) | M2 | Lactobacillus paracasei (L1R) | 1 | ||||
| UNIDENTIFIED | F | Bacillus flexus (L1R) | 1 | ||||
| Propionibacterium acnes (L1R) | F | UNRELIABLE IDENTIFICATION | 1 | ||||
| D | Paenibacillus durus (L1R) | S | Mycobacterium peregrinum (L2R) | 1 | |||
| Gram-positive cocci | Enterococcus faecalis (L1R) | M1 | Enterococcus faecalis (L1R) | 1 | 3 | ||
| Gemella morbillorum (L1R) | M1 | Gemella morbillorum (L1R) | 1 | ||||
| Helcococcus kunzii (L1R) | M1 | Helcococcus kunzii (L1R) | 1 | ||||
| Anaerobic
Gram-negative rods |
Propionibacterium acnes (L1R) | M1 | Propionibacterium acnes (L1R) | 1 | 2 | ||
| D | Streptococcus pseudopneumoniae (L1R) | S | Bilophila sp. (L2R) | 1 | |||
| Gram-negative rods | Helicobacter cinaedi (L1R) | M1 | Helicobacter cinaedi (L1R) | 1 | 1 | ||
N: Number of samples
SubT: Subtotal
D: Discrepant identification between conventional protocols and MALDI-TOF MS
M1: Matched identification on bacterial species
M2: Consistent identification at bacterial genus level
F: Unidentified with either VITEK-MS or Microflex LT
S: Inconsistently identified by VITEK-MS and Microflex LT