Table 3. List of samples that showed discordance by PCR-ESI/MS and MALDI-TOF/MS compared to the reference standard.
| PCR-ESI/MS and MALDI-TOF/MS combined discordance | |||
|---|---|---|---|
| Sample ID | Discordance | True identificationa | Discordant identification |
| 154 | Both FPb | No growth | PCR-ESI/MS: Ralstonia picketti |
| MALDI-TOF/MS: Staphylococcus warneri | |||
| MALDI-TOF/MS discordance | |||
|---|---|---|---|
| Sample ID | Discordance | True identification | Discordant identification |
| 125 | FN | Anaerobic diphtheroides | Unable to identify |
| 2027 | FN | Mycobacterium chelonae | Unable to identify |
| 2634 | FN | Fusobacterium sp. | Unable to identify |
| 145 | FP w/primary ID | Clostridium perfringens | Bacteroides vulgatus |
| 171 | FP w/primary ID | Clostridium perfringens | Enterococcus faecalis |
| 177 | FP w/primary ID | Pseudomonas aeruginosa | Staphylococcus epidermidis |
| 221 | FP w/primary ID | Streptococcus sp. (Viridans) | Staphylococcus hominis |
| 226 | FP w/primary ID | Pseudomonas aeruginosa | Staphylococcus aureus |
| 252 | FP w/primary ID | Candida albicans | Staphylococcus aureus |
| 329 | FP w/primary ID | Enterococcus faecalis | Staphylococcus saprophyticus |
| 259 | Discordant genus and species | Streptococcus sp. (β-hemolytic) | Staphylococcus aureus |
| 264 | Discordant genus and species | Actinomyces israelii | Clostridium butyricum |
| 429 | Discordant genus and species | Corynebacterium sp. | Actinomyces viscosus |
| 1609 | Discordant genus and species | Abiotrophia sp. | Gamella haemolysans |
| 249 | Discordant species | Bacteroides thetaiotaomicron | Bacteroides fragilis |
| 2566 | Discordant species | Achromobacter xylosoxidans | Achromobacter ruhlandii |
| 2889 | Discordant species | Aeromonas hydrophilia | Aeromonas caviae |
| 2573 | Discordant species | Achromobacter xylosoxidans | Achromobacter ruhlandii |
| 296 | Discordant species | Streptococcus sp. (Viridans) | Streptococcus australis |
| 440 | Discordant species | Streptococcus oralis/S. mitis | Streptococcus pneumoniae |
| PCR/ESI-MS discordance | |||
|---|---|---|---|
| Sample ID | Discordance | True identification | Discordant identification |
| 231 | FN | Candida albicans | Unable to identify |
| 1362 | FN | Candida lusitanae | Unable to identify |
| 2096 | FN | Bacteroides uniformis | Unable to identify |
| 2964 | FN | Eubacterium lentum | Unable to identify |
| 3138 | FN | Eubacterium lentum | Unable to identify |
| 3666 | FN | Eubacterium lentum | Unable to identify |
| 89 | FN w/primary ID | Streptococcus agalactiae | (Staphylococcus epidermidis) |
| 124 | FN w/primary ID | Streptococcus sp. (Viridans) | (Staphylococcus aureus) |
| 135 | FN w/primary ID | Streptococcus sp. (Viridans) | (Staphylococcus epidermidis) |
| 200 | FN w/primary ID | Streptococcus sp. (β-hemolytic) | (Staphylococcus sp. (Coagulase negative) and Enterococcus sp.) |
| 218 | FN w/primary ID | Streptococcus sp. (Viridans) | (Streptococcus pneumoniae) |
| 228 | FN w/primary ID | Staphylococcos epidermidis | (Enterococcus faecalis) |
| 271 | FN w/primary ID | Streptococcus agalactiae | (Staphylococcus sp., coagulase negative) |
| 223 | FN w/primary ID | Klebsiella pneumoniae | (Stenotrophomonas maltophilia) |
| 242 | FN w/primary ID | Staphylococcus epidermidis | (Streptococcus pyogenes) |
| 1272 | FN w/primary ID | Streptococcus sp. (Viridans) | (Neisseria sicca) |
| 76 | FP w/primary ID | Pantoea agglomerans | Erwinia tasmaniensis |
| 302 | FP w/primary ID | Haemophilus influenzae | Mannheimia haemolytica |
| 1647 | FP w/primary ID | Haemophilus influenzae | Mannheimia haemolytica |
| 276 | FP w/primary ID | Micrococcus luteus | Acidothermus cellulolyticus |
| 309 | FP w/primary ID | Staphylococcus aureus | Caudatispora biapiculata |
| 323 | FP w/primary ID | Lactobacillus casei | Bifidobacterium animalis |
| 341 | FP w/primary ID | Citrobacter freundii | Clostridium ramnosum |
| 482 | FP w/primary ID | Moraxella atlantae | Methylococcus capsulatus |
| 1499 | FP w/primary ID | Morganelli morganii | Aeromonas hydrophilia |
| 2889 | FP w/primary ID | Aeromonas hydrophilia | Pseudomonas entomophilia |
| 1033 | Discordant genus and species | Pantoea sp. | Citrobacter braakii |
| 1050 | Discordant genus and species | Pantoea sp. | Citrobacter braakii |
| 30 | Discordant species | Streptococcus gallolyticus | Streptococcus pneumoniae |
| 202 | Discordant species | Staphylococcus sp. (Coagulase negative) | Staphylococcus aureus |
| 2997 | Discordant species | Moraxella catarrhalis | Moraxella nonliquifaciens |
a
True identification indicates that the organism was identified by the reference standard. Discordant identification indicates that the organism was identified by the index test. Organism name in parentheses indicate the organism that was missed in a mixture.
b
FP, false positive; FN, false negative.