Table 1.
MALDI-TOF MS identification of Gram-negative isolates from monomicrobial positive blood cultures using Rapid Sepsityper and 4-h short-subculture protocols.
| Conventional Method (No. of Isolates) | Rapid Sepsityper (No. of Identified Isolates; %) | 4 h-Short Subculture (No. of Identified Isolates; %) | |||||
|---|---|---|---|---|---|---|---|
| Gram-Negative Organism | Species Level (Score ≥ 2.0) |
Genus Level (Score ≥ 1.8) |
Mis-Identification; (%) | Species Level (Score ≥ 2.0) |
Genus Level (Score ≥ 1.8) |
Mis-Identification; (%) | |
| Enterobacterales | 2229 | 1993; 89.4% | 2169, 97.3% | 9; 0.4% | 2140; 96% | 2206; 99% | 5; 0.2% |
| Escherichia coli | 1031 | 961; 93.2% | 1017; 98.6% | 3; 0.3% | 1009; 97.9% | 1029;99.8% | 0 |
| Klebsiella pneumoniae | 580 | 525; 90.5% | 572; 98.6% | 2; 0.3% | 561; 96.7% | 572; 98.6% | 0 |
| Enterobacter cloacae complex | 183 | 149; 81.4% | 176; 96.2% | 1; 0.5% | 169; 92.3% | 178; 97.3% | 1; 0.5% |
| Serratia marcescens | 97 | 82; 84.5% | 92; 94.8% | 0 | 90; 92.8% | 93; 95.9% | 0 |
| Klebsiella oxytoca | 72 | 61; 84.7% | 69; 95.8% | 1; 1.4% | 70; 97.2% | 72; 100% | 0 |
| Proteus mirabilis | 67 | 59; 88% | 63; 94% | 0 | 62; 92.5% | 66; 98.5% | 0 |
| Klebsiella aerogenes | 62 | 51; 82.2% | 56; 90.3% | 0 | 58; 93.5% | 62; 100% | 0 |
| Citrobacter koseri | 32 | 27; 84.4% | 30; 93.7% | 0 | 30; 93.7% | 31; 96.9% | 0 |
| Citrobacter freundii complex | 22 | 19; 86.4% | 21; 95.4% | 1; 4.5% | 21; 95.4% | 22; 100% | 0 |
| Morganella morganii | 17 | 14; 82.3% | 15; 88.2% | 0 | 14; 82.3% | 16; 94.1% | 0 |
| Klebsiella variicola | 15 | 14; 93.3% | 14; 93.3% | 1; 6.7% | 14; 93.3% | 14; 93.3% | 1; 6.7% |
| Salmonella enterica | 9 | 7; 77.8% | 8; 88.9% | 0 | 9; 100% | 9; 100% | 0 |
| Pantoea agglomerans | 8 | 5; 62.5% | 7; 87.5% | 0 | 7; 87.5% | 8; 100% | 0 |
| Hafnia alvei | 8 | 6; 75% | 8; 100% | 0 | 6; 75% | 8; 100% | 0 |
| Proteus vulgaris | 6 | 4; 66.7% | 5; 83.3% | 0 | 6; 100% | 6; 100% | 0 |
| Pantoea septica | 3 | 2; 66.7% | 2; 66.7% | 0 | 2; 66.7% | 3; 100% | 0 |
| Serratia liquefaciens | 3 | 1; 33.3% | 2; 66.7% | 0 | 2; 66.7% | 3; 100% | 0 |
| Pantoea eucrina | 2 | 1; 50% | 2; 100% | 0 | 2; 100% | 2; 100% | 0 |
| Providencia stuartii | 2 | 1; 50% | 2; 100% | 0 | 2; 100% | 2; 100% | 0 |
| Raoultella ornithinolytica | 2 | 1; 50% | 2; 100% | 0 | 1; 50% | 2; 100% | 0 |
| Serratia rubidea | 2 | 1; 50% | 1; 50% | 0 | 2; 100% | 2; 100% | 0 |
| Enterobacter bugandensis | 2 | 1; 50% | 2; 100% | 0 | 1; 50% | 2; 100% | 0 |
| Providencia rettgeri | 1 | 0 | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Yersinia enterocolitica | 1 | 1; 100% | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Proteus penneri | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Klebsiella ozaenae | 1 | 0 | 1; 100% | 0 | 0 | 1; 100% | 0 |
| Non-fermenting species | 525 | 349; 66.5% | 405; 77.1% | 7; 1.3% | 432; 82.3% | 487; 92.8% | 3; 0.6% |
| Pseudomonas aeruginosa | 310 | 244; 78.7% | 272; 87.7% | 1; 0.3% | 291; 93.9% | 305; 98.4% | 0 |
| Acinetobacter baumannii complex | 136 | 80; 58.8% | 94; 69.1% | 1; 0.7% | 101; 74.3% | 121; 89% | 1; 0.7% |
| Stenotrophomonas maltophilia | 22 | 11; 50% | 15; 68.2% | 0 | 17; 77.3% | 19; 86.4% | 0 |
| Achromobacter xylosoxidans | 9 | 5; 55.5% | 7; 77.8% | 1; 11.1% | 6; 66.7% | 8; 88.9% | 1; 11.1% |
| Acinetobacter lwoffii | 6 | 2; 33.3% | 3; 50% | 1; 16.7% | 4; 66.7% | 4; 66.7% | 1; 16.7% |
| Aeromonas caviae | 4 | 2; 50% | 2; 50% | 0 | 2; 50% | 3; 75% | 0 |
| Acinetobacter ursingii | 4 | 1; 25% | 1; 25% | 0 | 2; 50% | 3; 75% | 0 |
| Ochrobactrum anthropi | 3 | 1; 33.3% | 1; 66.7% | 0 | 1; 33.3% | 1; 33.3% | 0 |
| Paracoccus yeei | 3 | 0 | 0 | 1; 33.3% | 1; 33.3% | 2; 66.7% | 0 |
| Burkholderia cenocepacia | 2 | 0 | 1; 50% | 1; 50% | 1; 50% | 2; 100% | 0 |
| Pseudomonas putida | 2 | 1; 50% | 1; 50% | 0 | 1; 50% | 2; 100% | 0 |
| Pseudomonas oryzihabitans | 2 | 0 | 1, 50% | 0 | 0 | 1; 50% | 0 |
| Rhizobium radiobacter | 2 | 0 | 0 | 0 | 0 | 1; 50% | 0 |
| Acinetobacter radioresistens | 2 | 0 | 1; 50% | 0 | 0 | 1; 50% | 0 |
| Aeromonas veronii | 1 | 0 | 1; 100% | 0 | 0 | 1; 100% | 0 |
| Pseudochrobactrum asaccharolyticum | 1 | 0 | 0 | 1; 100% | 0 | 0 | 0 |
| Pseudomonas chlororaphis | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Pseudomonas pseudomallei | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Pseudomonas monteilii | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Pseudomonas kuykendallii | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Pseudomonas luteola | 1 | 0 | 0 | 0 | 1; 100% | 1; 100% | 0 |
| Stenotrophomonas rhizophila | 1 | 0 | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Acinetobacter vivianii | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Acinetobacter guillouiae | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Acinetobacter variabilis | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Acinetobacter radioresistens | 2 | 1; 50% | 1; 50% | 0 | 1; 50% | 1; 50% | 0 |
| Acinetobacter lactucae | 2 | 1; 50% | 1; 50% | 0 | 1; 50% | 1; 50% | 0 |
| Roseomonas mucosa | 1 | 0 | 0 | 0 | 0 | 1; 100% | 0 |
| Cupriavidus basilensis | 1 | 0 | 1; 100% | 0 | 0 | 1; 100% | 0 |
| Raoultella ornithinolityca | 1 | 0 | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Obligate anaerobic species | 54 | 16; 29.6% | 23; 42.6% | 1; 1.8% | - | - | - |
| Bacteroides fragilis | 37 | 12; 32.4% | 16; 43.2% | 1; 2.7% | - | - | - |
| Bacteroides vulgatus | 3 | 1; 33.3% | 2; 66.7% | 0 | - | - | - |
| Leptotrichia spp. | 2 | 0 | 0 | 0 | - | - | - |
| Bacteroides thetaiotaomicron | 2 | 0 | 0 | 0 | - | - | - |
| Fusobacterium gonidiaformans | 2 | 1; 50% | 1; 100% | 0 | - | - | - |
| Parabacteroides goldsteinii | 1 | 1; 100% | 1; 100% | 0 | - | - | - |
| Prevotella denticola | 1 | 1; 100% | 1; 100% | 0 | - | - | - |
| Prevotella melaninogenica | 1 | 0 | 1; 100% | 0 | - | - | - |
| Prevotella baroniae | 1 | 0 | 0 | 0 | - | - | - |
| Bacteroides uniformis | 1 | 0 | 0 | 0 | - | - | - |
| Bacteroides pyogenes | 1 | 0 | 0 | 0 | - | - | - |
| Bacteroides ovatus | 1 | 0 | 1; 100% | 0 | - | - | - |
| Veillonella dispar | 1 | 0 | 0 | 0 | - | - | - |
| Fastidious species | 50 | 13; 26% | 24; 48% | 0 | 23; 46% | 32; 64% | 1; 2% |
| Campylobacter jejuni | 19 | 5; 26.3% | 7; 36.8% | 0 | 9; 47.4% | 12; 63.1% | 1; 5.3% |
| Moraxella osloensis | 10 | 4; 40% | 7; 70% | 0 | 8; 80% | 9; 90% | 0 |
| Haemophilus influenzae | 5 | 1; 20% | 2; 40% | 0 | 2 | 2; 40% | 0 |
| Campylobacter fetus | 4 | 1; 25% | 2; 50% | 0 | 0 | 2; 50% | 0 |
| Campylobacter coli | 2 | 1; 50% | 2; 100% | 0 | 1 | 2; 100% | 0 |
| Leptotrichia trevisanii | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Moraxella liquefaciens | 2 | 0 | 1; 50% | 0 | 0 | 2; 100% | 0 |
| Eikenella corrodens | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Capnocytophaga canimorsus | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Capnocytophaga sputigena | 1 | 0 | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Neisseria meningitidis | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Neisseria gonorrhoeae | 1 | 1; 100% | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Moraxella nonliquefaciens | 1 | 0 | 1; 100% | 0 | 1; 100% | 1; 100% | 0 |
| Total isolates | 2858 | 2416, 84.5% | 2621, 91.7% | 17; 0.6% | 2595; 90.8% | 2725;95.3% | 9; 0.3% |