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Table 2 Direct MALDI-TOF results in monomicrobial cultures

From: Evaluation of three sample preparation methods for the direct identification of bacteria in positive blood cultures by MALDI-TOF

Bacterial Group Cut off value Identified using Saponin (%) Identified using SDS (%) Identified using SepsiTyper (%) Total
Concordant Discordant No ID Concordant Discordant No ID Concordant Discordant No ID
Staphylococci and Micrococci ≥2.000 33 (50) 0 (0) 33 (50) 35 (53) 0 (0) 31 (47) 37 (56) 0 (0) 29 (44) 66
≥1.700 55 (83) 1 (2) 10 (15) 51 (77) 1 (2) 14 (21) 51 (77) 1 (2) 14 (21) 66
Enterobacteriaceae ≥2.000 27 (77) 0 (0) 8 (23) 32 (91) 0 (0) 3 (9) 34 (97) 0 (0) 1 (3) 35
≥1.700 30 (86) 0 (0) 5 (14) 33 (94) 0 (0) 2 (6) 33 (94) 0 (0) 2 (6) 35
Streptococci and Enterococci ≥2.000 0 (0) 0 (0) 18 (100) 9 (50) 0 (0) 9 (50) 10 (56) 0 (0) 8 (44) 18
≥1.700 4 (22) 0 (0) 14 (78) 9 (50) 0 (0) 9 (50) 10 (56) 0 (0) 8 (44) 18
Other Gram negatives ≥2.000 9 (69) 0 (0) 4 (31) 8 (62) 0 (0) 5 (38) 8 (62) 0 (0) 5 (38) 13
≥1.700 10 (77) 0 (0) 3 (23) 8 (62) 0 (0) 5 (38) 9 (69) 0 (0) 4 (31) 13
Other Gram positives ≥2.000 0 (0) 0 (0) 12 (100) 2 (17) 0 (0) 10 (83) 2 (17) 0 (0) 10 (83) 12
≥1.700 1 (8) 0 (0) 11 (92) 2 (17) 0 (0) 10 (82) 3 (25) 1 (8) 8 (67) 12
Total ≥2.000 69 (48) 0 (0) 75 (52) 86 (60) 0 (0) 58 (40) 91 (63) 0 (0) 53 (37) 144
≥1.700 100 (69) 1 (1) 43 (30) 103 (72) 1 (1) 40 (28) 106 (74) 2 (1) 36 (25) 144
  1. Concordance and discordance are with identification by conventional culture and identification
  2. Cut off value ≥1.700 = ≥1.700 and top three results matching