Sensitive and fast identification of bacteria in blood samples by immunoaffinity mass spectrometry for quick BSI diagnosis

An immunoaffinity mass spectrometry method was proposed for quick BSI diagnosis.


Fig.S2
The frequency distribution of similarity scores between bacteria reference mass spectra for three groups: (A) reference spectra obtained from different bacteria; (B) reference spectra obtained from the same bacteria but at different cell numbers; (C) reference spectra obtained from different repetitions of the same bacteria at the same cell number.

Fig. S4
Immunoaffinity MALDI-TOF mass spectra obtained from aqueous solutions (1 mL) with 10 4 cells mL -1 E.coli when different amounts of Abs-MBs were used.

Fig. S5
Immunoaffinity MALDI-TOF mass spectra of pure blood serum and pure whole blood after sample pre-treatment by using anti-E.coli Abs-MBs in the mass range of 2,000-20,000 m/z.

Fig.S6
Immunoaffinity MALDI-TOF mass spectra (in blue) obtained from blood serum and whole blood spiked with 10 8 cells mL -1 of (A) E.coli, (B) B.subtilis, and (C) S.aureus and comparison with reference spectra (in green) of corresponding species at 10 5 cells with similarity score calculated by the cosine correlation method. r.int: relative intensity.

Fig.S8
Comparison between the reference spectra of E.coli (in green) and immunoaffinity MALDI-TOF mass spectra obtained from two BC bottles (I, II) with initial E.coli concentration of 10 2 cells mL -1 in 5 mL blood after different BC time (in blue, from Fig.4A and Fig.S7-A). I, II refer to bottle I and II, respectively. Similarity scores were calculated by the cosine correlation method. r.int: relative intensity.