Discrimination of Methicillin-resistant Staphylococcus aureus by MALDI-TOF Mass Spectrometry with Machine Learning Techniques in Patients with Staphylococcus aureus Bacteremia

Abstract

Early administration of proper antibiotics is considered to improve the clinical outcomes of Staphylococcus aureus bacteremia (SAB), but routine clinical antimicrobial susceptibility testing takes an additional 24 h after species identification. Recent studies elucidated matrix-assisted laser desorption/ionization time-of-flight mass spectra to discriminate methicillin-resistant strains (MRSA) or even incorporated with machine learning (ML) techniques. However, no universally applicable mass peaks were revealed, which means that the discrimination model might need to be established or calibrated by local strains’ data. Here, a clinically feasible workflow was provided. We collected mass spectra from SAB patients over an 8-month duration and preprocessed by binning with reference peaks. Machine learning models were trained and tested by samples independently of the first six months and the following two months, respectively. The ML models were optimized by genetic algorithm (GA). The accuracy, sensitivity, specificity, and AUC of the independent testing of the best model, i.e., SVM, under the optimal parameters were 87%, 75%, 95%, and 87%, respectively. In summary, almost all resistant results were truly resistant, implying that physicians might escalate antibiotics for MRSA 24 h earlier. This report presents an attainable method for clinical laboratories to build an MRSA model and boost the performance using their local data.

Distinguishing methicillin-resistant Staphylococcus aureus from methicillin-sensitive strains by combining Fe3O4 magnetic nanoparticle-based affinity mass spectrometry with a machine learning strategy

“…Moreover, our method has a relatively low LOD, i.e. ~ 8 × 10 3 CFU mL −1 compared with the existing methods [21,[23][24][25][26][35][36][37]. The accuracy of our method was 92-97%, which was relatively good, compared with most of the existing methods [21, 23-26, 35, 36].…”

“…ESM Table S4 shows a list comparing the existing methods [21,[23][24][25][26][35][36][37] with our approach. Although our method required a 6-h incubation time after MNP enrichment, all the existing methods [21,[23][24][25][26][35][36][37] required 12-24 h Fig.…”

“…ESM Table S4 shows a list comparing the existing methods [21,[23][24][25][26][35][36][37] with our approach. Although our method required a 6-h incubation time after MNP enrichment, all the existing methods [21,[23][24][25][26][35][36][37] required 12-24 h Fig. 6 MALDI mass spectra of the 100-fold diluted juice samples (1 mL) containing MRSA clinical strain with the concentrations in terms of the OD values of A 10 −4 , B 10 −5 , C 10 −6 , and D 10 −7 obtained after enriched by Fe 3 O 4 MNPs (50 µg) under microwave-heating followed by 6-h culture.…”

Haptoglobin-Conjugated Gold Nanoclusters as a Nanoantibiotic to Combat Bacteremia

“…With high mortality rates after the progression to sepsis, bacteremia requires urgent treatment via appropriate antibiotics. Bacteremia patients need administration of empiric antibiotic coverage to decrease morbidity and mortality [ 12 , 13 , 14 , 15 , 16 , 17 ]. In most cases, antibiotic therapy should be continued for 7~14 days [ 18 ].…”