MALDI-TOF mass spectrometry as a tool for the discrimination of high-risk Escherichia coli clones from phylogenetic groups B2 (ST131) and D (ST69, ST405, ST393)

• Published in: European journal of clinical microbiology & infectious diseases Vol. 33; no. 8; pp. 1391 - 1399
• Main Authors: Novais, Â., Sousa, C., de Dios Caballero, J., Fernandez-Olmos, A., Lopes, J., Ramos, H., Coque, T. M., Cantón, R., Peixe, L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2014; Springer; Springer Nature B.V
• Subjects: Animals; Antibiotics; Bacterial Typing Techniques; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cluster Analysis; Data analysis; Diagnosis, Differential; Disease control; Drug resistance; E coli; Early Diagnosis; Epidemiology; Escherichia coli; Escherichia coli Infections - diagnosis; Escherichia coli Infections - microbiology; Humans; Infections; Infectious diseases; Internal Medicine; Laboratories; Mass spectrometry; Medical Microbiology; Medical sciences; Multilocus Sequence Typing; Phylogenetics; Phylogeny; Public health; Risk; Scientific imaging; Shiga-Toxigenic Escherichia coli - genetics; Shiga-Toxigenic Escherichia coli - isolation & purification; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Madrid Spain; Portugal; Spain; Partial Little Square Discriminant Analysis; Clinical Microbiology Laboratory; Clonal Complex; Multivariate Data Analysis; Clonal Group; Infection; High risk; Microbiology; Escherichia coli; Bacteria; Exploration; Matrix assisted laser desorption ionization; Mass spectrometry; Enterobacteriaceae
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-014-2071-5

Reliable, quick and low-cost methods are needed for the early detection of multidrug-resistant and highly virulent high-risk B2 and D
Escherichia coli
clones or clonal complexes (HiRCC). Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) seems to have a good discriminatory potential at different subspecies levels, but it was never evaluated for the discrimination of
E. coli
clones. We assessed the potential of MALDI-TOF MS coupled to multivariate data analysis to discriminate representative
E. coli
B2 and D HiRCC. Seventy-three
E. coli
isolates from B2 (including ST131 and B2 non-ST131 clones) and D (ST69, ST393, ST405) with variable pulsed-field gel electrophoresis (PFGE) patterns, origins and dates (1980–2010) were tested. MS spectra were acquired from independent extracts obtained from different plate cultures in two different Microflex LT MALDI-TOF devices (Bruker) after a standard extraction procedure. MALDI-TOF MS fingerprinting analysis revealed a good discriminatory ability between the four HiRCC analysed (ST131, ST69, ST405, ST393) and between B2 ST131 and other B2 non-ST131 isolates. Clusters defined by MALDI-TOF MS were consistent with the clonal complexes assigned by multilocus sequence typing (MLST), although differences were detected regarding the composition of clusters obtained by the comparison of PFGE profiles. We demonstrate, for the first time, that characteristic mass fingerprints of different
E. coli
HiRCC are sufficiently discriminatory and robust to enable their differentiation by MALDI-TOF MS, which might represent a promising tool for the optimisation of infection control, individual patient management and large-scale epidemiological studies of public health relevance. The good correlation between phenotypic and genotypic features further corroborates phylogenetic relationships delineated by MLST.