Identification of Clinical Isolates via MALDI-TOF MS

All clinical samples were inoculated onto aerobic and anaerobic blood agar (BD Columbia Agar 5% Sheep Blood, Becton Dickinson, Franklin Lakes, NY), chocolate agar (BD Choco Agar, Becton Dickinson), mannitol agar (BD Mannitol Salt, Becton Dickinson), Mac Conkey agar (BD Mac Conkey II, Becton Dickinson), and thioglycolate broth (BD Fluid Thioglycolate Medium, Becton Dickinson), incubating all media at 35–37 °C for 5 days. Anaerobic plates were incubated in an anaerobic atmosphere generated with the AnaeroGen Compact anaerobic system (Oxoid Ltd., Wide Road, Basingstoke, England) at 35–37 °C. Identification of all isolates was carried out using MALDI-TOF MS (Bruker Biotyper, Bellerica, MA, USA), following the manufacturer’s recommendations. Only strains with a log (score) ≥2.0 were included and interpreted as high confidence [24 (link)] and identified only with this technique. Two isolates with the lowest log (score) were further identified by 16S rRNA gene sequencing [25 (link)].