Impact of MALDI-TOF MS identification on anaerobic species and genus diversity in routine diagnostics.

OBJECTIVES: Introduction of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized bacterial identification in the last decade. In 2013, MALDI-TOF MS was implemented for the identification of anaerobic bacteria at our laboratory. This study analyzed the impact of MALDI-TOF MS on the number of different anaerobic genera and species identified in diagnostics. METHODS: 155 anaerobic human clinical isolates, representing the most frequently isolated anaerobic species at our laboratory, were identified by conventional biochemical methods and by a Bruker MALDI Biotyper (Bruker Daltonics, Bremen, Germany). Discrepancies were resolved by partial 16S rRNA gene sequence analysis. In addition, we compared the frequencies of anaerobic genera and species prior to the implementation of MALDI-TOF MS from 2008 to 2012 to the frequencies of anaerobes from 2013 to 2020 when MALDI-TOF MS was used for identification. RESULTS: The diversity of anaerobic bacteria increased from 12 genera and 20 species in 2012, before the introduction of MALDI-TOF MS, to 16 genera and 31 species in 2013 and to 20 genera and 41 species in 2020 when MALDI-TOF MS was used as primary identification method. MALDI-TOF MS allowed species assignment within closely related species such as the Bacteroides fragilis group in accordance with 16S identification, and correctly identified newly described anaerobic species. CONCLUSION: Introduction of MALDI-TOF MS identification increased genus and species diversity of the reported anaerobes at our laboratory. Updates to the MALDI-TOF MS database and new species descriptions will further increase the diversity of anaerobic bacteria isolated from infectious processes.

Challenging cases during clinical clerkships beyond the domain of the "medical expert": an analysis of students' case vignettes.

Background: During clinical clerkships students experience complex and challenging clinical situations related to problems beyond the domain of the "Medical Expert". Workplace routine may leave little opportunity to reflect on these situations. The University of Zurich introduced a mandatory course directly after the clinical clerkship year (CCY) to work up these situations. Prior to the course each student submitted a vignette on a case he or she had perceived challenging during the CCY and which was not related to the domain of the "Medical Expert" role. In this paper we want to characterize these cases in respect to most prominent themes and related CanMEDS roles. The goal was to inform clinical supervisors about potential teaching demands during the CCY. Methods: All case vignettes submitted by a years' cohort were analysed by three researchers in two ways: for the clinical characteristics and the main theme of the underlying problem and the most prominent CanMEDS roles involved. Themes of the underlying problem were aggregated to overarching topics and subsequently to main categories by pragmatic thematic analysis. Results: 254 case vignettes covered the whole spectrum of clinical disciplines. A wide range of underlying themes could be assigned to five main categories: "communication within team" (23.2%), "communication with patients and relatives" (24.8%), "patient behavior and attitudes" (18.5%), "clinical decision making" (24.0%), and "social and legal issues" (9.4%). Most frequent CanMEDS roles were "Communicator" (26.9%) and "Professional" (23.5%). Conclusions: Cases students perceived as challenging beyond the "Medical Expert" were reported from all clinical disciplines. These were mainly related to communicational and professional issues, mirrored by the CanMEDS roles "Communicator" and "Professional". Therefore, supervisors in clinical clerkships should put an additional teaching focus on communication and professionalism.