A Low-Cost Tebuconazole-Based Screening Test for Azole-Resistant Aspergillus fumigatus.

The global emergence of azole resistance in Aspergillus fumigatus is resulting in health and food security concerns. Rapid diagnostics and environmental surveillance methods are key to understanding the distribution and prevalence of azole resistance. However, such methods are often associated with high costs and are not always applicable to laboratories based in the least-developed countries. Here, we present and validate a low-cost screening protocol that can be used to differentiate between azole-susceptible "wild-type" and azole-resistant A. fumigatus isolates. © 2020 The Authors. Basic Protocol 1: Preparation of Tebucheck multi-well plates Basic Protocol 2: Inoculation of Tebucheck multi-well plates.

Characterization and identification of clinically relevant microorganisms using rapid evaporative ionization mass spectrometry.

Rapid evaporative ionization mass spectrometry (REIMS) was investigated for its suitability as a general identification system for bacteria and fungi. Strains of 28 clinically relevant bacterial species were analyzed in negative ion mode, and corresponding data was subjected to unsupervised and supervised multivariate statistical analyses. The created supervised model yielded correct cross-validation results of 95.9%, 97.8%, and 100% on species, genus, and Gram-stain level, respectively. These results were not affected by the resolution of the mass spectral data. Blind identification tests were performed for strains cultured on different culture media and analyzed using different instrumental platforms which led to 97.8-100% correct identification. Seven different Escherichia coli strains were subjected to different culture conditions and were distinguishable with 88% accuracy. In addition, the technique proved suitable to distinguish five pathogenic Candida species with 98.8% accuracy without any further modification to the experimental workflow. These results prove that REIMS is sufficiently specific to serve as a culture condition-independent tool for the identification and characterization of microorganisms.