First Report: Application of MALDI-TOF MS within an External Quality Assurance Exercise for the Discrimination of Highly Pathogenic Bacteria from Contaminant Flora

In this article the authors describe the application of Matrix Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Intact Cell Mass Spectrometry (ICMS) within a proficiency test organized by a European Union (EU)-funded project on the topic of Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk (EQADeBa). In total 15 samples with native bacteria, including risk group 3 (RG3) target agents and non-RG3 bacteria as potential contaminants, were analyzed by five different labs with ICMS. Whereas the technique was used by all labs and showed good performance in the identification of the non-RG3 contaminants, only one lab used mass spectrometry (MS) for RG3 identification. One reason for this restricted application of the technique is the limited performance of the commercial database systems in the field of highly pathogenic organisms. Furthermore, the relatively new technology is in competition with well-established and highly effective mol...