Accurate microbial identification remains a crucial component of quality control and safety in the pharmaceutical industry. Among various methods of microbial identification, proteotypic-based MALDI-TOF (Matrix Assisted Laser Desorption/Ionization Time-of-Flight) technology has emerged as a rapid, high-throughput, and cost-effective method for microbial identification. However, the strength of this method hinges on the robustness and representativeness of the database, particularly its ability to capture intra-species variability. For this study, microbial library entries were generated from microbes isolated from diverse geographic regions to assess the impact of local diversity on identification. Findings showed that identification outcomes by these entries vary by species. For example, approximately 10% of Sphingomonas colocassiae and 13% of Penicillium brevicompactum identifications relied on intra-species geographic diversity entries. Whereas ∼83% of Aspergillus westerdijkiae and ∼78% of Beauveria pseudobassiana identified matched to similar intra-species entries. We further breakdown the impact of these database entries to identify organisms in their regional zone. Notably, regionally sourced entries assist in providing reliable identification for samples in that geographic region. This highlights the relevance of incorporating geographically diverse strains into proteotypic libraries. As microbial diversity varies across manufacturing environments, maintaining comprehensive, regionally representative databases is essential for ensuring accurate identification and effective contamination control.
Zavala et al. (Thu,) studied this question.