MALDI-TOF MS Based Intact Cell Microorganism Profiling in Tracking the Sources of Product Contamination at the Industrial Settings

摘要

Industrial production is strictly controlled to ensure microbiological safety. This is typically achieved by monitoring the microflora using cell metabolism oriented panels of microbiological tests. However, microorganism adaptation to industrial environments is known to induce phenotypical changes. This makes it difficult to conclude on a contaminant origin using the panels of biochemical/physiologic tests, thus forcing a costly sterilization of all potentially suspected sources. The use of intact protein based MALDI-TOF-MS microbial fingerprinting combined to statistical and spectra library based data mining, addresses this problem from a principally new angle. Industrial bacterial isolates from a facial creme and an enterprise plumbing system were harvested at different growth stages, killed and analyzed with mass spectrometry and bioinformatics tools. Spectra in a mass range of 2-20 KDa were obtained on the AutoFlex III MALDI-TOF mass spectrometer (Bruker Daltonics) in automated linear positive ion mode with HCCA as a matrix. To differentiate between the strains, a data set was subjected to PCA and master spectra based clustering; microorganisms were further identified using MALDI-TOF MS microbial spectra library and MALDI BioTyper software (Bruker Daltonics).