Abstract:

A total of 149 batches of facial mask products were tested for microorganism, and 4 batches did not meet the requirements. The bacterial colonies of these 4 batches of facial mask products were purified, and identified by MALDI-TOF MS, 16S rDNA sequencing and Vitek 2 biochemical test. The results show that they are all Pluralibacter gergoviae. In addition, Pluralibacter gergoviae CICC24132 and a food detected Pluralibacter gergoviae are analyzed with these four strains together by MALDI Biotyper 3 and VITEK 2. MALDI Biotyper 3 cluster analysis shows that the protein pattens detected in the four batches of facial mask are basically the same, with their relationship relatively close to each other, but far from the other 2 strains. Biochemical tests of VITEK 2 show that there are differences in the biochemical reactions of 6 strains of Pluralibacter gergoviae, among which the bacteria detected in 3 batches of masks from the same manufacturer are basically the same. The results suggest that the rapid identification results of MALDI-TOF MS are reliable. MALDI Biotyper 3 cluster analysis and biochemical reaction results show that the 4 strains of Pluralibacter gergoviae isolated from facial masks can be divided into two subtypes, and the contaminated bacteria detected from three batches of unqualified samples from the same manufacturer have high homology.

Key words: MALDI-TOF MS, facial mask, Pluralibacter gergoviae, rapid identification, homology analysis