Germ identification by means of MALDI-TOF at SQTS

Simon Bourguet
Simon Bourguet

We now offer you the possibility of identifying microbiological bacterias using MALDI-TOF technology.

For example, would you like to determine which Enterobacteriaceae are in your product or environment? Do you have unidentified bacteria on your plates?

Identifying the genus, group (such as the Bacillus cereus group or Bacillus subtilis group) or species (such as Listeria innocua or monocytogenes) will help you better assess the associated risks. Identifying bacterias using a general plate can also make it easier to understand a variety of problems when indicator germs do not provide answers.

We would be happy to carry out a microbiological analysis of your food and can identify the bacterial colonies on the plates if you would like.

We can also help you identify bacteria that you have already isolated (if you send us your isolates). In addition, we can identify your bacterias from plates(s) even if there are many colonies, and we can do it entirely according to your interests and requirements. If necessary, we will also re-inoculate (sub-cultivate) to enable identification of the highest quality.

Would you like some background on the methodology?

The MALDI-TOF technology is based on mass spectrometry and makes it possible to use a simple procedure to characterise the bacterias: the bacterial colony (sample) is typically applied to a metal plate either directly or after extraction and then covered with a matrix. A laser is then applied to the molecules present so they are ionised and vaporised and then separated according to charge and mass before reaching the detector. This provides us with a unique mass spectrum for each bacteria, which is compared with a database. Since the vast majority of the molecules detected are so-called “ribosomal proteins”, they can be accurately identified because the entire classification and nomenclature of bacteria is based on the sequencing of one such protein, 16S ribosomal RNA.

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