making microbiology easy

Isolation and Quantification of microorganisms

The isolation and quantification of one or several microorganisms present in a sample is often necessary to assess the impact of different conditions (compounds, physical, chemical or biological treatments, environmental changes, or to check the absence of microbial contamination). For this purpose, SMALTIS has been developing tools and methods to quantify, either directly of indirectly, the microbial populations of your samples.


Taking into account the nature of samples (liquid cultures, co-cultures, nucleic acid solutions, biopsies, swabs, soil, surfaces, etc.), we set up and validate with you the most appropriate method of sampling and extraction of microorganisms of interest.
They are subsequently quantified as follows:

Directly by culture on specific environments (viable cell cultures or colony forming units)
Indirectly with PCR real time by targeting specific genes of the species of interest or high throughput sequencing technologies


– Quantification by bacterial culture on infected viable skin explants.
– Quantification by qPCR of four bacterial species in co-cultures.
– Quantification by culture and qPCR of 2 bacterial species in reconstructed skin samples.
– Evaluation of bacterial and fungal contamination in nucleic acid solutions (Bioburden test – Bioburden according to the norms ISO 11737-1 and Ph. Eur.2.6.1).
– Titration of bacteriophage suspensions by Phage Plaque Assay.
– Assessment of microbial contamination (air and surface) in building with service activities. 
– Assessment of microbial contamination (air and surface) in hotel rooms.
– Evaluation of a cosmetic product on cutaneous microbiota (forehead).
– Isolation and quantification of coliforms present in biopsies.

Main bacterial species already studied:

      – Staphylococcus aureus
      – Staphylococcus epidermidis
      – Staphylococcus hominis
      – Propionibacterium acnes
      – Malassezia pachydermatis
      – Bacillus oleronius
      – Escherichia coli