Microbial Identification

Rapid Identification Service for the Medical Device and Pharmaceutical Markets

Microbial identification is the process used to identify and characterize microorganisms, such as bacteria and yeasts on or in a product.

Rapid methods for microbial identification (ID) in pharmaceutical and medical device manufacturing and packaging environments can be vital to an organization’s decision-making on contamination control and mitigation.

STERIS offers a range of both traditional and rapid methods of microbial identification. These include Gram stain testing, microscopy, selective media, MALDI-ToF mass spectrometry, and genetic sequencing.

MALDI-ToF (Matrix Assisted Light Desorption Ionization Time of Flight)

The MALDI-ToF microbial identification method utilizes mass spectrometry. Within minutes, this process can identify bacteria and yeasts to species level by characterizing the ribosomal protein mass spectra for each microorganism and match the results to an extensive database of known bacterial and fungal species.

This microbial identification method replaces our previous API testing, allowing STERIS to simultaneously improve ID accuracy and speed for our Customers. The MALDI-ToF method includes additional capabilities, such as identifying antimicrobial resistance.  Please contact your local site to discuss any additional microbial identification requirements you may have.

Why is microbial identification performed?

Microbial identification is performed based on the following:

  • ISO 11137-2 states manufacturers should not only quantify the microorganism on or in a product, but also to undertake characterization of the bioburden and identify the different types that may be present
  • Microbial identification assists in the control of cleanroom production areas through trending of background flora, in both quantity and type
  • Microbial identification improves traceability in raw materials, production processes, and surfaces
  • Based on the standard used, some products have objectionable organisms that are not acceptable and the microorganisms need to be identified to ensure this standard is met
  • Microbial identification provides additional information for out-of-specification investigations that may arise in dose audits, sterility testing, bioburden testing, bacterial endotoxin testing (LAL), and biological indicator testing

What are the levels of identification provided through microbial identification?

The levels of identification provided through microbial identification consist of:

  • Type of microorganism (bacteria, yeast, mold)
  • Genus (broad family name), such as Staphylococcus
  • Species level (identification within that family) such as Staphylococcus Aureus
  • Strains of same microorganism, such as Staphylococcus Aureus ATCC 12600

What are the different microbial identification methods?

The different microbial identification methods consist of:

  • Morphology (shape, color, hairy/furry, etc.)
  • Gram strain – gram positive or gram negative
    • Gram negative are water born, have more diseases, and are endotoxin producing
  • Absence testing
    • Product is free from a particular microorganism
  • APIs – genus level and uncertain species level ID
    • Colormetric (subjective – dependent on analyst)
    • Time consuming

What are the features of MALDI-ToF microbial identification?

MALDI-ToF microbial identification features:

  • High accuracy of results (nonobjective)
  • High speed
  • High volumes of IDs
  • Provides genus and species level identification

Watch our Introduction to MALDI-ToF webinar to find out more:

Contact our team of experts to find out more about our Global Contract Sterilization, Testing and Validation Services.