Microbiology

Microbiology is the study of microscopic organisms, such as bacteria, viruses, archaea, fungi and protozoa. This discipline includes fundamental research on the biochemistry, physiology, cell biology, ecology, evolution and clinical aspects of microorganisms, including the host response to these agents. (1)

Microbiology is crucial in the medical device, pharmaceutical, and cosmetics industries to ensure product safety and meet regulatory requirements. Scientists have known since the mid-1800’s that microbes are capable of causing disease when Louis Pasteur demonstrated that contamination of organic substances does not occur naturally.(2) This discovery led to the “Pasteurization” of milk and other dairy products, in order to eliminate microbes that were present.(2) The technological advancements continued, with Joseph Lister sterilizing his medical equipment for use.(2) Since the discovery of microbes, we have tried to strengthen our methods for removal of harmful ones. Today is no different, as we continue to develop technology to save lives, we must ensure it is safe for those using it. 

The field of microbiology is very broad, and the tasks that microbiologists conduct vary by where they work.(7) Some of these tasks include development of new drugs to treat infections, establishing sterilization procedures, identifying microorganisms, among many more.(7) We work with medical device manufacturers, test labs, sterilization companies, and others that are related to the field of microbiology. These products comprise a wide scope, displaying the overall depth of microbiology in device/product regulation. 

 

Microbiological methods are used worldwide, further demonstrating its ubiquity. Of the products that we work with, many of which are manufactured in a cleanroom. Cleanrooms require additional microbial testing to ensure that ISO and other regulatory requirements are met. Applicable cleanroom standards include: 

  • ISO 14968-1:2003 Cleanrooms and associated controlled environments – Biocontamination control – Part 1: General principles and methods 

  • ISO 14968-2:2003 Cleanrooms and associated controlled environments – Biocontamination control – Part 2: Evaluation and interpretation of biocontamination data 

  • USP Chapter 1116: Microbial Control and Monitoring of Aseptic Processing Environments 

Standards not applicable to cleanrooms, but applicable to the sterilization of products include: 

  • ISO 11737-1:2018 Sterilization of health care products — Microbiological methods — Part 1: Determination of a population of microorganisms on products 

  • ISO 11737-2:2019 Sterilization of health care products — Microbiological methods — Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process 

  • ISO 11137-1:2006 Sterilization of health care products — Radiation — Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices 

  • ISO 11137-2:2012 Sterilization of health care products — Radiation — Part 2: Establishing the sterilization dose 

  • ISO 11137-3:2017 Sterilization of health care products — Radiation — Part 3: Guidance on dosimetric aspects of development, validation and routine control 

  • ISO/TS 11137-4:2020 Sterilization of health care products — Radiation — Part 4: Guidance on process control 

  • ISO 11138-1:2017 Sterilization of health care products — Biological indicators — Part 1: General requirements 

  • ISO 11138-2:2017 Sterilization of health care products — Biological indicators — Part 2: Biological indicators for ethylene oxide sterilization processes 

  • ISO 11138-3:2017 Sterilization of health care products — Biological indicators — Part 3: Biological indicators for moist heat sterilization processes 

  • ISO 11138-4:2017 Sterilization of health care products — Biological indicators — Part 4: Biological indicators for dry heat sterilization processes 

  • ISO 11138-5:2017 Sterilization of health care products — Biological indicators — Part 5: Biological indicators for low-temperature steam and formaldehyde sterilization processes 

  • ISO/AWI 11138-6 (UNDER DEVELOPMENT) Sterilization of health care products — Biological indicators — Part 6: Biological indicators for hydrogen peroxide sterilization processes 

  • ISO 11138-7:2019 Sterilization of health care products — Biological indicators — Part 7: Guidance for the selection, use and interpretation of results 

 

These lists are not exhaustive, as there are many global standards and regulations to meet. Here at MicroBio Consulting, we seek to ensure safety and effectiveness in our client’s products by ensuring compliance with local and global regulations, as well as customer requirements. 

 

In terms of pharmaceuticals, microbiologists again ensure that products are free of microbes or toxins that could have contaminated the drug of interest. Certain pharmaceutical tests of interest include: 

  • sterility test; 

  • bacterial endotoxin test; 

  • microbial enumeration methods, such as the microbial limits test; 

  • tests for specified microorganisms; 

  • antimicrobial susceptibility testing; 

  • methods and limits for testing pharmaceutical grade water; 

  • disinfectant efficacy; 

  • pyrogen and abnormal toxicity tests; 

  • environmental monitoring; 

  • biological indicators.(3) 

For each of these methods, there are three important considerations to make: are microbes present, if so, how many microbes are present, and what are the microbes present?(3) Although some of these tests are applicable solely to the pharmaceutical industry, there is a significant amount of crossover between pharmaceutical testing and medical device testing. In terms of medical devices, there are many important microbiological characteristics for consideration. One key step is sterilization validation, which ensures that the sterilization method effectively eliminates microbes. This is also important for reusable medical devices, assuring that microbes are eliminated between use.(4) Bioburden and sterility testing are conducted on sterile products in order to ensure consumer safety.(5) Upon recent FDA guidelines, tattoo inks are recommended to undergo meticulous sterilization processes, ensuring products are free of microbial contamination.(6) Depending on the product, coordinating microbial testing with test labs or bringing testing in house can be overwhelming. As this step is of the utmost importance, it must be done right. MicroBio Consulting works directly with test labs to coordinate testing or develop protocols to conduct microbial testing in house.