1 – WHICH IS THE TERMINOLOGY (GLOSSARY) INVOLVED IN MAM?

Microbial Air Monitoring (MAM)

Microbiological monitoring of the air, i.e. checking how many and which microorganisms are present in the air of an environment.

Sampling techniques and parameters

  • Active sampling

    Air sampling performed with an instrument that aspirates a known volume of air and impacts it onto an agar plate.

    It is used to measure how many viable microorganisms are present in the air.

  • Passive sampling / Settle plates

    Sampling performed with plates left open in the environment, on which microbial particles settle by gravity from the air onto the agar surface.

    It is a simple method, but less quantitative than active sampling.

  • Air flow (L/min)

    Amount of air aspirated by the instrument every minute, expressed in litres per minute (e.g. 100 L/min, 200 L/min).

  • Particle counter

    Instrument that counts non-viable particles (dust, fibres, etc.) present in the air, without indicating whether they contain live microorganisms.

Microorganisms and particles

  • Micro-organism

    General term that includes bacteria, yeasts, moulds and other microscopic organisms.

  • Bacteria

    Unicellular microorganisms, often responsible for infections or product spoilage.

  • Yeast

    Unicellular fungi that can cause fermentations or spoilage of food and beverages.

  • Moulds

    Multicellular filamentous fungi that form typically “fuzzy” colonies and may produce spores.

  • Fungi

    Group that includes yeasts and moulds.

  • Viable particles

    Particles that contain live microorganisms capable of growing on a culture medium (bacteria, yeasts, moulds).

  • Unviable particles (non-viable particles)

    Inert particles (dust, fibres, etc.) that do not grow in culture.

  • CFU – Colony Forming Unit

    Visible colony that develops on a plate after incubation.

    1 CFU = at least one viable microorganism that has multiplied.

Culture media and plates

  • Culture media

    Nutrient mixture, solid or liquid, that allows microorganisms to grow.

  • Culture plate

    Plate (Petri or contact) filled with culture medium on which microorganisms are grown.

  • Petri dish

    Round plate, usually 90 mm in diameter, used to culture microorganisms.

  • Contact plate

    Smaller plate (about 55 mm), often used for surface sampling and, in some cases, for air sampling.

  • TSA – Tryptic Soy Agar

    “General-purpose” culture medium used for total bacterial count.

  • SDA – Sabouraud Dextrose Agar

    Culture medium mainly used for the growth of yeasts and moulds.

Microbiological and control processes

  • Incubation

    Period during which plates are kept at a controlled temperature to allow microorganisms to grow and form visible colonies.

  • Contamination

    Undesired presence of microorganisms in the air or on surfaces, products or equipment.

  • Disinfection

    Chemical or physical treatment that reduces or eliminates microorganisms on surfaces and equipment.

  • Sterilization

    Process that eliminates all forms of microbial life, including spores.

    It is more intensive than simple disinfection.

  • Micron / Micrometre (µm)

    Unit used to express particle size.

    1 µm = one millionth of a metre.

Standards, data quality and equipment qualification

  • ISO

    International standards that define requirements (for example for cleanrooms, compressed air, instruments, etc.).

  • USP – United States Pharmacopeia

    United States Pharmacopeia, which includes chapters dedicated to microbiological control and environmental monitoring (e.g. <1116>).

  • GMP – Good Manufacturing Practices

    Rules that define how to manufacture medicinal products (and other products) in a controlled, safe and traceable way.

  • Data integrity

    Principle stating that data must be complete, correct, traceable and not manipulated.

  • ALCOA

    Acronym summarising the key requirements for data integrity:

    • Attributable

    • Legible

    • Contemporaneous

    • Original

    • Accurate

      All data (including MAM data) must comply with these criteria.

  • IQ – Installation Qualification

    Verification that the instrument is installed correctly.

  • OQ – Operational Qualification

    Verification that the instrument operates according to its technical specifications under controlled conditions.

  • PQ – Performance Qualification

    Verification that the instrument, used in the real process, provides adequate and reproducible performance.