Environmental Microbiology

Endoscopy / CSSD

Weeklies

Hospitals are required to test the final rinse water from their endoscope washer-disinfectors on a weekly basis, this ensures a rapid response to emerging problems of deteriorating water quality. As required in the Health Technical Memorandum (HTM) 01-06 Management and Decontamination of Flexible Endoscopes.

Weekly water testing includes a Total Viable Count (TVC) by membrane filtration, hardness, and electrical conductivity. In addition to these tests, we can also test for Pseudomonas aeruginosa, pH and appearance.

Performance Qualification Testing

We can also provide quarterly and annual tests for endoscope washer-disinfectors. As required in the HTM 01-06 Management and Decontamination of Flexible Endoscopes.

The following tests are included as part of the quarterly and annual requirements:

  • Total Viable Count (TVC)
  • Pseudomonas aeruginosa
  • Conductivity, hardness, pH and appearance
  • Total Organic Carbon (TOC)
  • Environmental Mycobacteria
  • Surrogate devices (annual requirement only)
  • CESC Testing (Controlled Endoscope Storage Cabinets)

    HTM 01-06 Management and Decontamination of Flexible Endoscopes requires sites to perform quarterly and annual validations on their cabinets.

    The following tests are included as part of the quarterly and annual requirements:

  • Contact Plates
  • Dryness testing
  • Sterile Lumen Device (annual requirement only)
  • Settle Plates (annual requirement only)
  • HTM 01-01 Part C

    This part of the Health Technical Memorandum refers to sterilisers. This set of tests is an annual requirement and is usually performed by the site’s third-party service provider, as specialist equipment is required to extract the steam to enable us to analyse the water.

    Tests include:

  • Endotoxins
  • Chemical Suite
  • HTM 01-01 Part D

    This part of the standard refers to instrument washer-disinfectors. This set of tests is an annual requirement and is usually performed by the site’s third-party service provider.

    Tests include:

  • Total Viable Count (TVC)
  • Endotoxins
  • Chemical Suite
  • Potable Water Services

    Total Viable Count (TVC) by Pour Plate

    Potable water (drinking water), spa, pool and hydrotherapy water, and cooling towers should be routinely monitored using Total viable count (TVC). Unlike endoscopy waters that undergo TVC by membrane filtration, potable water is cultured on pour plates.

    TVC is a valuable trend analysis tool for monitoring the overall microbial quality of a water supply. It is a quantitative test that can determine the number of viable microorganisms present in a water sample but is unable to identify individual species.

    Legionella Analysis

    Under the Health & Safety at Work Act 1974, there is a duty of care in the UK to perform routine analysis of water samples for the presence of Legionella, a group of organisms that cause pneumonia-like illnesses particularly in those that are elderly or immunocompromised.

    The Health & Safety Executive (HSE) has published ‘The Approved Code of Practice: Legionnaires’ disease: The control of Legionella bacteria in water systems (L8)’; this is a practical guide for employers to help them manage and control the risks in their water systems.

    20/30 Labs is registered with the Legionella Control Association for Analytical Services and are a UKAS accredited laboratory (4236).

    Pseudomonas Analysis

    Pseudomonas aeruginosa is a common environmental bacterium typically found in soil and water. To the majority of people, it is harmless, however, in healthcare settings, it must be controlled due to its inclination to infect the immunocompromised and cause nosocomial or healthcare-acquired infections (HAIs).

    The Health Technical Memorandum (HTM) 04-01 Safe Water in Healthcare Premises and HTM 01-06 Management and Decontamination of Flexible Endoscopes detail the requirements for the sampling, methods of analysis and remediation of Pseudomonas aeruginosa in water in various settings including healthcare settings and public buildings.

    Escherichia Coli and Coliform Analysis

    Tests for coliform bacteria and Escherichia coli (E. coli) are the most important routine microbiological examinations carried out on drinking water. These tests provide a sensitive means for detecting faecal contamination, assessing raw water quality, the effectiveness of water treatment and disinfection, and for monitoring the quality of potable water in distribution.

    Cleanroom Validation

    Cleanroom

    Areas for which environmental cleanliness is of paramount importance, such as operating theatres, instrument reprocessing cleanrooms and pharmaceutical manufacturing cleanrooms are subject to regular monitoring and validation activities.

    These areas should be routinely sampled in accordance with the requirements of the International Organisation for Standards BS EN ISO 14644 and BS EN ISO 14698, which include testing for effective air filtration through air particle counting and testing for environmental flora (bacteria, yeast and other fungi) through contact plates, settle plates and personnel monitoring.

    Airborne Particulate Counts

    The International Organisation for Standards (ISO) 14644 Cleanrooms and Associated Controlled Environments specifies the classification of air cleanliness in terms of the concentration of airborne particles in cleanrooms and other controlled environments. Cleanrooms are classified in an 8-tier system, with class 1 cleanrooms being the most particle-free and class 8 cleanrooms allowing the most particles. Hospital cleanrooms are class 8, but they must still be routinely tested to demonstrate the suitability of the area for medical device processing.

    Environmental Monitoring

    ISO 14698 Cleanrooms and Associated Controlled Environments – Biocontamination Control describes the basic methodology to assess and control biocontamination in cleanrooms.

    Areas at risk of biocontamination can be routinely monitored using these methods below, allowing for trend analysis over time and enabling appropriate control measures to be implemented.

    Contact Plates
    – used to measure microbial contamination of work surfaces. The surface of an agar plate is pressed against a flat sampling surface to pick up any microorganisms that may have settled onto the location by operator contact or from the environment.

    Settle Plates
    – give an indication of airborne microbial contamination. Agar plates are left, uncovered, for a set period. Any airborne microorganisms that settle onto the surface of the agar plate will grow on incubation and give a representative measure of the microorganisms that may deposit onto surfaces and exposed medical devices within a cleanroom.

    Active Air Sampling
    – involves extracting a set volume of air within a given environment into a calibrated sampler which is then passed onto the surface on an agar plate. Plates are then incubated to allow the growth of colonies of airborne microbes.

    Swabs
    – are used on irregular, uneven surfaces where contact plates cannot otherwise be used. Swabs will be wiped over such surfaces and inserted into a vial that preserves the levels of bacteria present, before being returned to the laboratory for analysis. Swabs provide a reliable way of assessing contamination levels.

    Renal Testing

    Renal tests are performed to evaluate kidney (renal) functions. These tests use dialysis water, this water has been treated to meet the requirements of The International Organisation of Standards (BS ISO 23500-3:2019) Water for haemodialysis and related therapies and making it suitable for use in haemodialysis applications, including the preparation of dialysis fluid, reprocessing of dialysers, and the preparation of concentrates.

    Haemodialysis and haemodiafiltration can expose the patient to more than 500L of water per week. This increased exposure requires control and monitoring of water quality to avoid excess exposure to known or suspected harmful substances or microorganisms.

    We monitor and analyse dialysis water using the following methods:

    Total Viable Count (TVC)
    – this is a valuable trend analysis tool for monitoring the overall microbial quality of a water supply. It is a quantitative test that can determine the number of viable microorganisms present in a water sample but is unable to identify individual species.

    Compliance with ISO 13959 Water for haemodialysis and related therapies requires that renal waters be sampled for TVC monthly.

    Endotoxin Analysis
    – Endotoxins are found in Gram-negative bacteria, such as Pseudomonas aeruginosa, E. coli and Neisseria meningitidis. They are comprised of extremely antigenic molecules called lipopolysaccharides (LPS) that provoke a powerful immune response when detected by the immune system. The fever and inflammation that can be generated as the immune cells fight the infection, can lead to the onset of septic shock, an often fatal condition.

    Endotoxins are particularly dangerous due to their ability to generate an immune response even when their host bacterium is dead, and the bacterial cell has broken down. The endotoxin test can detect these freely circulating LPS molecules.

    Compliance with The International Organisation of Standard (ISO) 13959 Water for haemodialysis and related therapies requires that renal waters be sampled for endotoxin monthly.

    Chemical Analysis

    20/30 Labs uses the Thermo Scientific™ Gallery™. Plus, a fully automated, high-capacity analyser to provide fast, reproducible results on a suite of chemical tests to ensure full compliance with the following ISO standards.

    ISO 13959 Water for haemodialysis and related therapies stipulates the maximum allowable levels of toxic chemicals, dialysis fluid electrolytes and other trace elements permitted in renal dialysis water.

    ISO 13959 Water for haemodialysis and related therapies requires that renal waters be sampled for chemical analysis on a quarterly basis.