Microbiological contamination and instrument reprocessing

Dr Gerard Colleran

Institute of Technology Tallaght Dublin

Format of today’s presentation

• Microbiology – a core knowledge base that is required by staff involved in controlling microorganisms (decontamination)

• Education – provides the means to achieve Good Aseptic Practices in decontamination of medical devices

• Practical examples of microbiological training provided to healthcare workers at IT Tallaght

Microbiology – an important knowledge base for Healthcare staff

• Most healthcare staff have limited formal education in microbiology

• They are responsible for the control microbiological contamination.

• IT –Tallaght has developed a programme of education for staff

• To provide knowledge and understanding of microbes

• Tp provide pragmatic knowledge of how to find, measure and eradicate microorganisms from the workplace and in products

• To enable staff to make continued improvements

Significant microbiological issues making the news

Research into instrument decontamination is expanding

Understanding the guidance documents – education is essential

• Courses aim to provide educational support to Health Services Staff

• In understanding the microbiological controls required in reprocessing re-usable medical instruments • Courses are part of a Higher Certificate Level Award Level

6; Called Level 6 Minor Awards and Single subject award • Institute internationally recognised and will become the

Technological University of Dublin

Controlling Microbiological contaminants in reprocessing by GOOD ASEPTIC PRACTICES

• Good Aseptic Practice for handling, reprocessing, storage, transport and of medical instruments

• Clean, Disinfected to a high level/or sterile (depending on the medical device classification)

• Microbe free, lint free, endotoxin free, residue free and dry

• Aseptic practices - scientifically sound practices, proven to reduce potential for microbial transfer

• Aseptic Practice – Practices aimed at reducing sepsis occurring due to inadvertent contamination of medical instruments

Online Education in Microbiology and Instrument Decontamination

• On-line delivery of lectures to any internet ready device

• Course material has been accessed throughout Ireland

• Delivered over two academic terms (Sept to December) and (Feb to May)

• Delivery of interactive work-shop activities at one interval each academic term

• A Quality Improvement Project consolidates learning by pragmatic actions in the workplace

Issues that are addressed as part of IT Tallaght Courses

• Understanding infections agents: bacteria, viruses, fungi and prions

• Controlled cleaning, controlled high level disinfection, controlled sterilisation

• Aseptic practices for decontamination of instruments

• Microbiological sampling and measurement

• Practical Workshops with specialist tutors from hospitals and industry

Practical examples of microbiology education

provided

Materials used; Microscope, Microscope slide specimens

Examination of Gram-negative and Gram-positive bacteria using the light microscope

Gram-positive cocci shaped bacteria (Staphylococci) Gram-positive rod-shaped bacteria (Cdiff)

Gram-negative cocci (N. gonorrhoea) Gram-negative rod-shaped bacteria (E. coli

Evaluation of microbial contamination of hands and gloves by “finger-dab” testing on agar plates

Examples of pragmatic microbiological matters - Demonstrating the reduction in microbial transfer afforded by gloves

Comparision of naked hands & gloved hands in fingertip testing using three different agar media

Gloved Hands

Naked Hands

General Purpose Agar Staphylococcus agar Coliform agar

Close up image of test using Staphylococcus agar

Gloved Hands

Naked Hands

Infamous Staphylococcus species

• Staphylococcus aureus

• Staphylococcus epidermidis

• MRSA

• MRSE

Close up image of test using coliform agar

Gloved Hands

Naked Hands

Coliforms under the fingernails of transferred to hand contact surface when not wearing gloves

Gloved Hands

Naked Hands

Infamous coliform bacteria

• E. coli

• Salmonella

• CPE/CRE

Microbiology associated with air in rooms where staff work

Microbiological air quality of ISO CLASS 8 cleanrooms

No more than 100 CFU/4 hour settle plate are permitted in air of this quality in cleanrooms

No more than 50 CFU/Contact plate are permitted on surfaces in clean rooms of this classification

The concept of air sampling via settle plate analysis

The method relies on microbes that are

associated with air particles and dust settling

onto an open agar plate

The plate remains open for a period of 4

hours

The plate is then incubated for 48 hours and

the number of colonies counted on the agar

plate

A variety of agar plates can be used

To cound fungi, yeasts , bacteria, staphylococci etc

Demonstration of microbiological air sampling for non-specialist audiences

Capturing microbes in a “non-clean room environment” using 4 hour “settle plate” & mechanical air sampler (sampling 200 litres of air samples)

“Settle Plate” 4 hour exposure

200 Litre air samples taken using a Mechanical Air Sampler

Comparing microbes from a “non-cleanroom environment” and a clean room) using “settle plates” exposed for 4 hours

Lab Air samples by “settle plate”

Clean-Air Work Station (Clean Room) sampled by “settle plate”

Sample of air from Public Bathroom using a Mechanical Air Sampler to sample 200 Litres of air

General purpose agar Staphylococcus Agar Coliform agar (blue version)

Microbiology Associated with RO water supplies

RO Water Sampling and maintenance of RO water systems • RO water is used for the rinse and disinfection stages sof the washer-

disinfectors used to clean and disinfect surgical instruments

• RO water used in all stages of automated endoscope reprocessing

• RO water is also used to produce clean steam for autoclaves

• Microbial contamination of RO water is a recurrent issue across all hospitals

Examples of pragmatic microbiological matters - Aseptic Water Sampling and counting TVCs water samples

Microbiological results from 100 ml water samples filtered and grown on general purpose agar

RO water systems require regular maintenance • replacement of water filters and UV lamps

• thermal disinfection via circulating hot RO water

• Annual validation

• Weekly water sampling

• Samples should not exceed 10 cfu/100 ml

Microbiology of a cleaning validation of a surface made

simple

Aim

• To observe and measure TVCs before and after cleaning and ATP levels (Bioluminesence) again before and after cleaning

• To illustrate the simplicity of validating a cleaning process using microbiological swab analysis and cultivation for 48 hour and ATP Bioluminescence Analysis immediately before and after cleaning.

Microbiological analysis of swabs from 3.7 cm2 surface before and after cleaning

Contaminated surface 125 CFU/131CFU

Clean surface 0 CFU/OCFU

ATP Bioluminesence

ATP is a substance that is only found in living cells

ATP is detected using a handheld device and a series of swabs

Areas are swabbed and the swab is placed into a hand held device

ATP is a molecule that is made by the living cells.

It can be detected in a matter of minutes and can give us an indication of the presence of microbes on a surface in minutes

RODACS are mentioned in the picture. RODACS are small agar plates used to sample surfaces also known as contact plates

Results of ATP Bioluminesent Tests on the test surface before & after cleaning

Contaminated (Dirty Tray) Tray after cleaning

Swab 1 2589 RLU 25 RLU

Swab 2 4423 RLU 37 RLU

Swab 3 4040 RLU 42 RLU

Mean RLU Measured 3864 RLU 35 RLU

CFU Detected via cultivation 128 CFU CFU Detected via cultivation 0 CFU

RLU refers to Relative Light Units and CFU refers to Colony Forming Units

Demonstration of the affects of UV light on to

decontaminate a flat surface

Aim

• Do determine the effect of UV light on the numbers E. coli on a flat experimental surface for 5 and subsequently 10 minutes.

• To measure the numbers of E. coli surviving on a surface after 5 and then 10 minutes of continual UV light exposure.

Materials used

• A white plastic tray

• A culture of E. coli in liquid media

• A “UV Wand”

• A stop watch

• A pre-moistened sterile swab

• A sterile square of 3.7 cm2 area

Result of using the UV wand on a surface that was deliberately contaminated with E. coli

E. coli recovered from the surface before application of UV light

E. coli recovered from the surface after applying UV light for 5 minutes

E. coli recovered from the surface after applying UV light for 10 minutes

The concept of antibiotic resistant bacteria explained in

practical terms.

Examples of pragmatic microbiological matters - Demonstrating antibiotic resistance on agar plates

Different antibiotics on paper discs are preventing bacteria growing beside the discs on this agar plate. Bacteria are SENSITIVE to all these antibiotics

Different antibiotics on paper discs are not preventing bacteria growing beside the discs on this agar plate. Bacteria are RESISTANT to many of these antibiotics

Isolating coliforms from sink drain involved swabbing the interior of the drain and spreading the swab onto blue coliform agar and incubating the agar for 48 Hours

Coliform bacteria evident from the sink drain

• Approximately 300 coliforms recovered from sink drain

Coliforms are opportunistic pathogens and include CRE and CPE

groups of bacteria

Conclusion

• Microbiology is a core knowledge base that is required by healthcare staff that are responsible for decontaminating medical devices

• Continual professional development in this area IMPROVES PRACTICE in terms of the decontamination of medical instruments

• Education that is provided in this field provide staff with a continuum of education leading from single subject awards to Level 6 Certification and Level 7 degrees and more.