Healthcare Hygiene magazine August 2020 | Page 33

Here is what a
microbial jungle
might look like:
The CDC’s list of
ESKAPE Pathogens
can be accessed at:
View list of
ESKAPE Pathogens
Biofilms
Biofilms are densely packed communities of microbial cells
that grow on living or inert surfaces and surround themselves
with secreted polymers. Many bacterial species form biofilms,
and their study has revealed them to be complicated and diverse.
The structural and physiological complexity of biofilms has led
to the idea that they are coordinated and cooperative groups,
analogous to multicellular organisms.
Current research
and studies
conducted by
scientists at Cardiff
University, Dr.
Katarzyna Ledwoch
and professor
Jean-Yves Maillard,
introduce us to the
latest in another
type of biofilm, dry
surface biofilms
(DSB). DSB are
complex microbial
communities
formed and grown
in dry habitats.
SEM image of DSB containing mixed hospital culture
grown on stainless steel disc.
Much less attention has been paid to dry biofilms compared to
most commonly researched wet/hydrated biofilms. DSB colonize
various materials from textile (chair), hard surfaces including
plastic (PVC, PP), lacquered wood, wood, metal (stainless steel) to
many others. DSB have been isolated from diverse environmental
conditions: low moisture, varying temperature and nutrient levels.
Biofilm is the invisible film that is present and growing
on almost all surfaces in hospitals, restaurants, cruise ships,
entertainment venues, hotels, and homes. It is the accumulation
of microorganisms and their numerous chemical components.
Whenever people are, they add to the already existing jungle
of germs.
Real-world hospital testing for dry biofilm presence and removal
was most notably conducted by Ledwoch, et al., scientists at
the School of Pharmacy and Pharmaceutical Sciences at Cardiff
University and published is three articles: Candida auris Dry
Surface Biofilm (DSB) for Disinfectant Efficacy Testing (2018);
Beware biofilm! Dry biofilms containing bacterial pathogens on
multiple healthcare surfaces: a multicenter study (2018): and
Artificial dry surface biofilm models for testing the efficacy of
cleaning and disinfection (2019).
The results shared by Ledwoch, et al. as to the efficacy of
various microfiber wipes and wipers by EVS staff categorically
documented the effectiveness and superiority of Healthcare-Grade
Ultrafine Microfiber (H-GUM) in the physical removal of dry
biofilm. This type of microfiber was the only beneficial cloth to
effect physical disruption of biofilm, be it wet or dry. H-GUM is
constructed of split bi-component fibers and split to such fine
triangular filaments. It disrupts the physical condition of biofilm
to such an extent that the biofilm is removed.
Bacteria itself contribute to the microbial jungle through waste
products. Bacterial waste products are endotoxins, exotoxins,
cellular debris, proteins, lipids (fats), and mucopolysaccharides
(known in the microbiological trade as germ snot!).
If the jungle floors of Central and South America were casually
looked at, they would appear similar, yet they are vastly different.
They are different because of the variety of flora and fauna
living and dying there and are teeming with organic waste and
infinite microbes and bacteria. One would also find moist and
dry surface biofilm (DSB) serving as a festering microbial breeding
ground and germ graveyard, the equivalent of the sludge found in
septic tanks. Just as jungles from different parts of the world are
different, the “jungles” found in hospitals are different because
of where they are. Get the picture?
Planktonic
(1)
Attachment
to surface
Why DSB Can Be a Problem
●DSB are widespread on surfaces in hospitals
●DSB contribute to pathogens survival and
HAIs despite cleaning and disinfection
●DSB cannot be detected by swabbing or
contact plates
●All biofilms harbor Gram-positive bacteria, including
pathogens associated with HAIs
●DSB regrow within one day when provided with nutrients
How to solve the problem:
(5) Detachment and reversion
to planktonic growth, starting
new cycle
(2) Formation (3) Microcolony
➜ of monolayer ➜ formation, ➜
and production multi-layer
of matrix
Biofilm
(4) Mature biofilm,
with characteristic
“mushroom” formed of
polysaccharide
View Why DSB
Problem
●Improved hand hygiene
●Improved cleaning with Healthcare Grade Ultrafine Microfiber
(HGUM)©
●Disinfectants targeting DSB
●Improved monitoring of contamination levels
Know the Enemies
The complexity of the healthcare-associated microbial jungle
requires accurate, reliable reproducible testing. The key to effective
testing requires a standardized sample collection and testing
procedure. The results acquired represent a precise picture of
www.healthcarehygienemagazine.com • august 2020
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