Title : On site comparison of an enzymatic detergent and a non-enzymatic detergent-disinfectant for routine manual cleaning of flexible endoscopes Background and Aims Flexible endoscopes are potential vectors of pathogen transmission to patients. They are therefore subjected to cleaning and high-level disinfection after each procedure. High-level disinfection should only be performed on endoscopes free of organic soiling and biofilms. The goal of this study was to demonstrate the impact of the cleaning chemistry in the outcome of the manual cleaning of endoscopes.

1. Removing biofilms from endoscopes: the importance of the cleaning chemistry
Wafi Siala1,2, Françoise Van Bambeke1 , Thomas Vanzieleghem2
1 Louvain Drug Research Institute, Université catholique de Louvain, Brussels; 2 OneLIFE S.A., Louvain-la-Neuve - Belgium
Introduction
Several studies have associated the use of endoscopes with several
outbreaks of infection in various clinical settings, including
gastrointestinal, thoracic, urological, and other endoscopic procedures.
The ability of bacteria to form biofilms is a major cause for endoscopes
contamination. Staphylococcus aureus, Klebsiella pneumoniae,
Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa are
the most likely germs to cause these contaminations. We compared the
biofilm dispersion activity, against bacterial species mentioned above,
of one enzymatic cleaner developed by OneLIFE Sa (enziQure®) and
10 cleaners commonly used for the manual cleaning of endoscopes.
Results
References
1- Siala, W. et al. The antifungal caspofungin
increases fluoroquinolone activity against
Staphylococcus aureus biofilms by inhibiting N-
acetylglucosamine transferase. Nat Commun 2016;
7:13286.
Materials and Methods
Conclusions
While most of the current cleaning solutions are poorly active on biofilms, the enzymatic formulation of enziQure® allows marked
(> 50 %) biofilm dispersion for 80% of tested strains. This effect nevertheless remains strain-dependent, probably related to the
nature of the produced biofilm matrix.
Acknowledgements
WS is post-doctoral fellow of the program first
enterprise from the Region Wallonne. This work
was also supported by OneLIFE SA.
This poster will be available after the meeting at http://www.facm.ucl.ac.be/posters
We used 5 reference strains and 10 clinical isolates (C1-C10; infections
on medical devices and tissues). Biofilms were grown for 24 h in 96-
wells plates. biofilms were exposed for 1h at 40°C to concentrations
recommended by manufactures (0.5%-1%) of cleaners prepared in
standardized water (WSH :1.25 mM MgCl2, 2.5 mM CaCl2, 3.33 mM
NaHCO3). The ability of cleaners to remove biofilm biomass was
determined using crystal violet assay as previously described (1).
Tridimensional images were performed using confocal laser scanning
microscopy (CLSM). Biofilms were grown on coverslips, washed with
distilled water; after which coverslips were transferred into a fresh well
and incubated during 30 min at room temperature with LIVE/DEAD kit
(1). Image stacks were acquired at a resolution of 700x500 pixels,
recorded using Z-Stack module for acquisition of image series from
different focus planes, and used to construct three-dimensional images
with AxioVision software.
Figure 1 – Percentage of biomass reduction for 15 biofilms (formed by 3
isolates from 5 different species) after exposure to enziQure® and 10 other
cleaners in the absence of mechanical action (* : no enzyme; # : germicidal
activity). The dotted line shows the 50 % limit. Dots show the data for
individual strains, with mean and 95% confidence intervals shown in black for
each cleaner. Means (% ± SD): enziQure®: 62 ± 16; A: 48 ± 20; B: 45.7 ± 31;
C: 38 ± 35; D: 18 ± 17; E: 16 ± 23; F: 12 ± 24; G: 12 ± 19; H: 11 ± 17; I:
12 ± 14; J: 8± 12. Statistical analysis: one-way ANOVA with Dunnett’s multiple
comparison test (cleaner vs enziQure®): *: p < 0.05; ***: p < 0.001
Figure 2– Tridimensional images in confocal
laser scanning microscopy of PAO1 and
clinical isolate (C4) biofilms. Biofilms were
incubated during 1h at 40°C with 1%
enziQure®; 0.5% cleaner A or 0.5% cleaner J
and labelled with live/dead staining (red: dead;
green: live). PAO1 biofilms are shown on right ,
C4 biofilms are shown on left.
0
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enziQ
ure
A#
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ATCC33591
C1
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ATCC700603
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ATCC25922
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ATCC29512
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C10
%reductionofbiomass
S. aureus P. aeruginosa K. pneumoniae E. coli E. faecalis
* *** *** *** *** *** *** ***
P1484
PAO1 UNTREATED
PAO1 VS CLEANER A
PAO1 VS CLEANER J
C4 UNTREATED
C4 VS CLEANER A
C4 VS CLEANER J
C4 VS enziQure® PAO1 VS enziQure®