AMiCI (CA15114). Workshop for Early Career Investigators (ECIs) and Short Term Scientific Missions (STSM) Riga, Latvia, 7th of March 2019

1. Evaluation of bacterial adhesion on pelvic floor
implants: important considerations regarding
experimental set-up
K.W.J. Verhorstert1, Z. Guler1, L. de Boer2, M. Riool2, J.P.W.R. Roovers1, S.A.J. Zaat2
1. Dept. of Obstetrics and Gynecology and 2. Dept. of Medical Microbiology, Amsterdam Infection and Immunity Institute, Amsterdam UMC,
University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
INTRODUCTION
Within the field of urogynecology there is an urge to develop an
optimal biocompatible implant for the improvement of surgical repair
of pelvic organs prolapse.
Bacterial contamination of the implant seems unavoidable during
surgery. Even after infection prophylaxes, the vagina is colonized with
different bacterial species, with Staphylococcus aureus being one of
the most common (1). Subclinical contamination of the implant is
important since complications are linked to bacterial contamination (2-
3). Therefore, the susceptibly to bacterial adhesion and biofilm
formation is an important aspect during the development of new pelvic
floor implants. However, there is no gold standard test to assess biofilm
formation on implants in vitro.
AIM
We aim to discuss two important considerations regarding experimental
set-up we encountered during experiments with pelvic floor implants:
• Effect of the addition of 1% glucose or 1% plasma to the growth
medium for the enhancement of biofilm formation.
• Different bacterial detachment methods.
RESULTS
Kim Verhorstert, MD and PhD-student
Focus of research: Cellular and
immunologic response to a new
generation of pelvic floor implants.
k.w.verhorstert@amc.uva.nl
Addition of 1% plasma to growth
medium increases CFU/implant
Combination of vortexing and
sonication yields highest number
of CFU/implant
DISCUSSION AND CONCLUSION
 Addition of 1% human plasma significantly increases CFU/implant.
Plasma seems to enhance the stability of the biofilm, previous
research has shown an increase in the expression of adhesive matrix
molecules by the addition of plasma (4). This could be of importance
since incorporation of host factors might cause results to be more
comparable to an in vivo situation.
 Vortexing and sonication is a significant more effective way to
detach bacteria.
 Prolonged sonication does not affect bacterial viability.
 Though these results are based on experiments with a P4HB implant,
results might be applicable to other studies assessing staphylococcal
biofilm formation on different biomaterials.
SEM image of biofilm on P4HB implant
Prolonged sonication has no effect
on bacterial viability
METHODS
A biofilm was grown on degradable poly-4-hydroxybutyrates (P4HB)
implants (n = 6 per experimental group)
Statistical analysis were performed using the Kruskal Wallis test. In
case of a significant difference, manual posthoc testing was performed.
Light microscope image of P4HB Delaware implant
Quantitative
culture
SEM
Detach bacteria
S. aureus ATCC 49230 Grow biofilm
Medium components & 1*10^8 CFU/ml Two day
Detachment method
Bacterial viability 1*10^6 CFU/ml Two day
SEM 1*10^8 CFU/ml One day
REFERENCES
1. Vollebregt et al., 2009 2. de Tayrac, R. and V. Letouzey, 2011 3. Mamy et al.,
2011. 4. Cardile A.P., et al 2014
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