Transcatheter aortic valve implantation (TAVI) prostheses in vitro - biofilm formation and antibiotic effects

Torgny Sunnerhagen*, Thomas Bjarnsholt, Klaus Qvortrup, Henning Bundgaard, Claus Moser

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

Background: Transcatheter aortic valve implantation (TAVI) is a percutaneous catheter-based treatment of aortic stenosis as an alternative to open heart valve surgery. In cases of TAVI endocarditis, the treatment possibilities may be limited as surgical removal of the infected valve may be associated with a high risk in elderly, comorbid or frail patients. The propensity of bacteria to form a biofilm on foreign material is assumed to be of importance part of the disease process in TAVI endocarditis, but no studies on biofilm formation on TAVI valves have been conducted. We hypothesize that Staphylococcus aureus and Enterococcus faecalis biofilm formation on TAVI valves may have an impact on antibiotic tolerance and non-surgical cure rates. Methods: TAVI valves (pieces including part of the metal frame, approximately 1 cm wide) were exposed to either species in vitro in LB-Krebs Ringer medium at 37 °C, with the bacterial count being assessed by culturing of sonicated TAVI pieces and broth at 0, 4, 18 and 24 h after bacterial exposure. Scanning electron microscopy (SEM) was performed. Effects of ampicillin, gentamicin, moxifloxacin, rifampicin (for S. aureus), and ceftriaxone (for E. faecalis) at 5 times minimal inhibitory concentration were tested alone and in combination with ampicillin. Antibiotics were added to biofilm aged 0 or 24 h and the effects assessed. Results: Exposure for 15 min established attachment to all of valve pieces. SEM findings were consistent with biofilm formation and suggested lower amounts of bacteria on the metal compared to the tissue part of the TAVI valves. The number of bacteria attached to the TAVI valves increased until 24 h of incubation from less than 10^1 to a level of approximately 10^9 CFU/g. The bacteria became more tolerant to antibiotics on the TAVI valves over time, with the bactericidal effect against 24-h old biofilm being significantly less effective than against 0-h old biofilm depending on antibiotic. Conclusions: The results indicate that bacteria can adhere to metal and tissue parts of the TAVI valves within minutes after an exposure which is comparable to transient bacteremia in vivo, and that the bacteria rapidly gain biofilm properties, associated with significantly reduced antibiotic effect.

OriginalsprogEngelsk
Artikelnummer100236
TidsskriftBiofilm
Vol/bind8
Antal sider7
ISSN2590-2075
DOI
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
TS has received funding from the Swedish Society for Medical Research (PD20-0031), Tornspiran Foundation, Royal Physiographic Society of Lund, Swedish Society of Medicine (SLS-971382), Lund University Research Foundations (RMv2021-0002, RMh2021-0001, RMv2022-0004), Thelma Zo\u00E9gas Foundation for Medical Research (TZ2021-0008), Scandinavian Society for Antimicrobial Chemotherapy (SLS-971424), L\u00E4ngmanska kulturfonden (BA21-0430), Sigurd and Elsa Golje Memorial Foundation (LA2021-0027, LA2022-0068), Mats Kleberg Foundation (2022-109), Direkt\u00F8r Emil C. Hertz og Hustru Inger Hertz' Fond, Arvid Nilssons Fond, the Lars Hierta Memorial Foundation (FO2021-0058), and the Tore Nilson Foundation (2023-126). TB has received honorarium for consultancy from SoftOx and Lohmann and Rauscher. CM has received funding from Novo Nordisk Foundation with \u2018Borregaard Clinical Scientist Grant\u2019 (Grant no. NNF17OC0025074), honorarium from GSK and AstraZeneca for scientific presentations, and has received research materials from Boston Scientific International S.A. and for other projects received funding to the department from Reapplix A/S.

Funding Information:
The support from Boston Scientific International S.A. for donating 20 units of ACURATE neo Aortic Bioprosthesis (expired) is gratefully acknowledged. Boston Scientific International S.A. had no input on conducting the project or the interpretation or publication of the results. We received no additional fee or compensation from the company.

Publisher Copyright:
© 2024 The Authors

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