Kirby Lattwein1,2,3, Himanshu Shekhar2, Willem J.B. van Wamel3, Tammy Gonzales4, Andrew B. Herr4, Christy K. Holland2, and Klazina Kooiman1

Transcription

1 Kirby Lattwein1,2,3, Himanshu Shekhar2, Willem J.B. van Wamel3, Tammy Gonzales4, Andrew B. Herr4, Christy K. Holland2, and Klazina Kooiman1 1Dept. of Biomedical Engineering, Erasmus MC 2Dept. of Internal Medicine, Div. of Cardiovascular Health and Disease, Univ. of Cincinnat 3Dept. of Medical Microbiology and Infectious Diseases, Erasmus MC 4Div. of Immunobiology, Cincinnati Children s Hospital MC Nathan K. Archer et al., Virulence 2011

2 state of IE in LMIC now reflects that of IE in HIC in the middle of the twentieth century. 9 These temporal trends in HIC 12,23 25 are exemplified by three 1-year, population- Bacterial infective endocarditis based surveys (from 1991, 1999, and 2008) performed three French regions and including a total of 11 million inhabitants (aged 20 years) and 993 expertly-validated cases of IE. 26 The incidence of IE remained stable over time, with 35 (95% CI 31 39), 33 (95 CI 30 37), and 32 (95% CI 28 35) cases per million of the population Werdan, K et al., Nature Review 2014 Table 1 Microbial aetiology of infective endocarditis by region* Pathogen Percentage of total cohort (n = 2,781) North America (10 sites, n = 597) tioned by many physicians owing to a lack of evidence. Consequently, the authors of guidelines published in recommend restricting antibiotic prophylaxis to the highest-risk patients. 33,34 Neither in France, 26 nor across 37 US children s hospitals, 35 has an increased incidence of oral streptococcal IE been observed after the release of these guidelines. (IE) The National Institute for Health and Care Excellence in the UK went a step further (not without raising ethical Region (%) South America (8 sites, n = 254) Europe (22 sites, n = 1,213) Aortic valve Rest of world (18 sites, n = 717) Mitral valve Mirabel, M et al., Eur Heart Journal 2014 P value for difference between regions Staphylococcus aur eus <0.001 Coagulase-negative Staphylococcus Oral streptococci <0.001 Streptococcus bovis <0.001 Other streptococci Enterococci HACEK Fungi or yeast Polymicrobial Culture negative <0.001 Other * Data from the ICE-PCS study conducted from June 2000 to September Including Australia, India, Israel, Lebanon, Malaysia, New Zealand, Singapore, South Africa, and Thailand. Abbreviation: HACEK, Haemophilus spp., Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella spp % LUME per 100, Macmillan Publishers Limited. All rights reserved nrcardio Werdan, K et al., Nature Review 2014

3 Characteristics of endocarditis vegetations

4 Heart valve

5 Aim of sonobactericide Heart valve

6 Sonoporation: Sonothrombolysis: 5 µm before after 200 µm Unpublished data Bader et al., Ultrasound Med Biol 2015

7 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate testing Develop prototypes Histological examination Viability determination Treat infected clots in an in vitro flow system

8 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate characterization Develop infected clot model

9 Infected Clot Model S. aureus retracted clot 1,2,3 1Roessler et al. Blood Coagul. Fibrin, 2 2Holland et al. Thromb. Res., Bader et al. Ultrasound Med Biol 20

10 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate characterization Develop infected clot model Histological examination

11 Hematoxylin & Eosin Crystal violet Pink = fibrin Red = RBCs Yellow = fibrin Brown = RBCs Purple = bacteria Purple = bacteria 50 µm 50 µm

12 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate characterization Develop infected clot model Histological examination Viability determination

13 Syto 9: Green (Live) Propidium iodide: Red (Dead) 20 µm

14 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate characterization Develop infected clot model Histological examination Viability determination Treat infected clots in an in vitro flow system Experimental set-up

15 Experimental Set-up Infected Clot Light Source > 400 & < 700 μm Passive Cavitation Detector (PCD) Water Tank (37 C) 2.25-MHz Trasducer 0.44 MPa 50 s on, 30 s off 120-kHz Transducer 120-kHz Transducer Perfusate Reservoir Suture Infected Clot within Capillary Tube Acoustical Absorption Material Syringe Pump (0.65 ml/min) 10x CCD Camera CCD Camera Perfusate: rt-pa: 3.15 μg/ml Oxacillin: 172 μg/ml Definity : 2 μl/ml (2 10 6

16 Approach Develop a simulated IE vegetation (infected clot) on a suture Isolate procurement Isolate characterization Develop infected clot model Histological examination Viability determination Treat infected clots in an in vitro flow system Experimental set-up Results

17 Degradation of clots at 30 min µm ± 47.6 SD

18 Light microscopy post-treatment Red = Clot Beige Biofilm = 100 μm Black = Suture Plasma 200 μm 200 μm μm Plasma + rt-pa + OXA + US + Definity

19 Cavitation energy detected Ultraharmonic Broadband

20 Effluent Characterization 10.4 μm

21 Summary Presented an in vitro infective endocarditis model Used sonobactericide on bacterial clots Effluent and optical data suggest low emboli risk

22 Acknowledgements (1) Biomedical Engineering Ines Beekers Tom van Rooij Nico de Jong Ton van der Steen Medical Microbiology & Infectious Diseases Andi Sultan Pathology (EMC) King Lam Image-Guided Ultrasound Therapeutic Laboratories (UC) Kenneth Bader Shenwen Huang Kevin Haworth Karla Macado Robert Kleven Radiology (UC) Seetharam Chadalavada Laboratory Medicine Joel Mortensen Confocal Imaging Core Matthew Kofron Mike Muntifering Pathology (CCH) David Witte 22

23 Acknowledgements (2) Therapeutic Ultrasound Contrast Agent Group

24 Sonobactericide Heart valve

25

26 Light microscopy post-treatment Plasma 200 μm 200 μm μm Plasma + rt-pa + OXA + US + Definity Plasma + rt-pa + OXA