Session Type: 1-hour ePoster Review
Session Title: 1-hour ePoster Review
Authors(s): A. Dahl (1, 2), C. García-De-La-Mària (1), M.A. Cañas (1), J. García-González (1), B. Vidal (1), M. Hernandez-Meneses (1), A. Perissinotti (1), C. Falces (1), J.M. Pericàs (1), E. Quintana (1), J.M. Tolosana (1), M. Almela (1), J. Ambrosioni (1), A. Moreno (1), N.E. Bruun (3), J.M. Miró (1)
Authors Affiliations(s): (1) Hospital Clinic de Barcelona, Spain, (2) Herlev-Gentofte University Hospital, Denmark, (3) Zealand University Hospital, Denmark
Third Party Affiliation: On behalf of The Hospital Clínic Endocarditis Study group
Background:
No studies have described the natural history of vegetations in experimental endocarditis (EE) with Gram-positive cocci using daily sequential echocardiography. We aimed to compare the development of vegetations in EE caused by methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. epidermidis (MRSE), Streptococcus mitis and Enterococcus faecalis.
Methods:Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits with the polyethylene catheter left in place. Groups of 5 animals were then infected with MSSA with high biofilm production (MSSA-673), MSSA with low biofilm production (MSSA-236), S. mitis (SMIT-351), E. faecalis (EFAE-188) or MRSE (MRSE-375). Transthoracic echocardiography was performed before infection and daily until sacrifice at 48 hours post infection for MSSA and 96 hours post infection for S. mitis, E. faecalis and MRSE strains. At autopsy, tissue samples from cardiac vegetations, spleen and kidney were colonized for quantitative analysis of colony forming units (CFU) per gram tissue.
Results:Baseline mean length of the nonbacterial thrombotic vegetations was 2.4mm (±0.5mm) and the further evolution of vegetations is depicted in Figure 1. At 48 hours post infection, MSSA-673 caused an increase in vegetation size of 3.1mm (±0.6mm) compared to 2.2mm (±0.3mm) in MSSA-236 (p=0.03), 1.9mm (±0.7mm) in EFAE-188 (p=0.06), 1.6mm (±0.8mm) in SMIT-351 (p=0.02), and 1.6mm (±0.7mm) in MRSE-375 (p=0.01) (Figure 1). At 96 hours post infection the size of vegetations had increased 4.4mm (±1.6mm) in EFAE-188 compared to 2.8mm (±1.0mm) in SMIT-351 (p=0.15), and 2.9mm (±0.7mm) in MRSE-375 (p= 0.15). The correlation between vegetation weight at autopsy and vegetation size on echocardiography was very good (Pearson`s R = 0.86, p < 0.00001). The bacterial load in CFU found in the vegetations, the spleen and the kidney were comparable without any significant differences between the groups.
Conclusions:In experimental endocarditis, vegetation size on echocardiography correlated very well with vegetation weight at autopsy and vegetation size increased between two to three times in all cases being significantly greater in S. aureus with high biofilm production. This experimental study allows us to better understand the initial pathophysiological changes of the valve vegetations of IE caused by the most frequent Gram-positive bacteria.
Keyword(s): Experimental endocarditis, Vegetations, EchocardiographySession Type: 1-hour ePoster Review
Session Title: 1-hour ePoster Review
Authors(s): A. Dahl (1, 2), C. García-De-La-Mària (1), M.A. Cañas (1), J. García-González (1), B. Vidal (1), M. Hernandez-Meneses (1), A. Perissinotti (1), C. Falces (1), J.M. Pericàs (1), E. Quintana (1), J.M. Tolosana (1), M. Almela (1), J. Ambrosioni (1), A. Moreno (1), N.E. Bruun (3), J.M. Miró (1)
Authors Affiliations(s): (1) Hospital Clinic de Barcelona, Spain, (2) Herlev-Gentofte University Hospital, Denmark, (3) Zealand University Hospital, Denmark
Third Party Affiliation: On behalf of The Hospital Clínic Endocarditis Study group
Background:
No studies have described the natural history of vegetations in experimental endocarditis (EE) with Gram-positive cocci using daily sequential echocardiography. We aimed to compare the development of vegetations in EE caused by methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. epidermidis (MRSE), Streptococcus mitis and Enterococcus faecalis.
Methods:Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits with the polyethylene catheter left in place. Groups of 5 animals were then infected with MSSA with high biofilm production (MSSA-673), MSSA with low biofilm production (MSSA-236), S. mitis (SMIT-351), E. faecalis (EFAE-188) or MRSE (MRSE-375). Transthoracic echocardiography was performed before infection and daily until sacrifice at 48 hours post infection for MSSA and 96 hours post infection for S. mitis, E. faecalis and MRSE strains. At autopsy, tissue samples from cardiac vegetations, spleen and kidney were colonized for quantitative analysis of colony forming units (CFU) per gram tissue.
Results:Baseline mean length of the nonbacterial thrombotic vegetations was 2.4mm (±0.5mm) and the further evolution of vegetations is depicted in Figure 1. At 48 hours post infection, MSSA-673 caused an increase in vegetation size of 3.1mm (±0.6mm) compared to 2.2mm (±0.3mm) in MSSA-236 (p=0.03), 1.9mm (±0.7mm) in EFAE-188 (p=0.06), 1.6mm (±0.8mm) in SMIT-351 (p=0.02), and 1.6mm (±0.7mm) in MRSE-375 (p=0.01) (Figure 1). At 96 hours post infection the size of vegetations had increased 4.4mm (±1.6mm) in EFAE-188 compared to 2.8mm (±1.0mm) in SMIT-351 (p=0.15), and 2.9mm (±0.7mm) in MRSE-375 (p= 0.15). The correlation between vegetation weight at autopsy and vegetation size on echocardiography was very good (Pearson`s R = 0.86, p < 0.00001). The bacterial load in CFU found in the vegetations, the spleen and the kidney were comparable without any significant differences between the groups.
Conclusions:In experimental endocarditis, vegetation size on echocardiography correlated very well with vegetation weight at autopsy and vegetation size increased between two to three times in all cases being significantly greater in S. aureus with high biofilm production. This experimental study allows us to better understand the initial pathophysiological changes of the valve vegetations of IE caused by the most frequent Gram-positive bacteria.
Keyword(s): Experimental endocarditis, Vegetations, Echocardiography
Session Type: 1-hour ePoster Review
Session Title: 1-hour ePoster Review
Authors(s): A. Dahl (1, 2), C. García-De-La-Mària (1), M.A. Cañas (1), J. García-González (1), B. Vidal (1), M. Hernandez-Meneses (1), A. Perissinotti (1), C. Falces (1), J.M. Pericàs (1), E. Quintana (1), J.M. Tolosana (1), M. Almela (1), J. Ambrosioni (1), A. Moreno (1), N.E. Bruun (3), J.M. Miró (1)
Authors Affiliations(s): (1) Hospital Clinic de Barcelona, Spain, (2) Herlev-Gentofte University Hospital, Denmark, (3) Zealand University Hospital, Denmark
Third Party Affiliation: On behalf of The Hospital Clínic Endocarditis Study group
Background:
No studies have described the natural history of vegetations in experimental endocarditis (EE) with Gram-positive cocci using daily sequential echocardiography. We aimed to compare the development of vegetations in EE caused by methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. epidermidis (MRSE), Streptococcus mitis and Enterococcus faecalis.
Methods:Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits with the polyethylene catheter left in place. Groups of 5 animals were then infected with MSSA with high biofilm production (MSSA-673), MSSA with low biofilm production (MSSA-236), S. mitis (SMIT-351), E. faecalis (EFAE-188) or MRSE (MRSE-375). Transthoracic echocardiography was performed before infection and daily until sacrifice at 48 hours post infection for MSSA and 96 hours post infection for S. mitis, E. faecalis and MRSE strains. At autopsy, tissue samples from cardiac vegetations, spleen and kidney were colonized for quantitative analysis of colony forming units (CFU) per gram tissue.
Results:Baseline mean length of the nonbacterial thrombotic vegetations was 2.4mm (±0.5mm) and the further evolution of vegetations is depicted in Figure 1. At 48 hours post infection, MSSA-673 caused an increase in vegetation size of 3.1mm (±0.6mm) compared to 2.2mm (±0.3mm) in MSSA-236 (p=0.03), 1.9mm (±0.7mm) in EFAE-188 (p=0.06), 1.6mm (±0.8mm) in SMIT-351 (p=0.02), and 1.6mm (±0.7mm) in MRSE-375 (p=0.01) (Figure 1). At 96 hours post infection the size of vegetations had increased 4.4mm (±1.6mm) in EFAE-188 compared to 2.8mm (±1.0mm) in SMIT-351 (p=0.15), and 2.9mm (±0.7mm) in MRSE-375 (p= 0.15). The correlation between vegetation weight at autopsy and vegetation size on echocardiography was very good (Pearson`s R = 0.86, p < 0.00001). The bacterial load in CFU found in the vegetations, the spleen and the kidney were comparable without any significant differences between the groups.
Conclusions:In experimental endocarditis, vegetation size on echocardiography correlated very well with vegetation weight at autopsy and vegetation size increased between two to three times in all cases being significantly greater in S. aureus with high biofilm production. This experimental study allows us to better understand the initial pathophysiological changes of the valve vegetations of IE caused by the most frequent Gram-positive bacteria.
Keyword(s): Experimental endocarditis, Vegetations, EchocardiographySession Type: 1-hour ePoster Review
Session Title: 1-hour ePoster Review
Authors(s): A. Dahl (1, 2), C. García-De-La-Mària (1), M.A. Cañas (1), J. García-González (1), B. Vidal (1), M. Hernandez-Meneses (1), A. Perissinotti (1), C. Falces (1), J.M. Pericàs (1), E. Quintana (1), J.M. Tolosana (1), M. Almela (1), J. Ambrosioni (1), A. Moreno (1), N.E. Bruun (3), J.M. Miró (1)
Authors Affiliations(s): (1) Hospital Clinic de Barcelona, Spain, (2) Herlev-Gentofte University Hospital, Denmark, (3) Zealand University Hospital, Denmark
Third Party Affiliation: On behalf of The Hospital Clínic Endocarditis Study group
Background:
No studies have described the natural history of vegetations in experimental endocarditis (EE) with Gram-positive cocci using daily sequential echocardiography. We aimed to compare the development of vegetations in EE caused by methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. epidermidis (MRSE), Streptococcus mitis and Enterococcus faecalis.
Methods:Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits with the polyethylene catheter left in place. Groups of 5 animals were then infected with MSSA with high biofilm production (MSSA-673), MSSA with low biofilm production (MSSA-236), S. mitis (SMIT-351), E. faecalis (EFAE-188) or MRSE (MRSE-375). Transthoracic echocardiography was performed before infection and daily until sacrifice at 48 hours post infection for MSSA and 96 hours post infection for S. mitis, E. faecalis and MRSE strains. At autopsy, tissue samples from cardiac vegetations, spleen and kidney were colonized for quantitative analysis of colony forming units (CFU) per gram tissue.
Results:Baseline mean length of the nonbacterial thrombotic vegetations was 2.4mm (±0.5mm) and the further evolution of vegetations is depicted in Figure 1. At 48 hours post infection, MSSA-673 caused an increase in vegetation size of 3.1mm (±0.6mm) compared to 2.2mm (±0.3mm) in MSSA-236 (p=0.03), 1.9mm (±0.7mm) in EFAE-188 (p=0.06), 1.6mm (±0.8mm) in SMIT-351 (p=0.02), and 1.6mm (±0.7mm) in MRSE-375 (p=0.01) (Figure 1). At 96 hours post infection the size of vegetations had increased 4.4mm (±1.6mm) in EFAE-188 compared to 2.8mm (±1.0mm) in SMIT-351 (p=0.15), and 2.9mm (±0.7mm) in MRSE-375 (p= 0.15). The correlation between vegetation weight at autopsy and vegetation size on echocardiography was very good (Pearson`s R = 0.86, p < 0.00001). The bacterial load in CFU found in the vegetations, the spleen and the kidney were comparable without any significant differences between the groups.
Conclusions:In experimental endocarditis, vegetation size on echocardiography correlated very well with vegetation weight at autopsy and vegetation size increased between two to three times in all cases being significantly greater in S. aureus with high biofilm production. This experimental study allows us to better understand the initial pathophysiological changes of the valve vegetations of IE caused by the most frequent Gram-positive bacteria.
Keyword(s): Experimental endocarditis, Vegetations, Echocardiography