Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Rat model of experimental endocarditis.

J Santoro, M E Levison

    Infection and Immunity
    |March 1, 1978
    PubMed
    Summary
    This summary is machine-generated.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    A quality improvement strategy to reduce unintended extubation in the very low birth weight infant: A case report.

    Journal of neonatal-perinatal medicine·2024
    Same author

    1H, 13C, and 15N resonance assignments of the N-terminal domain of human Tubulin Binding Cofactor C.

    Biomolecular NMR assignments·2010
    Same author

    The solution structure and dynamics of human pancreatic ribonuclease determined by NMR spectroscopy provide insight into its remarkable biological activities and inhibition.

    Journal of molecular biology·2008
    Same author

    Femtosecond Ti:Sapphire Oscillator Electro-Optically Cavity Dumped at 50 kHz.

    Applied optics·2008
    Same author

    The validity and accuracy of the Work Productivity and Activity Impairment questionnaire--irritable bowel syndrome version (WPAI:IBS).

    Alimentary pharmacology & therapeutics·2004
    Same author

    Observation of an exotic S = +1 baryon in exclusive photoproduction from the deuteron.

    Physical review letters·2004
    Same journal

    A genome-wide CRISPR screen defines host determinants of early <i>Brucella</i> infection in human macrophage-like cells.

    Infection and immunity·2026
    Same journal

    Antiphospholipid antibodies in acute and post-treatment Lyme disease.

    Infection and immunity·2026
    Same journal

    The cholesterol-dependent cytolysin promotes <i>Streptococcus</i> systemic spread and induces arachidonic acid accumulation-mediated lethality in a murine intraperitoneal infection model.

    Infection and immunity·2026
    Same journal

    Phenotypic and genotypic analysis of <i>Candida albicans</i> vaginal isolates reveals that <i>ECE1</i> expression underpins pathogenicity.

    Infection and immunity·2026
    Same journal

    <i>Staphylococcus aureus</i> pore-forming toxins differentially shape disease severity in experimental endophthalmitis.

    Infection and immunity·2026
    Same journal

    Group B streptococcal membrane vesicles induce proinflammatory responses in neonatal meninges.

    Infection and immunity·2026
    See all related articles

    Researchers developed a new rat model to study infective endocarditis, a serious heart valve infection. By inserting a catheter into the heart and injecting specific bacteria, they successfully created persistent heart vegetations. This model allows scientists to test new treatments and better understand how these infections progress over time.

    Area of Science:

    • Cardiovascular pathology research within infective endocarditis studies
    • Experimental animal models in microbiology

    Background:

    Infective endocarditis remains a challenging condition to investigate due to limited reliable animal representations. Prior research has shown that creating consistent heart valve infections in small rodents is difficult. That uncertainty drove the need for a reproducible method to simulate human disease. Investigators previously struggled to maintain stable bacterial colonies within cardiac tissues. No prior work had resolved the issue of rapid clearance in non-catheterized subjects. This gap motivated the development of a surgical approach using indwelling devices. Scientists required a system that mimics the clinical progression of bacterial heart valve damage. Establishing such a platform provides a foundation for exploring the underlying mechanisms of this severe illness.

    Purpose Of The Study:

    The study aimed to establish a reliable and simple system for inducing infective endocarditis in laboratory animals. Researchers sought to overcome the limitations of previous methods that failed to produce consistent heart valve infections. They focused on creating a reproducible environment where bacterial colonies could thrive within cardiac tissues. This effort was driven by the need for a standardized platform to investigate disease progression. The team hypothesized that mechanical damage to the valves would facilitate persistent colonization. They designed a surgical protocol to test this premise using specific bacterial strains. By documenting the survival and infection rates, they intended to validate the utility of this approach. This research provides a necessary tool for future investigations into cardiac pathology and potential medical interventions.

    Keywords:
    cardiac surgerybacterial colonizationStreptococcus mitisStaphylococcus aureus

    Frequently Asked Questions

    The researchers propose that inserting a polyethylene catheter into the left ventricle creates a site for bacterial attachment. This mechanical disruption allows injected pathogens like Streptococcus mitis to colonize the heart valves, whereas non-catheterized animals clear the infection within five days.

    A polyethylene catheter serves as the primary tool to induce valvular damage. This device is passed through the right carotid artery into the left ventricle, creating the necessary conditions for bacterial vegetations to form and thrive.

    The authors note that the catheter must remain in the left ventricle to initiate the process. This placement is necessary because the mechanical trauma to the valve leaflets provides a surface for bacteria to adhere and multiply, unlike systemic circulation alone.

    Related Experiment Videos

    Main Methods:

    Review Approach: The investigators utilized a surgical technique involving Sprague-Dawley subjects weighing between 300 and 350 grams. A polyethylene tube was guided through the right carotid artery into the left ventricle. This procedure induced mechanical damage to the cardiac valves. One day after surgery, the team administered an intravenous injection containing one milliliter of bacterial culture. Three distinct strains, including Streptococcus mitis, were tested to evaluate colonization success. The researchers removed the indwelling devices twenty-four hours post-infection. They monitored blood cultures and tissue samples to assess the persistence of the microbial load. This systematic design ensured that the cardiac environment remained susceptible to sustained growth.

    Main Results:

    Key Findings From the Literature: The researchers observed that bacterial concentrations in heart vegetations reached 10(4)-fold higher levels than those found in other body tissues. Blood cultures consistently returned positive results six hours following the injection. Mortality reached 19% after the first week and climbed to 82% by the second week. When the catheter remained in place, vegetation titers exceeded 7.0 log10 colony-forming units per gram after five days. In contrast, subjects without the surgical device cleared all bacteria within three to five days. Staphylococcus aureus produced the highest vegetation density, exceeding 9.0 log10 colony-forming units per gram. Streptococcus faecalis showed a density of 8.8 plus or minus 0.3 log10 colony-forming units per gram after two days. These quantitative metrics confirm the successful establishment of persistent cardiac infections.

    Conclusions:

    The authors propose that this rat system serves as a viable platform for future investigations. Their findings suggest the methodology effectively mimics human disease progression. Investigators may utilize this approach to evaluate novel therapeutic interventions for heart valve infections. The team claims the model provides a consistent environment for studying bacterial colonization dynamics. Pathological assessments are now possible using this standardized surgical technique. The researchers indicate that the observed mortality rates align with severe clinical presentations. This work establishes a baseline for comparing different bacterial strains in cardiac environments. Future studies might leverage these results to refine treatment protocols for patients.

    The researchers utilize bacterial titers measured in colony-forming units per gram to quantify infection severity. These data indicate high colonization levels, specifically exceeding 9.0 log10 units for Staphylococcus aureus, confirming the model's effectiveness in sustaining localized heart infections.

    The team measured mortality rates, finding 19% at one week and 82% at two weeks. These metrics demonstrate the severe progression of the disease, providing a clear timeline for researchers to observe the impact of the infection on the subjects.

    The researchers propose that this system is suitable for future pathological and therapeutic studies. By providing a reliable way to induce and sustain endocarditis, the model allows for the testing of new medical treatments and a deeper understanding of cardiac infection pathology.