Pathological studies in experimental Candida endocarditis

Area of Science:

• Cardiology
• Mycology
• Pathology

Background:

• Catheter-associated infections pose a significant clinical challenge.
• Fungal endocarditis, particularly Candida albicans, is a serious complication.

Purpose of the Study:

• To investigate the pathological changes associated with Candida albicans-induced mycotic endocarditis in a rabbit model.
• To differentiate fungal endocardial lesions from sterile lesions caused by indwelling catheters.

Main Methods:

• Indwelling intracardiac catheters filled with Candida albicans suspension were used to induce mycotic endocarditis in rabbits.
• Control rabbits had sterile catheters inserted to create sterile endocardial lesions.
• Gross and microscopic pathological examinations were performed on cardiac tissues.

Main Results:

• Candida albicans induced massive fungoid valvular vegetations and sleeve thrombi around catheters.
• Microscopically, platelet-fibrin aggregates, neutrophylic collars with Candida cells, and subendothelial infiltration were observed.
• Sterile endocardial lesions presented as nodules and plaques composed of fibrous connective tissue without inflammatory cells.

Conclusions:

• Candida albicans forms characteristic vegetations and inflammatory responses in mycotic endocarditis.
• Retained catheters alone can induce sterile, fibrotic endocardial lesions.
• This model effectively differentiates fungal from sterile catheter-induced cardiac pathology.