In vitro activity of caspofungin against planktonic and sessile Candida sp. cells

Area of Science:

• Mycology
• Infectious Diseases
• Biomaterials Science

Background:

• Candida species are a major cause of hospital-acquired infections, particularly those linked to indwelling medical devices.
• Medical device colonization by Candida leads to biofilm formation, complicating treatment and increasing infection risk.

Purpose of the Study:

• To evaluate the in vitro susceptibility of planktonic and sessile Candida sp. cells to caspofungin.
• To assess caspofungin's efficacy in preventing adhesion and biofilm formation on two types of medical biomaterials.

Main Methods:

• In vitro susceptibility testing of Candida sp. (nasopharyngeal isolates) to caspofungin.
• Evaluation of caspofungin's effect on planktonic and sessile cells adhered to silicone elastomer-coated latex urinary Foley catheters and PCV Thorax catheters.
• Determination of minimal inhibitory concentrations (MIC), minimal fungicidal concentrations (MFC), and concentrations preventing adhesion and biofilm formation.

Main Results:

• Low MIC and MFC values for caspofungin against planktonic Candida sp. cells (MIC: 0.008–0.031 mg/l, MFC: 0.008–0.062 mg/l).
• Caspofungin demonstrated significant anti-adherent and anti-biofilm formation activity at low concentrations (0.004–0.062 mg/l).
• Eradication of mature biofilms required substantially higher caspofungin concentrations (0.25 to >8 mg/l), varying by strain and biomaterial.

Conclusions:

• Caspofungin exhibits potent in vitro anti-adherent activity against Candida sp. on medical biomaterials.
• The drug shows promise for the prophylaxis of yeast infections associated with medical devices.
• Caspofungin is less effective for treating established Candida biofilms on these materials.