β-lactam antibiotics & vancomycin increase the growth & virulence of Candida spp.

Abstract

Aim: To investigate the direct effect of antibiotics on growth and virulence of the major Candida species associated with invasive infections. Materials & methods: Cefepime, imipenem, meropenem, amoxicillin and vancomycin were tested at twofold the peak plasma concentration (2× PP) and the peak plasma concentration (PP). The effects of antibiotics on Candida albicans, Candida parapsilosis, Candida krusei and Candida tropicalis were investigated by colony counting, flow cytometry, proteolytic activity and virulence in Caenorhabditis elegans. Results: Antibiotics increase growth and proteolytic activity of Candida spp; In addition, amoxicillin potentiates virulence of C. krusei and C. tropicalis against Caenorhabditis elegans. Conclusion: These results suggest that antimicrobial therapy may have a direct effect on the pathophysiology of invasive fungal infections in patients at risk.