Candida Pathogenicity and Alternative Therapeutic Strategies

Human fungal infections are widespread and difficult to treat. Candida albicans, a common fungal pathogen, exhibits different strategies for growth, proliferation, and survival within the host, as it is armed with mechanisms to escape the host defense system. This opportunistic commensal expresses several virulence factors such as adhesins, yeast to hyphal transition, phenotypic switching, biofilm formation, and secretion of hydrolytic enzymes, mainly proteases and phospholipases. Depending upon the mode of action, several classes of antifungal drugs have been developed till date. However, most of them are toxic with side effects. Excessive use and abuse of these drugs have led to the evolution of multidrug-resistant strains at an alarming rate leading to treatment failures. Since a change has been observed in pathogenesis strategies of Candida species, the treatment strategies also need to be improved. Continuous chemotherapies in immunocompromised patients, especially in HIV patients with oropharyngeal Candida infections, have led to severe host tissue toxicity. Therefore, safer phytomedicines, which are more efficacious, nontoxic, easily available, and do not develop resistance in fungal strains, are required. Plant extracts, essential oils, and their constituents that show promising antifungal potential are better and safer alternatives. Alternate therapeutic strategies also include chemosensitizing the pathogenic fungi to conventional antifungals using natural plant products.