Candida parapsilosis complex: epidemiological peculiarities, virulence and mechanisms of antifungal resistance

Abstract

Candida albicans remains the most prevalent species in human superficial and invasive Candida infections, although there is concern over the increasing rates of non-C. albicans infections worldwide. C. parapsilosis is the second Candida species most frequently isolated from blood cultures in South America and in some European countries, such as Spain and Italy. Since 2005, when this taxon has been considered a complex of 3 closely related species: C. parapsilosis (sensu stricto), C. metapsilosis and C. orthopsilosis, few studies have evaluated potential biological, epidemiological and clinical peculiarities related to these three species. Thus it still remains in uncertain if the knowledge gained in relation to infections by Candida parapsilosis (sensu stricto) can be extrapolated to cases of invasive infections by Candida orthopsilosis and C. metapsilosis. In this scenario, the objectives of this work are: 1) To evaluate the epidemiology of Candida parapsilosis species complex in Latin America; 2) To evaluate the antifungal susceptibility profile of isolates of C. parapsilosis species complex; 3)To identify and characterize the mechanisms involved in resistance to azoles and echinocandins; 4) To assess, using Caenorhabditis elegans as an experimental model, the pathogenicity of isolates of Candida parapsilosis (sensu stricto), C, orthopsilosis and C. metapsilosis;.and, 5) To describe and characterize the virulence factors expressed by Candida parapsilosis (sensu stricto), C. orthopsilosis and C. metapsilosis during the development of infection. This project aims to assess the epidemiology of three species of Candida parapsilosis complex in medical centers in Latin America as well as identify the possible peculiarities of the three species with regard to antifungal susceptibility, expression of resistance mechanisms and pathogenicity involved with infection. This study has the support of the Laboratory of Pharmacology.