Candida haemulonii complex: species identification and antifungal susceptibility profiles of clinical isolates from Brazil

Abstract

Our results reinforce the importance of molecular identification in differentiating species of the C. haemulonii complex. Moreover, the antifungal multiresistant profile of clinical isolates of the C. haemulonii complex represents a challenge to the treatment of such infections.

Identification and Antifungal Susceptibility Profiles of Candida haemulonii Species Complex Clinical Isolates from a Multicenter Study in China

“…We recommend that C. haemulonii complex isolates with high MICs to fluconazole be assessed for susceptibility to the other azoles. Echinocandins demonstrated excellent in vitro potency against the isolates (9,22). In the present study, our in vitro antifungal susceptibility data showed that MICs to echinocandins were low, indicating that there may be better treatment options.…”

“…Overall, during the 5-year CHIF-NET study, C. haemulonii complex isolates represented 0.3% (31/9,673) of all yeast isolates, which was higher than the rate noted in the ARTEMIS study but similar to the rate found in Brazil (21,22). The identification and differentiation of C. haemulonii complex isolates relies on molecular methods, so it is difficult to compare the proportions because laboratories differ in the extent to which they identify uncommon Candida species to the species level; of laboratories that do identify to the species level, different methodologies are often used (8,9). In our study, we have reinforced that molecular methods are the preferred approach for definitive identification of members within the species complex.…”

“…In 2012, Cendejas-Bueno et al (8) proposed a reclassification of the C. haemulonii complex based on molecular methods; this taxonomic reclassification has prompted many laboratories to reexamine their culture collections for these species. To date, most of the C. haemulonii complex isolates identified by ITS sequencing were reported in Brazil (5,8,9,22), including 12 isolates and 31 isolates from two reports of a local national epidemiology study (9,22). We therefore determined the proportion of C. haemulonii complex isolates among clinical strains cultured from patients with IFDs in China and their antifungal susceptibilities by the broth microdilution method.…”

“…haemulonii complex often exhibits antifungal resistance, with clinical failure associated with in vitro resistance to amphotericin B and reduced susceptibility to azoles (6,7,9,10,(13)(14)(15). Moreover, C. haemulonii isolates with resistance to echinocandins have been reported (11).…”

“…Their differentiation relies on molecular methods with good discrimination to the species and varietal or intraspecies levels, such as sequence analysis of the ribosomal DNA (rDNA) internal transcribed spacer (ITS) genes. The use of ITS sequencing (considered the reference method) together with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) may provide improved discrimination of members of this complex for reference spectra that are contained within the used MS database (8,9). In contrast, phenotypic identification methods, such as the API 20C and Vitek yeast identification systems (bioMérieux, Marcy l'Etoile, France), typically lead to errors in identification (10,11).…”