Characterization of Candida parapsilosis complex isolates

Abstract

Candida parapsilosis former groups II and III have recently been established as independent species, named Candida orthopsilosis and Candida metapsilosis, respectively. We investigated the distribution of C. parapsilosis complex species in 122 isolates from blood and other sources in a southern Spain tertiary-care hospital, and we examined the relationship between species, site of isolation and biofilm positivity. We also evaluated the planktonic MICs and sessile MICs (SMICs) of voriconazole, amphotericin B and anidulafungin. One hundred and eleven isolates (91%) were categorized as C. parapsilosis sensu stricto, whereas ten isolates (8.2%) were categorized as C. orthopsilosis and one (0.8%) as C. metapsilosis. Biofilm positivity was observed in 58.5% (65 of 111) of C. parapsilosis sensu stricto isolates vs. 0% (0 of 11) of C. orthopsilosis and C. metapsilosis isolates (p <0.01). There was no difference in biofilm production among C. parapsilosis sensu stricto isolates from blood and other sources. MIC values showed that all isolates were susceptible to voriconazole and amphotericin B, whereas two isolates (1.8%) of C. parapsilosis sensu stricto were non-susceptible to anidulafungin. However, the MIC₉₀ value of voriconazole was higher (0.125 mg/L) for C. orthopsilosis than for C. parapsilosis sensu stricto (0.03 mg/L). In contrast to planktonic cells, the SMICs show that amphotericin B and anidulafungin are moderately effective against the biofilm of C. parapsilosis sensu stricto, whereas voriconazole is ineffective.

Prospective Multicenter Study of the Epidemiology, Molecular Identification, and Antifungal Susceptibility of Candida parapsilosis, Candida orthopsilosis, and Candida metapsilosis Isolated from Patients with Candidemia

“…On the other hand, the most common underlying condition contributing to fungemia for the three species is the presence of indwelling catheters (65.3 to 100%). These findings confirm and extend those reported in previous studies (17,20,32,46).…”

Prevalence, distribution and antifungal susceptibility profiles of Candida parapsilosis, Candida orthopsilosis and Candida metapsilosis bloodstream isolates

“…The lowest MIC values were obtained for itraconazole and voriconazole. These data contrast with those from de Toro et al (2011), who found a lower susceptibility to voriconazole for C. orthopsilosis than for C. parapsilosis sensu stricto. The MICs for all isolates analysed fell within previously published MIC ranges: amphotericin B, 0.03-2 mg l Fluconazole 1 14 62 43 12 5 0 1 0 0 Itraconazole 30 54 45 9 0 0 0 0 0 0 Voriconazole 114 17 4 Antifungal susceptibility of the C. parapsilosis group the potential for cross-resistance among the newer generation of azoles, such as posaconazole and ravuconazole.…”

Analysis of Inteins in the Candida parapsilosis Complex for Simple and Accurate Species Identification

“…The differentiation of the psilosis complex into C. parapsilosis, C. orthopsilosis, and C. metapsilosis species is important for epidemiological purposes and also for changes in resistance to antifungal therapy, since C. orthopsilosis and C. metapsilosis are more susceptible to some currently used antifungals (16,17,19) and may have a lower capacity for biofilm formation (19,21).…”

“…Although the prevalences, distributions, drug susceptibilities, and biofilm productions of these species remain unclear, there are several studies that demonstrate differences among them (12,(15)(16)(17)(18)(19)(20)(21)(22). For instance, the recently published genome of C. orthopsilosis shows a reduction in the gene families associated with pathogenesis compared with that of C. parapsilosis (23).…”