Changes in the epidemiological landscape of invasive candidiasis.

The epidemiology of invasive candidiasis has evolved in recent years, warranting a review of the changes and the implications for current and future diagnosis and treatment. The overall burden of invasive candidiasis remains high, particularly in the expanding populations of patients at risk of opportunistic infection, such as the elderly or immunosuppressed. Progressive shifts from Candida albicans to non-albicans Candida spp. have been observed globally. The recent emergence of novel, multiresistant species, such as Candida auris, amplifies the call for vigilance in detection and advances in treatment. Among the current treatment options, fluconazole is still widely used throughout the world. Increased resistance to fluconazole, both acquired and naturally emerging, has been observed. Resistance to echinocandins is presently low but this may change with increased use. Improvement of diagnostic techniques and strategies, development of international surveillance networks and implementation of antifungal stewardship programmes represent major challenges for a better epidemiological control of invasive candidiasis

In Vitro Activity of Novel Antifungal Olorofim against Filamentous Fungi and Comparison to Eight Other Antifungal Agents

Olorofim is a novel antifungal drug that belongs to the orotomide drug class which inhibits fungal dihydroorotate dehydrogenase (DHODH), thus halting pyrimidine biosynthesis and ultimately DNA synthesis, cell growth and division. It is being developed at a time when many invasive fungal infections exhibit antifungal resistance or have limited treatment options. The goal of this study was to evaluate the in vitro effectiveness of olorofim against a large collection of recently isolated, clinically relevant American mold isolates. In vitro antifungal activity was determined for 246 azole-susceptible Aspergillus fumigatus isolates, five A. fumigatus with TR34/L98H-mediated resistance, 19 Rhizopus species isolates, 21 Fusarium species isolates, and one isolate each of six other species of molds. Olorofim minimum inhibitory concentrations (MICs) were compared to antifungal susceptibility testing profiles for amphotericin B, anidulafungin, caspofungin, isavuconazole, itraconazole, micafungin, posaconazole, and voriconazole. Olorofim MICs were significantly lower than those of the echinocandin and azole drug classes and amphotericin B. A. fumigatus wild type and resistant isolates shared the same MIC50 = 0.008 μg/mL. In non-Aspergillus susceptible isolates (MIC ≤ 2 μg/mL), the geometric mean (GM) MIC to olorofim was 0.54 μg/mL with a range of 0.015–2 μg/mL. Olorofim had no antifungal activity (MIC ≥ 2 μg/mL) against 10% of the collection (31 in 297), including some isolates from Rhizopus spp. and Fusarium spp. Olorofim showed promising activity against A. fumigatus and other molds regardless of acquired azole resistance

Genomic insights into multidrug-resistance, mating and virulence in Candida auris and related emerging species

Candida auris is an emergent fungal pathogen that is resistant to multiple antifungals. Here, Muñoz et al. analyse genomic sequences for isolates from each of the four major C. auris clades and for three related species, and identify genetic features associated with virulence, antifungal resistance and mating

Evaluation of CHROMagar Candida Plus for the detection of C. auris with a panel of 206 fungal isolates and 83 colonization screening skin-swabs

ABSTRACTCHROMagar Candida Plus is a new formulation of chromogenic media designed for the detection and differentiation of major clinical Candida species, including Candida auris. The objective of this study is to evaluate CHROMagar Candida Plus when used according to manufacturer’s instructions with a panel of 206 fungal isolates and 83 skin-swab specimens originally collected for C. auris colonization screening. Of the 68 C. auris isolates tested, 66/68 displayed the expected light-blue colony morphology and blue halo within 48 h. None of the remaining 138 non-auris isolates appeared similar to C. auris. CHROMagarCandida Plus was, therefore, inclusive to 97% of 68 C. auris isolates tested and supported visual exclusion of 100% of the 138 non-C. auris isolates tested. For the 83 colonization screening specimens, direct plating onto CHROMagarCandida Plus was 60% sensitive and 100% specific when compared to the enrichment broth gold-standard reference method. In sum, these findings demonstrate the utility of this media when working with isolates but also notable limitations when working with primary skin-swabs specimens when competing yeast species are present.IMPORTANCECandida auris is an emerging fungal pathogen of public health concern. As it continues to spread, it is important to publish evaluations of new diagnostic tools. In this study, we share our experience with a new chromogenic media which can help distinguish C. auris from related species

Disruption of the Transcriptional Regulator Cas5 Results in Enhanced Killing of Candida albicans by Fluconazole.

<p>Azole antifungal agents such as fluconazole exhibit fungistatic activity against Candida albicans. Strategies to enhance azole antifungal activity would be therapeutically appealing. In an effort to identify transcriptional pathways that influence the killing activity of fluconazole, we sought to identify transcription factors (TFs) involved in this process. From a collection of C. albicans strains disrupted for genes encoding TFs (Homann et al., PLoS Genet. 2009;5:e1000783), four exhibited a marked reduction in minimum fungicidal concentration (MFC) in both RPMI and YPD media. One of these, UPC2, has been previously characterized with regard to its role in azole susceptibility. Of mutants representing the three remaining TF genes of interest, one (CAS5) was unable to recover from fluconazole exposure at concentrations as low as 2 μg/mL after 72 hours in YPD medium. This mutant also showed reduced susceptibility and a clear zone of inhibition by Etest, was unable to grow on solid media containing 10 μg/mL fluconazole, and exhibited increased susceptibility by time-kill analysis. CAS5 disruption in highly azole-resistant clinical isolates exhibiting multiple resistance mechanisms did not alter susceptibility. However, CAS5 disruption in strains with specific resistance mutations in ergosterol biosynthesis or efflux pumps resulted in a moderate reduction in MIC and MFC. Genome-wide transcriptional analysis was performed in the presence of fluconazole and was consistent with the suggested role of CAS5 in cell wall organization while also suggesting a role in iron transport and homeostasis. These findings suggest that Cas5 regulates a transcriptional network that influences the response of C. albicans to fluconazole. Further delineation of this transcriptional network may identify targets for potential co-therapeutic strategies to enhance the activity of the azole class of antifungals.</p

Ibrexafungerp:A novel oral triterpenoid antifungal in development for the treatment of candida auris infections

Candida auris is an emerging multidrug-resistant fungal pathogen reported worldwide. Infections due to C. auris are usually nosocomial and associated with high rates of fluconazole resistance and mortality. Echinocandins are utilized as the first-line treatment. However, echinocandins are only available intravenously and are associated with increasingly higher rates of resistance by C. auris. Thus, a need exists for novel treatments that demonstrate potent activity against C. auris. Ibrexafungerp is a first-in-class triterpenoid antifungal agent. Similar to echinocandins, ibrexafungerp inhibits (1&rarr;3)-&beta;-D-glucan synthase, a key component of the fungal cell wall, resulting in fungicidal activity against Candida spp. Ibrexafungerp demonstrates broad in vitro activity against various Candida spp. including C. auris and C. auris isolates with fks mutations. Minimum inhibitory concentration (MIC50 and MIC90) values in &gt;400 C. auris isolates were 0.5 &mu;g/mL and 1.0 &mu;g/mL, respectively. Clinical results were reported for two patients with invasive candidiasis or candidemia due to C. auris treated during the CARES (Candidiasis Caused by Candida Auris) trial, an ongoing open-label study. These patients experienced a complete response after treatment with ibrexafungerp. Thus, ibrexafungerp represents a promising new antifungal agent for treating C. auris infections