The first isolate of Candida auris in China: clinical and biological aspects

Abstract

The emerging human fungal pathogen Candida auris has been recognized as a multidrug resistant species and is associated with high mortality. This fungus was first described in Japan in 2009 and has been reported in at least 18 countries on five continents. In this study, we report the first isolate of C. auris from the bronchoalveolar lavage fluid (BALF) of a hospitalized woman in China. Interestingly, this isolate is susceptible to all tested antifungals including amphotericin B, fluconazole, and caspofungin. Copper sulfate (CuSO4) also has a potent inhibitory effect on the growth of this fungus. Under different culture conditions, C. auris exhibits multiple morphological phenotypes including round-to-ovoid, elongated, and pseudohyphal-like forms. High concentrations of sodium chloride induce the formation of a pseudohyphal-like form. We further demonstrate that C. auris is much less virulent than Candida albicans in both mouse systemic and invertebrate Galleria mellonella models.

Laboratory Analysis of an Outbreak of Candida auris in New York from 2016 to 2018-Impact and Lessons Learned

“…Candida auris was first described as a new species in 2009 from the ear discharge of a hospitalized patient in Japan (1). In the last decade, cases of C. auris have been reported from 18 countries on five continents including Asia, Africa, Europe, South America, and North America (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Fungemia caused by C. auris is associated with a high mortality rate and therapeutic failure (13).…”

Pseudohyphal growth of the emerging pathogenCandida aurisis triggered by genotoxic stress through the S phase checkpoint

“…Because the ability to switch between unicellular and filamentous forms plays a role in pathogenesis in some fungi (reviewed in (11,12)), we were interested whether C. auris has the capability to form filaments as well. Several conditions, which induce hyphal growth in C. albicans, such as incubation at 37 °C, and Lee's medium at pH3.5 or pH6.5, as well as media containing serum, isoamyl alcohol, or bleocin, were tested, but none of these triggered filamentous growth in the S. Asian (clade I) C. auris strain UACa11 (data not shown) (15). Likewise, growth at 25 °C did not produce filaments as described previously for a C. auris clinical isolate (21).…”

“…Filamentous growth allows the exploration of new environments and is considered a virulence trait in pathogenic fungi (reviewed in (13,14)). However, most cues causing filamentation in the best-studied and only distantly-related pathogen C. albicans do not induce filamentous growth in C. auris (15).…”

Impact of Candida auris infection in a neutropenic murine model

“…The current murine models for C. auris infection have used immunocompetent and immunosuppressed models. In the immunocompetent models, mice are infected with inoculums that range from 10 5 to 10 7 cells per animal (21, 22). However, there appears to be a difference in survival between the studies by Fahkim et al and Wang et al (21, 22).…”

“…In the immunocompetent models, mice are infected with inoculums that range from 10 5 to 10 7 cells per animal (21, 22). However, there appears to be a difference in survival between the studies by Fahkim et al and Wang et al (21, 22). Fakhim et al used ICR an outbred murine strain and infected them using two clinical isolates from the South Asian clade, that were characterized as non-aggregative and virulent (21).…”