candidozyma auris

Candida auris, which was first isolated from the external ear canal of a patient in Japan in 2009, was included in the genus Candidozyma in 2024 and named Candidozyma auris (1):

• C. auris is a yeast fungus that is resistant to many antifungals at varying rate
• C. auris is much less common than other types of yeast, such as Candida albicans (which causes thrush)
  • since it was first identified, C. auris has been found in patients across the world
  • is most commonly found in healthcare settings, such as hospitals
  • can result in colonisation (where individuals are carrying the organism without signs or symptoms of infection) as well as severe invasive infections
    • can also cause outbreaks; this is of concern within healthcare settings, particularly where there are critically unwell patients being cared for in high-dependency or intensive care settings for prolonged periods, or for patients who have weakened immune systems
    • in settings outside of the UK, invasive C. auris infections have been associated with a high mortality rate
    • has developed resistance to many available classes of antifungals, including the first-line agent fluconazole, and strains of C. auris which are resistant to all antifungals have been detected
• six genetically distinct clades of C. auris have been discovered to date, including (2):
  • the South Asian clade, first detected in India and Pakistan (clade I),
  • the East Asian clade, first detected in Japan (clade II),
  • the South African clade, first detected in South Africa (clade III),
  • the South American clade, first detected in Venezuela (clade IV), and
  • 2 further clades that have recently been detected in Iran (clade V) and Singapore (clade VI)

• each clade is associated with certain clinical presentations, resistance patterns, and differences in virulence

• prolonged exposure to broad-spectrum antibiotic and antifungal agents are identified risk factors for C. auris colonisation and infection
  
  
• a study in India investigated the susceptibility patterns of 350 C. auris isolates and showed that 90% were resistant to azoles (fluconazole) (3):
  • overall, 25% and 13% of isolates were multidrug resistance (MDR) and multi-azole resistant, respectively
    • most common resistance combination was azoles and 5-flucytosine in 14% followed by azoles and amphotericin B in 7% and azoles and echinocandins in 2% of isolates

Continuous carriage for more than a year after initial isolation of C. auris has been documented and routine screening of previously positive inpatients may produce unreliable, intermittent negative screens (2)

• due to the uncertainty about how long people may remain colonised, a precautionary approach to patient isolation is advised on readmission where feasible and appropriate for patient management and hospital pathways

Management of symptomatic/invasive candidiasis

• approach to the initial management of candidaemia or invasive candidiasis due to C. auris remains the same as with all invasive candidiasis, and includes source control, clearance blood cultures and excluding organ involvement
• seek expert advice and consult local guidance regarding choice of antifungal therapy
  • first-line therapy remains an echinocandin, pending susceptibility testing (2)
    • most C. auris isolates described worldwide are resistant to fluconazole and therefore fluconazole should not be used for treatment or de-escalation
    • liposomal amphotericin is recommended for patients infected with echinocandin-resistant C.auris, those experiencing treatment failure or breakthrough infection on an echinocandin, or those with infections at sites poorly penetrated by echinocandins (such as the CNS or eye)
    • for CNS candidiasis, combination therapy with liposomal amphotericin and flucytosine is recommended

Reference:

1. Satoh K, Makimura K, Hasumi Y, Nishiyama Y, Uchida K, Yamaguchi H. Candida auris sp. nov. a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital. Microbiol Immunol. 2009. Jan 15;53(1):41–4.
2. UK Health Security Agency (August 21st 2025). Management of patients who test positive for C. auris (colonised or infected).
3. Chowdhary A et al. A multicentre study of antifungal susceptibility patterns among 350 Candida auris isolates (2009-17) in India: role of the ERG11 and FKS1 genes in azole and echinocandin resistance. J Antimicrob Chemother. 2018 Apr 1;73(4):891-899.