Background

The CDC is recommending that US healthcare facilities be on the lookout for patients with Candida auris1 infection2. This concern is due to several factors: (1) C. auris can survive for weeks on inert surfaces3, (2) C. auris is multi-drug resistant against several classes of antifungals. Resistance to fluconazole and amphotericin B is common, and resistance to the echinocandins is emerging in some countries4. If the infection reaches the bloodstream, then treatment options are very limited. (3) There have been reports of several C. auris outbreaks around the world5–7, and reports of some patients with C. auris in the bloodstream.

C. auris and COVID

C. auris colonization/infection can impact COVID patients.

At a Florida hospital8, among 67 patients admitted to the COVID-19 unit and who were screened for C. auris colonization, 35 (52%) were positive.  6/35 (17%) colonized patients later had clinical cultures that grew C. auris. Among patients screened who had available medical records (20), eight (40%) died within 30 days of screening, but whether C. auris contributed to death is unknown.

At a New Delhi, India hospital9,  Candidemia affected 15 critically ill coronavirus disease patients admitted to an ICU unit during April–July 2020. C. auris accounted for two thirds of cases; and the case-fatality rate was high (60%).  A total of 596 patients with confirmed COVID were admitted to the 65-bed ICU during April–July 2020. Of these, 420 patients required mechanical ventilation. Overall, Candidemia was detected in 15 (2.5%) of the 596 ICU patients; the predominant agent was C. auris for 10 (67%) of those patients. For the remaining 5 patients, Candidemia was caused by C. albicans (n = 3), C. tropicalis (n = 1), and C. krusei (n = 1).  Most of the 10 patients with C. auris infection were elderly (8 patients were 66–88 years of age) and male (7 patients).  All of the COVID-19 patients in whom C. auris infections developed had been hospitalized in the ICU for prolonged periods (20–60 days) and had underlying chronic conditions (e.g., hypertension, n = 7; diabetes mellitus, n = 6; and chronic kidney and liver disease, n = 2). Candidemia caused by C. auris developed 10–42 days after admission.  Of note, 6 of the 10 patients died, possibly because of multiple underlying health conditions. However, 67% of those who died had persistent Candidemia, which may have contributed to their death.

Given these findings, public health agencies are advising that containment of C. auris is a public health priority.  For instance, the California Department of Public Health states10 “Containment of C. auris among patients and residents continues to be an urgent public health priority, particularly in the context of the COVID-19 pandemic and related challenges”, and that “healthcare providers be vigilant in considering C. auris status, in addition to COVID-19 status when caring for patients and residents”.

Our Technology

Status:  Coming soon

Media:  Our Candida auris test is based on our proprietary media that enables the differential detection and diagnosis of Candida auris, Candida albicans, Candida glabrata, Candida krusei and Candida tropicalis.  The media is implemented on a 96 well plate, and each well on the plate can support one sample.

Samples:  The test is meant for use on swabs of patient skin, which have been incubated and grown on the Sabourad-Dextrose media.  Isolated colonies from the SAB-DEX media are suspended in sterile saline to a concentration of 0.5 McFarland or greater (ie, visibly cloudy).  50 micro-liters of the suspension is added to one well in the 96 well plate.  Multiple isolated SAB-DEX colonies from each patient can be tested on each well.

Readout:  After an incubation period of 48 hours (36-54 hours), the color can be read visually and compared with a supplied color chart reader.  C. auris presents with a red coloration.  C. albicans presents with a red/green coloration (more red than green).  C. glabrata presents with a Yellow-Red coloration.  C. krusei presents with a Yellow coloration & C. tropicalis presents with a red-green coloration (more green than red)

Optional plate reader readout:  We also offer an optional plate reader readout that automates the readout and interfaces with your computer system.  Save the time involved in data entry, and reduce the possibility of human errors.

Advantages:  On competing ChromAgar Candida Auris media, different strains of C auris can present with different colors.  Sometimes, the same strain of C. auris can present with different colors, depending on the streaking method.  Finally, not all strains of C. auris grow on the traditional ChromAgar Candida Auris medium.  All of these , thereby introducing the possibility of errors.   

References

  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;53(1):41-44. doi:10.1111/j.1348-0421.2008.00083.x
  2. General Information about Candida auris | Candida auris | Fungal Diseases | CDC. Published November 13, 2019. Accessed September 10, 2021. https://www.cdc.gov/fungal/candida-auris/candida-auris-qanda.html
  3. Welsh RM, Bentz ML, Shams A, et al. Survival, Persistence, and Isolation of the Emerging Multidrug-Resistant Pathogenic Yeast Candida auris on a Plastic Health Care Surface. J Clin Microbiol. 2017;55(10):2996-3005. doi:10.1128/JCM.00921-17
  4. Lockhart SR. Candida auris and multidrug resistance: Defining the new normal. Fungal Genet Biol FG B. 2019;131:103243. doi:10.1016/j.fgb.2019.103243
  5. Vallabhaneni S, Kallen A, Tsay S, et al. Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus – United States, May 2013-August 2016. MMWR Morb Mortal Wkly Rep. 2016;65(44):1234-1237. doi:10.15585/mmwr.mm6544e1
  6. Chakrabarti A, Sood P, Rudramurthy SM, et al. Incidence, characteristics and outcome of ICU-acquired candidemia in India. Intensive Care Med. 2015;41(2):285-295. doi:10.1007/s00134-014-3603-2
  7. Lockhart SR, Etienne KA, Vallabhaneni S, et al. Simultaneous Emergence of Multidrug-Resistant Candida auris on 3 Continents Confirmed by Whole-Genome Sequencing and Epidemiological Analyses. Clin Infect Dis Off Publ Infect Dis Soc Am. 2017;64(2):134-140. doi:10.1093/cid/ciw691
  8. Prestel C. Candida auris Outbreak in a COVID-19 Specialty Care Unit — Florida, July–August 2020. MMWR Morb Mortal Wkly Rep. 2021;70. doi:10.15585/mmwr.mm7002e3
  9. Chowdhary A, Tarai B, Singh A, Sharma A. Multidrug-Resistant Candida auris Infections in Critically Ill Coronavirus Disease Patients, India, April–July 2020 – Volume 26, Number 11—November 2020 – Emerging Infectious Diseases journal – CDC. doi:10.3201/eid2611.203504
  10. Aragón TJ, Newsom G. California Department of Public Health. http://publichealth.lacounty.gov/acd/docs/Cauris_Surveillance_CAHAN_March2021.pdf.:3.