Tools for detecting a “superbug”: updates on Candida auris testing

Author(s):  
Shawn R. Lockhart ◽  
Meghan M. Lyman ◽  
D. Joseph Sexton

Candida auris is an emerging yeast species that has the unique characteristics of patient skin colonization and rapid transmission within healthcare facilities and the ability to rapidly develop antifungal resistance. When C. auris first started appearing in clinical microbiology laboratories, it could only be identified using DNA sequencing. In the decade since its first identification outside of Japan there have been many improvements in the detection of C. auris . These include the expansion of MALDI-TOF databases to include C. auris , the development of both laboratory-developed tests and commercially available kits for its detection, and special CHROMagar for identification from laboratory specimens. Here we discuss the current tools and resources that are available for C. auris identification and detection.

2019 ◽  
Vol 5 (4) ◽  
pp. 94 ◽  
Author(s):  
Jochem B. Buil ◽  
Henrich A. L. van der Lee ◽  
Ilse Curfs-Breuker ◽  
Paul E. Verweij ◽  
Jacques F. Meis

Background: Candida auris is a yeast that is causing nosocomial outbreaks in healthcare facilities around the world. There is a risk of the misidentification of C. auris with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)—when libraries are used that lack C. auris spectra, or when conventional biochemical methods are used. Methods: We conducted an external quality assessment to evaluate the ability of Dutch clinical microbiological laboratories to identify C. auris, and to raise awareness about the risk of misidentification. Results: 35/47 participating laboratories were able to identify C. auris correctly. Only 2/14 labs that potentially misidentified C. auris with their primary identification methods specified that they would perform additional tests to exclude C. auris when appropriate. 45/47 labs used MALDI-TOF MS systems to identify Candida species. Conclusions: There was a lack of awareness about the potential misidentification of C. auris in many labs that used MALDI-TOF MS with libraries that lacked C. auris spectra, and labs that used Vitek 2. However, as the currently available MALDI-TOF MS libraries in The Netherlands contain several C. auris spectra, we expect that currently almost all participating laboratories are able to identify C. auris correctly, as 45/47 participating laboratories use MALDI-TOF MS as their primary yeast identification method.


Author(s):  
Diane Meyer ◽  
Elena K. Martin ◽  
Syra Madad ◽  
Priya Dhagat ◽  
Jennifer B. Nuzzo

Abstract Objective: Candida auris infections continue to occur across the United States and abroad, and healthcare facilities that care for vulnerable populations must improve their readiness to respond to this emerging organism. We aimed to identify and better understand challenges faced and lessons learned by those healthcare facilities who have experienced C. auris cases and outbreaks to better prepare those who have yet to experience or respond to this pathogen. Design: Semi-structured qualitative interviews. Setting: Health departments, long-term care facilities, acute-care hospitals, and healthcare organizations in New York, Illinois, and California. Participants: Infectious disease physicians and nurses, clinical and environmental services, hospital leadership, hospital epidemiology, infection preventionists, emergency management, and laboratory scientists who had experiences either preparing for or responding to C. auris cases or outbreaks. Methods: In total, 25 interviews were conducted with 84 participants. Interviews were coded using NVivo qualitative coding software by 2 separate researchers. Emergent themes were then iteratively discussed among the research team. Results: Key themes included surveillance and laboratory capacity, inter- and intrafacility communication, infection prevention and control, environmental cleaning and disinfection, clinical management of cases, and media concerns and stigma. Conclusions: Many of the operational challenges noted in this research are not unique to C. auris, and the ways in which we address future outbreaks should be informed by previous experiences and lessons learned, including the recent outbreaks of C. auris in the United States.


2020 ◽  
Vol 41 (S1) ◽  
pp. s292-s292
Author(s):  
William Rutala ◽  
Hajime Kanamori ◽  
Maria Gergen ◽  
Emily Sickbert-Bennett ◽  
David Jay Weber

Background:Candida auris is an emerging fungal pathogen that is often resistant to major classes of antifungal drugs. It is considered a serious global health threat because it has caused severe infections with frequent mortality in over a dozen countries. C. auris can survive on healthcare environmental surfaces for at least 7 days, and it causes outbreaks in healthcare facilities. C. auris has an environmental route of transmission. Thus, infection prevention strategies, such as surface disinfection and room decontamination technologies (eg, ultraviolet [UV-C] light), will be essential to controlling transmission. Unfortunately, data are limited regarding the activity of UV-C to inactivate this pathogen. In this study, a UV-C device was evaluated for its antimicrobial activity against C. auris and C. albicans. Methods: We tested the antifungal activity of a single UV-C device using the vegetative bacteria cycle, which delivers a reflected dose of 12,000 µW/cm2. This testing was performed using Formica sheets (7.6 × 7.6 cm; 3 × 3 inches). The carriers were inoculated with C. auris or C. albicans and placed horizontal on the surface or vertical (ie, perpendicular) to the vertical UV-C lamp and at a distance from 1. 2 m (~4 ft) to 2.4 m (~8 ft). Results: Direct UV-C, with or without FCS (log10 reduction 4.57 and 4.45, respectively), exhibited a higher log10 reduction than indirect UV-C for C. auris (log10 reduction 2.41 and 1.96, respectively), which was statistically significant (Fig. 1 and Table 1). For C. albicans, although direct UV-C had a higher log10 reduction (log10 reduction with and without FCS, 5.26 and 5.07, respectively) compared to indirect exposure (log10 reduction with and without FCS, 3.96 and 3.56, respectively), this difference was not statistically significant. The vertical UV had statistically higher log10 reductions than horizontal UV against C. auris and C. albicans with FCS and without FCS. For example, for C. auris with FCS the log10 reduction for vertical surfaces was 4.92 (95% CI 3.79, 6.04) and for horizontal surfaces the log10 reduction was 2.87 (95% CI, 2.36–3.38). Conclusions:C. auris can be inactivated on environmental surfaces by UV-C as long as factors that affect inactivation are optimized (eg, exposure time). These data and other published UV-C data should be used in developing cycle parameters that prevent contaminated surfaces from being a source of acquisition by staff or patients of this globally emerging pathogen.Funding: NoneDisclosures: None


2020 ◽  
Vol 41 (S1) ◽  
pp. s76-s77
Author(s):  
Kathleen O'Donnell ◽  
Ellora Karmarkar ◽  
Brendan R Jackson ◽  
Erin Epson ◽  
Matthew Zahn

Background: In February 2019, the Orange County Health Care Agency (OCHCA) identified an outbreak of Candida auris, an emerging fungus that spreads rapidly in healthcare facilities. Patients in long-term acute-care hospitals (LTACHs) and skilled nursing facilities that provide ventilator care (vSNFs) are at highest risk for C. auris colonization. With assistance from the California Department of Public Health and the Centers for Disease Control and Prevention, OCHCA instituted enhanced surveillance, communication, and screening processes for patients colonized with or exposed to C. auris. Method: OCHCA implemented enhanced surveillance by conducting point-prevalence surveys (PPSs) at all 3 LTACHs and all 14 vSNFs in the county. Colonized patients were identified through axilla/groin skin swabbing with C. auris detected by PCR and/or culture. In facilities where >1 C. auris colonized patient was found, PPSs were repeated every 2 weeks to identify ongoing transmission. Retrospective case finding was instituted at 2 LTACHs with a high burden of colonized patients; OCHCA contacted patients discharged after January 1, 2019, and offered C. auris screening. OCHCA tracked the admission or discharge of all colonized patients, and facilities with ongoing transmission were required to report transfers of any patient, regardless of colonization status. OCHCA tracked all patients discharged from facilities with ongoing transmission to ensure that accepting facilities conducted admission surveillance testing of exposed patients and implemented appropriate environmental and contact precautions. Result: From February–October 2019, 192 colonized patients were identified. All 3 LTACHs and 6 of 14 VSNFs had at least 1 C. auris–colonized patient identified on initial PPS, and 2 facilities had ongoing transmission identified on serial PPS. OCHCA followed 96 colonized patients transferred a total of 230 times (an average of 2.4 transfers per patient) (Fig. 1) and 677 exposed patients discharged from facilities with ongoing transmission (Fig. 2). Admission screening of 252 exposed patients on transfer identified 13 (5.2%) C. auris–colonized patients. As of November 1, 2019, these 13 patients were admitted 21 times to a total of 6 acute-care hospitals, 2 LTACHs, and 3 vSNFs. Transferring facilities did not consistently communicate the colonized patient’s status and the requirements for isolation and testing of exposed patients. Conclusion: OCHCA oversight of interfacility transfer, though labor-intensive, improved identification of patients colonized with C. auris and implementation of appropriate environmental and contact precautions, reducing the risk of transmission in receiving healthcare facilities.Funding: NoneDisclosures: None


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S576-S577
Author(s):  
Brittany O’Brien ◽  
Sudha Chaturvedi ◽  
Vishnu Chaturvedi

Abstract Background Candida auris outbreak continues unabated in New York with the current case counts exceeding 300 patients. We used a modification of standard CLSI broth microdilution method (BMD) if two-drug combinations are efficacious against C. auris isolates with high-resistance to fluconazole (FZ, MIC50 >256 mg/L), and variable resistance to other broad-spectrum antifungal drugs. Methods BMD plates were custom-designed and quality controlled by TREK Diagnostic System. The combination tests of 15 drug-resistant C. auris involved microtiter wells with the initial 144 two-drug combinations and their two-fold dilutions (1/2–1/32) to get 864 two-drug combinations finally. We utilized MIC100 endpoints for the drug combination readings as reported earlier for the intra- and inter-laboratory agreements obtained against Candida species and Aspergillus fumigatus (Antimicrob Agents Chemother. 2015. 59:1759–1766). We also tested minimum fungicidal concentrations (MFC). Results We tested all possible 864 two-drug antifungal combinations for nine antifungal drugs in use to yield 12,960 MIC100 readings, and MFC readings for 15 C. auris isolates. Flucytosine (FLC) at 2.0 mg/L potentiated most successful combinations with other drugs. Micafungin (MFG), Anidulafungin (AFG), Caspofungin (CAS) at individual concentrations of 0.25 mg/L combined well with FLC (2.0 mg/L) to yield MIC100 for 14, 13, and 12 of 15 C. auris isolates tested, respectively. MFG/FLC combination was also fungicidal for 4 of 15 isolates. AMB / FLC (0.25/1.0 mg/L) yielded MIC100 for 13 isolates and MFC for three test isolates. Posaconazole (POS), and Isavuconazole (ISA) and Voriconazole (VRC) also combined well with FLC (0.25/2.0 mg/L) to yield MIC100 for 12, 13, and 13 isolates, respectively. POS/FLC combination was fungicidal for three isolates. Conclusion We identified seven two drug-combinations of antifungals efficacious against drug-resistant C. auris strains. The modified BMD combination susceptibility testing could be used by the clinical laboratories to assist providers with the selection of optimal treatment for C. auris candidemia. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 16 (8) ◽  
pp. 695-710 ◽  
Author(s):  
Martin Welker ◽  
Alex Van Belkum ◽  
Victoria Girard ◽  
Jean-Philippe Charrier ◽  
David Pincus

2020 ◽  
Vol 6 (2) ◽  
pp. 72 ◽  
Author(s):  
Andrés Ceballos-Garzon ◽  
Daniela Amado ◽  
Norida Vélez ◽  
María José Jiménez-A ◽  
Crescencio Rodríguez ◽  
...  

Background: Candida auris is characterized for having a high genetic variability among species. MALDI-TOF MS library contains spectra from only three strains of C. auris, which makes difficult the identification process and gives low scores at the species level. Our aim was to construct and validate an internal library to improve C. auris identification with Colombian clinical strains. Methods: From 30 clinical strains, 770 mass spectra were obtained for the construction of the database. The validation was performed with 300 strains to compare the identification results in the BDAL and C. auris Colombia libraries. Results: Our library allowed a complete, 100% identification of the evaluated strains and a significant improvement in the scores obtained, showing a better performance compared to the Bruker BDAL library. Conclusions: The strengthening of the database is a great opportunity to improve the scoring and C. auris identification. Library data are available via ProteomeXchange with identifier PXD016387.


Sign in / Sign up

Export Citation Format

Share Document