Inactivation of Candida auris and Candida albicans by Ultraviolet-C

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

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Susceptibility of Candida auris and Candida albicans to 21 germicides used in healthcare facilities

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2019.1 ◽

2019 ◽

Vol 40 (3) ◽

pp. 380-382 ◽

Cited By ~ 18

Author(s):

William A. Rutala ◽

Hajime Kanamori ◽

Maria F. Gergen ◽

Emily E. Sickbert-Bennett ◽

David J. Weber

Keyword(s):

Fungal Pathogen ◽

Infection Prevention ◽

Antifungal Drugs ◽

Prevention Strategies ◽

Candida Auris ◽

Healthcare Facilities ◽

Surface Disinfection ◽

Environmental Surfaces ◽

Severe Infections ◽

High Level

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 can cause severe infections with frequent mortality in more than a dozen countries. It can survive on healthcare environmental surfaces for at least 7 days and can cause outbreaks in healthcare facilities. Clearly, infection prevention strategies, such as surface disinfection, will be essential to controlling Candida transmission. Unfortunately, data on the activity of antiseptics and disinfectants used in healthcare to inactivate this pathogen are limited.1–5 In this study, we investigated 12 different disinfectants (ie, 8 low- and intermediate-level disinfectants in 2 dilutions of sodium hypochlorite and 5 high-level disinfectants/chemical sterilants) and 9 antiseptics commonly used in healthcare facilities for their antimicrobial activity against C. auris and C. albicans.

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Relative Resistance of the Emerging Fungal Pathogen Candida auris and Other Candida Species to Killing by Ultraviolet Light

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2017.239 ◽

2017 ◽

Vol 39 (1) ◽

pp. 94-96 ◽

Cited By ~ 26

Author(s):

Jennifer L. Cadnum ◽

Aaron A. Shaikh ◽

Christina T. Piedrahita ◽

Annette L. Jencson ◽

Emily L. Larkin ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Candida Species ◽

Fungal Pathogen ◽

Laboratory Testing ◽

Multidrug Resistant ◽

Relative Resistance ◽

Candida Auris ◽

Healthcare Facilities ◽

Ultraviolet C ◽

Uv C

Mobile ultraviolet-C (UV-C) light room decontamination devices are frequently used as an adjunct to standard cleaning in healthcare facilities, but their efficacy in killing Candida species is not clear. In laboratory testing, the emerging multidrug-resistant Candida auris and 2 other Candida species were significantly less susceptible to killing by UV-C than methicillin-resistant Staphylococcus aureus.Infect Control Hosp Epidemiol 2018;39:94–96

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1579. Multidrug-Resistant Candida auris Isolates From New York Hospitals and Healthcare Facilities Are Susceptible to Antifungal Combinations

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1443 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S576-S577

Author(s):

Brittany O’Brien ◽

Sudha Chaturvedi ◽

Vishnu Chaturvedi

Keyword(s):

New York ◽

Diagnostic System ◽

Multidrug Resistant ◽

Drug Combinations ◽

Antifungal Drugs ◽

Drug Resistant ◽

Candida Auris ◽

Current Case ◽

Healthcare Facilities ◽

Broth Microdilution Method

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.

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1215. Ultraviolet-C (UV-C) Monitoring Made Ridiculously Simple: UV-C Dose Indicators for Convenient Measurement of UV-C Dosing

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1078 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S437-S437

Author(s):

Jennifer Cadnum ◽

Annette Jencson ◽

Sarah Redmond ◽

Thriveen Sankar Chittoor Mana ◽

Curtis Donskey

Keyword(s):

Methicillin Resistant Staphylococcus Aureus ◽

Fetal Calf Serum ◽

Color Change ◽

Calf Serum ◽

Organic Load ◽

Healthcare Facilities ◽

Log Reduction ◽

Ultraviolet C ◽

Effective Doses ◽

Uv C

Abstract Background Ultraviolet-C (UV-C) light is increasingly used as an adjunct to standard cleaning in healthcare facilities. However, most facilities do not have a means to measure UV-C to determine whether effective doses are being delivered. We tested the efficacy of 2 easy-to-use colorimetric indicators for monitoring UV-C dosing in comparison to log reductions in pathogens. Methods In a laboratory setting, we exposed methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile spores on steel disk carriers with or without an organic load (5% fetal calf serum) to UV-C for varying times resulting in fluence exposures ranging from 10,000 to 100,000 µJ/cm2. The UV-C indicators were placed adjacent to the carriers. Log reductions were calculated in comparison to untreated controls and the change in color of the indicators was correlated with dose and log reductions. Results The UV-C doses required to achieve a 3-log reduction in MRSA and C. difficile were 10,000 and 46,000 µJ/cm2, respectively. For both indicators, there was a visible color change from baseline at 10,000 µJ/cm2 and a definite final color change by 46,000 µJ/cm2 (Figure 1). Organic load had only a modest impact on UV-C efficacy. The indicators required only a few seconds to place and were easy to read (Figure 2). Conclusion UV-C doses of 10,000 and 46,000 µJ/cm2 were required to achieve 3 log reductions of MRSA and C. difficile spores, respectively. The colorimetric indicators provide an easy means to monitor UV-C dosing. Disclosures All authors: No reported disclosures.

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Candida auris: a fungus with identity crisis

Pathogens and Disease ◽

10.1093/femspd/ftaa034 ◽

2020 ◽

Vol 78 (4) ◽

Author(s):

Taissa Vila ◽

Ahmed S Sultan ◽

Daniel Montelongo-Jauregui ◽

Mary Ann Jabra-Rizk

Keyword(s):

Fungal Species ◽

Antifungal Drugs ◽

Multiple Drug ◽

Rapid Diagnostics ◽

Contributing Factors ◽

Candida Auris ◽

Healthcare Facilities ◽

Drug Classes ◽

Recent Emergence ◽

Robust Response

ABSTRACT Candida auris is a new fungal species that has puzzlingly and simultaneously emerged on five continents. Since its identification in 2009, the scientific community has witnessed an exponential emergence of infection episodes and outbreaks in healthcare facilities world-wide. Candida auris exhibits several concerning features compared to other related Candida species, including persistent colonization of skin and nosocomial surfaces, ability to resist common disinfectants and to spread rapidly among patients. Resistance to multiple drug classes and misidentification by available laboratory identification systems has complicated clinical management, and outcomes of infection have generally been poor with mortality rates approaching 68%. Currently, the origins of C. auris are unclear, and therefore, it is impossible to determine whether environmental and climactic changes were contributing factors in its recent emergence as a pathogen. Nevertheless, a robust response involving rapid diagnostics, prompt interventions and implementation of precautions, are paramount in curtailing the spread of infections by this fungal species. Importantly, there is a pressing need for the development of new antifungal drugs. In this article, we present a brief overview highlighting some of the important aspects of C. auris epidemiology, pathogenesis and its puzzling global emergence.

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Reducing Dissemination of Viruses from Computer Touchscreens through Patient Hand Hygiene and an Automated Ultraviolet-C Touchscreen Disinfection Device

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx163.1026 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S410-S410

Author(s):

Heba Alhmidi ◽

Jennifer Cadnum ◽

Christina Piedrahita ◽

Amrita John ◽

Curtis Donskey

Keyword(s):

Hand Hygiene ◽

Healthcare Facilities ◽

Hand Sanitizer ◽

Enveloped Virus ◽

Education Of Patients ◽

Bacteriophage Ms2 ◽

Ultraviolet C ◽

Waiting Area ◽

C 30 ◽

Uv C

Abstract Background Computer touchscreens in patient waiting areas are a potential source for spread of viral and bacterial pathogens in healthcare facilities. Patient hand hygiene is recommended to prevent acquisition of pathogens on hands. Methods We tested the efficacy of patient hand hygiene alone or in combination with a novel automated ultraviolet-C (UV-C) touchscreen disinfection device for reduction in dissemination of the nonpathogenic non-enveloped virus bacteriophage MS2 from contaminated touchscreens. Subjects randomized to control, alcohol hand sanitizer (10 or 30 second application), UV-C (30-second cycle), or alcohol hand sanitizer plus UV-C contacted 4 sites routinely used during operation of the touchscreen and then fingerpads were cultured. The log plaque-forming units (PFU) recovered were compared for each group. Patients were observed to determine the frequency of hand hygiene after use of a touchscreen in a waiting area. Results As shown in the figure, the mean log10PFU of bacteriophage MS2 recovered from fingerpads was significantly reduced by each of the interventions (P < 0.001). However, only the combination of hand hygiene and UV-C was effective in completely preventing virus transfer. Of 20 patients observed in a waiting area, 0 (0%) used hand sanitizer that was available adjacent to the touchscreen. Conclusion Our results suggest that use of alcohol hand sanitizer alone or in combination with an automated UV-C touchscreen disinfection device could reduce transmission of viruses from contaminated touchscreens. There is a need for education of patients on the importance of hand hygiene after contact with touchscreens. Disclosures All authors: No reported disclosures.

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Molecular Diagnostics in the Times of Surveillance for Candida auris

Journal of Fungi ◽

10.3390/jof5030077 ◽

2019 ◽

Vol 5 (3) ◽

pp. 77 ◽

Cited By ~ 8

Author(s):

Milena Kordalewska ◽

David S. Perlin

Keyword(s):

Dna Amplification ◽

Antifungal Drugs ◽

Infection Prevention And Control ◽

Diagnostic Tools ◽

Candida Auris ◽

Accurate Identification ◽

Healthcare Facilities ◽

Antifungal Drug Resistance ◽

The Times ◽

Almost All

Recently, global health professionals have been significantly challenged by the emergence of Candida auris and its propensity to colonize human skin, persist in the healthcare environment, and cause healthcare-associated outbreaks. Additionally, C. auris isolates are often characterized by elevated minimal inhibitory concentration (MIC) values for antifungal drugs. Thus, rapid detection and accurate identification of C. auris together with an assessment of potential antifungal drug resistance has become essential for effective patient management, and infection prevention and control in healthcare facilities. Surprisingly, almost all of the commonly available diagnostic tools rely on recovery (growth) of yeast colonies from collected samples, which delays the diagnostic result by several days or longer. To circumvent these issues, molecular-based DNA amplification assays have been developed to identify C. auris DNA directly from patient samples. Moreover, allele discriminating detection probes can be used to rapidly assess validated mechanisms of echinocandin and azole resistance.

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Efficacy of relatively low-cost ultraviolet-C light devices against Candida auris

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2021.206 ◽

2021 ◽

pp. 1-5

Author(s):

Basya S. Pearlmutter ◽

Muhammed F. Haq ◽

Jennifer L. Cadnum ◽

Annette L. Jencson ◽

Matthew Carlisle ◽

...

Keyword(s):

Low Cost ◽

Test Method ◽

Clinical Settings ◽

Candida Auris ◽

Resource Limited ◽

Colorimetric Indicator ◽

Ultraviolet C ◽

American Society ◽

Carrier Test ◽

Uv C

Abstract Background: Ultraviolet-C (UV-C) light devices could be useful to reduce environmental contamination with Candida auris. However, variable susceptibility of C. auris strains to UV-C has been reported, and the high cost of many devices limits their use in resource-limited settings. Objective: To evaluate the efficacy of relatively low-cost (<$15,000 purchase price) UV-C devices against C. auris strains from the 4 major phylogenetic clades. Methods: A modification of the American Society for Testing and Materials (ASTM) standard quantitative disk carrier test method (ASTM E 2197) was used to examine and compare the effectiveness of UV-C devices against C. auris, methicillin-resistant Staphylococcus aureus (MRSA), and bacteriophage Phi6. Reductions of 3 log10 were considered effective. UV-C irradiance measurements and colorimetric indicators were used to assess UV-C output. Results: Of 8 relatively low-cost UV-C devices, 6 met the criteria for effective decontamination of C. auris isolates from clades I and II, MRSA, and bacteriophage Phi6, including 3 room decontamination devices and 3 UV-C box devices. Candida auris isolates from clades III and IV were less susceptible to UV-C than clade I and II isolates; 1 relatively low-cost room decontamination device and 2 enclosed box devices met the criteria for effective decontamination of clade III and IV isolates. UV-C irradiance measurements and colorimetric indicator results were consistent with microorganism reductions. Conclusions: Some relatively low-cost UV-C light technologies are effective against C. auris, including isolates from clades III and IV with reduced UV-C susceptibility. Studies are needed to evaluate the effectiveness of UV-C devices in clinical settings.

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Tuning a UV-C device to challenge new threats in the sanitization setting of healthcare facilities

European Journal of Public Health ◽

10.1093/eurpub/ckaa165.171 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

D Amodeo ◽

L Pallecchi ◽

C Nagaia ◽

G Spataro ◽

R Cardaci ◽

...

Keyword(s):

Light Exposure ◽

Multidrug Resistant ◽

Candida Auris ◽

Healthcare Facilities ◽

Hospital Environments ◽

Cross Transmission ◽

Different Strains ◽

Healthcare Associated ◽

Uv Technology ◽

Uv C

Abstract Background Environmental hospital hygiene plays a role in healthcare-associated infections emergency caused by resistant multi-drug organisms. The implementation of new and effective disinfection procedures is now more than ever important to prevent the cross-transmission of pathogens in the hospital facilities. In combination with common chemicals biocides, UV technology is a realistic option for environmental disinfection. In this study, we evaluate a UV device for its effectiveness on an emerging pathogen. Methods A laboratory cross section experiment was performed between August and October 2019. Two different strains of Candida auris (CBS 10913 and CBS 12372) were tested on 20 cm2 stainless steel carriers inoculated with 10 µl of bacterial culture at a concentration of 1x105 CFU/mL. The inoculum was spread until dry in aseptic condition. Carriers were placed parallel to the UV device, having 4 UV-C lamps that emit 325 W, at a fixed distance of 2.44 m. Biocidal tests were carried out in triple at three different light exposure times (5, 10 and 20 minutes). After treatment, laboratories procedures were used to detach and transfer the remaining microorganisms from the carriers to plates and compared them to controls after incubation at 37 °C for 48 h. Results A significant inactivation of C. auris already occurred at 5 minutes, reaching 3-4 log10 reduction at 20 minutes of UV-C exposure. No substantial differences were identified by analyzing the results between the two strains. Conclusions The chosen distance of 2.44 m from the target allows to ideally sanitize an entire hospital room. However, to avoid the limit of shaded areas due to the presence of non-movable objects, a couple of positions are recommended, so that shorter distances can reduce the exposure time or increase the average irradiance level of exposed surfaces. Key messages In sanitation of hospital environments, the use of viable alternatives as UV-C can contribute to the reduction of infections caused by multidrug-resistant microorganisms. Accurate testing of different space-time irradiation configurations allows to achieve important results related to the biocidal effects of UV devices.

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Clade-specific variation in susceptibility of Candida auris to broad-spectrum ultraviolet C light (UV-C)

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.410 ◽

2020 ◽

Vol 41 (12) ◽

pp. 1384-1387

Author(s):

Piyali Chatterjee ◽

Hosoon Choi ◽

Brennan Ochoa ◽

Gennifer Garmon ◽

John D. Coppin ◽

...

Keyword(s):

Broad Spectrum ◽

Multidrug Resistant ◽

Uv Exposure ◽

Candida Auris ◽

Cumulative Impact ◽

Colony Forming Units ◽

Ultraviolet C ◽

Specific Variation ◽

Uv C

AbstractBackground:Candida auris is an emerging and often multidrug-resistant fungal pathogen with an exceptional ability to persist on hospital surfaces. These surfaces can act as a potential source of transmission. Therefore, effective disinfection strategies are urgently needed. We investigated the efficacy of ultraviolet C light (UV-C) disinfection for C. auris isolates belonging to 4 different clades.Methods:In vitro testing of C. auris isolates was conducted using 106 colony-forming units (CFU) spread on 20-mm diameter steel carriers and exposed to a broad-spectrum UV-C light source for 10, 20, and 30 minutes at a 1.5 m (5 feet) distance. Post-UV survivors on the coupons were subsequently plated. Colony counts and log reductions were recorded, calculated, and compared to untreated control carriers. Identification of all isolates were confirmed by MALDI-TOF and morphology was visualized by microscopy.Results:We observed an increased susceptibility of C. auris to UV-C in 8 isolates belonging to clades I, II and IV with increasing UV exposure time. The range of log kill (0.8–1.19) was highest for these isolates at 30 minutes. But relatively no change in log kill (0.04–0.35) with increasing time in isolates belonging to clade III were noted. Interestingly, C. auris isolates susceptible to UV-C were mostly nonaggregating, but the isolates that were more resistant to UV exposure formed aggregates.Conclusions:Our study suggests variability in susceptibility to UV-C of C. auris isolates belonging to different clades. More studies are needed to assess whether a cumulative impact of prolonged UV-C exposure provides additional benefit.

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