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

2020 ◽  
Vol 41 (12) ◽  
pp. 1384-1387
Author(s):  
Piyali Chatterjee ◽  
Hosoon Choi ◽  
Brennan Ochoa ◽  
Gennifer Garmon ◽  
John D. Coppin ◽  
...  

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.

2017 ◽  
Vol 39 (1) ◽  
pp. 94-96 ◽  
Author(s):  
Jennifer L. Cadnum ◽  
Aaron A. Shaikh ◽  
Christina T. Piedrahita ◽  
Annette L. Jencson ◽  
Emily L. Larkin ◽  
...  

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


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


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S439-S439
Author(s):  
Jessica Kumar ◽  
Jennifer Cadnum ◽  
Y Karen Ng Wong ◽  
Thriveen Sankar Chittoor Mana ◽  
Heba Alhmidi ◽  
...  

Abstract Background Currently, sporicidal disinfectants such as bleach are recommended for daily and terminal disinfection of the rooms of patients with Candida auris colonization and/or infection. However, bleach and other chlorine-based disinfectants can have adverse effects on surfaces and personnel. Disinfectant solutions with reduced chlorine concentrations are commonly used for other pathogens, but it is not known if diluted or alternative products maintain efficacy against C. auris both in vitro and in vivo. Methods We tested the efficacy of different concentrations of a sodium dichloroisocyanurate (NaDCC) product and sodium hypochlorite using the method recommended by the Environmental Protection Agency (EPA) for evaluation of the efficacy of liquid disinfectants against C. auris (EPA MLB SOP MB-35-00) and in a simulated patient room. Carriers were exposed to each disinfectant for 1 and 2 minutes. Log reductions were calculated by subtracting viable organisms recovered after disinfectant exposure vs. deionized water controls. Results As shown in the figure, the NaDCC product at 4306 ppm tested with a 2 minute contact time reduced C. auris by ≥5 log10 colony-forming units (CFU) but had reduced efficacy with shorter exposure time or lower concentrations. Sodium hypochlorite was effective with 1 or 2 minute exposure times at a concentration of 6,500 ppm, and was effective at 4,000 ppm with an exposure time of 2 minutes. In the simulated patient room, NaDCC reduced C. auris contamination by ≥6 log10 CFUs on all surfaces. Conclusion A chlorine-based NaDCC product was effective at reducing C. auris. Both NaDCC and sodium hypochlorite products exhibited reduced efficacy at lower concentrations, particularly at concentrations below 4000 ppm. The NaDCC products were also effective in reducing contamination in the simulated patient room. UV-C treatment was an effective adjunct to manual cleaning. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 63 (12) ◽  
Author(s):  
A. L. Bidaud ◽  
F. Botterel ◽  
A. Chowdhary ◽  
E. Dannaoui

ABSTRACT Candida auris is an emerging, multidrug-resistant pathogen responsible for invasive hospital-acquired infections. Flucytosine is an effective anti-Candida species drug, but which cannot be used as a monotherapy because of the risk of development of resistant mutants during treatment. It is, therefore, noteworthy to test possible combinations with flucytosine that may have a synergistic interaction. In this study, we determined the in vitro interaction between flucytosine and amphotericin B, micafungin, or voriconazole. These combinations have been tested against 15 C. auris isolates. The MIC ranges (geometric mean [Gmean]) of flucytosine, amphotericin B, micafungin, and voriconazole were 0.125 to 1 μg/ml (0.42 μg/ml), 0.25 to 1 μg/ml (0.66 μg/ml), 0.125 to 0.5 μg/ml (0.3 μg/ml), and 0.03 to 4 μg/ml (1.05 μg/ml), respectively. When tested in combination, indifferent interactions were mostly observed with fractional inhibitory concentration index values from 0.5 to 1, 0.31 to 1.01, and 0.5 to 1.06 for the combinations of flucytosine with amphotericin B, micafungin, and voriconazole, respectively. A synergy was observed for the strain CBS 10913 from Japan. No antagonism was observed for any combination. The combination of flucytosine with amphotericin B or micafungin may be relevant for the treatment of C. auris infections.


2019 ◽  
Vol 5 (4) ◽  
pp. 92 ◽  
Author(s):  
Wall ◽  
Herrera ◽  
Lopez-Ribot

Background. Candida auris has spread rapidly around the world as a causative agent of invasive candidiasis in health care facilities and there is an urgent need to find new options for treating this emerging, often multidrug-resistant pathogen. Methods. We screened the Pathogen Box® chemical library for inhibitors of C. auris strain 0390, both under planktonic and biofilm growing conditions. Results. The primary screen identified 12 compounds that inhibited at least 60% of biofilm formation or planktonic growth. After confirmatory dose-response assays, iodoquinol and miltefosine were selected as the two main leading repositionable compounds. Iodoquinol displayed potent in vitro inhibitory activity against planktonic C. auris but showed negligible inhibitory activity against biofilms; whereas miltefosine was able to inhibit the growth of C. auris under both planktonic and biofilm-growing conditions. Subsequent experiments confirmed their activity against nine other strains C. auris clinical isolates, irrespective of their susceptibility profiles against conventional antifungals. We extended our studies further to seven different species of Candida, also with similar findings. Conclusion. Both drugs possess broad spectrum of activity against Candida spp., including multiple strains of the emergent C. auris, and may constitute promising repositionable options for the development of novel therapeutics for the treatment of candidiasis.


2011 ◽  
Vol 56 (3) ◽  
pp. 1646-1649 ◽  
Author(s):  
Seth T. Housman ◽  
Christina Sutherland ◽  
David P. Nicolau

ABSTRACTWe describe the activities of RX-P763, RX-P766, RX-P770, RX-P792, RX-P793, and RX-P808 against strains of resistantPseudomonas aeruginosa. These compounds target the large subunit of the bacterial ribosome and have broad-spectrum activities against multidrug-resistant pathogens. All compounds demonstratedin vitroactivity againstP. aeruginosa, with MIC90values of 4 to 8 μg/ml (range, 0.5 to 64). These novel compounds had narrow MIC distributions and maintained activity despite resistance phenotypes to other commonly utilized agents.


2013 ◽  
Vol 34 (5) ◽  
pp. 466-471 ◽  
Author(s):  
Deverick J. Anderson ◽  
Maria F. Gergen ◽  
Emily Smathers ◽  
Daniel J. Sexton ◽  
Luke F. Chen ◽  
...  

Objective.To determine the effectiveness of an automated ultraviolet-C (UV-C) emitter against vancomycin-resistant enterococci (VRE),Clostridium difficile, andAcinetobacterspp. in patient rooms.Design.Prospective cohort study.Setting.Two tertiary care hospitals.Participants.Convenience sample of 39 patient rooms from which a patient infected or colonized with 1 of the 3 targeted pathogens had been discharged.Intervention.Environmental sites were cultured before and after use of an automated UV-C-emitting device in targeted rooms but before standard terminal room disinfection by environmental services.Results.In total, 142 samples were obtained from 27 rooms of patients who were colonized or infected with VRE, 77 samples were obtained from 10 rooms of patients withC. difficileinfection, and 10 samples were obtained from 2 rooms of patients with infections due toAcinetobacter. Use of an automated UV-C-emitting device led to a significant decrease in the total number of colony-forming units (CFUs) of any type of organism (1.07 log10reduction;P< .0001), CFUs of target pathogens (1.35 log10reduction;P< .0001), VRE CFUs (1.68 log10reduction;P< .0001), and C.difficileCFUs (1.16 log10reduction;P< .0001). CFUs ofAcinetobacteralso decreased (1.71 log10reduction), but the trend was not statistically significantP= .25). CFUs were reduced at all 9 of the environmental sites tested. Reductions similarly occurred in direct and indirect line of sight.Conclusions.Our data confirm that automated UV-C-emitting devices can decrease the bioburden of important pathogens in real-world settings such as hospital rooms.


Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 539
Author(s):  
Mahmoud Ghannoum ◽  
Maiken Cavling Arendrup ◽  
Vishnu P. Chaturvedi ◽  
Shawn R. Lockhart ◽  
Thomas S. McCormick ◽  
...  

Candida auris is an emerging multidrug-resistant fungal pathogen reported worldwide. Infections due to C. auris are usually nosocomial and associated with high rates of fluconazole resistance and mortality. Echinocandins are utilized as the first-line treatment. However, echinocandins are only available intravenously and are associated with increasingly higher rates of resistance by C. auris. Thus, a need exists for novel treatments that demonstrate potent activity against C. auris. Ibrexafungerp is a first-in-class triterpenoid antifungal agent. Similar to echinocandins, ibrexafungerp inhibits (1→3)-β-D-glucan synthase, a key component of the fungal cell wall, resulting in fungicidal activity against Candida spp. Ibrexafungerp demonstrates broad in vitro activity against various Candida spp. including C. auris and C. auris isolates with fks mutations. Minimum inhibitory concentration (MIC50 and MIC90) values in >400 C. auris isolates were 0.5 μg/mL and 1.0 μg/mL, respectively. Clinical results were reported for two patients with invasive candidiasis or candidemia due to C. auris treated during the CARES (Candidiasis Caused by Candida Auris) trial, an ongoing open-label study. These patients experienced a complete response after treatment with ibrexafungerp. Thus, ibrexafungerp represents a promising new antifungal agent for treating C. auris infections.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Hamed Fakhim ◽  
Anuradha Chowdhary ◽  
Anupam Prakash ◽  
Afsane Vaezi ◽  
Eric Dannaoui ◽  
...  

ABSTRACT We determined the in vitro interactions between echinocandins and azoles against 10 multidrug-resistant Candida auris strains by use of a microdilution checkerboard technique. Our results suggest synergistic interactions between micafungin and voriconazole with fractional inhibitory concentration index (FICI) values of 0.15 to 0.5, and we observed indifferent interactions when micafungin was combined with fluconazole (FICI, 0.62 to 1.5). Combinations of caspofungin with fluconazole or voriconazole exhibited indifferent interactions. No antagonism was observed for any combination.


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