A high‐throughput and rapid method for accurate identification of emerging multidrug‐resistant Candida auris

Mycoses ◽  
2019 ◽  
Vol 62 (6) ◽  
pp. 513-518 ◽  
Author(s):  
Ausaf Ahmad ◽  
Jonathan E. Spencer ◽  
Shawn R. Lockhart ◽  
Sabrina Singleton ◽  
David J. Petway ◽  
...  
Author(s):  
Yu-Shan Cheng ◽  
Jose Santinni Roma ◽  
Min Shen ◽  
Caroline Mota Fernandes ◽  
Patricia S. Tsang ◽  
...  

Candida auris is an emerging fatal fungal infection that has resulted in several outbreaks in hospitals and care facilities. Current treatment options are limited by the development of drug resistance. Identifying new pharmaceuticals to combat these drug-resistant infections will thus be required to overcome this unmet medical need. We have established a bioluminescent ATP-based assay to identify new compounds and potential drug combinations showing effective growth inhibition against multiple strains of multidrug resistant Candida auris. The assay is robust and suitable for assessing large compound collections by high throughput screening. Utilizing this assay, we conducted a screen of 4,314 approved drugs and pharmacologically active compounds which yielded 25 compounds including 6 novel anti-Candida auris compounds and 13 sets of potential two drug combinations. Among the drug combinations, the serine palmitoyltransferase inhibitor myriocin demonstrated a combinational effect with flucytosine against all tested isolates during screening. This combinational effect was confirmed in 13 clinical isolates of Candida auris.


2018 ◽  
Vol 56 (7) ◽  
Author(s):  
Ruben Ramos ◽  
Diego H. Caceres ◽  
Marilyn Perez ◽  
Nicole Garcia ◽  
Wendy Castillo ◽  
...  

ABSTRACT Candida duobushaemulonii , a yeast closely related to Candida auris , is thought to cause infections in rare cases and is often misidentified. In October 2016, the Panamanian Ministry of Health implemented laboratory surveillance for C. auris . Suspected C. auris isolates were forwarded to the national reference laboratory for identification by matrix-assisted laser desorption ionization–time of flight mass spectrometry and antifungal susceptibility testing. Between November 2016 and May 2017, 17 of 36 (47%) isolates suspected to be C. auris were identified as C. duobushaemulonii. These 17 isolates were obtained from 14 patients at six hospitals. Ten patients, including three children, had bloodstream infections, and MICs for fluconazole, voriconazole, and amphotericin B were elevated. No resistance to echinocandins was observed. C. duobushaemulonii causes more invasive infections than previously appreciated and poses a substantial problem, given its resistance to multiple antifungals. Expanded laboratory surveillance is an important step in the detection and control of such emerging pathogens.


Author(s):  
Hadis Jafarian ◽  
Hossein Khodadadi ◽  
Parisa Badiee

Background and Purpose: Candida auris is an emerging multidrug-resistant pathogen. The identification of this species with the conventional phenotypic or biochemical mycological methods may lead to misidentification. Molecular-based species-specific identification methods such as quantitative real-time polymerase chain reaction (qPCR) facilitate a more reliable identification of C. auris than mycological methods. Regarding this, the present study aimed to develop a hydrolysis probe-based qPCR assay for the rapid, accurate identification of C. auris. Materials and Methods: The internal transcribed spacer 2 regions in the nuclear ribosomal DNA of C. auris and other related yeasts were assayed to find a specific PCR target for C. auris. A 123-base-pair target was selected, and primers and a probe were designed for hydrolysis probe-based real-time PCR with TaqMan chemistry. Ten-fold serial dilutions of C. auris ranging from 106 to 100 CFU/mL were prepared to establish a standard curve to quantify the yeast. Results: The qPCR assay was able to identify and quantify C. auris with a detection limit of 1 C. auris CFU per reaction. Specificity was confirmed by the non-amplification of the sequences belonging to other Candida species, yeasts, molds, bacteria, or human DNAs. The standard curve of the assay showed a highly significant linearity between threshold values and dilution rates (R2=0.99; slope=−3.42). Conclusion: The applied qPCR assay facilitated the rapid and accurate identification and quantification of emerging opportunistic C. auris. Therefore, considering the promising test validation results, we succeeded to develop a rapid and accurate hydrolysis probe-based qPCR assay for the screening and identification of C. auris.


2021 ◽  
Vol 7 (1) ◽  
pp. 62 ◽  
Author(s):  
Majid Rasool Kamli ◽  
Vartika Srivastava ◽  
Nahid H. Hajrah ◽  
Jamal S. M. Sabir ◽  
Khalid Rehman Hakeem ◽  
...  

Candida auris is an emergent multidrug-resistant pathogen that can lead to severe bloodstream infections associated with high mortality rates, especially in hospitalized individuals suffering from serious medical problems. As Candida auris is often multidrug-resistant, there is a persistent demand for new antimycotic drugs with novel antifungal action mechanisms. Here, we reported the facile, one-pot, one-step biosynthesis of biologically active Ag-Cu-Co trimetallic nanoparticles using the aqueous extract of Salvia officinalis rich in polyphenols and flavonoids. These medicinally important phytochemicals act as a reducing agent and stabilize/capping in the nanoparticles’ fabrication process. Fourier Transform-Infrared, Scanning electron microscopy, Transmission Electron Microscopy, Energy dispersive X-Ray, X-ray powder diffraction and Thermogravimetric analysis (TGA) measurements were used to classify the as-synthesized nanoparticles. Moreover, we evaluated the antifungal mechanism of as-synthesized nanoparticles against different clinical isolates of C. auris. The minimum inhibitory concentrations and minimum fungicidal concentrations ranged from 0.39–0.78 μg/mL and 0.78–1.56 μg/mL. Cell count and viability assay further validated the fungicidal potential of Ag-Cu-Co trimetallic nanoparticles. The comprehensive analysis showed that these trimetallic nanoparticles could induce apoptosis and G2/M phase cell cycle arrest in C. auris. Furthermore, Ag-Cu-Co trimetallic nanoparticles exhibit enhanced antimicrobial properties compared to their monometallic counterparts attributed to the synergistic effect of Ag, Cu and Co present in the as-synthesized nanoparticles. Therefore, the present study suggests that the Ag-Cu-Co trimetallic nanoparticles hold the capacity to be a lead for antifungal drug development against C. auris infections.


2020 ◽  
Vol 41 (S1) ◽  
pp. s145-s146
Author(s):  
Kelly Walblay ◽  
Tristan McPherson ◽  
Elissa Roop ◽  
David Soglin ◽  
Ann Valley ◽  
...  

Background:Candida auris and carbapenemase-producing organisms (CPO) are multidrug-resistant organisms that can colonize people for prolonged periods and can cause invasive infections and spread in healthcare settings, particularly in high-acuity long-term care facilities. Point-prevalence surveys (PPSs) conducted in long-term acute-care hospitals in the Chicago region identified median prevalence of colonization to be 31% for C. auris and 24% for CPO. Prevalence of C. auris colonization has not been described in pediatric populations in the United States, and limited data exist on CPO colonization in children outside intensive care units. The Chicago Department of Public Health (CDPH) conducted a PPS to assess C. auris and CPO colonization in a pediatric hospital serving high-acuity patients with extended lengths of stay (LOS). Methods: CDPH conducted a PPS in August 2019 in a pediatric hospital with extended LOS to screen for C. auris and CPO colonization. Medical devices (ie, gastrostomy tubes, tracheostomies, mechanical ventilators, and central venous catheters [CVC]) and LOS were documented. Screening specimens consisted of composite bilateral axillae and groin swabs for C. auris and rectal swabs for CPO testing. The Wisconsin State Laboratory of Hygiene tested all specimens. Real-time polymerase chain reaction (PCR) assays were used to detect C. auris DNA and carbapenemase genes: blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP (Xpert Carba-R Assay, Cepheid, Sunnyvale, CA). All axillae and groin swabs were processed by PCR and culture to identify C. auris. For CPO, culture was only performed on PCR-positive specimens. Results: Of the 29 patients hospitalized, 26 (90%) had gastrostomy tubes, 24 (83%) had tracheostomies, 20 (69%) required mechanical ventilation, and 3 (10%) had CVCs. Also, 25 (86%) were screened for C. auris and CPO; 4 (14%) lacked parental consent and were not swabbed. Two rectal specimens were unsatisfactory, producing invalid CPO test results. Median LOS was 35 days (range, 1–300 days). No patients were positive for C. auris. From CPO screening, blaOXA-48 was detected in 1 patient sample, yielding a CPO prevalence of 3.4% (1 of 29). No organism was recovered from the blaOXA-48 positive specimen. Conclusions: This is the first documented screening of C. auris colonization in a pediatric hospital with extended LOS. Despite a high prevalence of C. auris and CPOs in adult healthcare settings of similar acuity in the region, C. auris was not identified and CPOs were rare at this pediatric facility. Additional evaluations in pediatric hospitals should be conducted to further understand C. auris and CPO prevalence in this population.Funding: NoneDisclosures: None


2021 ◽  
Vol 7 (5) ◽  
pp. 380
Author(s):  
Joerg Steinmann ◽  
Thomas Schrauzer ◽  
Lisa Kirchhoff ◽  
Jacques F. Meis ◽  
Peter-Michael Rath

Candida auris has become a global fungal public health threat. This multidrug-resistant yeast is associated with nosocomial intra- and interhospital transmissions causing healthcare-associated infections. Here, we report on two C. auris cases from Germany. The two patients stayed in Germany for a long time before C. auris was detected during their hospitalization. The patients were isolated in single rooms with contact precautions. No nosocomial transmissions were detected within the hospital. Both C. auris isolates exhibited high minimum inhibitory concentrations (MICs) of fluconazole and one isolate additionally high MICs against the echinocandins. Microsatellite genotyping showed that both strains belong to the South Asian clade. These two cases are examples for appropriate in-hospital care and infection control without further nosocomial spread. Awareness for this emerging, multidrug-resistant pathogen is justified and systematic surveillance in European health care facilities should be performed.


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.


2021 ◽  
Vol 7 (6) ◽  
pp. 433
Author(s):  
Ahmad Ibrahim ◽  
Lucie Peyclit ◽  
Rim Abdallah ◽  
Saber Khelaifia ◽  
Amanda Chamieh ◽  
...  

Candida auris is an emerging multidrug-resistant yeast causing nosocomial infections and associated with high mortality in immunocompromised patients. Rapid identification and characterisation are necessary for diagnosis and containing its spread. In this study, we present a selective culture medium for all C. auris clades. This medium is sensitive with a limit of detection ranging between 101 and 102 CFU/mL. The 100% specificity of SCA (specific C. auris) medium is confirmed on a set of 135 Candida strains, 50 bacterial species and 200 human stool samples. Thus, this medium specifically selects for C. auris isolation from clinical samples, allowing the latter to study its phenotypic profile.


2020 ◽  
Author(s):  
Emily N. Junkins ◽  
Bradley S. Stevenson

AbstractMolecular techniques continue to reveal a growing disparity between the immense diversity of microbial life and the small proportion that is in pure culture. The disparity, originally dubbed “the great plate count anomaly” by Staley and Konopka, has become even more vexing given our increased understanding of the importance of microbiomes to a host and the role of microorganisms in the vital biogeochemical functions of our biosphere. Searching for novel antimicrobial drug targets often focuses on screening a broad diversity of microorganisms. If diverse microorganisms are to be screened, they need to be cultivated. Recent innovative research has used molecular techniques to assess the efficacy of cultivation efforts, providing invaluable feedback to cultivation strategies for isolating targeted and/or novel microorganisms. Here, we aimed to determine the efficiency of cultivating representative microorganisms from a non-human, mammalian microbiome, identify those microorganisms, and determine the bioactivity of isolates. Molecular methods indicated that around 57% of the ASVs detected in the original inoculum were cultivated in our experiments, but nearly 53% of the total ASVs that were present in our cultivation experiments were not detected in the original inoculum. In light of our controls, our data suggests that when molecular tools were used to characterize our cultivation efforts, they provided a more complete, albeit more complex, understanding of which organisms were present compared to what was eventually cultivated. Lastly, about 3% of the isolates collected from our cultivation experiments showed inhibitory bioactivity against a multidrug-resistant pathogen panel, further highlighting the importance of informing and directing future cultivation efforts with molecular tools.ImportanceCultivation is the definitive tool to understand a microorganism’s physiology, metabolism, and ecological role(s). Despite continuous efforts to hone this skill, researchers are still observing yet-to-be cultivated organisms through high-throughput sequencing studies. Here, we use the very same tool that highlights biodiversity to assess cultivation efficiency. When applied to drug discovery, where screening a vast number of isolates for bioactive metabolites is common, cultivating redundant organisms is a hindrance. However, we observed that cultivating in combination with molecular tools can expand the observed diversity of an environment and its community, potentially increasing the number of microorganisms to be screened for natural products.


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