In Vitro Antifungal Resistance of Candida auris Isolates from Bloodstream Infections, South Africa
| Autor: | Erika van Schalkwyk, Arshad Ismail, Trusha Nana, for Germs-Sa, Tsidiso G. Maphanga, Jennifer Coetzee, Phillip Senzo Mtshali, Jeannette Wadula, Nelesh P. Govender, Serisha D. Naicker, Ruth S. Mpembe, Chetna N. Govind, Stanford Kwenda, José F. Muñoz |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Pharmacology 030106 microbiology Broth microdilution Biology bacterial infections and mycoses Microbiology Flucytosine 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology Infectious Diseases Candida auris chemistry Mechanisms of Resistance Amphotericin B medicine Anidulafungin Pharmacology (medical) Caspofungin Fluconazole Etest medicine.drug |
| Zdroj: | Antimicrob Agents Chemother |
| Popis: | Candida auris is a multidrug-resistant fungal pathogen that is endemic in South African hospitals. We tested bloodstream C. auris isolates that were submitted to a reference laboratory for national laboratory-based surveillance for candidemia in 2016 and 2017. We confirmed the species identification by phenotypic/molecular methods. We tested susceptibility to amphotericin B, anidulafungin, caspofungin, micafungin, itraconazole, posaconazole, voriconazole, fluconazole, and flucytosine using broth microdilution and Etest methods. We interpreted MICs using tentative breakpoints. We sequenced the genomes of a subset of isolates and compared them to the C. auris B8441 reference strain. Of 400 C. auris isolates, 361 (90%) were resistant to at least one antifungal agent, 339 (94%) to fluconazole alone (MICs of ≥32 µg/ml), 19 (6%) to fluconazole and amphotericin B (MICs of ≥2 µg/ml), and 1 (0.3%) to amphotericin B alone. Two (0.5%) isolates from a single patient were pan-resistant (resistant to fluconazole, amphotericin B, and echinocandins). Of 92 isolates selected for whole-genome sequencing, 77 clustered in clade III, including the pan-resistant isolates, 13 in clade I, and 2 in clade IV. Eighty-four of the isolates (91%) were resistant to at least one antifungal agent; both resistant and susceptible isolates had mutations. The common substitutions identified across the different clades were VF125AL, Y132F, K177R, N335S, and E343D in ERG11; N647T in MRR1; A651P, A657V, and S195G in TAC1b; S639P in FKS1HP1; and S58T in ERG3. Most South African C. auris isolates were resistant to azoles, although resistance to polyenes and echinocandins was less common. We observed mutations in resistance genes even in phenotypically susceptible isolates. |
| Databáze: | OpenAIRE |
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