PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 8707736

Antifungal susceptibility testing using the E test: comparison with the broth macrodilution technique.

S C Chen·M L O'Donnell·S Gordon·G L Gilbert
View original source ↗Export metadata ↓

Abstract

The National Committee for Clinical Laboratory Standards reference broth macrodilution method for antifungal susceptibility testing was compared with the E test by testing 86 clinical isolates of Candida spp. and Cryptococcus neoformans. The MIC agreement rates for the two methods for Candida spp. were 73-89% within +/-1 doubling dilution and 87-100% within +/-2 dilutions. For C. neoformans, agreement within +/-1 dilution was > 70% for all the agents tested except fluconazole for which agreement was 35%. Our data support the further evaluation of the E test as an alternative method for antifungal susceptibility testing. However, E test MICs of fluconazole for C. neoformans, particularly C. neoformans var. gattii should be interpreted with caution, as falsely elevated MICs may occur.

Explore related subjects

Antifungal AgentsCandidaCryptococcus neoformansCulture MediaFluconazoleItraconazoleKetoconazoleMicrobial Sensitivity TestsReproducibility of ResultsComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S C Chen, M L O'Donnell, S Gordon, G L Gilbert. 1996. Antifungal susceptibility testing using the E test: comparison with the broth macrodilution technique.. https://doi.org/10.1093/jac%2F37.2.265

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Machine learning-based drug susceptibility prediction from Candida genomic data.

OBJECTIVES: Invasive Candida infection is an increasing clinical concern, with antifungal resistance rising across multiple species. However, rapid and accurate antifungal susceptibility testing (AFST) remains limited in routine practice. The study evaluated species distribution and antifungal susceptibility of invasive Candida isolates in China and assessed the feasibility of combining whole-genome sequencing (WGS) with machine learning to predict minimum inhibitory concentrations (MICs). METHODS: Consecutive non-repetitive isolates were collected from 20 hospitals in 13 provinces during 2022-2023. MICs of nine antifungal agents were determined by broth microdilution, and WGS was performed for species accounting for >5% of the total isolates. Genomic 11-mer features were extracted and used to train random forest (RF), support vector machine (SVM), and extreme gradient boosting (XGBoost) models, followed by optimization of the best-performing algorithm. RESULTS: A total of 337 isolates were obtained from blood (n = 232) and sterile body fluids (n = 105), comprising C. albicans (n = 103), C. tropicalis (n = 71), C. parapsilosis (n = 67), and C. glabrata (n = 63). Non-albicans Candida showed higher azole and echinocandin resistance, with C. tropicalis notably resistant to azoles and C. glabrata to echinocandins. Among the three models, RF demonstrated the best performance on 304 sequenced isolates. The optimized RF model was evaluated by the receiver operating characteristic (ROC) curve analysis and achieved an average area under the ROC curve (AUC) of 0.979 (95% CI: 0.974-0.984), essential agreement over 90.1%, and categorical agreement over 93.2% across species. CONCLUSIONS: These findings underscore the clinical challenge posed by non-albicans Candida resistance, and indicate that WGS-based MIC prediction may offer a highly accurate reference for earlier antifungal therapy.

Antifungal Agents↗
PubMed2026

Clade-dependent antifungal resistance and susceptibility in Candidozyma auris: A global scoping review.

BACKGROUND: Candidozyma auris (formerly Candida auris) is an emerging multidrug-resistant fungal pathogen that has spread globally since its first identification in 2009 and is now classified as a critical-priority pathogen by the World Health Organization. Distinct genetic clades are associated with variations in geographic distribution, antifungal susceptibility, and resistance mechanisms; however, clade-specific evidence remains fragmented. AIMS: To systematically map global evidence on clade diversity, antifungal susceptibility patterns, resistance mechanisms, and clinical implications of C. auris. METHODS: A scoping review was conducted following PRISMA-ScR guidelines. Peer-reviewed primary studies published between 2009 and September 2025 were included if they reported clade attribution and antifungal susceptibility or resistance data. PubMed/MEDLINE, Scopus, and Web of Science were searched. Two reviewers independently screened studies and extracted data using a standardized form. RESULTS: Of 2050 records identified, 105 studies met inclusion criteria, representing 29 countries and diverse study designs. Whole-genome sequencing was the most common typing method. Antifungal susceptibility varied substantially across clades. High fluconazole resistance was consistently reported (MIC 4 to >256μg/mL). Echinocandins generally retained activity, although reduced susceptibility associated with FKS1 mutations was observed. Resistance mechanisms primarily involved mutations in ERG11, FKS1, and efflux-related genes. Studies also reported challenges in healthcare-associated transmission, environmental persistence, and diagnostic misidentification. CONCLUSIONS: C. auris exhibits marked clade-dependent variability in antifungal susceptibility and resistance mechanisms. These findings support the need for clade-informed interpretation of susceptibility data, standardized surveillance, improved diagnostics, and development of novel antifungal therapies.

Antifungal Agents↗
PubMed2026

Microbe Profile: Candidozyma auris: an emergent and resilient yeast and new antifungal strategies.

Candidozyma auris is an emerging opportunistic yeast that is important because of its multidrug resistance, persistence in healthcare environments and ability to cause outbreaks. Since its discovery in 2009 in Japan, it has rapidly spread worldwide and is now recognized as a major global public health threat and was recognized by the World Health Organization (WHO) in 2022 as a critical priority fungal pathogen. Distinct phylogeographic clades demonstrate simultaneous emergence on different continents, suggesting ecological or environmental triggers. Clinical management is complicated by frequent resistance to fluconazole, reduced susceptibility to amphotericin B and echinocandins, and frequent misidentification by traditional laboratory methods. Continued genomic surveillance, improved diagnostics and new antifungal strategies are urgently needed, supported by enhanced infection prevention and control procedures.

Antifungal Agents↗