Objectives: The emergence of fluconazole resistance in Candida parapsilosis healthcare-associated infections has recently been increasingly reported. Antifungal susceptibility profiles and mechanisms of fluconazole resistance in C. parapsilosis (n = 199) from nine hospitals in India collected over a period of 3 years were studied. Further, clonal transmission of fluconazole-resistant isolates in different hospitals was investigated.
Methods: Antifungal susceptibility testing of five azoles, amphotericin B and 5-flucytosine was performed by the CLSI microbroth dilution method. The azole target ERG11 gene was sequenced, and the significance of a novel ERG11 mutation in C. parapsilosis was determined using a gap-repair cloning approach in Saccharomyces cerevisiae. In addition, microsatellite analysis was performed to determine the clonal lineage of C. parapsilosis-resistant strains circulating among different hospitals.
Results: A total of 64 (32%) C. parapsilosis isolates were non-susceptible to fluconazole, which included resistant (n = 55; MIC >4 mg/L) and susceptible dose-dependent (n = 9) isolates. Of these 64 non-susceptible isolates, a novel K143R amino acid substitution was noted in 92%, and the remaining five isolates had the Y132F substitution. Elevated azole MICs (≥16-fold) were detected in S. cerevisiae upon expression of C. parapsilosis ERG11 alleles carrying Y132F or K143R substitutions. Two major clusters of non-susceptible isolates were circulating in seven Indian hospitals.
Conclusions: We report a novel K143R amino acid substitution in ERG11p causing fluconazole resistance in C. parapsilosis. Fluconazole-non-susceptible C. parapsilosis isolates carrying the novel K143R amino acid substitution should be identified in clinical microbiology laboratories to prevent further clonal transmission.
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http://dx.doi.org/10.1093/jac/dkz029 | DOI Listing |
Microbiol Spectr
January 2025
Clinical Microbiology Laboratory, "Attikon" University General Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
The lack of clinical breakpoints and epidemiological cut-off values (ECOFFs) for antifungals prescribed for vulvovaginal candidiasis (VVC) make interpretation of antifungal susceptibility data difficult. This leads to empirical prescribing, poor clinical management and emergence of resistance. The susceptibilities of 152 , 105 , 31 and 8 VVC isolates against eight antifungals, were determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) E.
View Article and Find Full Text PDFMycoses
January 2025
Departamento Micología-Instituto Nacional de Enfermedades Infecciosas "Dr. Carlos G. Malbrán", Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
Background: Epidemiological surveillance of Candidozyma sp. has become important because many species of this new genus have been reported to be responsible for nosocomial outbreaks and to exhibit elevated minimal inhibitory concentrations (MIC) to one or more classes of antifungal drugs.
Objectives: To describe the genetic relationships among Argentinian clinical isolates belonging to the Candidozyma genus and to study the molecular mechanisms associated with antifungal resistance.
Curr Top Med Chem
January 2025
Laboratory of Analytical and Molecular Chemistry, Faculty of Sciences Ben M'Sik, Hassan II University of Casablanca, B. P 7955 Casablanca, Morocco.
Background: The search for new antifungal agents is critical due to the rising resistance of fungal pathogens to existing treatments. This study focuses on the synthesis and evaluation of a novel compound, 1-benzyl-5-methyl-1H-pyrazole-3-carboxylic acid (compound L1), as a potential antifungal agent.
Methods: Compound L1 was synthesized and characterized using a range of analytical techniques, including 1H^1H1H NMR, 13C^{13}C13C NMR, FT-IR, GC-MS, and X-ray single crystal diffraction (XRD).
Mycoses
January 2025
Department of Clinical Microbiology, General Hospital "G. Gennimatas", Athens, Greece.
Background: The epidemiology of vulvovaginal candidiasis (VVC) in Greece remains poorly reported and outdated.
Objectives: We therefore conducted a 2-year retrospective survey to assess the epidemiological aspects of the infection among symptomatic Greek patients.
Patients/methods: High vaginal swab samples were collected from adult women with clinically suspected VVC attending a private diagnostic laboratory in Athens.
J Mycol Med
December 2024
Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran; Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Electronic address:
Introduction: Nakaseomyces glabratus is considered a high priority of attention according to WHO, and also is an important yeast species due to its high rate of intrinsic/acquired resistance against fluconazole. This study aimed at the possible mechanisms of action of thymol, as the promising new antifungal agent, in N. glabratus.
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