Metabolic Patterns of Fluconazole Resistant and Susceptible Candida auris Clade V and I.

Candida auris, an emerging non-albicans multidrug-resistant yeast, has become a significant cause of invasive candidiasis in healthcare settings. So far, data on the metabolites of C. auris in different clades are minimal, and no studies have focused on clade V metabolites. Therefore, Gas chromatography-mass spectrometry (GC-MS) was used for the metabolomic profiling of clade I C. auris compared with fluconazole-resistant and susceptible C. auris in clade V strains. GC-MS chromatography revealed 28, 22, and 30 compounds in methanolic extracts of the fluconazole-susceptible and fluconazole-resistant C. auris clade V and C. auris clade I strain, respectively. Some compounds, such as acetamide and metaraminol, were found in fluconazole-susceptible and resistant C. auris clade V and clade I. N-methyl-ethanamine and bis(2-ethylhexyl) phthalate metabolites were found in both fluconazole -susceptible and resistant C. auris clade V, as well as 3-methyl-4-isopropylphenol, 3,5-bis(1,1-dimethyl)-1,2-benzenediol, and diisostyl phthalate metabolites in both fluconazole resistant C. auris clade V and I. Identifying these metabolites contributes to understanding the morphogenesis and pathogenesis of C. auris, highlighting their potential role in antifungal drug resistance and the control of fungal growth. However, further experiments are warranted to fully comprehend the identified metabolites' regulatory responses, and there may be potential challenges in translating these findings into clinical applications.

Insights from Three Pan-European Multicentre Studies on Invasive Candida Infections and Outlook to ECMM Candida IV.

Invasive candidiasis and candidemia remain a significant public health concern. The European Confederation of Medical Mycology (ECMM) conducted three pan-European multicentre studies from 1997 to 2022 to investigate various aspects of invasive Candida infections. These studies revealed shifting trends in Candida species distribution, with an increase of non-albicans Candida species as causative pathogens, increasing rates of antifungal resistance, and persistently high mortality rates. Despite advancements in antifungal treatment, the persistently high mortality rate and increasing drug resistance, as well as limited drug access in low-income countries, underscore the need for continued research and development in the treatment of Candida infections. This review aims to summarize the findings of the three completed ECMM Candida studies and emphasize the importance of continued research efforts. Additionally, it introduces the upcoming ECMM Candida IV study, which will focus on assessing candidemia caused by non-albicans Candida species, including Candida auris, investigating antifungal resistance and tolerance, and evaluating novel treatment modalities on a global scale.

Short Tandem Repeat Genotyping of Medically Important Fungi: A Comprehensive Review of a Powerful Tool with Extensive Future Potential.

Fungal infections pose an increasing threat to public health. New pathogens and changing epidemiology are a pronounced risk for nosocomial outbreaks. To investigate clonal transmission between patients and trace the source, genotyping is required. In the last decades, various typing assays have been developed and applied to different medically important fungal species. While these different typing methods will be briefly discussed, this review will focus on the development and application of short tandem repeat (STR) genotyping. This method relies on the amplification and comparison of highly variable STR markers between isolates. For most common fungal pathogens, STR schemes were developed and compared to other methods, like multilocus sequence typing (MLST), amplified fragment length polymorphism (AFLP) and whole genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis. The pros and cons of STR typing as compared to the other methods are discussed, as well as the requirements for the development of a solid STR typing assay. The resolution of STR typing, in general, is higher than MLST and AFLP, with WGS SNP analysis being the gold standard when it comes to resolution. Although most modern laboratories are capable to perform STR typing, little progress has been made to standardize typing schemes. Allelic ladders, as developed for Aspergillus fumigatus, facilitate the comparison of STR results between laboratories and develop global typing databases. Overall, STR genotyping is an extremely powerful tool, often complimentary to whole genome sequencing. Crucial details for STR assay development, its applications and merit are discussed in this review.

Epidemiology of Candidemia in Mashhad, Northeast Iran: A Prospective Multicenter Study (2019-2021).

Candidemia is a major cause of morbidity and mortality in health care settings, and its epidemiology is changing. In the last two decades, the proportion of non-albicans Candida (NAC) yeasts in candidemia has increased. These yeasts more often display resistance to common antifungals. In many western countries, candidemia is mainly caused by susceptible C. albicans, while in resource-limited countries, including Iran, the candidemia species distribution is studied less often. Here, we investigated the species distribution, resistance levels, and characteristics of patients with candidemia in five hospitals in Mashhad (northeast Iran) for two years (2019-2021). Yeast isolates from blood were identified with MALDI-TOF MS and subjected to antifungal susceptibility testing (AFST) using the broth microdilution method, while molecular genotyping was applied to Candida parapsilosis isolates. In total, 160 yeast isolates were recovered from 160 patients, of which the majority were adults (60%). Candidemia was almost equally detected in men (48%) and women (52%). Almost half of patients (n = 67, 49%) were from intensive care units (ICUs). C. parapsilosis (n = 58, 36%) was the most common causative agent, surpassing C. albicans (n = 52, 33%). The all-cause mortality rate was 53%, with C. albicans candidemia displaying the lowest mortality with 39%, in contrast to a mortality rate of 59% for NAC candidemia. With microbroth AFST, nearly all tested isolates were found to be susceptible, except for one C. albicans isolate that was resistant to anidulafungin. By applying short tandem repeat (STR) genotyping to C. parapsilosis, multiple clusters were found. To summarize, candidemia in Mashhad, Iran, from 2019 to 2021, is characterized by common yeast species, in particular C. parapsilosis, for which STR typing indicates potential nosocomial transmission. The overall mortality is high, while resistance rates were found to be low, suggesting that the high mortality is linked to limited diagnostic options and insufficient medical care, including the restricted use of echinocandins as the first treatment option.

Detection and characterisation of a sixth Candida auris clade in Singapore: a genomic and phenotypic study.

BACKGROUND: The emerging fungal pathogen Candida auris poses a serious threat to global public health due to its worldwide distribution, multidrug resistance, high transmissibility, propensity to cause outbreaks, and high mortality. We aimed to characterise three unusual C auris isolates detected in Singapore, and to determine whether they constitute a novel clade distinct from all previously known C auris clades (I-V). METHODS: In this genotypic and phenotypic study, we characterised three C auris clinical isolates, which were cultured from epidemiologically unlinked inpatients at a large tertiary hospital in Singapore. The index isolate was detected in April, 2023. We performed whole-genome sequencing (WGS) and obtained hybrid assemblies of these C auris isolates. The complete genomes were compared with representative genomes of all known C auris clades. To provide a global context, 3651 international WGS data from the National Center for Biotechnology Information (NCBI) database were included in a high-resolution single nucleotide polymorphism (SNP) analysis. Antifungal susceptibility testing was done and antifungal resistance genes, mating-type locus, and chromosomal rearrangements were characterised from the WGS data of the three investigated isolates. We further implemented Bayesian logistic regression models to classify isolates into known clades and simulate the automatic detection of isolates belonging to novel clades as their WGS data became available. FINDINGS: The three investigated isolates were separated by at least 37 000 SNPs (range 37 000-236 900) from all existing C auris clades. These isolates had opposite mating-type allele and different chromosomal rearrangements when compared with their closest clade IV relatives. The isolates were susceptible to all tested antifungals. Therefore, we propose that these isolates represent a new clade of C auris, clade VI. Furthermore, an independent WGS dataset from Bangladesh, accessed via the NCBI Sequence Read Archive, was found to belong to this new clade. As a proof-of-concept, our Bayesian logistic regression model was able to flag these outlier genomes as a potential new clade. INTERPRETATION: The discovery of a new C auris clade in Singapore and Bangladesh in the Indomalayan zone, showing a close relationship to clade IV members most commonly found in South America, highlights the unknown genetic diversity and origin of C auris, particularly in under-resourced regions. Active surveillance in clinical settings, along with effective sequencing strategies and downstream analysis, will be essential in the identification of novel strains, tracking of transmission, and containment of adverse clinical effects of C auris infections. FUNDING: Duke-NUS Academic Medical Center Nurturing Clinician Researcher Scheme, and the Genedant-GIS Innovation Program.

Susceptibility Testing of Environmental and Clinical Aspergillus sydowii Demonstrates Potent Activity of Various Antifungals.

The genus Aspergillus consists of a vast number of medically and environmentally relevant species. Aspergillus species classified in series Versicolores are ubiquitous in the environment and include the opportunistic pathogen Aspergillus sydowii, which is associated with onychomycosis and superficial skin infections. Despite frequent clinical reports of A. sydowii and related series Versicolores species, antifungal susceptibility data are scarce, hampering optimal treatment choices and subsequent patient outcomes. Here, we employed antifungal susceptibility testing (AFST) based on microbroth dilution on a set of 155 series Versicolores strains using the common antifungals amphotericin B, itraconazole, voriconazole, posaconazole, isavuconazole and micafungin with the addition of luliconazole and olorofim. All strains were identified using partial calmodulin gene sequencing, with 145 being A. sydowii, seven A. creber and three A. versicolor, using the latest taxonomic insights. Overall, tested antifungals were potent against the entire strain collection. In comparison to A. fumigatus, azole and amphotericin B MICs were slightly elevated for some strains. AFST with luliconazole and olorofim, here reported for the first time, displayed the highest in vitro activity, making these antifungals interesting alternative drugs but clinical studies are warranted for future therapeutic use.

Multicenter Candida auris outbreak caused by azole-susceptible clade IV in Pernambuco, Brazil.

BACKGROUND: Candida auris is an emerging multidrug-resistant yeast, frequently causing outbreaks in health care facilities. The pathogen persistently colonises human skin and inanimate surfaces such as catheters, aiding to its spread. Moreover, colonisation is a risk factor to develop invasive infection. OBJECTIVES: We investigated 61 C. auris strains isolated from non-sterile human body sites (n = 53) and the hospital environment (n = 8), originating from four different centres in a single Brazilian state. MATERIALS AND METHODS: Antifungal susceptibility testing (AFST) against common antifungals was performed, and resistance-associated genes were evaluated. Genetic relatedness was investigated with short tandem repeat (STR) genotyping and validated with whole-genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis. RESULTS: Antifungal susceptibility testing demonstrated that all isolates were susceptible to azoles, echinocandins and amphotericin B. No mutations were detected in ERG11 and FKS1 genes. With STR typing, isolates were allocated to clade IV and appeared closely related. This was confirmed by WGS SNP analysis of 6 isolates, which demonstrated a maximal difference of only 41 SNPs between these strains. Furthermore, the Brazilian isolates formed a distinct autochthonous branch within clade IV, excluding recent introductions from outside the country. A molecular clock analysis of clade IV isolates from various countries suggests that early in the previous century there was a unique event causing environmental spread of a C. auris ancestor throughout the Latin-American continent, followed by human introduction during the last decades. CONCLUSION: We report the emergence of C. auris patient colonisation in multiple centres by fluconazole-susceptible clade IV close-related strains in Pernambuco State, Brazil.

The yeast genus Tardiomyces gen. nov. with one new species and two new combinations.

PURPOSE: Rare yeasts species are increasingly reported as causative agents of invasive human infection. Proper identification and antifungal therapy are essential to manage these infections. Candida blankii is one of these emerging pathogens and is known for its reduced susceptibility to multiple antifungals. METHODS: To obtain more insight into the characteristics of this species, 26 isolates reported as C. blankii were investigated using genetic and phenotypical approaches. RESULTS: Among the 26 isolates, seven recovered either from blood, sputum, urine, or the oral cavity, displayed substantial genetic and some phenotypical differences compared to the other isolates, which were confirmed as C. blankii. We consider these seven strains to represent a novel species, Tardiomyces depauwii. Phylogenomics assigned C. blankii, C. digboiensis, and the novel species in a distinct branch within the order Dipodascales, for which the novel genus Tardiomyces is erected. The new combinations Tardiomyces blankii and Tardiomyces digboiensis are introduced. Differences with related, strictly environmental genera Sugiyamaella, Crinitomyces, and Diddensiella are enumerated. All three Tardiomyces species share the rare ability to grow up to 42 °C, display slower growth in nutrient-poor media, and show a reduced susceptibility to azoles and echinocandins. Characteristics of T. depauwii include high MIC values with voriconazole and a unique protein pattern. CONCLUSION: We propose the novel yeast species Tardiomyces depauwii and the transfer of C. blankii and C. digboiensis to the novel Tardiomyces genus.

Sphingolipid diversity in Candida auris: unraveling interclade and drug resistance fingerprints.

In this study, we explored the sphingolipid (SL) landscape in Candida auris, which plays pivotal roles in fungal biology and drug susceptibility. The composition of SLs exhibited substantial variations at both the SL class and molecular species levels among clade isolates. Utilizing principal component analysis, we successfully differentiated the five clades based on their SL class composition. While phytoceramide (PCer) was uniformly the most abundant SL class in all the isolates, other classes showed significant variations. These variations were not limited to SL class level only as the proportion of different molecular species containing variable number of carbons in fatty acid chains also differed between the isolates. Also a comparative analysis revealed abundance of ceramides and glucosylceramides in fluconazole susceptible isolates. Furthermore, by comparing drug-resistant and susceptible isolates within clade IV, we uncovered significant intraclade differences in key SL classes such as high PCer and low long chain base (LCB) content in resistant strains, underscoring the impact of SL heterogeneity on drug resistance development in C. auris. These findings shed light on the multifaceted interplay between genomic diversity, SLs, and drug resistance in this emerging fungal pathogen.

Evaluation of the Vitek 2 system for antifungal susceptibility testing of Candida auris using a representative international panel of clinical isolates: overestimation of amphotericin B resistance and underestimation of fluconazole resistance.

Although the Vitek 2 system is broadly used for antifungal susceptibility testing of Candida spp., its performance against Candida auris has been assessed using limited number of isolates recovered from restricted geographic areas. We therefore compared Vitek 2 system with the reference Clinical and Laboratory Standards Institute (CLSI) broth microdilution method using an international collection of 100 C. auris isolates belonging to different clades. The agreement ±1 twofold dilution between the two methods and the categorical agreement (CA) based on the Centers for Disease Control and Prevention's (CDC's) tentative resistance breakpoints and Vitek 2-specific wild-type upper limit values (WT-ULVs) were determined. The CLSI-Vitek 2 agreement was poor for 5-flucytosine (0%), fluconazole (16%), and amphotericin B (29%), and moderate for voriconazole (61%), micafungin (67%), and caspofungin (81%). Significant interpretation errors were recorded using the CDC breakpoints for amphotericin B (31% CA, 69% major errors; MaEs) and fluconazole (69% CA, 31% very major errors; VmEs), but not for echinocandins (99% CA, 1% MaEs for both micafungin and caspofungin) for which the Vitek 2 allowed correct categorization of echinocandin-resistant FKS1 mutant isolates. Discrepancies were reduced when the Vitek 2 WT-ULV of 16 mg/L for amphotericin B (98% CA, 2% MaEs) and of 4 mg/L for fluconazole (96% CA, 1% MaEs, 3% VmEs) were used. In conclusion, the Vitek 2 system performed well for echinocandin susceptibility testing of C .auris. Resistance to fluconazole was underestimated whereas resistance to amphotericin B was overestimated using the CDC breakpoints of ≥32 and ≥2 mg/L, respectively. Vitek 2 minimun inhibitory concentrations (MICs) >4 mg/L indicated resistance to fluconazole and Vitek 2 MICs ≤16 mg/L indicated non-resistance to amphotericin B.

Genotyping and clonal origin of Sporothrix brasiliensis in human sporotrichosis cases in Argentina.

Sporothrix brasiliensis is considered a highly virulent emerging pathogen that causes sporotrichosis in humans, mainly after zoonotic transmission from infected cats. The epidemic of this zoonosis that originated from Brazil has spread in the last decades, generating hyperendemic regions in Latin America. We present two cases of human sporotrichosis causes by S. brasiliensis in Buenos Aires, Argentina, with good clinical response to differing treatments after contact with sick cats. Using Short tandem repeat (STR) genotyping, the two S. brasiliensis cases appear to be introduced from Brazil and likely originate from the same source.

Revised ISHAM-ABPA working group clinical practice guidelines for diagnosing, classifying and treating allergic bronchopulmonary aspergillosis/mycoses.

BACKGROUND: The International Society for Human and Animal Mycology (ISHAM) working group proposed recommendations for managing allergic bronchopulmonary aspergillosis (ABPA) a decade ago. There is a need to update these recommendations due to advances in diagnostics and therapeutics. METHODS: An international expert group was convened to develop guidelines for managing ABPA (caused by Aspergillus spp.) and allergic bronchopulmonary mycosis (ABPM; caused by fungi other than Aspergillus spp.) in adults and children using a modified Delphi method (two online rounds and one in-person meeting). We defined consensus as ≥70% agreement or disagreement. The terms "recommend" and "suggest" are used when the consensus was ≥70% and <70%, respectively. RESULTS: We recommend screening for A. fumigatus sensitisation using fungus-specific IgE in all newly diagnosed asthmatic adults at tertiary care but only difficult-to-treat asthmatic children. We recommend diagnosing ABPA in those with predisposing conditions or compatible clinico-radiological presentation, with a mandatory demonstration of fungal sensitisation and serum total IgE ≥500 IU·mL-1 and two of the following: fungal-specific IgG, peripheral blood eosinophilia or suggestive imaging. ABPM is considered in those with an ABPA-like presentation but normal A. fumigatus-IgE. Additionally, diagnosing ABPM requires repeated growth of the causative fungus from sputum. We do not routinely recommend treating asymptomatic ABPA patients. We recommend oral prednisolone or itraconazole monotherapy for treating acute ABPA (newly diagnosed or exacerbation), with prednisolone and itraconazole combination only for treating recurrent ABPA exacerbations. We have devised an objective multidimensional criterion to assess treatment response. CONCLUSION: We have framed consensus guidelines for diagnosing, classifying and treating ABPA/M for patient care and research.

Skin innate immune response against fungal infections and the potential role of trained immunity.

Fungal skin infections are distributed worldwide and can be associated with economic and social traits. The immune response related to skin cells is complex and its understanding is essential to the comprehension of each cell's role and the discovery of treatment alternatives. The first studies of trained immunity (TI) described the ability of monocytes, macrophages and natural killer (NK) cells to develop a memory-like response. However, the duration of TI does not reflect the shorter lifespan of these cells. These conclusions supported later studies showing that TI can be observed in stem and haematopoietic cells and, more recently, also in non-immune skin cells such as fibroblasts, highlighting the importance of resident cells in response to skin disorders. Besides, the participation of less studied proinflammatory cytokines in the skin immune response, such as IL-36γ, shed light into a new possibility of inflammatory pathway blockade by drugs. In this review, we will discuss the skin immune response associated with fungal infections, the role of TI in skin and clinical evidence supporting opportunities and challenges of TI and other inflammatory responses in the pathogenesis of fungal skin infections.

Disseminated Basidiobolomycosis Caused by Basidiobolus omanensis in a Child with Acute Lymphoblastic Leukemia (ALL). Case Report and Literature Review.

Basidiobolomycosis is an uncommon fungal infection caused by the genus Basidiobolus. In immunocompetent children, it usually causes cutaneous infection and rarely affects the gastrointestinal tract, and it is extremely rare for the disease to spread. The present study reports the first case of disseminated basidiobolomycosis caused by Basidiobolus omanensis in a child with acute lymphoblastic leukemia who died as a result of uncontrolled infection and multi-organ failure despite surgical and antifungal therapy with L-AMB and voriconazole. A review of the literature yielded 76 cases, including the current case with the majority of which were reported as invasive gastrointestinal infection. The median age was 4 years (61 male and 15 female) and the majority of these children were from the Middle East (80%), specifically Saudi Arabia (45%). Most patients were treated with systemic antifungal agents (mostly itraconazole and amphotericin B). Surgical intervention was done in 25% of these patients and the death rate was 12%.

Molecular typing and antifungal susceptibility profile of Candida krusei bloodstream isolates from Türkiye.

Candida krusei also known as Pichia kudriavzevii is a potentially multidrug-resistant yeast because it is intrinsically resistant to fluconazole and develops acquired resistance to echinocandins and polyenes. Here, we aim to provide a better understanding of the epidemiology and transmission modes of C. krusei infections by comparing invasive bloodstream (n = 35) and non-invasive vaginal (n = 20) C. krusei isolates. The genetic relatedness of the isolates was assessed using a newly described short tandem repeat (STR) analysis and their sensitivity to eight antifungal compounds was evaluated by antifungal susceptibility testing using the CLSI microbroth dilution method. All C. krusei isolates revealed unique STR genotypes, indicating the absence of clonal transmission in the study group. Furthermore, no drug-resistant or non-wild-type isolates were identified. Our findings demonstrated high resolution of STR genotyping for the detection and simultaneous genetic analysis of multiple C. krusei strains in clinical samples and excellent in vitro activity of common antifungal agents against invasive strains.

An Autochthonous Susceptible Candida auris Clade I Otomycosis Case in Iran.

Candida auris is a newly emerging multidrug-resistant fungal pathogen considered to be a serious global health threat. Due to diagnostic challenges, there is no precise estimate for the prevalence rate of this pathogen in Iran. Since 2019, only six culture-proven C. auris cases have been reported from Iran, of which, five belonged to clade V and one to clade I. Herein, we report a case of otomycosis due to C. auris from 2017 in a 78-year-old man with diabetes mellitus type II without an epidemiological link to other cases or travel history. Short tandem repeat genotyping and whole genome sequencing (WGS) analysis revealed that this isolate belonged to clade I of C. auris (South Asian Clade). The WGS single nucleotide polymorphism calling demonstrated that the C. auris isolate from 2017 is not related to a previously reported clade I isolate from Iran. The presence of this retrospectively recognized clade I isolate also suggests an early introduction from other regions or an autochthonous presence. Although the majority of reported C. auris isolates worldwide are resistant to fluconazole and, to a lesser extent, to echinocandins and amphotericin B, the reported clade I isolate from Iran was susceptible to all antifungal drugs.

A conceptual framework for nomenclatural stability and validity of medically important fungi: a proposed global consensus guideline for fungal name changes supported by ABP, ASM, CLSI, ECMM, ESCMID-EFISG, EUCAST-AFST, FDLC, IDSA, ISHAM, MMSA, and MSGERC.

The rapid pace of name changes of medically important fungi is creating challenges for clinical laboratories and clinicians involved in patient care. We describe two sources of name change which have different drivers, at the species versus the genus level. Some suggestions are made here to reduce the number of name changes. We urge taxonomists to provide diagnostic markers of taxonomic novelties. Given the instability of phylogenetic trees due to variable taxon sampling, we advocate to maintain genera at the largest possible size. Reporting of identified species in complexes or series should where possible comprise both the name of the overarching species and that of the molecular sibling, often cryptic species. Because the use of different names for the same species will be unavoidable for many years to come, an open access online database of the names of all medically important fungi, with proper nomenclatural designation and synonymy, is essential. We further recommend that while taxonomic discovery continues, the adaptation of new name changes by clinical laboratories and clinicians be reviewed routinely by a standing committee for validation and stability over time, with reference to an open access database, wherein reasons for changes are listed in a transparent way.

The Fourier-transform infrared spectroscopy-based method as a new typing tool for Candida parapsilosis clinical isolates.

The Fourier-transform infrared spectroscopy-based IR Biotyper is a straightforward typing tool for bacterial species, but its use with Candida species is limited. We applied IR Biotyper to Candida parapsilosis, a common cause of nosocomial bloodstream infection (BSI), which is aggravated by the intra-hospital spread of fluconazole-resistant isolates. Of 59 C. parapsilosis isolates studied, n = 56 (48 fluconazole-resistant and 8 fluconazole-susceptible) and n = 3 (2 fluconazole-resistant and 1 fluconazole-susceptible) isolates, respectively, had been recovered from BSI episodes in 2 spatially distant Italian hospitals. The latter isolates served as an outgroup. Of fluconazole-resistant isolates, n = 40 (including one outgroup) harbored the Y132F mutation alone and n = 10 (including one outgroup) harbored both Y132F and R398I mutations in the ERG11-encoded azole-target enzyme. Using a microsatellite typing method, which relies on the amplification of genomic short tandem repeats (STR), two major clusters were obtained based on the mutation(s) (Y132F or Y132F/R398I) present in the isolates. Regarding IR Biotyper, each isolate was analyzed in quintuplicate using an automatic (i.e., proposed by the manufacturer's software) or tentative (i.e., proposed by us) cutoff value. In the first case, four clusters were identified, with clusters I and II formed by Y132F or Y132F/R398I isolates, respectively. In the second case, six subclusters (derived by the split of clusters I and II) were identified. This allowed to separate the outgroup isolates from other isolates and to increase the IR Biotyper typeability. The agreement of IR Biotyper with STR ranged from 47% to 74%, depending on type of cutoff value used in the analysis. IMPORTANCE Establishing relatedness between clinical isolates of Candida parapsilosis is important for implementing rapid measures to control and prevent nosocomial transmission of this Candida species. We evaluated the FTIR-based IR Biotyper, a new typing method in the Candida field, using a collection of fluconazole-resistant C. parapsilosis isolates supposed to be genetically related due to the presence of the Y132F mutation. We showed that IR Biotyper was discriminatory but not as much as the STR method, which is still considered the method of choice. Further studies on larger series of C. parapsilosis isolates or closely related Candida species will be necessary to confirm and/or extend the results from this study.