The relationship between antifungal usage and antifungal susceptibility in clinical isolates of Candida: a multicenter Korean study

Surveillance of Antifungal Resistance in Candidemia Fails to Inform Antifungal Stewardship in European Countries

Background: The increasing burden of candidemia and the emergence of resistance, especially among non-Candida albicans strains, represent a new threat for public health. We aimed to assess the status of surveillance and to identify publicly accessible resistance data in Candida spp blood isolates from surveillance systems and epidemiological studies in 28 European and 4 European Free Trade Association member states. Methods: A systematic review of national and international surveillance networks, from 2015 to 2020, and peer-reviewed epidemiological surveillance studies, from 2005 to 2020, lasting for at least 12 consecutive months and with at least two centers involved, was completed to assess reporting of resistance to amphotericin B, azoles, and echinocandins in C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. auris. Results: Only 5 (Austria, Italy, Norway, Spain, and United Kingdom) of 32 countries provided resistance data for Candida spp blood isolates. Among 322 surveillance studies identified, 19 were included from Belgium, Denmark, Iceland, Italy, Portugal, Spain, Sweden, Switzerland, and United Kingdom. C. albicans and C. glabrata were the most monitored species, followed by C. parapsilosis and C. tropicalis. C. krusei was not included in any national surveillance system; 13 studies assessed resistance. No surveillance system or study reported resistance for C. auris. Fluconazole, voriconazole, caspofungin, and amphotericin B resistance in C. albicans, C. glabrata, and C. parapsilosis were the most common drug–species combination monitored. Quality of surveillance data was poor, with only two surveillance systems reporting microbiological methods and clinical data. High heterogeneity was observed in modalities of reporting, data collection, and definitions. Conclusion: Surveillance of antifungal resistance in Candida spp blood-isolates is fragmented and heterogeneous, delaying the application of a translational approach to the threat of antifungal resistance and the identification of proper targets for antifungal stewardship activities. International efforts are needed to implement antifungal resistance surveillance programs in order to adequately monitor antifungal resistance.

Utilization Trends of Antiviral and Antifungal Agents for Human Systemic Use in Tanzania From 2010 to 2017 Using the World Health Organization Collaborating Centre for Drug Statistics Methodology

Introduction

The increase in antimicrobial consumption contributes to the emergence of antimicrobial resistance (AMR). Many studies have investigated the patterns of antibacterial consumption and antibacterial resistance. However, there is a paucity of data on the utilization of antivirals and antifungals in low and middle-income countries to serve as a baseline for monitoring and surveillance of AMR. Therefore, this study determined Tanzania’s systemic antifungal and antiviral utilization trends from 2010 to 2017, based on the Tanzania Medicines and Medical Devices Authority (TMDA) medicine importation archives.

Methodology

An analytical, longitudinal retrospective survey covering 2010 to 2017 was conducted. The study utilized the Anatomical Therapeutic and Chemical (ATC) classification and Defined Daily Dose (DDD) developed by the World Health Organization (WHO) Collaborating Centre for Drug Statistics and the WHO Collaboration Centre for International Drug Consumption Monitoring. Human medicine importation data were collected from TMDA headquarters and used to assess the systemic antiviral and antifungal consumption trends. The importation data included the date, generic name, strength, brand name, currency, quantity, ATC classification, supplier country, port of entry and product supplier. The data were cleaned, reorganized and analyzed. Reference was made to the latest revised DDD list to assign antifungals and antivirals to their respective ATC/DDDs and then adjusted to the population estimates from the National Bureau of Statistics of Tanzania.

Results

There was a high proportion of systemic antivirals and antifungals utilization with 367.1 and 10.8 DDD per 1000 inhabitants per day (DID) respectively over eight years. In regression model, there was a significant increase in both antiviral (p-value = 0.043) and antifungal (p-value = 0.015) agents’ utilization trends in Tanzania in the study period. Fluconazole had the highest proportion of utilization for antifungals, followed by ketoconazole, itraconazole, miconazole and amphotericin B. For systemic antivirals, a high proportion was attributed to antiretrovirals used for HIV infections.

Conclusion

Findings from this study suggest an increase in the utilization of systemic antiviral and antifungal agents. These findings may be used to further benchmark utilization and AMR studies in Tanzania.

Species Distribution and Antifungal Susceptibility Pattern of Candida Recovered from Intensive Care Unit Patients, Vietnam National Hospital of Burn (2017-2019)

INTRODUCTION

Candida species is the most common cause of invasive fungal infection. With the wide variation in species distribution and antifungal susceptibility of causative agents, local epidemiological profiles are needed to provide effective guidelines for the treatment of invasive candidiasis.

OBJECTIVE

To find out the species distribution and antifungal susceptibilities of Candida strains isolated from patients in an intensive care unit (ICU) of Vietnam.

METHODS

All patients in ICU of Vietnam National Hospital of Burn with Candida isolation reported from January 2017 to December 2019 were retrospectively studied. Species identification and antifungal susceptibility testing were performed using VITEK 2 Compact. The identification was reconfirmed by sequencing of the internal transcribed spacer regions when needed.

RESULTS

A total of 186 yeasts belonging to ten species were collected. The most common agent was C. tropicalis (45.7%), followed by C. albicans (42.4%), and C. parapsilosis (7.53%). The isolated yeasts showed less susceptibility to fluconazole (resistant rate R 10.7%) than to micafungin, caspofungin, flucytosine and amphotericin B (R 0%, 0.6%, 2.3% and 3.4%, respectively, p < 0.05). C. albicans isolates were more susceptible to fluconazole (R 5.2%) than C. tropicalis (R 15.7%). Resistance to voriconazole was seen only among C. albicans (3.9%) and C. tropicalis isolates (9.9%).

CONCLUSION

Non-albicans species (especially C. tropicalis) is the predominant species, and there is a significant proportion of isolates with reduced susceptibility to azole but not to echinocandin.

Core Recommendations for Antifungal Stewardship: A Statement of the Mycoses Study Group Education and Research Consortium

In recent years, the global public health community has increasingly recognized the importance of antimicrobial stewardship (AMS) in the fight to improve outcomes, decrease costs, and curb increases in antimicrobial resistance around the world. However, the subject of antifungal stewardship (AFS) has received less attention. While the principles of AMS guidelines likely apply to stewarding of antifungal agents, there are additional considerations unique to AFS and the complex field of fungal infections that require specific recommendations. In this article, we review the literature on AMS best practices and discuss AFS through the lens of the global core elements of AMS. We offer recommendations for best practices in AFS based on a synthesis of this evidence by an interdisciplinary expert panel of members of the Mycoses Study Group Education and Research Consortium. We also discuss research directions in this rapidly evolving field. AFS is an emerging and important component of AMS, yet requires special considerations in certain areas such as expertise, education, interventions to optimize utilization, therapeutic drug monitoring, and data analysis and reporting.

Expression of ERG11 and efflux pump genes CDR1, CDR2 and SNQ2 in voriconazole susceptible and resistant Candida glabrata strains

Candida glabrata causes difficult to treat invasive candidiasis due to its antifungal resistance, mainly to azoles. The aim of the present work was to study the role of the genes ERG11, CDR1, CDR2, and SNQ2 on the resistance to voriconazole (VRC) in a set of C. glabrata strains with known in vitro and in vivo susceptibility to this drug. Eighteen clinical isolates of C. glabrata were exposed in vitro to VRC, and the expression of the cited genes was quantified by real time quantitative polymerase chain reaction (q-PCR). In addition, the ERG11 gene was amplified and sequenced to detect possible mutations. Ten synonymous mutations were found in 15 strains, two of them being reported for the first time; however, no amino acid changes were detected. ERG11 and CDR1 were the most expressed genes in all the strains tested, while the expression of CDR2 and SNQ2 was modest. Our results show that gene expression does not directly correlate with the VRC MIC. In addition, the expression profiles of ERG11 and efflux pump genes did not change consistently after exposure to VRC. Although individual analysis did not result in a clear correlation between MIC and gene expression, we did observe an increase in ERG11 and CDR1 expression in resistant strains. It is of interest that considering both in vitro and in vivo results, the slight increase in such gene expression correlates with the observed resistance to VRC.

Epidemiology of antifungal susceptibility: Review of literature

Fungal infections are a major cause of morbidity and mortality despite the latest developments of diagnostic tools and therapeutic options. Early initiation of the appropriate antifungal therapy has been demonstrated to have a direct impact on the patient's outcome. Antifungal susceptibility testing methods are available to detect antifungal resistance and to determine the best treatment for a specific fungus. American and European standards have been developed, as well as equivalent commercial systems, which are more appropriate for clinical laboratories. These studies have allowed the development of interpretative breakpoints against the most frequent agents of fungal infections in the world. Surveillance of antifungal susceptibility patterns can provide the local drug resistance data to the clinicians, which can further aid better management of patients. Antifungal susceptibility tests have become essential tools to identify resistance to antifungals, to know the local and global disease epidemiology and to guide the treatment of fungal diseases. The distribution of species and the prevalence of antifungal resistance in fungi isolates varied among different areas. Here we summarize the epidemiology of antifungal susceptibility pattern of different fungal species.

Antifungal stewardship considerations for adults and pediatrics

Antifungal stewardship refers to coordinated interventions to monitor and direct the appropriate use of antifungal agents in order to achieve the best clinical outcomes and minimize selective pressure and adverse events. Antifungal utilization has steadily risen over time in concert with the increase in number of immunocompromised adults and children at risk for invasive fungal infections (IFI). Challenges in diagnosing IFI often lead to delays in treatment and poorer outcomes. There are also emerging data linking prior antifungal exposure and suboptimal dosing to the emergence of antifungal resistance, particularly for Candida. Antimicrobial stewardship programs can take a multi-pronged bundle approach to ensure suitable prescribing of antifungals via post-prescription review and feedback and/or prior authorization. Institutional guidelines can also be developed to guide diagnostic testing in at-risk populations; appropriate choice, dose, and duration of antifungal agent; therapeutic drug monitoring; and opportunities for de-escalation and intravenous-to-oral conversion.

Resistance Mechanisms and Clinical Features of Fluconazole-Nonsusceptible Candida tropicalis Isolates Compared with Fluconazole-Less-Susceptible Isolates

We investigated the azole resistance mechanisms and clinical features of fluconazole-nonsusceptible (FNS) isolates of Candida tropicalis recovered from Korean surveillance cultures in comparison with fluconazole-less-susceptible (FLS) isolates. Thirty-five clinical isolates of C. tropicalis, comprising 9 FNS (fluconazole MIC, 4 to 64 μg/ml), 12 FLS (MIC, 1 to 2 μg/ml), and 14 control (MIC, 0.125 to 0.5 μg/ml) isolates, were assessed. CDR1, MDR1, and ERG11 expression was quantified, and the ERG11 and UPC2 genes were sequenced. Clinical features of 16 patients with FNS or FLS bloodstream isolates were analyzed. Both FNS and FLS isolates had >10-fold higher mean expression levels of CDR1, MDR1, and ERG11 genes than control isolates (P values of <0.02 for all). When FNS and FLS isolates were compared, FNS isolates had 3.4-fold higher mean ERG11 expression levels than FLS isolates (P = 0.004), but there were no differences in those of CDR1 or MDR1 Of all 35 isolates, 4 (2 FNS and 2 FLS) and 28 (8 FNS, 11 FLS, and 9 control) isolates exhibited amino acid substitutions in Erg11p and Upc2p, respectively. Both FNS and FLS bloodstream isolates were associated with azole therapeutic failure (3/4 versus 4/7) or uncleared fungemia (4/6 versus 4/10), but FNS isolates were identified more frequently from patients with previous azole exposure (6/6 versus 3/10; P = 0.011) and immunosuppression (6/6 versus 3/10; P = 0.011). These results reveal that the majority of FNS C. tropicalis isolates show overexpression of CDR1, MDR1, and ERG11 genes, and fungemia develops after azole exposure in patients with immunosuppression.

Antifungal susceptibilities of bloodstream isolates of Candida species from nine hospitals in Korea: application of new antifungal breakpoints and relationship to antifungal usage

We applied the new clinical breakpoints (CBPs) of the Clinical and Laboratory Standards Institute (CLSI) to a multicenter study to determine the antifungal susceptibility of bloodstream infection (BSI) isolates of Candida species in Korea, and determined the relationship between the frequency of antifungal-resistant Candida BSI isolates and antifungal use at hospitals. Four hundred and fifty BSI isolates of Candida species were collected over a 1-year period in 2011 from nine hospitals. The susceptibilities of the isolates to four antifungal agents were determined using the CLSI M27 broth microdilution method. By applying the species-specific CBPs, non-susceptibility to fluconazole was found in 16.4% (70/428) of isolates, comprising 2.6% resistant and 13.8% susceptible-dose dependent isolates. However, non-susceptibility to voriconazole, caspofungin, or micafungin was found in 0% (0/370), 0% (0/437), or 0.5% (2/437) of the Candida BSI isolates, respectively. Of the 450 isolates, 72 (16.0%) showed decreased susceptibility to fluconazole [minimum inhibitory concentration (MIC) ≥4 μg/ml]. The total usage of systemic antifungals varied considerably among the hospitals, ranging from 190.0 to 7.7 defined daily dose per 1,000 patient days, and fluconazole was the most commonly prescribed agent (46.3%). By Spearman’s correlation analysis, fluconazole usage did not show a significant correlation with the percentage of fluconazole resistant isolates at hospitals. However, fluconazole usage was significantly correlated with the percentage of fluconazole non-susceptible isolates (r = 0.733; P = 0.025) or the percentage of isolates with decreased susceptibility to fluconazole (MIC ≥4 μg/ml) (r = 0.700; P = 0.036) at hospitals. Our work represents the first South Korean multicenter study demonstrating an association between antifungal use and antifungal resistance among BSI isolates of Candida at hospitals using the new CBPs of the CLSI.

Hospital use of systemic antifungal drugs: a multi-center surveillance update from Germany

BACKGROUND

The consumption of antifungal agents increased over the last decade, resulting in the development of resistant organisms and causing a significant pharmaco economic burden. Antifungal drugs are widely used for the treatment of systemic fungal infections and high-risk patients, especially with severe hematological or oncological conditions. Up to date, there are no reliable and systematically reported data on the consumption of antifungal substances on a nationwide level available. The presented study gives an update to the previously published multicenter study investigating antifungal consumption in different settings from five university hospital centers in Germany from 2001 to 2003.

METHODS

Consumption data for systemic antifungal drugs were obtained through the hospital pharmacies for 2001-2003 and 2008-2011 regarding the medical and surgical services of five university hospital centers in Germany (A-E). Drug use densities were calculated as yearly RDDs/100 patient days. These calculations were performed for the surgical and medical services, and independently for surgical and medical ICUs, as well as for the hematology-oncology services.

RESULTS

We report an increased utilization of systemic antifungal drugs in both study periods. The mean drug use density (mean value of all 5 hospitals) in the medical services increased by 24% between 2001 and 2003. In 2011, this value was 37% above the level from 2001 (12.4 RDD/100 patient days in 2001, 15.4 RDD/100 patient days in 2003, 17.0 RDD/100 patient days in 2011). The 4-year average drug use density (2008-2011) of medical services ranged between 11.6 RDD/100 patient days (hospital E) and 23.8 RDD/100 patient days (hospital A). Drug use densities were in medical intensive care units 29.4 RDD/100 patient days and hematology-oncology services 49.9 RDD/100 patient days.

CONCLUSIONS

Despite the variability of the prescribing patterns between the tertiary hospitals, the presented pharmaco-epidemiological data are a cornerstone for the initiation and implementation of effective antifungal stewardship programmes and might serve as important benchmarking information for other hospitals with similar structures and baseline settings.

Surveillance of antifungal susceptibilities in clinical isolates of Candida species at 36 hospitals in China from 2009 to 2013

BACKGROUND

The purpose of this study was to determine the species distribution and to monitor the antifungal susceptibility profiles of clinical Candida isolates collected in China from 2009 to 2013.

METHODS

The antifungal susceptibilities of 952 Candida isolates were tested.

RESULTS

Candida albicans was the most common species, accounting for 65.7% of the total isolates. The most frequently isolated non-albicans Candida species in this study was Candida glabrata (193, 20.3%). Nearly 7.6%, 3.2%, 1.8%, and 1.1% of the 952 isolates exhibited decreased susceptibility to fluconazole, voriconazole, itraconazole, and flucytosine, respectively. Moreover, seven C. albicans and one Candida krusei had an amphotericin B minimum inhibitory concentration (MIC) of 2 μg/ml.

CONCLUSIONS

The distribution of species and the prevalence of antifungal resistance in Candida isolates varied among different areas in China. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in clinical isolates of Candida species.

Usefulness of defined daily dose and days of therapy in pediatrics and obstetrics-gynecology: a comparative analysis of antifungal drugs (2000-2001, 2005-2006, and 2010-2011)

OBJECTIVES

The objective was to describe antifungal drug use by using the number of defined daily doses (DDD)/1000 patient-days per antifungal, the number of days of therapy (DOT)/1000 patient-days per antifungal, and the mean dose in mg/kg/day per antifungal during a 10-year period.

METHODS

Retrospective, cross-sectional, descriptive study, in a mother-child university hospital center, with 400 pediatric beds and 100 obstetrics-gynecology beds. All inpatients who received 1 of the 7 authorized antifungals on the institution's local formulary in 2000-2001, 2005-2006, or 2010-2011 were included. Prescriptions for emergency department and outpatient clinics were excluded. The data were extracted from the patients' computerized medication profiles linked to patient admission, discharge, and transfer data. The DDD, DOT, and the mean dose in mg/kg/day were calculated for each antifungal and overall.

RESULTS

There was a 2.97-fold increase in the overall number of DDD/1000 patient-days, from 14.8 in 2000-2001 to 37.5 in 2005-2006 and 43.9 in 2010-2011. There was a 2.97-fold increase in the overall number of DOT/1000 patient-days, from 22.8 in 2000-2001 to 50.3 in 2005-2006 and 67.8 in 2010-2011.

CONCLUSIONS

It can be difficult to compare the use of antifungal drugs among institutions, owing to numerous factors, but it gives an idea about the consumption outside the studied center. Moreover, these ratios help to evaluate the use of antifungals within a same institution. These data could be correlated among others, with resistance patterns, in order to improve our daily practice concerning antifungal prescription.

Emergence of echinocandin-resistant Candida spp. in a hospital setting: a consequence of 10 years of increasing use of antifungal therapy?

Since their introduction in the 2000s, echinocandin drugs have become widely used for the treatment and prophylaxis of invasive fungal infections and, notably, invasive candidiasis. Although cases of breakthrough candidiasis in patients receiving echinocandins have been reported, clinical failure during echinocandin treatment due to the acquisition of resistance by a normally susceptible Candida spp. isolate is considered rare. To date, no publications have been published correlating the use of echinocandins and the emergence of echinocandin resistance among Candida species. So, our goal is to report an initial analysis of echinocandin use in relation to the emergence of resistant Candida isolates. We report here a single-centre experience of the emergence of eight resistant isolates belonging to normally susceptible Candida species in six patients receiving echinocandins. We describe the context and analyse the use of echinocandins over the previous decade. For seven of these isolates, we identified FKS gene mutations involved in decreased susceptibility. Seven isolates were obtained in 2011, on the heels of a ten-fold increase in caspofungin use over the preceding decade. In contrast, in 2012, the use of echinocandins decreased in our institution by 19.5 % and, in that year, only one Candida-resistant isolate was detected, despite the stable global epidemiology of invasive candidaemia. This work underlines the necessity of improving the prescription of antifungal drugs. Improvement in the monitoring of strain susceptibility should also be considered in order to better detect the emergence of resistant or non-susceptible yeast strains.

In vitro fluconazole and voriconazole susceptibilities of Candida bloodstream isolates in Korea: use of the CLSI and EUCAST epidemiological cutoff values

Background

At present, the clinical breakpoints (CBPs) of both fluconazole and voriconazole are available only for 3 common Candida species in the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methods. Epidemiological cutoff values (ECVs) were recently applied to both methods to detect the emergence of acquired resistance (i.e., non-wild-type isolates) among 5 common Candida species.

Methods

We performed a nationwide study to determine the fluconazole and voriconazole susceptibility of Candida bloodstream isolates (BSIs) using both the CLSI and EUCAST methods. A total of 423 BSIs of 5 Candida species were collected from 8 hospitals. The azole susceptibilities were assessed on the basis of the species-specific CBPs and ECVs.

Results

Of the 341 BSIs of 3 common Candida species (i.e., C. albicans, C. tropicalis, and C. parapsilosis), 0.3% and 0.9%, 0.0% and 1.5% of isolates were categorized as fluconazole and voriconazole resistant according to the CLSI and EUCAST CBPs, respectively. Of 423 total BSIs, 1.4% and 2.6% had fluconazole minimum inhibitory concentrations (MICs) exceeding the ECVs according to the CLSI and EUCAST, respectively; 1.0% and 2.1% had voriconazole MICs exceeding the ECVs according to the CLSI and EUCAST, respectively. Categorical agreement between the methods using ECVs was 98.3% for fluconazole and 98.3% for voriconazole.

Conclusions

The EUCAST and CLSI methods using ECVs provide highly concordant results. Moreover, non-wild-type isolates with possibly acquired azole resistance were rare among the BSIs of 5 common Candida species in Korea.

[Species distribution and antifungal susceptibilities of yeast clinical isolates from three hospitals in Korea, 2001 to 2007]

BACKGROUND

We utilized results from the ARTEMIS DISK Global Antifungal Surveillance Program to evaluate the species distribution and fluconazole and voriconazole susceptibilities of yeast isolates from clinical specimens in South Korea from 2001 to 2007.

METHODS

Data were collected on 5,665 yeast isolates from all body sites at three locations. All investigators tested clinical yeast isolates using the CLSI M44-A disk diffusion method. Test plates were automatically read and results were recorded using the BIOMIC image analysis plate reader system (Giles Scientific, USA). Species, drug, zone diameter, susceptibility category, and quality control results were collected quarterly via e-mail for analysis.

RESULTS

Candida albicans was the most common isolate, but a progressive increase in non-C. albicans Candida and noncandidal yeast species has been observed in recent years. The overall percentages of isolates in each category (susceptible, susceptible dose dependent, and resistant) were 98.8%, 0.5%, and 0.7% and 99.2%, 0.2%, and 0.6% for fluconazole and voriconazole, respectively. Candida of 3 species exhibited decreased susceptibility to fluconazole (<90% S) in the order of that seen with the resistant (R) species: C. krusei, C. guilliermondii, and C. glabrata. Emerging resistance to fluconazole or voriconazole was documented among isolates of Cryptococcus neoformans, Trichosporon spp., and Rhodotorula spp.

CONCLUSIONS

The species distribution and antifungal susceptibilities of yeasts may differ according to specimen type, testing method, hospital, and geographic region. Therefore, further large-scaled, long-term surveillance studies are needed to isolate yeasts and to confirm the species distribution and antifungal susceptibilities of yeast isolates from clinical specimens in Korea.

Multicenter surveillance of species distribution and antifungal susceptibilities of Candida bloodstream isolates in South Korea

Multicenter data on in vitro susceptibility of Candida bloodstream isolates to echinocandin antifungal agents is still lacking in South Korea. We performed a prospective multicenter study to determine the species distribution of Candida bloodstream isolates and their susceptibility to five antifungal agents, including caspofungin and micafungin. A total of 639 isolates were collected from 20 tertiary hospitals between September 2006 and August 2007. Antifungal susceptibilities were determined through the use of the CLSI broth microdilution method M27-A3. The overall species distribution was as follows; Candida albicans (38%), Candida parapsilosis (26%), Candia tropicalis (20%), Candida glabrata (11%), and miscellaneous Candida species (5%). Although C. parapsilosis and miscellaneous Candida species were less susceptible to both echinocandins, all 639 isolates were susceptible to both caspofungin and micafungin (MIC, <or= 2 microg/ml). Nearly all isolates (99.7%) had a MIC <or= 1 microg/ml to amphotericin B. Resistance to fluconazole and voriconazole was found in 0.8% and 0.3%, respectively, among all Candida isolates, with C. glabrata and C. krusei isolates displaying the greatest level of resistance. This is the largest multicenter candidemia study conducted in South Korea and shows that non-C. albicans Candida species, including C. parapsilosis, constitutes over 60% of all Candida species isolates recovered from the bloodstream. In addition, the rates of resistance to all five antifungals, including two echinocandins, are still low among bloodstream isolates in South Korea.

Evaluation of the V404I and V509M amino acid substitutions of ERG11 gene in Candida albicans isolates by pyrosequencing

The molecular mechanisms underlying fluconazole resistance in C. albicans involve mutations and the overexpression of the ERG11 gene and membrane transport proteins. We examined the relationship between the reduced fluconazole susceptibility of C. albicans and mutations of V404I and V509M in the ERG11 gene in 182 C. albicans clinical isolates using the Pyrosequencing method. DNAs from these clinical isolates with different levels of in-vitro fluconazole susceptibility--one resistant, five susceptible dose-dependent (SDD), four trailer, and 172 susceptible--were analyzed. None of the fluconazole-susceptible, SDD, trailer or resistant isolates had mutations of V404I or V509M. Our results showed that no correlation can be found between the V404I or V509M mutation and fluconazole susceptibility in C. albicans.