Species distribution and antifungal susceptibility of Candida spp. isolated from superficial candidiasis in outpatients in Iran

Transcriptomic meta-analysis to identify potential antifungal targets in Candida albicans

BACKGROUND

Candida albicans is a fungal pathogen causing human infections. Here we investigated differential gene expression patterns and functional enrichment in C. albicans strains grown under different conditions.

METHODS

A systematic GEO database search identified 239 "Candida albicans" datasets, of which 14 were selected after rigorous criteria application. Retrieval of raw sequencing data from the ENA database was accompanied by essential metadata extraction from dataset descriptions and original articles. Pre-processing via the tailored nf-core pipeline for C. albicans involved alignment, gene/transcript quantification, and diverse quality control measures. Quality assessment via PCA and DESeq2 identified significant genes (FDR < = 0.05, log2-fold change > = 1 or <= -1), while topGO conducted GO term enrichment analysis. Exclusions were made based on data quality and strain relevance, resulting in the selection of seven datasets from the SC5314 strain background for in-depth investigation.

RESULTS

The meta-analysis of seven selected studies unveiled a substantial number of genes exhibiting significant up-regulation (24,689) and down-regulation (18,074). These differentially expressed genes were further categorized into 2,497 significantly up-regulated and 2,573 significantly down-regulated Gene Ontology (GO) IDs. GO term enrichment analysis clustered these terms into distinct groups, providing insights into the functional implications. Three target gene lists were compiled based on previous studies, focusing on central metabolism, ion homeostasis, and pathogenicity. Frequency analysis revealed genes with higher occurrence within the identified GO clusters, suggesting their potential as antifungal targets. Notably, the genes TPS2, TPS1, RIM21, PRA1, SAP4, and SAP6 exhibited higher frequencies within the clusters. Through frequency analysis within the GO clusters, several key genes emerged as potential targets for antifungal therapies. These include RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101 which exhibited higher occurrence within the identified clusters.

CONCLUSION

This comprehensive study significantly advances our understanding of the dynamic nature of gene expression in C. albicans. The identification of genes with enhanced potential as antifungal drug targets underpins their value for future interventions. The highlighted genes, including TPS2, TPS1, RIM21, PRA1, SAP4, SAP6, RSP5, GLC7, SOD2, SOD5, SOD1, SOD6, SOD4, SOD3, and RIM101, hold promise for the development of targeted antifungal therapies.

A Comprehensive Review of Identification Methods for Pathogenic Yeasts: Challenges and Approaches

Given the increasing incidence of yeast infections and the presence of drug-resistant isolates, accurate identification of the pathogenic yeasts is essential for the management of yeast infections. In this review, we tried to introduce the routine and novel techniques applied for yeast identification. Laboratory identification methods of pathogenic yeast are classified into three categories; I. conventional methods, including microscopical and culture-base methods II. biochemical/physiological-processes methods III. molecular methods. While conventional and biochemical methods require more precautions and are not specific in some cases, molecular diagnostic methods are the optimum tools for diagnosing pathogenic yeasts in a short time with high accuracy and specificity, and having various methods that cover different purposes, and affordable costs for researchers. Nucleotide sequencing is a reference or gold standard for identifying pathogenic yeasts. Since it is an expensive method, it is not widely used in developing countries. However, novel identification techniques are constantly updated, and we recommend further studies in this field. The results of this study will guide researchers in finding more accurate diagnostic method(s) for their studies in a short period of time.

Uncovering the Yeast Diversity in the Female Genital Tract: An Exploration of Spatial Distribution and Antifungal Resistance

Candida albicans is the leading cause of vulvovaginal yeast infections; however, other species are becoming relevant in this niche. The spatial distribution of these fungi in the female genital tract remains poorly understood. In this study, swab samples were collected from 33 patients, first from the anterior vulva and then from the upper third and right lateral wall of the vagina: 16 were with symptoms of vulvovaginal candidiasis and 17 were without characteristic symptoms; furthermore, the genus and species of each isolate were identified. In vitro susceptibility testing for fluconazole and clotrimazole was performed for all isolates. Candida albicans was the most common species (63.6%), followed by Rhodotorula spp. (51.5%), and then Candida parapsilosis (15.2%). Rhodotorula spp. and C. parapsilosis were more commonly associated with colonization, and C. albicans with infection. Rhodotorula spp. isolates presented a low susceptibility to fluconazole, with the MIC ranging from 32 to >64 µg/mL. Differences in susceptibility to fluconazole and clotrimazole between the pairs of vaginal and vulvar isolates were found for Candida albicans, Rhodotorula spp., and Nakaseomyces glabratus. The results suggest that different niches may impact the susceptibility profiles of the isolates, as well as their different clinical behaviors.

Meyerozyma guilliermondii species complex: review of current epidemiology, antifungal resistance, and mechanisms

Meyerozyma guilliermondii has been accepted as a complex composed of Meyerozyma guilliermondii, Meyerozyma carpophila, and Meyerozyma caribbica. M. guilliermondii is a saprophyte detected on human mucosa and skin. It can lead to serious infections in patients with risk factors like chemotherapy, immunodeficiency, gastrointestinal or cardiovascular surgery, and oncology disorders. Most deaths related to M. guilliermondii infections occur in individuals with malignancy. In recent decades, incidence of M. guilliermondii infections is increased. Sensitivity of this microorganism to conventional antifungals (e.g., amphotericin B, fluconazole, micafungin and anidulafungin) was reduced. Prophylactic and empirical uses of these drugs are linked to elevated minimal inhibitory concentrations (MICs) of M. guilliermondii. Drug resistance has concerned many researchers across the world. They are attempting to discover appropriate solution to combat this challenge. This study reviews the most important mechanisms of resistance to antifungals developed by in M. guilliermondii species complex.

Temporal changes in gastrointestinal fungi and the risk of autoimmunity during early childhood: the TEDDY study

Fungal infections are a major health problem that often begin in the gastrointestinal tract. Gut microbe interactions in early childhood are critical for proper immune responses, yet there is little known about the development of the fungal population from infancy into childhood. Here, as part of the TEDDY (The Environmental Determinants of Diabetes in the Young) study, we examine stool samples of 888 children from 3 to 48 months and find considerable differences between fungi and bacteria. The metagenomic relative abundance of fungi was extremely low but increased while weaning from milk and formula. Overall fungal diversity remained constant over time, in contrast with the increase in bacterial diversity. Fungal profiles had high temporal variation, but there was less variation from month-to-month in an individual than among different children of the same age. Fungal composition varied with geography, diet, and the use of probiotics. Multiple Candida spp. were at higher relative abundance in children than adults, while Malassezia and certain food-associated fungi were lower in children. There were only subtle fungal differences associated with the subset of children that developed islet autoimmunity or type 1 diabetes. Having proper fungal exposures may be crucial for children to establish appropriate responses to fungi and limit the risk of infection: the data here suggests those gastrointestinal exposures are limited and variable.

Inhibitory effects of cold atmospheric plasma on the growth, virulence factors and HSP90 gene expression in Candida albicans

In spite of the abundance of antifungal therapies, 75% of women in the world suffer from the second most common cause of vaginal infection named vulvovaginal candidiasis. This complication is characterized with overgrowth of Candida albicans. The low efficacy and side effects of current antifungal therapies have convinced the researchers to look for a non-antibiotic based treatment such as cold atmospheric plasmas (CAP). The aim of this research was to evaluate the effects of CAP on C. albicans growth, ergosterol and biofilm formation. In addition, antibiotic resistance, phospholipase and proteinase activity, and structural properties were examined with different exposure duration. Putative critical effect of CAP on the expression of HSP90 as a target of anti-fungal therapy was investigated. ROS production in C. albicans exposed to CAP was assessed. For this purpose, C. albicans subjected to 0, 90, 120, 150, 180 and 210 s of He/O2 (2%), and non-treated cells as control were examined in terms of the mentioned virulence factors. The results showed that CAP had a significant effect on inhibition of C. albicans growth, Inhibition of biofilm formation, ergosterol content, and fluconazole and amphotericin B antibiotic sensitivity were significant in 210 s treatment group. This effect was validated based on changes of the cell architecture and morphology given the microscopy imaging results. The expression of HSP90 in both C. albicans ATCC 10231 and C. albicans PFCC 9362 was inhibited in 210 s of exposition. CAP exposition induced intracellular ROS, which may cause membrane damage and cell death in C. albicans. Taken together, the potential of CAP for therapeutic purposes in C. albicans-induced fungal infections is supported.

In vivo and in vitro Pathogenesis and Virulence Factors of Candida albicans Strains Isolated from Cutaneous Candidiasis

Background

The Candida albicans is one of the most important global opportunistic pathogens, and the incidence of candidiasis has increased over the past few decades. Despite the established role of skin in defense against fungal invasion, little has been documented about the pathogenesis of Candida species when changing from normal flora to pathogens of vaginal and gastrointestinal epithelia. This study was carried out to determine the in vivo and in vitro pathogenesis of clinical C. albicans strains isolated from skin lesions.

Methods

In this study, association of in vivo and in vitro pathogenesis of C. albicans isolates with different evolutionary origins was investigated. Oral and systemic experimental candidiasis was established in BALB/C mice. The expression levels of secreted aspartyl proteinases (SAP1-3 genes), morphological transformation, and biofilm-forming ability of C. albicans were evaluated.

Results

All the strains showed in vitro and in vivo pathogenicity by various extents. The SAP1, SAP2, and SAP3 genes were expressed in 50%, 100%, and 75% of the strains, respectively. The biofilm formation ability was negative in 12% of the strains, while it was considerable in 38% of the strains. Fifty percent of the strains had no phospholipase activity, and no one demonstrated high level of this pathogenesis factor. Relatively all the strains had very low potency to form pseudohyphae.

Conclusion

Our findings demonstrated that Candida albicans strains isolated from cutaneous candidiasis were able to cause oral and systemic infections in mice, so they could be considered as the potential agents of life-threatening nosocomial candidiasis in susceptible populations.

Characterization of Candida species isolated from the hands of the healthcare workers in the neonatal intensive care unit

Colonization of health professional hands by potentially pathogenic microorganisms capable to expressing virulence factors, such as Candida spp., is worrisome because of the high contact between patients and professionals. The study aims to evaluate, in vitro, the following virulence factors: hemolytic activity, DNAse expression, biofilm formation, and susceptibility for antifungal agents of Candida species isolated from health professionals hands of a neonatal intensive care unit (NICU). The study includes 50 isolates of Candida spp.: 19 C. parapsilosis sensu stricto, three C. metapsilosis, one C. orthopsilosis, seven C. albicans, six C. famata, five C. lusitaniae, three C. krusei, two C. kefyr, two C. tropicalis, one C. glabrata, and one C. guilliermondii. The hemolytic activity and DNAse were investigated using blood agar and DNAse agar, respectively. Biofilm production was evaluated through XTT sodium salt reduction ability, and the susceptibility of the isolates to antifungals through the microdilution methodology. Forty-nine isolates presented at least one of the three virulence factors investigated. C. albicans showed more intense hemolytic activity. DNAse production was statistically significant between the C. parapsilosis complex and C. albicans, as well as between the C. parapsilosis complex and C. krusei, even as between C. famata and C. albicans, and between C. famata and C. krusei. Forty-three isolates produced biofilm. Seventy-eight percent of the isolates were sensitive to the three antifungals tested. This study demonstrated that Candida isolated from healthcare professionals' hands has virulence.

Candida isolates causing refractory or recurrent oropharyngeal candidiasis in 11 hospitals in China

Introduction: We studied the species distribution and antifungal susceptibilities of Candida isolates causing refractory or recurrent oropharyngeal candidiasis (OPC) in a multicenter study in China (2013–2016).

Methods: Species identification was performed using the Bruker Biotyper (Bruker Daltonics, Germany) matrix-assisted laser desorption/ionization time of flight mass spectrometry system supplemented by internal transcribed spacer sequencing as required. Antifungal susceptibilities were determined by the Clinical and Laboratory Standards Institute document (CLSI) M27-A3 broth microdilution methodology.

Results: A total of 558 non-duplicate Candida isolates comprising 10 species were obtained from 535 patients. Candida albicans was the most common species (89.6%), followed by C. glabrata (5.2%), C. tropicalis (2.9%), and C. parapsilosis (0.7%). Azoles were active against C. albicans with susceptibility rates of 96% and 95.8% for fluconazole and voriconazole, respectively. MIC₅₀ values of C. albicans to fluconazole, voriconazole, itraconazole, and miconazole were 1, 0.03, 0.25 and 0.12 μg/mL, respectively, higher than those in previous studies of which OPC patients (corresponding MIC₅₀ values of 0.25 , 0.015 , 0.06 , and 0.03 μg/mL). Except for itraconazole, the MIC₅₀ and MIC₉₀ values of 58 non-C. albicans to other azoles were two to threefold higher than C. albicans. Miconazole, amphotericin B, nystatin, and 5-flucytosine had good in vitro antifungal activity for all isolates.

Conclusion: The study provides valuable data on the species distribution and antifungal susceptibility of oropharyngeal Candida isolates from geographically diverse areas of China. C. albicans remains the most common species but with increasing rates of azoles resistance.

Epidemiological survey of onychomycosis pathogens in Japan by real-time PCR

In Japan, an epidemiological survey of onychomycosis pathogens was performed using culture methods; however, the positive culture rate was 40% or less. As part of an epidemiological survey of dermatomycoses in Japan, we overcame this low positive rate by employing a real-time polymerase chain reaction (PCR) assay that allowed rapid and accurate detection and identification. In 2011, nail specimens were collected from patients at nine institutes in various prefectures in Japan and diagnosed as onychomycosis. For the detection and identification of the main pathogens causing onychomycosis, we performed real-time PCR using specific TaqMan® MGB probes and primer sets. Of the 496 onychomycosis samples, real-time PCR detected 382 cases (77.0%) caused by Trichophyton rubrum; 74 cases (15.0%) caused by Trichophyton interdigitale; and eight cases (1.6%) caused by Candida albicans. The real-time PCR positive rate was 96.2%. The most frequent pathogen was T. rubrum throughout life, with the number of patients affected peaking in the range of 60 to 69 years of age and no significant differences in the composition of causative pathogens by sex. We were able to detect and identify pathogens from almost all specimens and succeeded in analyzing the pathogens involved in onychomycosis cases in Japan. These data confirmed that our real-time PCR method was effective for detecting and identifying the main fungal pathogens from onychomycosis specimens.

Prevalence and antifungal susceptibility profiles of Candida glabrata, Candida parapsilosis and their close-related species in oral candidiasis

OBJECTIVE

To evaluate the importance of Candida glabrata, Candida parapsilosis and their close-related species, Candida bracarensis, Candida nivariensis, Candida metapsilosis and Candida orthopsilosis in patients with oral candidiasis and, to determine the in vitro activities of antifungal drugs currently used for the treatment.

METHODS

One hundred fourteen isolates of C. glabrata and 97 of C. parapsilosis, previously identified by conventional mycological methods, were analysed by molecular techniques. In vitro antifungal susceptibility to fluconazole, itraconazole, miconazole, and nystatin was evaluated by CLSI M44-A2 disk diffusion test, and by CLSI M27-A3 microdilution for fluconazole.

RESULTS

All C. glabrata isolates were identified as C. glabrata sensu stricto, 93 out of 97 C. parapsilosis isolates as C. parapsilosis sensu stricto, three as C. orthopsilosis and one as C. metapsilosis. Candida glabrata was mainly isolated in mixed cultures but C. parapsilosis complex was more frequent in pure culture. Candida metapsilosis and C. orthopsilosis were isolated as pure culture and both species were susceptible to all antifungal agents tested. Most C. glabrata isolates were susceptible to miconazole and nystatin, but resistant to fluconazole and itraconazole. Azole cross resistance was also observed. Candida parapsilosis isolates were susceptible to fluconazole although azole cross resistance to miconazole and itraconazole was observed.

CONCLUSION

This study highlights the importance of accurate identification and antifungal susceptibility testing of oral Candida isolates in order to have an in-depth understanding of the role of C. glabrata and C. parapsilosis in oral candidiasis.

Candida Infections and Therapeutic Strategies: Mechanisms of Action for Traditional and Alternative Agents

The Candida genus comprises opportunistic fungi that can become pathogenic when the immune system of the host fails. Candida albicans is the most important and prevalent species. Polyenes, fluoropyrimidines, echinocandins, and azoles are used as commercial antifungal agents to treat candidiasis. However, the presence of intrinsic and developed resistance against azole antifungals has been extensively documented among several Candida species. The advent of original and re-emergence of classical fungal diseases have occurred as a consequence of the development of the antifungal resistance phenomenon. In this way, the development of new satisfactory therapy for fungal diseases persists as a major challenge of present-day medicine. The design of original drugs from traditional medicines provides new promises in the modern clinic. The urgent need includes the development of alternative drugs that are more efficient and tolerant than those traditional already in use. The identification of new substances with potential antifungal effect at low concentrations or in combination is also a possibility. The present review briefly examines the infections caused by Candida species and focuses on the mechanisms of action associated with the traditional agents used to treat those infections, as well as the current understanding of the molecular basis of resistance development in these fungal species. In addition, this review describes some of the promising alternative molecules and/or substances that could be used as anticandidal agents, their mechanisms of action, and their use in combination with traditional drugs.

Comparative analysis of proteinase, phospholipase, hydrophobicity and biofilm forming ability in Candida species isolated from clinical specimens

Candida species are the commensal organisms of human and animal mucosa that cause a wide range of debilitating diseases in immunocompromised patients and other susceptible individuals. The present study aimed to investigate the ability of clinical isolates of various Candida species to produce proteinase and phospholipase, hydrophobicity and biofilm forming ability that assumed to have a vital role in Candida pathogenicity. Eighty-four Candida strains belonged to Candida albicans (44.1%), C. glabrata (5.9%), C. guilliermondii (5.9%), C. krusei (10.8%), C. parapsilosis (26.2%), and C. tropicalis (7.1%) were examined for proteinase and phospholipase production, cell surface hydrophobicity and biofilm forming ability. The production of proteinase and phospholipase was detected in 81 (96.4%) and 79 (94.1%) of the strains, respectively. C. albicans showed the highest proteinase and phospholipase activity (mean Pz values of 0.42±0.25 and 0.72±0.28) and biofilm formation ability (0.66±0.22). C. parapsilosis had the highest hydrophobicity (42.97±16.1), which showed a good correlation with biofilm formation ability. A considerable percentage of non-albicans Candida strains produced significant amounts of proteinase and phospholipase with a good ability of biofilm formation in vitro. Taken together, our results further substantiated that enzymatic activity, hydrophobicity and the ability for biofilm formation are important virulence factors which may be account for pathogenicity of various Candida species distributed in albicans and non-albicans groups.

Oropharyngeal candidiasis in head and neck cancer patients in Iran: Species identification, antifungal susceptibility and pathogenic characterization

OBJECTIVE

Oropharyngeal candidiasis (OPC) is the most frequent opportunistic fungal infection in head and neck cancer patients. This study was done to identify the Candida species, which cause OPC, and to evaluate their antifungal susceptibility pattern and pathogenic characteristics in Iranian head and neck cancer patients treated by radiotherapy.

MATERIAL AND METHODS

The oral clinical samples were determined by culturing on CHROMagar, carbohydrate assimilation and ITS sequencing methods. Biofilm formation, phospholipase and proteinase activity and antifungal susceptibility were examined too.

RESULTS

Among 54 patients with confirmed OPC, 39 (72.22%) patients were male and 15 (27.77%) were female. The most frequently Candida species from a total of 60 isolates was C. albicans (53.3%), followed by C. tropicalis (21.66%), C. glabrata (15%), C. kefyr (5%) and C. dubliniensis (1.66%). All the isolates were high-producers of biofilm. All of Candida isolates were proteinase positive and 47 isolates (81.04%) represented phospholipase activity. The maximum and minimum rates of antifungal resistance belonged to ketoconazole (93.75% of C. albicans and 89.28% of Candida non-albicans) and fluconazole (62.50% and 42.85% of C. albicans and Candida non-albicans), respectively. The most effective antifungal against all candida isolates was fluconazole.

CONCLUSION

Our data can estimate abundance of OPC in male and female head and neck cancer patients and is helpful to use effective strategies for antifungal treatment, prophylaxis, and preventive therapies in these patients.

Emergence of non-Candida albicans species: Epidemiology, phylogeny and fluconazole susceptibility profile

OBJECTIVE

Non-Candida albicans (NCA) species now account for a significant part of clinical candidiasis worldwide. In the present study, epidemiology and antifungal susceptibility profile of NCA isolated from various forms of candidiasis were studied with special focus on their phylogenetic relationship by ITS sequencing.

PATIENTS AND METHODS

Seventy-nine NCA isolates were isolated from skin and nail scrapings (67.0%), vaginal discharges (8.8%), blood (8.8%), sputa (5.0%), urine (5.0%), oral swabs (2.6%), biopsy and eye tumor, each (1.4%). These isolates were identified by morphological, biochemical and molecular (ITS sequencing) techniques. In vitro antifungal susceptibility of the isolates to fluconazole (FCZ) was tested according to the CLSI method (M27-S4).

RESULTS

Among a total number of 79 cases of proven NCA infections, C. parapsilosis (36.8%) was the most prevalent species followed by C. glabrata (32.9%), C. orthopsilosis (11.4%), C. tropicalis (8.9%), C. krusei (5.0%) and C. guilliermondii (5.0%). The susceptibility to FCZ was assessed for C. parapsilosis (96.5%), C. orthopsilosis (88.9%), C. tropicalis (85.7%) and C. guilliermondii (50.0%). C. glabrata and C. krusei isolates were not susceptible to FCZ. NCA species were distributed in various phylogenetic clades including C. glabrata (1), C. tropicalis (3), C. parapsilosis (6) and C. orthopsilosis, C. krusei and C. guilliermondii (each 2).

CONCLUSION

C. parapsilosis and C. glabrata were the most predominant NCA species involve in the etiology of candidiasis. C. orthopsilosis was reported from superficial candidiasis. Taken together, our results further substantiate the increasing importance of the involvement of NCA species in the etiology of candidiasis.

Molecular Identification and Antifungal Susceptibility Pattern of Non-albicans Candida Species Isolated from Vulvovaginal Candidiasis

Background

Vulvovaginal candidiasis (VVC) is an important health problem caused by Candida spp. The aim of this study was molecular identification, phylogenetic analysis, and evaluation of antifungal susceptibility of non-albicans Candida isolates from VVC.

Methods

Vaginal secretion samples were collected from 550 vaginitis patients at Sayyad Shirazi Medical and Educational Center of Gorgan (Golestan Province, Iran) from May to October 2015. Samples were analyzed using conventional mycological and molecular approaches. Clinical isolates were analyzed with specific PCR using CGL primers, and the internal transcribed spacer region and the D1-D2 domain of the large-subunit rRNA gene were amplified and sequenced. Susceptibility to amphotericin B, fluconazole, itraconazole, and clotrimazole was determined by the guidelines of the Clinical and Laboratory Standard Institute.

Results

In total, 35 non-albicans Candida isolates were identified from VVC patients. The isolates included 27 strains of Candida glabrata (77.1%), 5 Candida krusei (Pichia kudriavzevii; 14.3%), 2 Candida kefyr (Kluyveromyces marxianus; 5.7%), and 1 Candida lusitaniae (Clavispora lusitaniae; 2.9%). The fungicides itraconazole and amphotericin B were effective against all species. One isolate of C. glabrata showed resistance to fluconazole and clotrimazole, and 26 isolates of C. glabrata indicated dose-dependent susceptibility to fluconazole. C. lusitaniae was susceptible in a dose-dependent manner to fluconazole and resistant to clotrimazole.

Conclusion

Non-albicans Candida spp. are common agents of vulvovaginitis, and C. glabrata is the most common species in the tested patients.

Candida glabrata Biofilms: How Far Have We Come?

Infections caused by Candida species have been increasing in the last decades and can result in local or systemic infections, with high morbidity and mortality. After Candida albicans, Candida glabrata is one of the most prevalent pathogenic fungi in humans. In addition to the high antifungal drugs resistance and inability to form hyphae or secret hydrolases, C. glabrata retain many virulence factors that contribute to its extreme aggressiveness and result in a low therapeutic response and serious recurrent candidiasis, particularly biofilm formation ability. For their extraordinary organization, especially regarding the complex structure of the matrix, biofilms are very resistant to antifungal treatments. Thus, new approaches to the treatment of C. glabrata's biofilms are emerging. In this article, the knowledge available on C. glabrata's resistance will be highlighted, with a special focus on biofilms, as well as new therapeutic alternatives to control them.

In Vitro Antifungal Susceptibility of Oral Candida Isolates from Patients Suffering from Caries and Chronic Periodontitis

Caries and chronic periodontitis are common oral diseases where a higher Candida colonization is reported. Antifungal agents could be adjuvant drugs for the therapy of both clinical conditions. The aim of the current study has been to evaluate the in vitro activities of conventional and new antifungal drugs against oral Candida isolates from patients suffering from caries and/or chronic periodontitis. In vitro activities of amphotericin B, fluconazole, itraconazole, miconazole, nystatin, posaconazole and voriconazole against 126 oral Candida isolates (75 Candida albicans, 18 Candida parapsilosis, 11 Candida dubliniensis, six Candida guilliermondii, five Candida lipolytica, five Candida glabrata, four Candida tropicalis and two Candida krusei) from 61 patients were tested by the CLSI M27-A3 method. Most antifungal drugs were highly active, and resistance was observed in less than 5% of tested isolates. Miconazole was the most active antifungal drug, being more than 98% of isolates susceptible. Fluconazole, itraconazole, and the new triazoles, posaconazole and voriconazole, were also very active. Miconazole, fluconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent suitable treatment for a hypothetically adjunctive therapy of caries and chronic periodontitis.

In Vitro Activities of Six Antifungal Drugs Against Candida glabrata Isolates: An Emerging Pathogen

Background

Candida glabrata is a pathogenic yeast with several unique biological features and associated with an increased incidence rate of candidiasis. It exhibits a great degree of variation in its pathogenicity and antifungal susceptibility.

Objectives

The aim of the present study was to evaluate the in vitro antifungal susceptibilities of the following six antifungal drugs against clinical C. glabrata strains: amphotericin B (AmB), ketoconazole (KTZ), fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), and caspofungin (CASP).

Materials and Methods

Forty clinical C. glabrata strains were investigated using DNA sequencing. The in vitro antifungal susceptibility was determined as described in clinical laboratory standard institute (CLSI) documents (M27-A3 and M27-S4).

Results

The sequence analysis of the isolate confirmed as C. glabrata and deposited on NCBI GenBank under the accession number no. KT763084-KT763123. The geometric mean MICs against all the tested strains were as follows, in increasing order: CASP (0.17 g/mL), VCZ (0.67 g/mL), AmB (1.1 g/mL), ITZ (1.82 g/mL), KTZ (1.85 g/mL), and FCZ (6.7 g/mL). The resistance rates of the isolates to CASP, FCZ, ITZ, VZ, KTZ, and AmB were 5%, 10%, 72.5%, 37.5%, 47.5%, and 27.5%, respectively.

Conclusions

These findings confirm that CASP, compared to the other antifungals, is the potent agent for treating candidiasis caused by C. glabrata. However, the clinical efficacy of these novel antifungals remains to be determined.