Performance of CHROMAGAR candida and BIGGY agar for identification of yeast species

Denture Stomatitis and Candida albicans in the Indian Population: A Systematic Review and Meta-Analysis

Denture stomatitis (DS), a common oral condition among denture wearers, is frequently associated with Candida albicans (C. albicans) colonization. This systematic review and meta-analysis aimed to provide a comprehensive assessment of DS prevalence and its relationship with C. albicans in the Indian population. We conducted a thorough search of multiple databases for studies without any limitation to the publication timeframe, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were assessed for quality and included in the meta-analysis. Data regarding DS prevalence, risk factors, and C. albicans colonization were extracted and analyzed. A total of four studies comprising 415 participants were included in the review. The overall odds ratio (OR) and risk ratio (RR) for the prevalence of C. albicans in DS patients were 0.75 (95% CI 0.56 to 0.99) and 0.83 (95% CI 0.70 to 1.00), respectively, indicating a statistically significant association between DS and C. albicans colonization. Several risk factors, including continuous denture wearing, advanced denture age, poor denture hygiene, and high sugar intake, were identified as contributing to DS development. This systematic review and meta-analysis highlight the substantial burden of DS and its association with C. albicans colonization in the Indian population. The findings emphasize the need for comprehensive oral care, improved denture hygiene, dietary counseling, and interventions to enhance salivary flow in denture wearers to mitigate the risk of DS. These insights can inform healthcare providers and policymakers to develop targeted strategies for DS prevention and management in India. Furthermore, this study emphasizes the significance of oral health awareness and preventive strategies in groups with a high frequency of denture usage in a larger population.

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.

Phytochemical profiling of Piper crocatum and its antifungal mechanism action as Lanosterol 14 alpha demethylase CYP51 inhibitor: a review

Mycoses or fungal infections are general health problem that often occurs in healthy and immunocompromised people in the community. The development of resistant strains in Fungi and the incidence of azole antibiotic resistance in the Asia Pacific which reached 83% become a critical problem nowadays. To control fungal infections, substances and extracts isolated from natural resources, especially in the form of plants as the main sources of drug molecules today, are needed. Especially from Piperaceae, which have long been used in India, China, and Korea to treat human ailments in traditional medicine. The purpose of this review is to describe the antifungal mechanism action from Piper crocatum and its phytochemical profiling against lanosterol 14a demethylase CYP51. The methods used to search databases from Google Scholar to find the appropriate databases using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Flow Diagram as a clinical information retrieval method. From 1.150.000 results searched by database, there is 73 final results article to review. The review shows that P. crocatum contains flavonoids, tannins, terpenes, saponins, polyphenols, eugenol, alkaloids, quinones, chavibetol acetate, glycosides, triterpenoids or steroids, hydroxychavikol, phenolics, glucosides, isoprenoids, and non-protein amino acids. Its antifungal mechanisms in fungal cells occur due to ergosterol especially lanosterol 14a demethylase (CYP51) inhibition, which is one of the main target sites for antifungal activity because it functions to maintain the integrity and function of cell membranes in Candida. P. crocatum has an antifungal activity through its phytochemical profiling against fungal by inhibiting the lanosterol 14a demethylase, make damaging cell membranes, fungal growth inhibition, and fungal cell lysis.

Rapid discrimination of Candida species based on optical diffraction pattern

Candidiasis occurs mainly in immunocompromised patients. Rapid detection of Candida species can play a major role in the successful management of fungal infections and treatment monitoring. Detection and discrimination of five common strains of Candida species was performed using the optical elastic scattering diffraction pattern of their colonies. Using laser light with 632 nm wavelength and the designed optical system, optical diffraction patterns of C. albicans (ATCC12261), C. tropicalis (ATCC20336), C. glabrata (15545), C. guilliermondii (20216), and C. parapsilosis (22019) were recorded, processed and analyzed. The results of our study show that based on the different structure of Candida species and dissimilar structure of their colonies, the difference between acquired diffraction patterns are recognizable. In addition, through extraction of statistical feature of the diffraction pattern images and using classification techniques, the detection and discrimination could be performed in a semi-automatic way. The analysis of the colonies of five different Candida species by the optical diffraction patterns generated from the interaction of the laser with colonies' structures demonstrated that the technique had the potential to be applied for the detection and discrimination of various species.

Phytochemical profiling of Piper crocatum and its antifungal mechanism action as Lanosterol 14 alpha demethylase CYP51 inhibitor: a review

Mycoses or fungal infections are a general health problem that often occurs in healthy and immunocompromised people in the community. The development of resistant strains in Fungi and the incidence of azole antibiotic resistance in the Asia Pacific which reached 83% become a critical problem nowadays. To control fungal infections, substances and extracts isolated from natural resources, especially in the form of plants as the main sources of drug molecules today, are needed. Especially from Piperaceae, which have long been used in India, China, and Korea to treat human ailments in traditional medicine. The purpose of this review is to describe the antifungal mechanism action from Piper crocatum and its phytochemical profiling against lanosterol 14a demethylase CYP51. The methods used to search databases from Google Scholar to find the appropriate databases using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Flow Diagram as a clinical information retrieval method. From 1.150.000 results searched by database, there is 73 final results article to review. The review shows that P. crocatum contains flavonoids, tannins, terpenes, saponins, polyphenols, eugenol, alkaloids, quinones, chavibetol acetate, glycosides, triterpenoids or steroids, hydroxychavikol, phenolics, glucosides, isoprenoids, and non-protein amino acids. Its antifungal mechanisms in fungal cells occur due to ergosterol, especially lanosterol 14a demethylase (CYP51) inhibition, which is one of the main target sites for antifungal activity because it functions to maintain the integrity and function of cell membranes in Candida. P. crocatum has an antifungal activity through its phytochemical profiling against fungal by inhibiting the lanosterol 14a demethylase, make damaging cell membranes, fungal growth inhibition, and fungal cell lysis.

Photoinactivation of Catalase Sensitizes Candida albicans and Candida auris to ROS-Producing Agents and Immune Cells

Microbes have developed their own specific strategies to cope with reactive oxygen species (ROS). Catalase, a heme-containing tetramer expressed in a broad range of aerobic fungi, shows remarkable efficiency in degrading hydrogen peroxide (H2 O2 ) for fungal survival and host invasion. Here, it is demonstrated that catalase inactivation by blue light renders fungal cells highly susceptible to ROS attack. To confirm catalase as a major molecular target of blue light, wild type Candida albicans are systematically compared with a catalase-deficient mutant strain regarding their susceptibility to ROS through 410 nm treatment. Upon testing a wide range of fungal species, it is found that intracellular catalase can be effectively and universally inactivated by 410 nm blue light. It is also found that photoinactivation of catalase in combination with ROS-generating agents is highly effective in total eradication of various fungal species, including multiple Candida auris strains, the causative agent of the global fungal epidemic. In addition, photoinactivation of catalase is shown to facilitate macrophage killing of intracellular Candida albicans. The antifungal efficacy of catalase photoinactivation is further validated using a C. albicans-induced mouse model of skin abrasion. Taken together, the findings offer a novel catalase-photoinactivation approach to address multidrug-resistant Candida infections.

Prevalence of Candida among denture wearers and nondenture wearers

Introduction:

A denture wearer is highly prone to develop Candida-associated denture stomatitis (CADS) due to the conversion of the normal oral commensal Candida spp. into a pathogen under favorable conditions. Immuno-compromised status, trauma from the prosthesis, other systemic conditions, and improper maintenance of the dentures by the patient are few of the causative agents which turn the oral balance into an unhealthy and unsuitable foundation for the wearing of the prosthesis.

Objective:

The objective of this study was to compare subjects wearing complete dentures and nondenture wearers regarding Candida isolates associated with disease and colonization among the different age groups.

Methodology:

A cross-sectional study was conducted among 60 subjects, 30 wearing complete dentures (Group-A) and 30 nondentures wearers (Group-B), were matched for gender, race, and age. The unstimulated saliva sample was collected and cultured in CHROMagar using standard protocols.

Results:

The mean value of the candidal colony-forming units with respect to Group A is Candida Albicans 0.36 ± 2.008, Candida krusei 0.27 ± 1.061, P value Group B: C. albicans 0.73 ± 2.196, C. krusei 0.36 ± 1.084. There was a significant relation between denture wearers and heavy growth of C. albicans and C. krusei in saliva culture with a P value of P-0.054 and P-0.036, respectively.

Conclusions:

These results indicate that denture wearers with oral Candida had a higher prevalence of CADS. Patients with removable prostheses should be informed about the importance of proper prosthesis and personal hygiene since dentures and age-related immunosuppression are both well-known risk factors associated with candidiasis development, the presence of yeast, even in healthy denture wearers, should be considered a risk factor for denture stomatitis that increases with the duration of denture use.

Susceptibility of Fluconazole-Resistant Candida albicans to Thyme Essential Oil

Candida spp. is the most common microbial pathogen in fungal infections. There has been a tremendous increase in cases of candidiasis, especially among critically ill non-neutropenic patients. Candida albicans’ isolates were procured from the Prince Sultan Military Hospital, Riyadh, KSA. The isolates were characterized for their identification using CHROMagar, carbohydrate metabolism, germ tube formation, and RAPD-PCR techniques. The essential oil of Thymus vulgaris was obtained by hydro-distillation and characterized to decipher the major bioactive phytoconstituents. The antifungal activity of the thyme essential oil (TEO) was evaluated against fluconazole-resistant C. albicans isolates. The major phytocomponents identified by GC/MS were thymol (68.1%) followed by γ-terpinene (8.9%), cymol (7.7%), caryophyllene (1.1%), linalool (1.4%). The TEO successfully reduced the growth of C. albicans isolates. At very low doses, the TEO proved to be fungi static and fungicidal. TEO also effectively inhibited the germ tube formation and budging of fungal pathogens. The time kill assays have shown that TEO was more effective against drug resistant clinical isolates than fluconazole. This study provides an array of experimental evidence regarding the therapeutic efficacy of TEO against the drug-resistant clinical isolates of C. albicans. The findings may be used in the development of a new antifungal agent accordingly.

Synthesized zinc peroxide nanoparticles (ZnO2-NPs): a novel antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory approach toward polymicrobial burn wounds

Increasing of multidrug resistance (MDR) remains an intractable challenge for burn patients. Innovative nanomaterials are also in high demand for the development of new antimicrobial biomaterials that inevitably have opened new therapeutic horizons in medical approaches and lead to many efforts for synthesizing new metal oxide nanoparticles (NPs) for better control of the MDR associated with the polymicrobial burn wounds. Recently, it seems that metal oxides can truly be considered as highly efficient inorganic agents with antimicrobial properties. In this study, zinc peroxide NPs (ZnO₂-NPs) were synthesized using the co-precipitation method. Synthesized ZnO₂-NPs were characterized by X-ray diffraction, Fourier transformed infrared, transmission electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and ultraviolet-visible spectroscopy. The characterization techniques revealed synthesis of the pure phase of non-agglomerated ZnO₂-NPs having sizes in the range of 15–25 nm with a transition temperature of 211°C. Antimicrobial activity of ZnO₂-NPs was determined against MDR Pseudomonas aeruginosa (PA) and Aspergillus niger (AN) strains isolated from burn wound infections. Both strains, PA6 and AN4, were found to be more susceptible strains to ZnO₂-NPs. In addition, a significant decrease in elastase and keratinase activities was recorded with increased concentrations of ZnO₂-NPs until 200 µg/mL. ZnO₂-NPs revealed a significant anti-inflammatory activity against PA6 and AN4 strains as demonstrated by membrane stabilization, albumin denaturation, and proteinase inhibition. Moreover, the results of in vivo histopathology assessment confirmed the potential role of ZnO₂-NPs in the improvement of skin wound healing in the experimental animal models. Clearly, the synthesized ZnO₂-NPs have demonstrated a competitive capability as antimicrobial, anti-elastase, anti-keratinase, and anti-inflammatory candidates, suggesting that the ZnO₂-NPs are promising metal oxides that are potentially valued for biomedical applications.

Performance of chromogenic media for Candida in rapid presumptive identification of Candida species from clinical materials

Background:

In perspective of the worldwide increase in a number of immunocompromised patients, the need for identification of Candida species has become a major concern. The development of chromogenic differential media, introduced recently, facilitate rapid speciation. However, it can be employed for routine mycology workup only after an exhaustive evaluation of its benefit and cost effectiveness. This study was undertaken to evaluate the benefit and cost effectiveness of chromogenic media for speciation of Candida clinical isolates.

Materials and Methods:

Sputum samples of 382 patients were screened for the presence of Candida spp. by Gram stain and culture on sabouraud dextrose agar. Candida species were identified using Gram stain morphology, germ tube formation, cornmeal agar with Tween-80, sugar fermentation tests and morphology on HiCrome Candida differential agar. All the Candida isolates were inoculated on HiCrome Candida agar (HiMedia, Mumbai, India).

Results:

The sensitivity and specificity of HiCrome agar for identification of Candida albicans were 90% and 96.42%, respectively whereas sensitivity and specificity of carbohydrate fermentation test were 86.67% and 74.07%, respectively. Sensitivity and specificity values of HiCrome agar for detection of C. albicans, Candida parapsilosis and Candida glabrata were above 90%.

Conclusions:

We found HiCrome agar has high sensitivity and specificity comparable to that of the conventional method. In addition, use of this differential media could significantly cut down the turnaround time as well as cost of sample processing.

Identifying Candida and other yeast-like fungi: utility of an identification algorithm in resource limited setting

AIM

The increasing recovery rates of unusual yeasts with innate drug resistance make accurate identification crucial for successful therapy and infection control measures. The current study was undertaken to study the utility of CHROMagar Candida (CC) and evaluate an identification algorithm, using germ tube test (GT), CC and a commercial identification kit, API ID 32C.

SETTINGS AND DESIGN

The prospective study was carried out at a private laboratory in Mumbai, India.

MATERIALS AND METHODS

Identification of 533 yeast and yeast like isolates was carried out using an identification algorithm, comprising of the GT, CC and API tests.

RESULTS

CC was useful to detect mixed cultures. We were able to identify 393/533, i.e. 73.7 % of isolates using GT and CC Tests only. This was because C. albicans and C. tropicalis, which can be reliably identified using CC, constituted 75.2 % of the isolates. We were unable to identify 140 isolates, i.e. 26.3 %, using GT and CC tests only and performed additional testing using API ID 32C. CC was not found to be reliable in identifying C. krusei.

CONCLUSION

The diverse identification profile obtained in our study substantiates the need for all diagnostic microbiology laboratories to be better prepared for identifying unusual yeasts. Though GT or CC testing cannot alone suffice for identification of all clinically encountered Candida and yeast-like fungi, use of GT, CC and automated identification systems in a step-wise algorithm can enable the same in a more cost effective manner.

Evaluation of chromogenic media and seminested PCR in the identification of Candida species

Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. seminested polymerase chain reaction (sn PCR) for identification of Candida species. One hundred and twenty seven Candida strains isolated from various clinical specimens were identified by conventional methods, four different chromogenic media and sn PCR. HiCrome Candida Differential and CHROMagar Candida media showed comparably high sensitivities and specificities in the identification of C. albicans, C. tropicalis, C. glabrata and C. krusei. CHROMagar Candida had an extra advantage of identifying all C. parapsilosis isolates. CHROMagar-Pal’s medium identified C. albicans, C. tropicalis and C. krusei with high sensitivities and specificities, but couldn’t identify C. glabrata or C. parapsilosis. It was the only medium that identified C. dubliniensis with a sensitivity and specificity of 100%. Biggy agar showed the least sensitivities and specificities. The overall concordance of the snPCR compared to the conventional tests including CHROMAgar Candida in the identification of Candida species was 97.5%. The use of CHROMAgar Candida medium is an easy and accurate method for presumptive identification of the most commonly encountered Candida spp.

[Recommendations for the diagnosis of candidemia in Latin America. Grupo Proyecto Épico]

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the diagnosis of candidemia in Latin America', was written to provide guidance to healthcare professionals on the diagnosis of candidemia, as well as on the usefulness and application of susceptibility testing in patients who have a confirmed diagnosis of candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the diagnosis of candidemia in Latin America' includes diagnostic methods used to detect candidemia, Candida species identification, and susceptibility testing. The availability of methods, their costs and treatment settings are considered. This manuscript is the first of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the management of candidemia in adults in Latin America', 'Recommendations for the management of candidemia in children in Latin America', and 'Recommendations for the management of candidemia in neonates in Latin America'.

Recommendations for the diagnosis of candidemia in Latin America. Latin America Invasive Mycosis Network

Candidemia is one of the most frequent opportunistic mycoses worldwide. Limited epidemiological studies in Latin America indicate that incidence rates are higher in this region than in the Northern Hemisphere. Diagnosis is often made late in the infection, affecting the initiation of antifungal therapy. A more scientific approach, based on specific parameters, for diagnosis and management of candidemia in Latin America is warranted. 'Recommendations for the diagnosis and management of candidemia' are a series of manuscripts that have been developed by members of the Latin America Invasive Mycosis Network. They aim to provide a set of best-evidence recommendations for the diagnosis and management of candidemia. This publication, 'Recommendations for the diagnosis of candidemia in Latin America', was written to provide guidance to healthcare professionals on the diagnosis of candidemia, as well as on the usefulness and application of susceptibility testing in patients who have a confirmed diagnosis of candidemia. Computerized searches of existing literature were performed by PubMed. The data were extensively reviewed and analyzed by members of the group. The group also met on two occasions to pose questions, discuss conflicting views, and deliberate on a series of management recommendations. 'Recommendations for the diagnosis of candidemia in Latin America' includes diagnostic methods used to detect candidemia, Candida species identification, and susceptibility testing. The availability of methods, their costs and treatment settings are considered. This manuscript is the first of this series that deals with diagnosis and treatment of invasive candidiasis. Other publications in this series include: 'Recommendations for the management of candidemia in adults in Latin America', 'Recommendations for the management of candidemia in children in Latin America', and 'Recommendations for the management of candidemia in neonates in Latin America'.

Identification of Candida species associated with vulvovaginal candidiasis by multiplex PCR

BACKGROUND

Vulvovaginal candidiasis is a common infection. The aim of this study was to identify the species of vaginal Candida isolates by using multiplex PCR technique.

METHODS

191 isolates from patients admitted to Mahdieh hospital were identified. The vaginal swab specimens were cultured on Sabouraud Dextrose Agar. The ITS1 region between the 18S and 5.8S rRNA genes and a specific DNA fragment within the ITS2 region were amplified. The multiplex PCR products were separated by electrophoresis in 2% agarose gel, visualized by staining with ethidium bromide, and photographed. Descriptive statistics, Chi-square test, and Spearman correlation were used to summarize the findings.

RESULTS

C. albicans and C. glabrata were the most common species isolated from the specimens. A mix of C. glabrata and C. albicans was the most common mixed infection isolated from the samples. The analysis revealed a significant positive association between older age and infection with C. glabrata isolates (Spearman's rho = 0.89, P = 0.015).

CONCLUSION

Multiplex PCR is a fast, yet reliable method to identify Candida species. C. albicans and then C. glabrata are the two most common causes of vulvovaginal candidiasis. The number of mixed fungal infections is higher among Iranian population compared to international reports.

Biosurfactants production by yeasts using soybean oil and glycerol as low cost substrate

Biosurfactants are bioactive agents that can be produced by many different microorganisms. Among those, special attention is given to yeasts, since they can produce many types of biosurfactants in large scale, using several kinds of substrates, justifying its use for industrial production of those products. For this production to be economically viable, the use of residual carbon sources is recommended. The present study isolated yeasts from soil contaminated with petroleum oil hydrocarbons and assessed their capacity for producing biosurfactants in low cost substrates. From a microbial consortium enriched, seven yeasts were isolated, all showing potential for producing biosurfactants in soybean oil. The isolate LBPF 3, characterized as Candida antarctica, obtained the highest levels of production - with a final production of 13.86 g/L. The isolate LBPF 9, using glycerol carbon source, obtained the highest reduction in surface tension in the growth medium: approximately 43% of reduction after 24 hours of incubation. The products obtained by the isolates presented surfactant activity, which reduced water surface tension to values that varied from 34 mN/m, obtained from the product of isolates LBPF 3 and 16 LBPF 7 (respectively characterized as Candida antarctica and Candida albicans) to 43 mN/m from the isolate LPPF 9, using glycerol as substrate. The assessed isolates all showed potential for the production of biosurfactants in conventional sources of carbon as well as in agroindustrial residue, especially in glycerol.

Oral Candida carriage of patients attending a dental clinic in Braga, Portugal

BACKGROUND

The ability of the Candida species to colonize surfaces can be considered as a risk factor for oral infection.

AIMS

To establish oral Candida carriage in patients attending a dental clinic in Braga, Portugal.

METHODS

A total of 97 patients were analysed. Swab samples were collected and directly cultured onto CHROMagar Candida. Representative yeasts were identified by polymerase chain reaction.

RESULTS

From the samples analysed 54.6% (n=53) were Candida positive, and Candida albicans was the most frequently isolated species, accounting for 79% of all the species identified. Non-C. albicans Candida (NCAC) species recovered included Candida parapsilosis, Candida glabrata, Candida tropicalis, and Candida guilliermondii. There was a lack of association between the presence of C. albicans or NCAC species, and age, gender, or prostheses wearing in this population. In 17% of the cases (n=9), polymicrobial cultures, with two different Candida species, were identified.

CONCLUSIONS

This study shows a high Candida carriage rate among this population, thus pointing to the relevance of an accurate diagnostic approach in Candida species identification.

Yeast identification--past, present, and future methods

The focus of this review is the evolution of biochemical phenotypic yeast identification methods with emphasis on conventional approaches, rapid screening tests, chromogenic agars, comprehensive commercial methods, and the eventual migration to genotypic methods. As systemic yeast infections can be devastating and resistance is common in certain species, accurate identification to the species level is paramount for successful therapy and appropriate patient care.

Evaluation of Albicans ID2 and Biggy agar for the isolation and direct identification of vaginal yeast isolates

In this study, 250 vaginal samples from patients with vulvovaginal candidosis were inoculated onto two chromogenic media, Albicans ID2 and Biggy agar, as well as onto Sabouraud chloramphenicol agar, yielding a total of 63 yeast (25.2 %) on all three media. These strains were identified as Candida glabrata in 20 (31.8 %) samples, Candida albicans in 15 samples (23.8 %), Candida tropicalis in 10 samples (15.9 %), Candida krusei in five samples (7.9 %), Candida kefyr in five samples (7.9 %), Candida dubliniensis in four samples (6.3 %), Candida parapsilosis in two samples (3.2 %) and Candida guilliermondii in two samples (3.2 %). Mixed fungal cultures and bacterial growth or filamentous fungi were not detected on any of the selected media. The sensitivity and specificity of the Albicans ID2 and Biggy agar with regard to the identification of C. albicans were 80.0 and 64.6 %, and 86.7 and 56.3 %, respectively. This study showed these two chromogenic media to be as effective as Sabouraud chloramphenicol agar with respect to fungal detection. However, neither Albicans ID2 nor Biggy agar was sufficient for reliable differentiation of yeasts to the species level.

Evaluation of 5 new media containing extracts of seeds applied to Candida dubliniensis screening

Candida dubliniensis is a recently described pathogenic species that shares many phenotypic features with Candida albicans and so may be misidentified in microbiologic laboratories. The aim of this study is to find a useful and cost-effective method suitable for screening C. dubliniensis before proceeding to further identification. We examined the colony morphology and chlamydospore production of 26 C. dubliniensis isolates and 100 C. albicans isolates on the following 5 proposed media: sesame seed agar (SSA), rapeseed agar, canary grass seed agar, millet seed agar, and linseed agar (LA). The best results were obtained with SSA and LA because all 26 C. dubliniensis isolates showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 h of incubation at 25 degrees C. All C. albicans isolates (100%) showed smooth colonies without hyphal fringes or chlamydospores. These 2 media consist of new and simple tools for presumptive differentiation of C. dubliniensis from C. albicans.

Four cases of Candida albicans infections with isolates developing pink colonies on CHROMagar Candida plates

Candida albicans, the most commonly isolated yeast species, is typically identified by its green colony-colour on CHROMagar Candida plates. We here report four cases of Candida albicans infections, in which the initial identification was non-albicans isolates due to a clear pink colour of the colonies on CHROMagar Candida plates. However, classical phenotypic criteria, biochemical assimilation pattern and molecular characterisation identified all four isolates as C. albicans isolates.