Use of CHROMagar Candida for the presumptive identification of Candida species directly from clinical specimens in resource-limited settings

Antifungal and antibiofilm effects of probiotic Lactobacillus salivarius, zinc nanoparticles, and zinc nanocomposites against Candida albicans from Nile tilapia (Oreochromis niloticus), water and humans

Introduction

Candida albicans (C. albicans) can form biofilms; a critical virulence factor that provides effective protection from commercial antifungals and contributes to public health issues. The development of new antifungal therapies, particularly those targeting biofilms, is imperative. Thus, this study was conducted to investigate the antifungal and antibiofilm effects of Lactobacillus salivarius (L. salivarius), zinc nanoparticles (ZnNPs) and nanocomposites (ZnNCs) on C. albicans isolates from Nile tilapia, fish wash water and human fish sellers in Sharkia Governorate, Egypt.

Methods

A cross-sectional study collected 300 samples from tilapia, fish wash water, and fish sellers (100 each). Probiotic L. salivarius was immobilized with ZnNPs to synthesize ZnNCs. The study assessed the antifungal and antibiofilm activities of ZnNPs, L. salivarius, and ZnNCs compared to amphotericin (AMB).

Results

Candida spp. were detected in 38 samples, which included C. albicans (42.1%), C. glabrata (26.3%), C. krusei (21.1%), and C. parapsilosis (10.5%). A total of 62.5% of the isolates were resistant to at least one antifungal agent, with the highest resistance to nystatin (62.5%). However, 75% of the isolates were highly susceptible to AMB. All C. albicans isolates exhibited biofilm-forming capabilities, with 4 (25%) isolates showing strong biofilm formation. At least one virulence-associated gene (RAS1, HWP1, ALS3, or SAP4) was identified among the C. albicans isolates. Probiotics L. salivarius, ZnNPs, and ZnNCs displayed antibiofilm and antifungal effects against C. albicans, with ZnNCs showing significantly higher inhibitory activity. ZnNCs, with a minimum inhibitory concentration (MIC) of 10 µg/mL, completely reduced C. albicans biofilm gene expression. Additionally, scanning electron microscopy images of C. albicans biofilms treated with ZnNCs revealed asymmetric, wrinkled surfaces, cell deformations, and reduced cell numbers.

Conclusion

This study identified virulent, resistant C. albicans isolates with strong biofilm-forming abilities in tilapia, water, and humans, that pose significant risks to public health and food safety.

Disseminated Lodderomyces elongisporus and Pantoea dispersa: A Rare Dual Infection in an Immunocompromised Patient

With the advancement of modern medicine and the prolonged survival of critically ill patients, unusual organisms are increasingly emerging. Initially found in the environment, these rare organisms started presenting as human pathogens, causing significant morbidity and mortality. Here, we present a rare case of disseminated Lodderomyces elongisporus fungemia and Pantoea dispersa bacteremia in a patient with parapneumonic effusion and ruptured liver abscess. This yeast was identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Although this organism has no antifungal breakpoint, the isolate shows low minimum inhibitory concentration (MIC) to a wide range of antifungals. The importance of effective communication between microbiologists and clinicians and early referral to the infectious disease team was also highlighted in this case for prompt treatment.

Five-year cross-sectional study to determine the burden of Candida spp. infections of the urinary tract system among patients attending tertiary hospital in Northwestern Tanzania

OBJECTIVE

Urinary tract infections (UTIs) stand as a prominent global health concern. This study entails a 5-year retrospective analysis, using a cross-sectional study design to examine microbiology laboratory data of individuals clinically diagnosed with UTIs at Bugando Medical Centre to gain insights into the prevalence and factors linked to candiduria.

METHODOLOGY

Data extracted were meticulously cleaned and coded in an MS Excel sheet, subsequently transferred to STATA V.15 for analysis. Binary logistic regression analysis was used to identify factors associated with candiduria. A probability value below 0.05 at a 95% CI was considered statistically significant.

RESULTS

Urine samples for culture and sensitivity comprised 33.4% (20755) of the total biological samples (62335). The median age of the patients stood at 19 years. A slight majority were female, accounting for 52.8% (10051), and two-thirds sought treatment at outpatient departments (67.5%, 12843). Among patients with significant pathogenic growth, the prevalence of candiduria was 4.6% (221 out of 4772). Notably, inpatients exhibited a higher incidence of candiduria compared with outpatients, with rates of 9.4% (1882) versus 1.6% (2890), p value of 0.000. Non-albicans Candida spp. (NAC) remained the most prevalent pathogen. Factors significantly associated with candiduria included being female (OR=1.7, 95% CI 1.3 to 2.3) and hospital admission (OR=6.6, 95% CI 4.7 to 9.2). In conclusion, candiduria affect 5 out of every 100 UTI-diagnosed patients, predominantly among females and those admitted to the hospital. Clinicians at tertiary hospitals should consider urinary candidiasis as a potential diagnosis for patients at risk who present with UTI-like symptoms.

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.

Aqueous spice extracts as alternative antimycotics to control highly drug resistant extensive biofilm forming clinical isolates of Candida albicans

Candida albicans form biofilm by associating with biotic and abiotic surfaces. Biofilm formation by C. albicans is relevant and significant as the organisms residing within, gain resistance to conventional antimycotics and are therefore difficult to treat. This study targeted the potential of spice-based antimycotics to control C. albicans biofilms. Ten clinical isolates of C. albicans along with a standard culture MTCC-3017 (ATCC-90028) were screened for their biofilm-forming ability. C. albicans M-207 and C. albicans S-470 were identified as high biofilm formers by point inoculation on Trypticase Soy Agar (TSA) medium as they formed a lawn within 16 h and exhibited resistance to fluconazole and caspofungin at 25 mcg and 8 mcg respectively. Aqueous and organic spice extracts were screened for their antimycotic activity against C. albicans M-207 and S-470 by agar and disc diffusion and a Zone of Inhibition was observed. Minimal Inhibitory Concentration was determined based on growth absorbance and cell viability measurements. The whole aqueous extract of garlic inhibited biofilms of C. albicans M-207, whereas whole aqueous extracts of garlic, clove, and Indian gooseberry were effective in controlling C. albicans S-470 biofilm within 12 h of incubation. The presence of allicin, ellagic acid, and gallic acid as dominant compounds in the aqueous extracts of garlic, clove, and Indian gooseberry respectively was determined by High-Performance Thin Layer Chromatography and Liquid Chromatography-Mass Spectrometry. The morphology of C. albicans biofilm at different growth periods was also determined through bright field microscopy, phase contrast microscopy, and fluorescence microscopy. The results of this study indicated that the alternate approach in controlling high biofilm-forming, multi-drug resistant clinical isolates of C. albicans M-207 and S-470 using whole aqueous extracts of garlic, clove, and Indian gooseberry is a safe, potential, and cost-effective one that can benefit the health care needs with additional effective therapeutics to treat biofilm infections.

Identification of Pathogenic and Opportunistic Yeasts in Pigeon Excreta by MALDI-TOF Mass Spectrometry and Their Prevalence in Chon Buri Province, Thailand

Pigeon excreta can cause environmental and public health issues, particularly in urban and public areas. They are reservoirs of several human pathogens including fungi, bacteria, and viruses. Epidemiological data of pathogenic and opportunistic yeasts in pigeon droppings in Chon Buri, one of the most reputable tourist cities of Thailand, are scarce. The present study aimed to identify yeasts in pigeon droppings by MALDI-TOF mass spectrometry, and to study their prevalence in Chon Buri, Thailand. A total of 200 pigeon fecal samples were collected randomly from all 11 districts of Chon Buri. A sum of 393 yeast-like colonies were isolated on Sabourand's dextrose agar and CHROMagar media. These isolates were further confirmed for their species by MALDI-TOF MS. Twenty-four yeast species belonging to 11 different genera were identified in pigeon fecal samples. Candida spp., predominantly C. krusei (14.32%), were the most prevalent yeast species. Other yeast species, including C. glabrata (12.73%), C. metapsilosis (11.93%), Lodderomyces elongisporus (10.87%), C. tropicalis (7.16%), C. albicans (5.83%), and Cryptococcus neoformans (4.77%) were identified. This study provides valuable epidemiological data and diversity of yeasts in pigeon droppings in Chon Buri, Thailand, and also supports the use of MALDI-TOF MS for yeast identification and epidemiological surveillance.

In Vitro Antifungal Activity of Azoles and Other Antifungal Agents Against Pathogenic Yeasts from Vulvovaginal Candidiasis in China

BACKGROUND

Vulvovaginal candidiasis (VVC) is a public health issue worldwide. Little is known of the optimal treatment of recurrent VVC (RVVC) has not been established.

OBJECTIVE

Through the in vitro antifungal susceptibility profiling of VVC isolates, we hope to foster significant improvements in the control and treatment of this disease.

METHODS

Candida isolates from VVC patients were collected from 12 hospitals in 10 cities across China. Species were identified by phenotype analysis and DNA sequencing. Species were identified by phenotype analysis and DNA sequencing. Susceptibilities to 11 drugs were determined by Clinical and Laboratory Standards Institute broth microdilution.

RESULTS

543 strains were isolated from those VVC patients enrolled in this study, of which, 15.7% were from RVVC. The most commonly identified species was C. albicans (460, 84.71%), and the most commonly non-albicans Candida spp. (NAC) was C. glabrata (47, 8.66%). NAC also included C. Krusei, Meyerozyma Guillermondii, Meyerozyma Caribbica, C. Tropicalis, C. Parapsilosis, and C. Nivariensis. Most C. albicans isolates were susceptible to caspofungin (99.8%), followed by fluconazole (92%) and voriconazole (82.6%). The proportion of C. albicans strains with wild type (WT) MICs that were susceptible to amphotericin B and caspofungin were 98%, followed by posaconazole at 95%, itraconazole at 86%, fluconazole at 74% and voriconazole at 54%. The fluconazole MICs for C. albicans were lower than those for NAC (P < 0.05), while the itraconazole MICs showing no significant difference (P > 0.05). The susceptible rate of uncomplicated VVC to fluconazole was 92%. The proportion of WT strains to fluconazole in RVVC was much lower than that in other types of VVC (67 vs. 77%, P < 0.05). However, the proportions of WT strains to itraconazole in RVVC was over 85%, which was much higher than that to fluconazole (87 vs. 67%, P < 0.05).

CONCLUSIONS

C. albicans was still the predominant pathogen for VVC in China, while C. glabrata was the main species in NAC. Fluconazole could still be used as an empirical treatment for uncomplicated VVC. However, fluconazole may not be the first choice for the therapy of RVVC. In such cases, itraconazole appears to be the more appropriate treatment. As for VVC caused by NAC, nonfluconazole drugs, such as itraconazole, may be a good choice.

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.

Candida albicans Biofilm Formation and Growth Optimization for Functional Studies Using Response Surface Methodology

AIM

Optimization of Candida growth and biofilm formation is essential for understanding the recalcitrance of this pathogen to advance functional analysis on hospital tools and material surfaces. Optimization and quantification of biofilm have always been a challenge using the conventional One Variable at a Time (OVAT) method. The present study uses Central Composite Design-based Response Surface Methodology for optimization of conditions to induce growth and biofilm formation in Candida albicans on polystyrene microtitre plates.

METHODS & RESULTS

The variables considered in the design matrix were pH, temperature, incubation period, shaker speed, and inoculum size. A four-pronged quantification approach with XTT assay (cell viability), crystal violet assay (biofilm), calcofluor white assay, and wet/dry weight measurements (cell mass) were used to understand different aspects of biofilm. Heterogeneity in growth conditions for local strains of C. albicans clinical isolates were observed. Cell viability and cell mass were inversely related; however, biofilm was independent of these two factors. The study also highlighted the fact that Foetal Bovine Serum does not significantly contribute to cell adhesion and biofilm formation in vitro.

CONCLUSIONS

A high throughput optimization of C. albicans growth and biofilm formation on polystyrene microplate has been developed & validated.

SIGNIFICANCE AND IMPACT OF STUDY

The microtiter plate-based approach can be used for future screening of therapeutics for the control of C. albicans.

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.

Investigation of Candidal Species among People Who Suffer from Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma

AIM AND OBJECTIVE

The aim of the present study was to evaluate the candidal species among masses with oral potentially malignant disorders and oral squamous cell carcinoma.

MATERIALS AND METHODS

This prospective and observational study was conducted by the Department of Oral Pathology and Microbiology, S. B. Patil Dental College, Bidar, Karnataka, India, from February 2018 to January 2019. The study composed of total of 150 individuals, of which 50 individuals did not had any visible manifestations, 50 were analyzed with potentially malignant disorders (PMDs) in particular oral leukoplakia, oral lichen planus, and oral submucous fibrosis and last group of 50 individuals were suffering from oral squamous cell carcinoma (OSCC). First, the swab samples were elicited from culture technique after that incisional biopsy of the discernible investigated lesion was done for the purpose of justopathological verification. The swab samples were streak on Sabouraud dextrose agar (SDA) and HiCrome Candida Differential HiVeg agar/CHROMagar medium and incubation at 37°C for 24-48 h. Biopsy was done for all the samples.

RESULTS

The proportion of candidates as men and women in control was 45 (90%) and 5 (10%), in PMD was 30 (60%) and 20 (40%), and in OSCC was 45 (90%) and 5 (10%), correspondingly. On evaluation on SDA medium in controls, PMD and OSCC groups, Candida was founded in 14 (28%), 20 (40%), and 42 (84%) and not founded in 36 (72%), 30 (60%), and 8 (16%) folks, subsequently. Intragroup contrast illustrated exceedingly necessary distinction with P = 0.000 between both controls versus OSCC and PMD in comparison to OSCC. Nevertheless, controls versus PMD manifested insignificant, P = 0.119. Investigation on CHROM AGAR media among controls, PMD and OSCC groups, Candida species was seen in 11 (22%), 19 (38%), and 40 (80%) and absent in 39 (78%), 31 (62%), and 10 (20%) individuals, respectively. On statistical inspection, the variations noted were enormous, (P = 0.000). On speciation of Candida in CHROM agar among the controls, PMD and OSCC groups, Candida albicans species was present in 9 (18%), 16 (32%), and 6 (12%), Candida krusei in 3 (6%), 6 (12%), and 13 (26%), Candida glabrata in 0, 0, and 8 (16%), and Candida tropicalis in 0, 0, and 3 (6%) cases, respectively. Nonetheless, only OSCC group reveal amalgamation of species such as C. glabrata and C. krusei was present in 2 (4%) case, C. tropicalis and C. krusei in was present 3 (6%) cases, C. tropicalis and C. glabrata was present in 2 (4%) case, C. albicans and C. tropicalis was present in 2 (4%) cases, and C. krusei, C. glabrata with C. albicans was present in 1 (2%) case, respectively. All other types of fungi were regarded as infectious excluding Candida, on analysis on SDA medium, infestation in the form of fungal molds was seen in 18 (36%) in controls, 12 (24%) in PMD and 8 (16%) in OSCC groups.

CONCLUSION

We interpreted that the chief carrier of candidal species in PMDs and OSCC, yet more light is to be thrown on the topic that Candida has particular establishment in PMDs or in malignancy.

SCA Medium: A New Culture Medium for the Isolation of All Candida auris Clades

Candida auris is an emerging multidrug-resistant yeast causing nosocomial infections and associated with high mortality in immunocompromised patients. Rapid identification and characterisation are necessary for diagnosis and containing its spread. In this study, we present a selective culture medium for all C. auris clades. This medium is sensitive with a limit of detection ranging between 10¹ and 10² CFU/mL. The 100% specificity of SCA (specific C. auris) medium is confirmed on a set of 135 Candida strains, 50 bacterial species and 200 human stool samples. Thus, this medium specifically selects for C. auris isolation from clinical samples, allowing the latter to study its phenotypic profile.

Diagnostic clinical microbiology

Technological advancements have changed the way clinical microbiology laboratories are detecting and identifying bacterial, viral, parasitic, and yeast/fungal pathogens. Such advancements have improved sensitivity and specificity and reduce turnaround time to reporting of clinically important results. This article discusses and reviews some traditional methodologies along with some of the technological innovations introduced into diagnostic microbiology laboratories. Some insight to what might be available in the coming years is also discussed.

Study on Periplaneta americana (Blattodea: Blattidae) Fungal Infections in Hospital Sewer System, Esfahan City, Iran, 2017

Background

American cockroaches contaminated with pathogens inside hospital manholes can be one of the major problems that health care systems face.

Objectives

The aim of this study was to investigate the fungal infections of American cockroaches in the Esfahan hospital sewage network. The principle goal of the study was about the roaches as a vector of fungi and other pathogens.

Method

The type of study was descriptive-analytical. A total of 55 American cockroach specimens from the manhole walls of the sewerage system of 7 large hospitals were captured. Samples were taken from the surface of the body, digestive tract, and haemocoel of cockroaches. The specimens were then cultured on Sabouraud dextrose agar separately, and fungi were identified according to the macroscopic and microscopic characteristics.

Results

All cockroaches collected from hospitals were infected with fungi. Among the 24 (13 infected and 11 noninfected) (44%) female cockroaches and 31 (18 infected and 13 noninfected) (56%) male cockroaches, it was identified that 40.00% was infected with Aspergillus niger, 3.64% with Rhizopus, 7.27% with Penicillium, and 5.45% with Mucor. 6 cockroaches had no yeast contamination. 17 (30.91%) cockroaches were contaminated with Candida glabrata, 23 (41.82%) cockroaches were contaminated with Candida krusei, and 22 (40%) cockroaches were contaminated with other yeast species. The results of this study showed that Candida krusei had the highest prevalence among the isolated fungi with 35.37% of the digestive system and Aspergillus niger with 70.97% of the surface of the cockroach body.

Conclusion

The results emphasized the role played by cockroaches as potential pathogenic vectors in hospital environments. Therefore, suitable management is needed for controlling this insect to prevent disease transmission in hospitals.

Evaluation of a novel chromogenic medium for Candida spp. identification and comparison with CHROMagar™ Candida for the detection of Candida auris in surveillance samples

A shift to Candida non-albicans infections has been noted during the last years, and the emergence of multi-resistant Candida auris has complicated their management. The aim of this study was first to compare the performance of the novel chromogenic medium CHROMagar™ Candida Plus (CHROMagar, France) with CHROMagar™ Candida (Becton Dickinson, Germany) for the presumptive identification of Candida species; and then, to evaluate its utility in the detection of C. auris in surveillance samples. CHROMagar™ Candida Plus showed a good performance compared with the reference medium CHROMagar™ Candida. Sensitivity and specificity were 100% in both media for tested species at 48 h of incubation, except for Candida glabrata and Candida lusitaniae. Furthermore, the new medium allows a reliable presumptive identification of C. auris, as a new specific color for this species is assigned (light blue with a blue halo), obtaining a sensitivity and specificity of 100% at 36 h of incubation.

Candida spp. Determination and Th1/Th2 Mixed Cytokine Profile in Oral Samples From HIV+ Patients With Chronic Periodontitis

Background: Chronic periodontitis (CP), caused by bacteria and fungi, appears in up to 66% of HIV-patients. The impact and association of HIV-treatment (HAART) and Candida itself has not been properly evaluated in the development and progression of CP. The immunopathogenesis is characterized by CD4⁺ T-cells activation and the balance between the T-helper 1 (Th1) and T-helper 2 (Th2) or a mixed cytokine profile. Currently, the associated causes of an immune response in HIV-patients with CP is controversial. Our aims were the determination of Candida spp. and cytokine profile in oral samples from HIV-positive patients with CP, considering the CD4⁺ T cells levels and HAART use.

Methods: From 500 HIV-positive patients evaluated, 228 patients were enrolled. Patients were separated in groups: (A) n = 53 (≤200 CD4⁺ T-cells on HAART); (B) n = 57 (≤200 CD4⁺ T-cells without HAART); (C) n = 50 (>200 CD4⁺ T-cells without HAART); (D) n = 68 (>200 CD4⁺ T-cells on HAART). Candida spp. were isolated from the oral biofilm and crevicular fluid in CHROMagar and confirmed by endpoint PCR. Cytokine levels were measured by beads-based immunoassay in saliva by flow cytometry.

Results: 147 patients (64.5%) were positive to Candida spp. and 204 strains were isolated; 138 (67.6%) were C. albicans and the remaining C. non-albicans species (C. glabrata>C. tropicalis>C. krusei>C. dubliniensis). In this study, CHROMagar showed good sensitivity (95%) but poor specificity (68%); since of the 152 samples identified as C. albicans, only 131 were confirmed by PCR; from the 10 samples identified as C. glabrata, only six were confirmed. Finally, of the 42 samples detected as C. tropicalis, only five were confirmed. When evaluating Candida spp. presence, group A and D had higher isolation, while group B had the highest species diversity. Whereas, group C had a significant reduction of Candida spp. Despite the presence of Candida and HAART, we found a Th1/Th2 hybrid profile in the saliva of patients with low CD4⁺ T-cell count (group A).

Conclusion: Abundance and diversity of the Candida spp. detected in HIV-patients with CP could be related to HAART and low CD4⁺ T-cells levels. Also, the immunosuppression might promote a local Th1/Th2 hybrid cytokine profile.

Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study

Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum.

Evaluation of candidal species among individuals with oral potentially malignant disorders and oral squamous cell carcinoma

CONTEXT

Cancer afflicts almost all communities worldwide. Although it arises de novo in many instances, a significant proportion of oral squamous cell carcinoma (OSCC) develops from potentially malignant disorders (PMDs). Further, the association of Candida with various potentially malignant and malignant lesions has been reported as a causative agent.

AIMS

The aim of the study is to evaluate and intercompare the predominant candidal species among individuals with PMD and OSCC.

SUBJECTS AND METHODS

The swab samples were collected for the microbiological culture followed by incisional biopsy for histopathological confirmation. The swab samples were streaked and incubated on Sabouraud-dextrose agar medium and positive candidal colonies were incubated on CHROM agar for speciation.

SETTINGS AND DESIGN

A total of clinically diagnosed 95 subjects of which 25 as normal controls, 30 as PMDs and 40 as OSCC were included. The collected swab samples were initially streaked and incubated on Sabouraud dextrose agar (SDA) medium, and later, only positive candidal colonies were incubated on CHROM agar for speciation.

STATISTICAL ANALYSIS

Chi-square test was utilized.

RESULTS

Positive candidal growth on SDA medium was seen in 24%, 43% and 82% and negative in 76%, 57% and 18% individuals of normal controls, PMDs and OSCC, respectively. On evaluation on Chromagar medium, Candida species was present in 20%, 40% and 77% and absent in 80%, 60% and 23% individuals among controls, PMDs and OSCC group, respectively. On speciation of Candida in CHROMagar among the controls, PMDs and OSCC, Candida albicans species was present in 4 (16%), 7 (23%) and 4 (10%); Candida krusei in 1 (4%), 5 (17%) and 10 (25%); Candida glabrata in nil, nil and 6 (20%) and Candida tropicalis in nil, nil, and 2 (5%) cases, respectively.

CONCLUSION

There was predominant carriage of candidal species in PMDs and OSCC, but whether Candida has specific establishment in PMDs or in malignancy is still a matter of debate.

Speciation of Candida using CHROMagar in cases with oral epithelial dysplasia and squamous cell carcinoma

Background

Candida albicans is most frequently isolated from oral cavity but identification of other Candida species such as C. tropicalis, C. krusei, C. glabrata & C. dubliniensis is increasing proportionately. A constant rise in immuno-suppressed patients, widening range of recognized pathogens, and resistance to antifungal drugs are contributing factors which stress the need for species identification of Candida, an opportunistic pathogen. Objectives: 1. To detect the prevalence of Candida albicans and Non albicans Candida albicans (NAC) species in the oral cavity of patients with epithelial dysplasia, Oral squamous cell carcinoma (OSCC) and healthy controls. 2. To identify and differentiate Candidal species using CHROMagar, a differential media.

Material and Methods

The study included smears from 50 patients with histopathological confirmation of epithelial dysplasia & OSCC and 50 normal controls. Candida albicans was identified using Sabouraud dextrose agar media (SDA) as primary culture followed by species identification using CHROMagar on the basis of colony color and morphology.

Results

Non albicans candida predominated (66%) over Candida albicans (34%) in speciation on CHROMagar media in the study group. Non albicans Candida species isolated were C. tropicalis (38%), C. glabrata (24%) and 2 cases showing polyfungal population of C. albicans & C. glabrata.

Conclusions

Species level isolation of Candida helps in early identification of resistant non Candida strains and prompt treatment of the cases there by preventing the dissemination of infection in case of immuno-compromised individuals. The data presented also supports the use of CHROMagar Candida as a pertinent media for the rapid identification of Candida species directly from clinical specimens in resource challenged settings, which could be helpful in developing appropriate therapeutic strategy and management of patients. Key words:Candida, CHROMagar, epithelial dysplasia, oral cancer.

Identification of Candida species and susceptibility testing with Sensititre YeastOne microdilution panel to 9 antifungal agents

Objectives:

To determine the species incidence and susceptibility pattern to 9 antifungal agents of yeasts isolated from various clinical specimens of colonized or infected patients treated in the coronary and surgical intensive care units (ICU).

Methods:

A total of 421 ICU patients were treated at the Cardiology Institute, Istanbul University, Istanbul, Turkey between June 2013 and May 2014, and 44 Candida species were isolated from blood, urine, endotracheal aspiration fluid, sputum, and wounds of 16 ICU patients. Identification of Candida was performed using CHROMagar. Antifungal susceptibility was determined by a Sensititre YeastOne colorimetric microdilution panel.

Results:

Candida albicans (C. albicans) was the most commonly observed microorganism 23 (54%); the other microorganisms isolated were Candida tropicalis 12 (27%), Candida glabrata 5 (11%), Candida parapsilosis 1 (2%), Candida lusitaniae 1 (2%), Candida sake 1 (2%), and Geotrichum capitatum 1 (2%). All isolates were susceptible to amphotericin B and 5-flucytosine. Geotrichum capitatum excepted, the other isolates were also susceptible to anidulafungin, micafungin, and caspofungin. Candida parapsilosis was found to be susceptible to all the studied antifungals. High MIC rates for azole group of antifungal drugs were found for C. albicans, C. tropicalis, and C. glabrata. The rate of colonisation was 3.8% (16/421). Only 0.7% (3/421) patients out of a total of 421 developed candidemia.

Conclusion:

We found that the yeast colonization and infection rates of patients in our ICUs are very low. Candida albicans is still the most common species. We detected a decreasing susceptibility to azole compounds.

Isolation, speciation and antifungal susceptibility testing of Candida isolates from various clinical specimens at a tertiary care hospital, Nepal

BACKGROUND

Candida species are responsible for various clinical infections ranging from mucocutaneous infection to life threatening invasive diseases along with increased resistance to antifungal drugs has made a serious concern. Resistance to antifungal agents has increased during the last decade. Thus, identification of Candida up to species level and its antifungal susceptibility testing has a paramount significance in the management of Candidal infections. The aim of the study was to speciate Candida species and to determine antifungal susceptibility pattern of Candida species to antifungal agents.

METHODS

A total of 100 consecutive Candida species were isolated from 1248 clinical specimens over 7 months period. Growths on Sabouraud dextrose agar were evaluated for colony appearance, macroscopic examination, Gram staining, germ tube test and urea hydrolysis test. Further, they were processed for Candida speciation on CHROMagar. Antifungal susceptibility testing was performed as recommended by Clinical and Laboratory Standards Institute (CLSI) M44-A document.

RESULTS

Out of 100 Candida isolates, Candida albicans (56%) was the most common species. Among the non-albicans Candida species, Candida tropicalis (20%) was the predominant isolate followed by Candida glabrata (14%). Regarding antifungal susceptibility pattern, Candida species were more susceptible to clotrimazole (82%) followed by fluconazole (64%) and miconazole (44%).

CONCLUSIONS

Candida albicans was the predominant species responsible for various Candidal infections. Among commonly used antifungal drugs clotrimazole, miconazole and fluconazole were most effective.

Prevalence and characterization of opportunistic candidal infections among patients with pulmonary tuberculosis

Background:

Although Candida albicans remains the most common cause of human candidiasis, the frequency of infection attributed to other members of the genus is also increasing. Hence, the present study was carried out to know the prevalence of opportunistic candidal infection in tuberculosis, and if positive, the species of Candida that is most commonly associated.

Materials and Methods:

The present study comprised sixty pulmonary tuberculosis patients who were divided into (1) fresh or untreated group, (2A) chronic or treated group having no complications and (2B) having complications, comprising twenty patients each, respectively. The collected sputum samples were initially stained with Ziehl–Neelsen stain for confirmation of presence of tubercle Bacilli. Primary isolation was done on Sabouraud Dextrose Agar (SDA). The candidal colonies were confirmed microscopically for the presence of pseudohyphae. Further speciation of the positive candidal samples was carried out using ChromAgar.

Result:

The total fungal prevalence among 60 patients with pulmonary tuberculosis on SDA was 33 (55%) Candida and 3 (5%) Aspergillus. The prevalence of different candidal species on ChromAgar showed C. albicans as the predominant one, followed by Candida tropicalis and Candida krusei. Freshly diagnosed or untreated group was less commonly associated with pulmonary mycoses than chronic or treated group. The prevalence of Candida had increased with treatment, duration and age, and it was more in males than females.

Conclusion:

The present study confirms the phenomenon of opportunistic candidal infections in pulmonary tuberculosis patients. Rapid and reliable identification of Candida species is essential as they differ in their virulence and sensitivity to antifungal drugs.

Evaluation of Antifungal Efficacy of Ethanolic Crude Lawsone and Listerine Mouthwash in Uncontrolled Diabetics and Denture Wearers - A Randomized Clinical Trial

INTRODUCTION

Lawsonia Inermis (LI) is a shrub cultivated throughout India. Many in vitro studies have been done on antifungal activity of LI, although none of the studies have been conducted invivo.

AIM

To evaluate the antifungal efficacy of ethanolic extract of crude lawsone in comparison with listerine mouth wash in known diabetics and wearing dentures.

MATERIALS AND METHODS

A total of 60 subjects were taken and randomly divided into two groups of 30 each. Group 1 received crude lawsone mouthwash and Group 2 received listerine mouth wash. Oral rinse technique was performed. Each subject was given distilled water at baseline and Colony Forming Units (CFU) of candidal species was determined. Post therapeutic samples were then collected 1hr and 1week following drug usage and they were further advised to use given mouth washes twice daily with volume of 5ml/rinse for 30 seconds and CFU was evaluated.

RESULTS

Crude lawsone mouthwash showed superior antifungal activity when compared to listerine mouthwash. On individual comparison of both mouth washes at baseline, 1hr and 1week highly significant results were obtained using inferential statistics. The inter group comparison was done using independent t-test where lawsone was considered to be more effective in reducing CFU, at 1hr and 1week of using the mouth wash (p<0.01). Subjective symptoms like taste and smell were determined by chi square test where good taste was felt for lawsone and olfactory satisfaction was good with listerine (p<0.01). Burning sensation was found to be more with listerine mouth wash.

CONCLUSION

The present study revealed superior antifungal activity with ethanolic extract of crude lawsone mouth wash compared with listerine mouthwash.

Identification of Candida species in the oral cavity of diabetic patients

Background and Purpose:

Diabetic patients are more susceptible to oral candidiasis infection than non-diabetics due to the factors promoting oral carriage of Candida. Several factors can increase colonization of Candida species in the oral cavity such as xerostomia, which reduces the salivary flow and is a salivary pH disorder. In the current study, we aimed to identify and compare the colonization level of Candida spp. in the oral cavity of diabetic and non-diabetic groups.

Materials and Methods:

Swabs were taken from the mouth of 106 participants and were cultured on Sabouraud dextrose agar (SDA) medium. Likewise, the saliva samples were collected for salivary glucose and pH measurements. The study was performed during June 2014-September 2015 on two groups of diabetic patients (n=58) and non-diabetics (n=48) as the control group. The Candida spp. were identified with PCR-restriction fragment length polymorphism (RFLP) using the restriction enzymes HinfI and MspI and were differentiated by culture on CHROMagar Candida medium.

Results:

The frequency of Candida spp. was higher in diabetic patients compared to non-diabetics. The most frequent Candida spp. in the diabetic patients were Candidaalbicans (%36.2),C. Krusei (%10.4), C. Glabrata (%5.1), and C. tropcalis .(%3.4)Likewise, C. albicans was the most frequent species (%27) in the non-diabetic individuals. In this study, the results of both methods for identification of the isolates were consistent with each other.

Conclusion:

Xerostomia and disturbance of physiological factors including pH and glucose can promote overgrowth of Candida flora in the oral cavity. These factors are considered important predisposing factors for oral candidiasis in diabetic patients. In the present study, it was observed that application of CHROMagar Candida and PCR-RFLP methods at the same time contributes to more accurate identification of isolates.

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.

Identificação das espécies de Candida em portadores de estomatite protética e avaliação da susceptibilidade ao miconazol e à terapia fotodinâmica

INTRODUÇÃO: Próteses mucossuportadas são consideradas facilitadoras, em potencial, da estomatite protética (EP), condição caracterizada pelo aspecto eritematoso, difuso ou pontilhado da mucosa palatina sob a base das próteses. A etiologia da doença é multifatorial, embora a infecção por Candida seja uma causa bastante comum. OBJETIVO: Relacionar a EP com a presença de Candida, identificar as espécies de Candida mais prevalentes, a partir do meio CHROMagar Candida(r), e caracterizar o perfil de sensibilidade das colônias ao miconazol e à terapia fotodinâmica (TFD). MATERIAL E MÉTODO: A amostra foi constituída por 45 usuários de prótese total, sendo 30 com diagnóstico clínico de EP e 15 sem a doença. Realizou-se raspagem com swab da mucosa palatina e das próteses, e as amostras foram semeadas em CHROMagar Candida(r), para identificação de espécies de C. albicans, C. krusei e C. tropicalis. Após incubação e leitura das placas, as colônias foram reisoladas em Ágar Sabouraud, para caracterização da sensibilidade ao miconazol e à TFD. RESULTADO: Espécies de Candida estiveram presentes em 53,33% das amostras dos pacientes com EP e em 6,67% das amostras dos pacientes sem EP, considerando-se o total de amostras de mucosa (p=0,008) e próteses (p=0,001). As espécies mais prevalentes foram C. albicans (36,67% e 53,33%), seguida de C. tropicalis (13,33% e 16,67%) e C. krusei (13,33% e 6,67%), em mucosa e prótese, respectivamente. As amostras mostraram maior sensibilidade ao miconazol que à TFD (p<0,0001). CONCLUSÃO: Existiu uma associação entre a presença de Candida e EP, sendo C. albicans a espécie mais prevalente. Miconazol proveu melhores resultados na eliminação in vitro de colônias de Candida quando comparado à TFD.

Relationship between acetaldehyde concentration in mouth air and tongue coating volume

OBJECTIVE

Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration and oral condition in healthy volunteers.

MATERIAL AND METHODS

Sixty-five volunteers (51 males and 14 females, aged from 20 to 87 years old) participated in the present study. Acetaldehyde concentration in mouth air was measured using a portable monitor. Oral examination, detection of oral Candida species and assessment of alcohol sensitivity were performed.

RESULTS

Acetaldehyde concentration [median (25%, 75%)] in mouth air was 170.7 (73.5, 306.3) ppb. Acetaldehyde concentration in participants with a tongue coating status score of 3 was significantly higher than in those with a score of 1 (p<0.017). After removing tongue coating, acetaldehyde concentration decreased significantly (p<0.05). Acetaldehyde concentration was not correlated with other clinical parameters, presence of Candida species, smoking status or alcohol sensitivity.

CONCLUSION

Physiological acetaldehyde concentration in mouth air was associated with tongue coating volume.

Antifungal susceptibility patterns, in vitro production of virulence factors, and evaluation of diagnostic modalities for the speciation of pathogenic Candida from blood stream infections and vulvovaginal candidiasis

Candida spp. have emerged as successful pathogens in both invasive and mucosal infections. Varied virulence factors and growing resistance to antifungal agents have contributed to their pathogenicity. We studied diagnostic accuracy of HiCrome Candida Differential Agar and Vitek 2 Compact system for identification of Candida spp. in comparison with species-specific PCR on 110 clinical isolates of Candida from blood stream infections (54, 49%) and vulvovaginal candidiasis (56, 51%). C. albicans (61%) was the leading pathogen in VVC, while C. tropicalis (46%) was prominent among BSIs. HiCrome Agar and Vitek 2 Compact had good measures of agreement (κ) 0.826 and 0.895, respectively, in comparison with PCR. We also tested these isolates for in vitro production of proteinase, esterase, phospholipases, and biofilms. Proteinase production was more among invasive isolates (P = 0.017), while phospholipase production was more among noninvasive isolates (P = 0.001). There was an overall increase in the production of virulence factors among non-albicans Candida. Identification of clinical isolates of Candida up to species level either by chromogenic agar or by Vitek 2 Compact system should be routinely done to choose appropriate therapy.

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.

Species identification of invasive yeasts including Candida in Pakistan: limitations of phenotypic methods

OBJECTIVE

To compare phenotypic and genotypic methods of yeast identification.

METHODS

The in-vitro cross-sectional study was conducted from January 2006 to May 2009. Invasive yeasts isolated at the clinical microbiology laboratory at the Aga Khan University (AKU), Karachi, Pakistan, were identified. Speciation by phenotypic and molecular methods was compared. All yeasts isolated during the study period from blood and other invasive sites were identified using standard methods. Isolates were shipped to Mycotic Diseases Branch, Centres for Disease Control and Prevention, Atlanta, Georgia, USA, for identification by Luminex flow cytometric multianalyte profiling (xMAP) system. Ribosomal ITS2 DNA sequencing was performed on isolates not identified by Luminex.

RESULT

Of the 214 invasive yeasts evaluated, Candida species were 209 (97.7%) while the frequency of non-Candida species was 5 (2.3%). Overall agreement between phenotypic and molecular identification was 81.3%, 90.3% amongst the more common Candida species, and only 38.8% amongst the uncommon yeasts.

CONCLUSION

Phenotypic methods of identification proved adequate for common Candida species, but were deficient in recognising rare Candida and non-Candida yeasts, highlighting the importance of molecular methods for identification.