Prospective evaluation of the new chromogenic medium CandiSelect 4 for differentiation and presumptive identification of the major pathogenic Candida 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 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.

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.

Comparison of four commercially available chromogenic media to identify Candida albicans and other medically relevant Candida species

BACKGROUND

The number of invasive Candida infections has significantly increased in recent decades. For the successful treatment of fungal infections, rapid identification at the species level, particularly in polyfungal infections, is a key factor. In this study, four commercially available chromogenic media, CandiSelect™ 4 (CS4), chromID™ Candida Agar (CCA), BBL™ CHROMagar™ Candida Medium (BBL) and Brilliance™ Candida Agar (BCA) were evaluated for Candida identification.

MATERIAL/METHODS

Overall, 181 bronchial secretion samples from intensive care patients were analysed prospectively. In addition, 18 primarily sterile materials, previously tested positive for Candida, were investigated retrospectively. All samples were cultured as recommended by the manufacturer and visually inspected after 24 and 48 hours by three independent investigators. As a control, colonies were identified by MALDI-TOF MS. Specificity and sensitivity were determined for C albicans identification prospectively.

RESULTS

CS4 and BCA showed the best overall consensus with the identification results reached by MALDI-TOF MS for Candida albicans and species. A clear differentiation between the species could be ascertained via easily identifiable, species-specific coloration in contrast to BBL and CCA. Sensitivity for C albicans (n = 73) identification varied between 32% (BCA) and 69% (CS4 and CCA) after 24 hours and 68% (BBL) and 82% (BCA) after 48 hours incubation, while specificity ranged between 62% (BBL) and 81% (CCA) after 24 hours and 82% (BBL) and 85% (CS4) after 48 hours.

CONCLUSION

CS4 and BCA are recommended for routine identification of Candida species in human samples.

A Small Aromatic Compound Has Antifungal Properties and Potential Anti-Inflammatory Effects against Intestinal Inflammation

Resistance of the opportunistic pathogen Candida albicans to antifungal drugs has increased significantly in recent years. After screening 55 potential antifungal compounds from a chemical library, 2,3-dihydroxy-4-methoxybenzaldehyde (DHMB) was identified as having potential antifungal activity. The properties of DHMB were then assessed in vitro and in vivo against C. albicans overgrowth and intestinal inflammation. Substitution on the aromatic ring of DHMB led to a strong decrease in its biological activity against C. albicans. The MIC of DHMB was highly effective at eliminating C. albicans when compared to that of caspofungin or fluconazole. Additionally, DHMB was also effective against clinically isolated fluconazole- or caspofungin-resistant C. albicans strains. DHMB was administered to animals at high doses. This compound was not cytotoxic and was well-tolerated. In experimental dextran sodium sulphate (DSS)-induced colitis in mice, DHMB reduced the clinical and histological score of inflammation and promoted the elimination of C. albicans from the gut. This finding was supported by a decrease in aerobic bacteria while anaerobic bacteria populations were re-established in mice treated with DHMB. DHMB is a small organic molecule with antifungal properties and anti-inflammatory activity by exerting protective effects on intestinal epithelial cells.

Remodeling of the Candida glabrata cell wall in the gastrointestinal tract affects the gut microbiota and the immune response

The gastrointestinal (GI) microbiota acts a natural barrier to the proliferation of opportunistic pathogens. Candida glabrata is an opportunistic yeast pathogen that has adapted to colonize all segments of the human GI tract. We observed an increase in Escherichia coli, Enterococcus faecalis, and Bacteroides vulgatus populations, and a decrease in Lactobacillus johnsonii, Bacteroides thetaiotaomicron, and Bifidobacterium animalis in mice with DSS-induced colitis. This reduction was more pronounced for L. johnsonii during C. glabrata overgrowth. In addition, C. glabrata overgrowth increased mouse mortality and inflammatory parameters, and modulated the expression of intestinal receptors and signaling pathways. The C. glabrata cell wall underwent various changes during the course of C. glabrata colonization, and showed a significant increase in chitin. C. glabrata deficient in chitin synthase-3 induced fewer inflammatory parameters than the parental strain during intestinal inflammation. Oral administration of chitin attenuated the impact of colitis, and reduced the number of aerobic bacteria and C. glabrata overgrowth, while chitinase-3-like protein-1 increased. This study provides evidence that inflammation of the gut alters the microbial balance and leads to C. glabrata cell wall remodeling through an increase in chitin, which is involved in promoting persistence of C. glabrata in the gut.

A Decade of Development of Chromogenic Culture Media for Clinical Microbiology in an Era of Molecular Diagnostics

In the last 25 years, chromogenic culture media have found widespread application in diagnostic clinical microbiology. In the last decade, the range of media available to clinical laboratories has expanded greatly, allowing specific detection of additional pathogens, including Pseudomonas aeruginosa, group B streptococci, Clostridium difficile, Campylobacter spp., and Yersinia enterocolitica. New media have also been developed to screen for pathogens with acquired antimicrobial resistance, including vancomycin-resistant enterococci, carbapenem-resistant Acinetobacter spp., and Enterobacteriaceae with extended-spectrum β-lactamases and carbapenemases. This review seeks to explore the utility of chromogenic media in clinical microbiology, with particular attention given to media that have been commercialized in the last decade. The impact of laboratory automation and complementary technologies such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is also assessed. Finally, the review also seeks to demarcate the role of chromogenic media in an era of molecular diagnostics.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

Comparative evaluation of six chromogenic media for presumptive yeast identification

AIMS

The present study was undertaken to evaluate the discrimination ability of six chromogenic media in presumptive yeast identification.

METHODS

We analysed 108 clinical isolates and reference strains belonging to eight different species: Candida albicans,Candida dubliniensis, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis,Candida lusitaniae and Trichosporon mucoides.

RESULTS

C. albicans, C. tropicalis and C. krusei could be distinguished from one another in all the tested chromogenic media, as predicted by the manufacturers. In addition, C. albicans could be distinguished from C. dubliniensis on BBL CHROMagar Candida, Kima CHROMagar Candida and Brilliance Candida, and C. parapsilosis could be identified on CHROMATIC Candida agar, CHROMOGENIC Candida agar, and Brilliance Candida agar.

CONCLUSIONS

Brilliance Candida provided the widest discrimination ability, being able to discriminate five out of the seven Candida species tested. Interestingly, C. tropicalis and C. krusei could be already distinguished from each other after 24 hours of incubation.

Candida species isolation in peristomal skin in patients with abdominal stomas and correlation to clinical signs: a descriptive pilot study

The reported prevalence of candidiasis in peristomal skin varies greatly. Very few studies exist that correlate the clinical findings around the peristomal skin to the mycology. In this study, the authors report on Candida species prevalence, clinical correlation, and mycology.

Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species

Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine recognition of Candida albicans and presumptive identification of Candida tropicalis, Candida glabrata, and Candida krusei. We evaluated an extension of this method with 46 non-Candida albicans Candida (NCAC) and 7 Malassezia species. The medium supported growth of all species tested and a wide diversity of cultural types were observed. Colony colours were in violet, turquoise (including green and blue), or white tinges. Eight NCAC species produced violet pigmentation similar to that of C. albicans. Most NCAC species, including C. glabrata and C. tropicalis were distributed in the turquoise group. Malassezia species were invariably blue.

Current state and future perspectives of loop-mediated isothermal amplification (LAMP)-based diagnosis of filamentous fungi and yeasts

Loop-mediated isothermal amplification is a rather novel method of enzymatic deoxyribonucleic acid amplification which can be applied for the diagnosis of viruses, bacteria, and fungi. Although firmly established in viral and bacterial diagnosis, the technology has only recently been applied to a noteworthy number of species in the filamentous fungi and yeasts. The current review gives an overview of the literature so far published on the topic by discussing the different groups of fungal organisms to which the method has been applied. Moreover, the method is described in detail as well as the different possibilities available for signal detection and quantification and sample preparation. Future perspective of loop-mediated isothermal amplification-based assays is discussed in the light of applicability for fungal diagnostics.

Fungal diagnostics: review of commercially available methods

Fungi and yeasts are critical causes of acute infection. As such, the detection and identification of these organisms are crucial in the diagnosis of affected patient populations. There is a vast array of commercial tests currently available for diagnostic purposes. These vary from traditional culture and biochemical methods to advanced multiparameter molecular tests. Recent technological advances have driven the development of rapid tests which are complementing and in some cases replacing the more traditional methods of detection. Irrespective of the method used the ultimate goal is timely detection of the infectious agent allowing appropriate treatment and improved outcome for the patient.

A simple and rapid method to differentiate Arthroderma benhamiae from Microsporum canis

BACKGROUND

Arthroderma benhamiae is increasingly isolated in Central Europe. In culture, this dermatophyte is difficult to differentiate macroscopically from Microsporum canis, which is microscopically also true for weak or non-sporulating strains. Although there are valid molecular methods for differentiating between these two dermatophytes, in everyday practice it would be helpful for epidemiological and treatment considerations to have a simple and rapid method available for discrimination.

METHODS

Five commercially available chromogenic agar media were incubated with culture material of M. canis and A. benhamiae of different ages (2-21 days). Their color was evaluated at different temperatures (4, 20, 25, and 30 ∞C) and for different incubation periods (2 hours - 7 days).

RESULTS

Under the selected conditions, Candi-Select(TM) 4 was most suitable. All M. canis strains tested (n = 21) showed a pink or purple coloration of the agar, while 5 out of 6 A. benhamiae strains (n = 30) showed a turquoise coloration. The best results were achieved with an incubation temperature of 25 ∞C and small inocula derived from primary cultures. Results could be evaluated after 2-4 hours.

CONCLUSIONS

In addition to searching for the origin of infection (in A. benhamiae almost exclusively guinea pigs, and for M. canis dogs and cats), distinguishing between the Trichophyton and Microsporum genera is most important, especially for the selection of a systemic antimycotic agent in the treatment of tinea capitis in children. In the case of M. canis terbinafine is not the first choice, but rather griseofulvin, fluconazole or itraconazole. We present a method of differentiation using Candi-Select(TM) 4. When done with a primary culture, this allows for presumptive identification within a few hours and thus prompt initiation of pathogen-specific therapy.

Modulation of intestinal inflammation by yeasts and cell wall extracts: strain dependence and unexpected anti-inflammatory role of glucan fractions

Yeasts and their glycan components can have a beneficial or adverse effect on intestinal inflammation. Previous research has shown that the presence of Saccharomyces cerevisiae var. boulardii (Sb) reduces intestinal inflammation and colonization by Candida albicans. The aim of this study was to identify dietary yeasts, which have comparable effects to the anti-C. albicans and anti-inflammatory properties of Sb and to assess the capabilities of yeast cell wall components to modulate intestinal inflammation. Mice received a single oral challenge of C. albicans and were then given 1.5% dextran-sulphate-sodium (DSS) for 2 weeks followed by a 3-day restitution period. S. cerevisiae strains (Sb, Sc1 to Sc4), as well as mannoprotein (MP) and β-glucan crude fractions prepared from Sc2 and highly purified β-glucans prepared from C. albicans were used in this curative model, starting 3 days after C. albicans challenge. Mice were assessed for the clinical, histological and inflammatory responses related to DSS administration. Strain Sc1-1 gave the same level of protection against C. albicans as Sb when assessed by mortality, clinical scores, colonization levels, reduction of TNFα and increase in IL-10 transcription. When Sc1-1 was compared with the other S. cerevisiae strains, the preparation process had a strong influence on biological activity. Interestingly, some S. cerevisiae strains dramatically increased mortality and clinical scores. Strain Sc4 and MP fraction favoured C. albicans colonization and inflammation, whereas β-glucan fraction was protective against both. Surprisingly, purified β-glucans from C. albicans had the same protective effect. Thus, some yeasts appear to be strong modulators of intestinal inflammation. These effects are dependent on the strain, species, preparation process and cell wall fraction. It was striking that β-glucan fractions or pure β-glucans from C. albicans displayed the most potent anti-inflammatory effect in the DSS model.

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.

Evaluation of CHROM-Pal medium for the isolation and direct identification of Candida dubliniensis in primary cultures from the oral cavity

Candida albicans is the species most frequently isolated from oral specimens, but the recovery of other Candida species such as Candida dubliniensis is increasing. Differentiation of C. dubliniensis from C. albicans requires special tests and both species are misidentified in some studies. CHROM-Pal (CH-P) is a novel chromogenic medium used in our laboratory for differentiation between C. albicans and C. dubliniensis on the basis of colony colour and morphology, and chlamydospore production. The performance of CH-P and CHROMagar Candida (CAC) was compared for primary isolation and presumptive identification of yeasts from oral specimens from human immunodeficiency virus (HIV)-infected and uninfected individuals. The identification of Candida species on both media was compared with two reference identification methods (API ID 32 C and multiplex PCR). A total of 137/205 oral swabs (66.8 %) plated onto CH-P and CAC media were positive by culture and resulted in the growth of 171 isolates of Candida species on CH-P, whilst only 159 isolates grew on CAC. C. albicans was the most frequently isolated species in both groups of patients, followed by Candida parapsilosis in the HIV-negative group, and by C. dubliniensis in the HIV-infected group. The other Candida species isolated were Candida guilliermondii, Candida glabrata, Candida krusei, Candida tropicalis, Candida famata, Candida rugosa, Candida kefyr, Candida pelliculosa and Candida pulcherrima. The sensitivity and specificity for identifying C. albicans, C. krusei, C. tropicalis and C. dubliniensis on CH-P were over 98.5 %, always equal to or higher than those obtained when CAC was used. CH-P is a simple reliable medium for primary isolation and presumptive identification of yeast isolates from oral samples. The ability of CH-P to discriminate between C. dubliniensis and C. albicans was significantly higher (P <0.05) than that of CAC.

Saccharomyces boulardii decreases inflammation and intestinal colonization by Candida albicans in a mouse model of chemically-induced colitis

The present study was designed to investigate the effects of Saccharomyces boulardii on inflammation and intestinal colonization by Candida albicans in a BALB/c mouse model of colitis that had been induced by dextran-sulfate-sodium (DSS). Colonization with C. albicans was established by oral gavage with a 200 microL suspension of 10(7) yeast cells. A 1.5% solution of DSS was administered in drinking water 1 h after C. albicans oral challenge, while 10(7) cells of S. boulardii was inoculated daily by oral gavage for 1 week. Faeces were collected daily for 2 weeks. Seven groups of mice consisting of those that were administered either C. albicans or S. boulardii or both were sacrificed after 14 days and samples of the colon were taken for histological scoring and real-time PCR (RT-PCR) analysis of inflammatory cytokines and toll-like receptors (TLRs). Compared to control animals that did not receive DSS, the number of C. albicans colonies recovered from faeces was significantly greater in mice receiving DSS. In contrast, the colony forming units (CFUs) of C. albicans were greatly reduced in mice receiving S. boulardii. The administration of this yeast decreased the severity of DSS-induced clinical scores and histological inflammation. At the mRNA expression level, an increase in TLR2 and TLR4 resulting from the presence of S. boulardii was associated with a reduction in the inflammatory cytokines TNFalpha and INFgamma. In mice receiving DSS and C. albicans, TLR4 was over-expressed by stimulation with both yeasts, but TLR2 and TNFalpha, which were increased by the administration of C. albicans alone, were decreased in the presence of S. boulardii. These results indicate that S. boulardii decreased inflammation and C. albicans colonization in this BALB/c mouse model of colitis.