Mucosal candidiasis

Anticandidal effect of cinnamic acid characterized from Cinnamomum cassia bark against the fluconazole resistant strains of Candida

Candida spp., causes invasive fungal infections, especially in immune-compromised patients and the propensity of antifungal resistance against azole-based drugs need to be addressed. This study is thus aimed to characterize the anticandidal effect of the cinnamic acid extracted from the barks of Cinnamomum cassia. Five species of Fluconazole-resistant Candida sp. were retrieved from the department repertoire. The extraction of CA was performed by three different methods followed by silica gel column chromatography. Eluant was subjected to FTIR and XRD analysis for confirmation. The anticandidal activity of the CA was checked by the agar disc diffusion method and the MIC and MFC were determined. The anti-biofilm effect of CA was assessed using the CLSM technique followed by the biocompatibility check using MTT assay in normal HGF cell lines. CA was best extracted with the hot maceration method using ethanol with a maximum yield of 6.73 mg. Purification by column chromatography was achieved using benzene, acetic acid, and water (6:7:3) mobile phase. CA was confirmed by FTIR with absorption peaks and by XDR based on strong intensity. CA was found to possess promising anticandidal activity at 8 µg/mL with MIC and MFC values determined as 0.8 µg/mL and 0.08 µg/mL respectively. Antibiofilm activity by CLSM analysis revealed biofilm inhibition and was biocompatible at 8.5 µg/ml concentrations in HGF cell lines until 24 h. The study findings conclude that CA is the best alternative to treat candidal infection warranting further experimental preclinical studies.

Neonatal innate immunity response in invasive candidiasis

Infections caused by Candida spp. are frequent in critically hospitalized patients, especially among premature neonates, representing one of the most common healthcare-related infections. Although there is considerable production of current knowledge about the mechanisms of immune response, aspects involved in the newborn's innate defense are not fully understood. The aim of this study was to describe the innate immune mechanisms involved in the defense of neonates against invasive candidiasis. This is an integrative literature review from the Scopus, Scifinder, Medline, Web of Science databases and the electronic libraries ScienceDirect and Scielo, in the period between 2002 and 2020, with rescue based on primary descriptor Immunity Innate plus secondary descriptors Candidiasis Invasive AND Infant Newborn. We have observed the involvement of various mechanisms in the neonatal response against invasive candidiasis, including the recognition, signaling, recruitment, and initiation of an effective immune response. These mechanisms encompass the presence of antimicrobial peptides, phagocytosis, synthesis of reactive oxygen species, inflammatory mediators, and complex cell signaling systems mediated by Pattern Recognition Receptors (PRRs). With this study, it is expected to contribute to the expansion of knowledge about the immunological mechanisms involved in the innate immune response of the newborn against disseminated infections caused by Candida species, and in the same sense, highlight the importance of this knowledge as a reflex in the decrease in mortality in the neonatal period.

Re-estimation of the burden of serious fungal diseases in Uganda

Background

It is of utmost importance to monitor any change in the epidemiology of fungal diseases that may arise from a change in the number of the at-risk population or the availability of local data.

Objective

We sought to update the 2015 publication on the incidence and prevalence of serious fungal diseases in Uganda.

Methods

Using the Leading International Fungal Education methodology, we reviewed published data on fungal diseases and drivers of fungal diseases in Uganda. Regional or global data were used where there were no Ugandan data.

Results

With a population of ~45 million, we estimate the annual burden of serious fungal diseases at 4,099,357 cases (about 9%). We estimated the burden of candidiasis as follows: recurrent Candida vaginitis (656,340 cases), oral candidiasis (29,057 cases), and esophageal candidiasis (74,686 cases) in HIV-infected people. Cryptococcal meningitis annual incidence is estimated at 5553 cases, Pneumocystis pneumonia at 4604 cases in adults and 2100 cases in children. For aspergillosis syndromes, invasive aspergillosis annual incidence (3607 cases), chronic pulmonary aspergillosis (26,765 annual cases and 63,574 5-year-period prevalent cases), and prevalence of allergic bronchopulmonary aspergillosis at 75,931 cases, and severe asthma with fungal sensitization at 100,228 cases. Tinea capitis is common with 3,047,989 prevalent cases. For other mycoses, we estimate the annual incidence of histoplasmosis to be 646 cases and mucormycosis at 9 cases.

Conclusion

Serious fungal diseases affect nearly 9% of Ugandans every year. Tuberculosis and HIV remain the most important predisposition to acute fungal infection necessitating accelerated preventive, diagnostic, and therapeutic interventions for the management of these diseases.

The Spectrum of Infections in Patients with Lung Cancer

Although diagnostic and therapeutic advances in lung cancer (LC) have increased the survival of patients, infection and its complications are still among the most important causes of mortality. The disruption of tissue caused by tumor mass, management of cancer therapy and alteration in the humoral/cellular immune systems due to both cancer itself and therapy considerably increase susceptibility to infection in cancer patients. Particularly, opportunistic microorganisms should be considered, then applying rapid and sensitive diagnostic methods for them. Thus, cancer patients who are already exposed to difficult, long-term and expensive treatments can be prevented from dying from complications related to infections.

Small, Cationic Antifungal Proteins from Filamentous Fungi Inhibit Candida albicans Growth in 3D Skin Infection Models

The emerging resistance of human-pathogenic fungi to antifungal drugs urges the development of alternative therapeutic strategies. The small, cationic antifungal proteins (AFPs) from filamentous ascomycetes represent promising candidates for next-generation antifungals. These bio-molecules need to be tested for tolerance in the host and efficacy against fungal pathogens before they can be safely applied in humans. Testing of the efficacy and possible adverse effects of new drug candidates in three-dimensional (3D) human-cell based models represents an advantageous alternative to animal experiments. In, this study, as a proof-of-principle, we demonstrate the usefulness of 3D skin infection models for screening new antifungal drug candidates for topical application. We established a cutaneous infection with the opportunistic human-pathogenic yeast Candida albicans in a commercially available 3D full-thickness (FT) skin model to test the curative potential of distinct AFPs from Penicillium chrysogenum (PAFopt, PAFB, and PAFC) and Neosartorya (Aspergillus) fischeri (NFAP2) in vitro. All tested AFPs were comparably well tolerated by the skin models. The infected 3D models exhibited reduced epidermal permeability barriers, allowing C. albicans to colonize the epidermal and dermal layers, and showed increased secretion of the pro-inflammatory cytokine IL-6 and the chemokine IL-8. AFP treatment diminished the fungal burden and penetration depth of C. albicans in the infected models. The epidermal permeability barrier was restored and the secretion of IL-8 was decreased following AFP treatment. In summary, our study proves that the tested AFPs exhibit antifungal potential against cutaneous C. albicans infection in a 3D FT skin model. IMPORTANCE Candida albicans represents one of the most prevalent opportunistic fungal pathogens, causing superficial skin and mucosal infections in humans with certain predisposing health conditions and life-threatening systemic infections in immunosuppressed patients. The emerging drug resistance of this human-pathogenic yeast and the limited number of antifungal drugs for prevention and treatment of infections urgently demands the identification of new antifungal compounds with novel mechanisms of action. Small, cationic antifungal proteins (AFPs) from filamentous fungi represent promising candidates for next-generation antifungals for topical application. These bio-molecules need to be tested for tolerance by the host and efficacy in pathogen clearance prior to being involved in clinical trials. In a proof-of-principle study, we provide evidence for the suitability of 3D human-cell based models as advantageous alternatives to animal experiments. We document the tolerance of specific AFPs and their curative efficacy against cutaneous C. albicans infection in a 3D skin model.

Herbal Products and Their Active Constituents Used Alone and in Combination with Antifungal Drugs against Drug-Resistant Candida sp

Clinical isolates of Candida yeast are the most common cause of opportunistic fungal infections resistant to certain antifungal drugs. Therefore, it is necessary to detect more effective antifungal agents that would be successful in overcoming such infections. Among them are some herbal products and their active constituents.The purpose of this review is to summarize the current state of knowledge onherbal products and their active constituents havingantifungal activity against drug-resistant Candida sp. used alone and in combination with antifungal drugs.The possible mechanisms of their action on drug-resistant Candida sp. including (1) inhibition of budding yeast transformation into hyphae; (2) inhibition of biofilm formation; (3) inhibition of cell wall or cytoplasmic membrane biosynthesis; (4) ROS production; and (5) over-expression of membrane transporters will be also described.

Significant Differences in Host-Pathogen Interactions Between Murine and Human Whole Blood

Murine infection models are widely used to study systemic candidiasis caused by C. albicans. Whole-blood models can help to elucidate host-pathogens interactions and have been used for several Candida species in human blood. We adapted the human whole-blood model to murine blood. Unlike human blood, murine blood was unable to reduce fungal burden and more substantial filamentation of C. albicans was observed. This coincided with less fungal association with leukocytes, especially neutrophils. The lower neutrophil number in murine blood only partially explains insufficient infection and filamentation control, as spiking with murine neutrophils had only limited effects on fungal killing. Furthermore, increased fungal survival is not mediated by enhanced filamentation, as a filament-deficient mutant was likewise not eliminated. We also observed host-dependent differences for interaction of platelets with C. albicans, showing enhanced platelet aggregation, adhesion and activation in murine blood. For human blood, opsonization was shown to decrease platelet interaction suggesting that complement factors interfere with fungus-to-platelet binding. Our results reveal substantial differences between murine and human whole-blood models infected with C. albicans and thereby demonstrate limitations in the translatability of this ex vivo model between hosts.

Human inborn errors of immunity underlying superficial or invasive candidiasis

Candida species, including C. albicans in particular, can cause superficial or invasive disease, often in patients with known acquired immunodeficiencies or iatrogenic conditions. The molecular and cellular basis of these infections in patients with such risk factors remained largely elusive, until the study of inborn errors of immunity clarified the basis of the corresponding inherited and "idiopathic" infections. Superficial candidiasis, also known as chronic mucocutaneous candidiasis (CMC), can be caused by inborn errors of IL-17 immunity. Invasive candidiasis can be caused by inborn errors of CARD9 immunity. In this chapter, we review both groups of inborn errors of immunity, and discuss the contribution of these studies to the deciphering of the critical mechanisms of anti-Candida immunity in patients with other conditions.

In silico Design of a Multivalent Vaccine Against Candida albicans

Invasive candidiasis (IC) is the most common nosocomial infection and a leading cause of mycoses-related deaths. High-systemic toxicity and emergence of antifungal-resistant species warrant the development of newer preventive approaches against IC. Here, we have adopted an immunotherapeutic peptide vaccine-based approach, to enhance the body's immune response against invasive candida infections. Using computational tools, we screened the entire candida proteome (6030 proteins) and identified the most immunodominant HLA class I, HLA class II and B- cell epitopes. By further immunoinformatic analyses for enhanced vaccine efficacy, we selected the 18- most promising epitopes, which were joined together using molecular linkers to create a multivalent recombinant protein against Candida albicans (mvPC). To increase mvPC's immunogenicity, we added a synthetic adjuvant (RS09) to the mvPC design. The selected mvPC epitopes are homologous against all currently available annotated reference sequences of 22 C. albicans strains, thus offering a higher coverage and greater protective response. A major advantage of the current vaccine approach is mvPC's multivalent nature (recognizing multiple-epitopes), which is likely to provide enhanced protection against complex candida antigens. Here, we describe the computational analyses leading to mvPC design.

Candida albicans Cannot Acquire Sufficient Ethanolamine from the Host To Support Virulence in the Absence of De Novo Phosphatidylethanolamine Synthesis

Candida albicans mutants for phosphatidylserine (PS) synthase (cho1ΔΔ) and PS decarboxylase (psd1ΔΔ psd2ΔΔ) are compromised for virulence in mouse models of systemic infection and oropharyngeal candidiasis (OPC). Both of these enzymes are necessary to synthesize phosphatidylethanolamine (PE) by the de novo pathway, but these mutants are still capable of growth in culture media, as they can import ethanolamine from media to synthesize PE through the Kennedy pathway. Given that the host has ethanolamine in its serum, the exact mechanism by which virulence is lost in these mutants is not clear. There are two competing hypotheses to explain their loss of virulence. (i) PE from the Kennedy pathway cannot substitute for de novo-synthesized PE. (ii) The mutants cannot acquire sufficient ethanolamine from the host to support adequate PE synthesis. These hypotheses can be simultaneously tested if ethanolamine availability is increased for Candida while it is inside the host. We accomplish this by transcomplementation of C. albicans with the Arabidopsis thaliana serine decarboxylase gene (AtSDC), which converts cytoplasmic serine to ethanolamine. Expression of AtSDC in either mutant restores PE synthesis, even in the absence of exogenous ethanolamine. AtSDC also restores virulence to cho1ΔΔ and psd1ΔΔ psd2ΔΔ strains in systemic and OPC infections. Thus, in the absence of de novo PE synthesis, C. albicans cannot acquire sufficient ethanolamine from the host to support virulence. In addition, expression of AtSDC restores PS synthesis in the cho1ΔΔ mutant, which may be due to causing PS decarboxylase to run backwards and convert PE to PS.

Modulation of Cyp450, ALS1 and COX-2 signaling pathways induced by Candida albicans infection via novel antifungal agents

Although, fluconazole is widely used in clinical treatment as an antifungal drug, it recorded potential problems as resistance and intracellular accumulation. Female albino mice were injected with single ip dose of Candida albicans (1.5 × 10⁶ CFU). Three weeks post treatment with fluconazole and two novel synthesized compounds [(2-(4-(Pyridin-2-yl) aminosulfonylphenylamino)-6-(naphthalen-2-yl)-4-(pyridin-2-yl) pyridine-3carbonitrile) and (2-(4-(Pyrimidin-2-yl) aminosulfonylphenylamino)-6-(naphthalen-2-yl)-4-(pyridine-2-yl)pyridine-3-carbonitrile) (13b & 14b, respectively)] in both low and high doses (50 mg/kg & 200 mg/kg), liver function and vaginal inflammation were assessed. Candida albicans significantly elevated serum alanine aminotransferase (ALT) and butrylcholinesterase (BCHE) as well as hepatic malondialdehyde (MDA). Molecular analysis confirmed a significant up-regulation in mRNA gene expression of Agglutinin-like sequence (ALS1), hepatic cytochrome p450 (Cyp450). Vaginal COX-2 gene expression was also elevated. Nevertheless, a significant down-regulation was apparent in mice treated with the aforementioned compounds. Meanwhile, administration of 14b in a high dose noticeably down-regulated the altered parameters expression showing a significant effect in comparison to animals treated with the variable doses of the tested compounds. Histopathological finding confirmed the obtained results. The current work investigated the efficiency of new synthetic pyrimidine derivatives 14bas anti-microbial agents and recommended to be improved and evaluated as a novel antifungal drug to overcome the emergence of resistance problem.

High prevalence of candiduria due to non-albicans Candida species among diabetic patients: A matter of concern?

BACKGROUND

Among the fungal pathogens, Candida species are the most common cause of urinary tract infection (UTI). Some predisposing factors such as diabetes mellitus, urinary retention, urinary stasis, renal transplantation, and hospitalization can increase the risk of candiduria. The aim of this cross-sectional study was to evaluate candiduria among type 2 diabetic patients and identification of the Candida isolates.

METHOD

Four hundred clean-catch midstream urine specimens were obtained from patients with type 2 diabetes mellitus. The specimens were centrifuged and the sediments were examined by direct examination and cultured on Sabouraud dextrose agar. The plates were incubated for 2-3 days at 35°C. The Candida colonies were counted and purified using CHROMagar Candida. The isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system.

RESULTS

Of the 400 urine specimens, 40 (10%) had positive cultures for Candida species with a colony count of ≥1 × 10³ colony forming units (CFU)/mL. The frequencies of the Candida species were as follows: C. albicans (n = 19, 47.5%), C. glabrata (n = 15, 37.5%), C. kefyer (n = 4, 10%) and C. krusei (n = 2, 5%). Seventy-three (88%) of the patients with candiduria had hemoglobin A1c (HbA1c) levels above 7%.

CONCLUSION

The rate of candiduria was relatively high in type 2 diabetic patients and they were also suffering from a lack of proper blood glucose control. Although the frequency of non-albicans Candida species had not significantly higher than C. albicans, however, they obtained more from those with symptomatic candiduria.

Global and Multi-National Prevalence of Fungal Diseases-Estimate Precision

Fungal diseases kill more than 1.5 million and affect over a billion people. However, they are still a neglected topic by public health authorities even though most deaths from fungal diseases are avoidable. Serious fungal infections occur as a consequence of other health problems including asthma, AIDS, cancer, organ transplantation and corticosteroid therapies. Early accurate diagnosis allows prompt antifungal therapy; however this is often delayed or unavailable leading to death, serious chronic illness or blindness. Recent global estimates have found 3,000,000 cases of chronic pulmonary aspergillosis, ~223,100 cases of cryptococcal meningitis complicating HIV/AIDS, ~700,000 cases of invasive candidiasis, ~500,000 cases of Pneumocystis jirovecii pneumonia, ~250,000 cases of invasive aspergillosis, ~100,000 cases of disseminated histoplasmosis, over 10,000,000 cases of fungal asthma and ~1,000,000 cases of fungal keratitis occur annually. Since 2013, the Leading International Fungal Education (LIFE) portal has facilitated the estimation of the burden of serious fungal infections country by country for over 5.7 billion people (>80% of the world's population). These studies have shown differences in the global burden between countries, within regions of the same country and between at risk populations. Here we interrogate the accuracy of these fungal infection burden estimates in the 43 published papers within the LIFE initiative.

Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype

Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274 patients from 167 kindreds originating from 40 countries from 5 continents. Demographic data, clinical features, immunological parameters, treatment, and outcome were recorded. The median age of the 274 patients was 22 years (range, 1-71 years); 98% of them had CMC, with a median age at onset of 1 year (range, 0-24 years). Patients often displayed bacterial (74%) infections, mostly because of Staphylococcus aureus (36%), including the respiratory tract and the skin in 47% and 28% of patients, respectively, and viral (38%) infections, mostly because of Herpesviridae (83%) and affecting the skin in 32% of patients. Invasive fungal infections (10%), mostly caused by Candida spp. (29%), and mycobacterial disease (6%) caused by Mycobacterium tuberculosis, environmental mycobacteria, or Bacille Calmette-Guérin vaccines were less common. Many patients had autoimmune manifestations (37%), including hypothyroidism (22%), type 1 diabetes (4%), blood cytopenia (4%), and systemic lupus erythematosus (2%). Invasive infections (25%), cerebral aneurysms (6%), and cancers (6%) were the strongest predictors of poor outcome. CMC persisted in 39% of the 202 patients receiving prolonged antifungal treatment. Circulating interleukin-17A-producing T-cell count was low for most (82%) but not all of the patients tested. STAT1 GOF mutations underlie AD CMC, as well as an unexpectedly wide range of other clinical features, including not only a variety of infectious and autoimmune diseases, but also cerebral aneurysms and carcinomas that confer a poor prognosis.

The Evolving View of IL-17-Mediated Immunity in Defense Against Mucocutaneous Candidiasis in Humans

The discovery of interleukin (IL)-17-mediated immunity has provided a robust framework upon which our current understanding of the mechanism involved in host defense against mucocutaneous candidiasis (CMC) has been built. Studies have shed light on how pattern recognition receptors expressed by innate immune cells recognize various components of Candida cell wall. Inborn errors of immunity affecting IL-17+ T cell differentiation have recently been defined, such as deficiencies of signal transducer and activator of transcription (STAT)3, STAT1, IL-12Rβ1 and IL-12p40, and caspase recruitment domain 9. Impaired receptor-ligand coupling was identified in patients with IL-17F and IL-17 receptor A (IL17RA) deficiency and autoimmune polyendocrine syndrome (APS) type 1. Mutation in the nuclear factor kappa B activator (ACT) 1 was described as a cause of impaired IL-17R-mediated signaling. CMC may be part of a complex clinical phenotype like in patients with deficiencies of STAT3, IL-12Rβ1/IL-12p40 and APS-1 or may be the only or dominant phenotypic manifestation of disease which is referred to as CMC disease. CMCD may result from deficiencies of STAT1, IL-17F, IL-17RA and ACT1. In this review we discuss how recent research on IL-17-mediated immunity shed light on host defense against mucocutaneous infection by Candida and how the discovery of various germ-line mutations and the characterization of associated clinical phenotypes have provided insights into the role of CD4+IL-17+ lymphocytes in the regulation of anticandidal defense of body surfaces.

Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype

Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274 patients from 167 kindreds originating from 40 countries from 5 continents. Demographic data, clinical features, immunological parameters, treatment, and outcome were recorded. The median age of the 274 patients was 22 years (range, 1-71 years); 98% of them had CMC, with a median age at onset of 1 year (range, 0-24 years). Patients often displayed bacterial (74%) infections, mostly because of Staphylococcus aureus (36%), including the respiratory tract and the skin in 47% and 28% of patients, respectively, and viral (38%) infections, mostly because of Herpesviridae (83%) and affecting the skin in 32% of patients. Invasive fungal infections (10%), mostly caused by Candida spp. (29%), and mycobacterial disease (6%) caused by Mycobacterium tuberculosis, environmental mycobacteria, or Bacille Calmette-Guérin vaccines were less common. Many patients had autoimmune manifestations (37%), including hypothyroidism (22%), type 1 diabetes (4%), blood cytopenia (4%), and systemic lupus erythematosus (2%). Invasive infections (25%), cerebral aneurysms (6%), and cancers (6%) were the strongest predictors of poor outcome. CMC persisted in 39% of the 202 patients receiving prolonged antifungal treatment. Circulating interleukin-17A-producing T-cell count was low for most (82%) but not all of the patients tested. STAT1 GOF mutations underlie AD CMC, as well as an unexpectedly wide range of other clinical features, including not only a variety of infectious and autoimmune diseases, but also cerebral aneurysms and carcinomas that confer a poor prognosis.

The Host's Reply to Candida Biofilm

Candida spp. are among the most common nosocomial fungal pathogens and are notorious for their propensity toward biofilm formation. When growing on a medical device or mucosal surface, these organisms reside as communities embedded in a protective matrix, resisting host defenses. The host responds to Candida biofilm by depositing a variety of proteins that become incorporated into the biofilm matrix. Compared to free-floating Candida, leukocytes are less effective against Candida within a biofilm. This review highlights recent advances describing the host's response to Candida biofilms using ex vivo and in vivo models of mucosal and device-associated biofilm infections.

Rapid detection of Candida species in bronchoalveolar lavage fluid from patients with pulmonary symptoms

Candida species, especially C. albicans, are commensals on human mucosal surfaces, but are increasingly becoming one of the important invasive pathogens as seen by a rise in its prevalence in immunocompromised patients and in antibiotic consumption. Thus, an accurate identification of Candida species in patients with pulmonary symptoms can provide important information for effective treatment. A total of 75 clinical isolates of Candida species were obtained from the bronchoalveolar lavage fluid of both immunocompromised and immunocompetent patients with pulmonary symptoms. Candida cultures were identified based on nuclear ribosomal Internal Transcribed Spacer (ITS1-ITS2 rDNA) sequence analysis by polymerase chain reaction–restriction fragment length polymorphisms (PCR-RFLP). Molecular identification indicated that the isolates belonged predominantly to C. albicans (52%), followed by C. tropicalis (24%), C. glabrata (14.7%), C. krusei (5.3%), C. parapsilosis (1.3%), C. kefyr (1.3%) and C. guilliermondii (1.3%). Given the increasing complexity of disease profiles and their management regimens in diverse patients, rapid and accurate identification of Candida species can lead to timely and appropriate antifungal therapy.

Neonatal Candidiasis: New Insights into an Old Problem at a Unique Host-Pathogen Interface

Candida species are the leading cause of invasive fungal infections in premature infants. Associated with substantial morbidity and mortality, these infections represent serious and sometimes catastrophic complications in the course of hospitalization of a preterm infant in the neonatal intensive care unit. Although virulence factors of Candida and the host defense mechanisms that are important in protection from candidiasis have been the subject of intensive study, considerably less is known about the features of this disease that are specific to premature neonates. As animal models for neonatal candidiasis have been developed, efforts to understand the similarities and differences of candidiasis in the neonatal host relative to other immunocompromised patients have begun to provide insights to these questions.

Interleukin 17-Mediated Host Defense against Candida albicans

Candida albicans is part of the normal microbiota in most healthy individuals. However, it can cause opportunistic infections if host defenses are breached, with symptoms ranging from superficial lesions to severe systemic disease. The study of rare congenital defects in patients with chronic mucocutaneous candidiasis led to the identification of interleukin-17 (IL-17) as a key factor in host defense against mucosal fungal infection. Experimental infections in mice confirmed the critical role of IL-17 in mucocutaneous immunity against C. albicans. Research on mouse models has also contributed importantly to our current understanding of the regulation of IL-17 production by different cellular sources and its effector functions in distinct tissues. In this review, we highlight recent findings on IL-17-mediated immunity against C. albicans in mouse and man.

Antifungal Properties of Crude Extracts, Fractions, and Purified Compounds from Bark of Curatella americana L. (Dilleniaceae) against Candida Species

The ethnomedicinal plant Curatella americana L. (Dilleniaceae) is a common shrub in the Brazilian cerrado, in which crude extract showed antifungal activity in a preliminary study. In this work, the antifungal and cytotoxic properties of the crude extract, fractions, and isolated compounds from C. americana were evaluated against the standard yeast strains Candida albicans, C. tropicalis, and C. parapsilosis, clinical isolates, and fluconazole-resistant strains. The combinatory effects between subfractions and isolated compounds and effects on cell morphology, virulence factors, and exogenous ergosterol were also evaluated. The MIC obtained against the Candida species including fluconazole-resistant strain ranged from 15.3 to 31.3 µg/mL for crude extract, 3.9 to 15.6 µg/mL for ethyl acetate fraction, and 7.8 to 31.3 µg/mL for subfractions. The isolated compounds identified as 4′-O-methyl-catechin, epicatechin-3-O-gallate, and 4′-O-methyl-catechin-3-O-gallate showed lower antifungal activity than the crude extract and fractions (MIC ranging from 31.3 to 125.0 µg/mL). The addition of exogenous ergosterol to yeast culture did not interfere in the antifungal activity of the extract and its fractions. Synergistic antifungal activity was observed between subfractions and isolated compounds. The effects on virulence factors and the different mechanisms of action compared to fluconazole and nystatin suggest that this ethnomedicinal plant may be an effective alternative treatment for candidiasis.

Activity of fluconazole and its Cu(II) complex towards Candida species

Candida species, although they are present as commensal organisms in the digestive tract of healthy individuals, can produce a broad spectrum of serious illnesses in compromised hosts. Fluconazole, a water-soluble triazole with bioavailability greater than 90 %, has been extensively used to treat a wide range of Candida infections. However, a growing resistance of microorganisms in the treatment leads to the discovery of new drugs or modifications of existing ones. The aim of the present study was to investigate whether coordination of Cu(II) ions to fluconazole affects its antifungal activity. The in vitro susceptibility tests and antifungal studies were performed with two Candida spp.: Candidaglabrata and Candida albicans. Overall, 34 strains of the former and 16 strains of the latter were treated with fluconazole, its Cu(II) complex and free Cu(II) ions. The obtained MIC values in 16 cases of the C. glabrata and in 5 cases of the C. albicans were lower for the complex in comparison to the drug. This implies that the complex is more effective against particular strains than the parent drug. The most significant improvement in the complex drug efficacy was observed for fluconazole-resistant species.

CX3CR1 is dispensable for control of mucosal Candida albicans infections in mice and humans

Candida albicans is part of the normal commensal microbiota of mucosal surfaces in a large percentage of the human population. However, perturbations of the host's immune response or bacterial microbiota have been shown to predispose individuals to the development of opportunistic Candida infections. It was recently discovered that a defect in the chemokine receptor CX3CR1 increases susceptibility of mice and humans to systemic candidiasis. However, whether CX3CR1 confers protection against mucosal C. albicans infection has not been investigated. Using two different mouse models, we found that Cx3cr1 is dispensable for the induction of interleukin 17A (IL-17A), IL-22, and IL-23 in the tongue after infection, as well as for the clearance of mucosal candidiasis from the tongue or lower gastrointestinal (GI) tract colonization. Furthermore, the dysfunctional human CX3CR1 allele CX3CR1-M280 was not associated with development of recurrent vulvovaginal candidiasis (RVVC) in women. Taken together, these data indicate that CX3CR1 is not essential for protection of the host against mucosal candidiasis, underscoring the dependence on different mammalian immune factors for control of mucosal versus systemic Candida infections.

Mononuclear phagocyte-mediated antifungal immunity: the role of chemotactic receptors and ligands

Over the past two decades, fungal infections have emerged as significant causes of morbidity and mortality in patients with hematological malignancies, hematopoietic stem cell or solid organ transplantation and acquired immunodeficiency syndrome. Besides neutrophils and CD4(+) T lymphocytes, which have long been known to play an indispensable role in promoting protective antifungal immunity, mononuclear phagocytes are now being increasingly recognized as critical mediators of host defense against fungi. Thus, a recent surge of research studies has focused on understanding the mechanisms by which resident and recruited monocytes, macrophages and dendritic cells accumulate and become activated at the sites of fungal infection. Herein, we critically review how a variety of G-protein coupled chemoattractant receptors and their ligands mediate mononuclear phagocyte recruitment and effector function during infection by the most common human fungal pathogens.

Systemic Staphylococcus aureus infection mediated by Candida albicans hyphal invasion of mucosal tissue

Candida albicans and Staphylococcus aureus are often co-isolated in cases of biofilm-associated infections. C. albicans can cause systemic disease through morphological switch from the rounded yeast to the invasive hyphal form. Alternatively, systemic S. aureus infections arise from seeding through breaks in host epithelial layers although many patients have no documented portal of entry. We describe a novel strategy by which S. aureus is able to invade host tissue and disseminate via adherence to the invasive hyphal elements of Candida albicans. In vitro and ex vivo findings demonstrate a specific binding of the staphylococci to the candida hyphal elements. The C. albicans cell wall adhesin Als3p binds to multiple staphylococcal adhesins. Furthermore, Als3p is required for C. albicans to transport S. aureus into the tissue and cause a disseminated infection in an oral co-colonization model. These findings suggest that C. albicans can facilitate the invasion of S. aureus across mucosal barriers, leading to systemic infection in co-colonized patients.

Incontinence-associated dermatitis: a cross-sectional prevalence study in the Australian acute care hospital setting

The purpose of this cross-sectional study was to identify the prevalence of incontinence and incontinence-associated dermatitis (IAD) in Australian acute care patients and to describe the products worn to manage incontinence, and those provided at the bedside for perineal skin care. Data on 376 inpatients were collected over 2 days at a major Australian teaching hospital. The mean age of the sample group was 62 years and 52% of the patients were male. The prevalence rate of incontinence was 24% (91/376). Urinary incontinence was significantly more prevalent in females (10%) than males (6%) (χ(2)  = 4·458, df = 1, P = 0·035). IAD occurred in 10% (38/376) of the sample group, with 42% (38/91) of incontinent patients having IAD. Semi-formed and liquid stool were associated with IAD (χ(2)  = 5·520, df = 1, P = 0·027). Clinical indication of fungal infection was present in 32% (12/38) of patients with IAD. Absorbent disposable briefs were the most common incontinence aids used (80%, 70/91), with soap/water and disposable washcloths being the clean-up products most commonly available (60%, 55/91) at the bedside. Further data are needed to validate this high prevalence. Studies that address prevention of IAD and the effectiveness of management strategies are also needed.

Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains (ATCC) by Piper betle L. extract

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of P. betle was identified using liquid chromatography-mass spectrophotometry (LC-MS/MS). Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments: (i) in the absence of P. betle extract; and in the presence of P. betle extract at respective concentrations of (ii) 1 mg⋅mL(-1); (iii) 3 mg⋅mL(-1); and (iv) 6 mg⋅mL(-1). The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates (µ). Scanning electron microscopy (SEM) was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the µ-values of the treated cells were significantly different than those of the untreated cells (P<0.05), indicating the fungistatic properties of the P. betle extract. The candidal population was also reduced from an average of 13.44×10(6) to 1.78×10(6) viable cell counts (CFU)⋅mL(-1). SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity.

Fluconazole for the treatment of candidiasis: 15 years experience

Candidia spp. are responsible for contributing to the increasing global prevalence of fungal infections. Fluconazole (Diflucan((R)), Pfizer) is a triazole that has established an exceptional therapeutic record for candida infections including oropharyngeal and esophageal candidiasis, vulvovaginal candidiasis, candidemia and disseminated candidiasis. It is both an oral and parenteral fungistatic agent that inhibits ergosterol synthesis in yeasts. Extensive clinical studies have demonstrated fluconazole's remarkable efficacy, favorable pharmacokinetics and reassuring safety profile, all of which have contributed to its widespread use. Fluconazole became the first antifungal with worldwide sales exceeding billions of dollars, therefore providing an incentive for the pharmaceutical industry to develop new antifungals. This review will examine the contributions and limitations of fluconazole in the treatment of superficial and invasive candidiasis syndromes.

Brazilian guidelines for the management of candidiasis - a joint meeting report of three medical societies: Sociedade Brasileira de Infectologia, Sociedade Paulista de Infectologia and Sociedade Brasileira de Medicina Tropical

Candida infections account for 80% of all fungal infections in the hospital environment, including bloodstream, urinary tract and surgical site infections. Bloodstream infections are now a major challenge for tertiary hospitals worldwide due to their high prevalence and mortality rates. The incidence of candidemia in tertiary public hospitals in Brazil is approximately 2.5 cases per 1000 hospital admissions. Due to the importance of this infection, the authors provide a review of the diversity of the genus Candida and its clinical relevance, the therapeutic options and discuss the treatment of major infections caused by Candida. Each topography is discussed with regard to epidemiological, clinical and laboratory diagnostic and therapeutic recommendations based on levels of evidence.

Antifungal activity, biofilm-controlling effect, and biocompatibility of poly(N-vinyl-2-pyrrolidinone)-grafted denture materials

Colonization and biofilm-formation of Candida species on denture surfaces cause Candida-associated denture stomatitis (CADS), a common, recurring disease affecting up to 67% of denture wearers. We developed poly(N-vinyl-2-pyrrolidinone)-grafted denture materials that can be repeatedly recharged with various antifungal drugs to achieve long-term antifungal and biofilm-controlling effects. The monomer, N-vinyl-2-pyrrolidinone (NVP), was grafted onto poly(methyl methacrylate) denture resins through plasma-initiated grafting polymerization. The physical properties and biocompatibility of the resulting resins were not negatively affected by the presence of up to 7.92% of grafted poly (N-vinyl-2-pyrrolidinone) (PNVP). Miconazole and chlorhexidine digluconate (CD) were used as model antifungal drugs. PNVP grafting significantly increased the drug absorption capability of the resulting denture materials. Further, the new materials showed sustained drug release and provided antifungal effects for weeks (in the case of CD) to months (in the case of miconazole). The drug-depleted resins could be recharged with the same or a different class of antifungal drug to further extend antifungal duration. If needed, drugs on the PNVP-grafted denture materials could be "washed out" (quenched) by treating with PNVP aqueous solutions to stop drug release. These results point to great potentials of the new materials in controlling biofilm-formation in a wide range of device-related applications.

Oral candidiasis in patients with psoriasis: correlation of oral examination and cytopathological evaluation with psoriasis disease severity and treatment

BACKGROUND

Infections are known to trigger and exacerbate psoriasis. Although oral candidiasis is often clinically diagnosed, it is not always confirmed by laboratory tests such as oral cytopathology.

OBJECTIVES

The aims of this study were to determine the prevalence of oral candidiasis in patients with psoriasis through clinical and cytopathological diagnosis and to investigate the association between oral candidiasis and psoriasis with regards to the severity of the clinical presentation and the type of treatment for psoriasis.

METHODS

A total of 140 patients with psoriasis and 140 healthy control subjects received an oral examination. Scrapings of the tongue were also obtained for a cytopathological examination.

RESULTS

The oral examination and the results of the cytopathological smear revealed 37 (26%) cases of candidiasis in the patients with psoriasis and no cases of candidiasis in the healthy control subjects. There was no correlation between the type of psoriasis treatment and the presence of oral candidiasis (P = .616). There was a statistically significant association (P = .033) between the clinical severity of psoriasis and the presence of Candida.

LIMITATIONS

This study was limited by the small number of subjects and the lack of follow-up to determine the development of psoriasis after treatment for oral candidiasis.

CONCLUSIONS

The presence of oral candidiasis is higher in patients with psoriasis and it is associated with disease severity. This increased presence of oral candidiasis was apparent despite any type of treatment for the psoriasis. Cytopathology to rule out oral candidiasis should be used in the routine medical workup of patients with psoriasis.

Bacterial flora of the human oral cavity, and the upper and lower esophagus

This reference study aims to survey the bacterial flora of the healthy lower human esophagus and to compare it with that of the upper esophagus and oral mucosa. The use of biopsies, in addition to brush samples, allows inclusion of not only transient bacteria present on the surface but also bacteria residing in the epithelia, and the yield of the two methods can be compared. Forty patients scheduled for surgery for reasons with no known influence on esophageal flora and with no symptoms or endoscopic signs of esophageal disease were included. Samples were collected from the oral, upper esophageal, and lower esophageal mucosa using sealed brushes and biopsy forceps. Colonies cultivated on agar plates were classified and semiquantified. Twenty-three different bacterial species were identified, with similar strains present at the three sites. The most common group of bacteria was viridans streptococci, with an occurrence rate in brush samples and biopsies of 98% and 95%, respectively. The median number of species occurring in the oral cavity, upper esophagus, and lower esophagus was between 3 and 4 (range 0-7). The total number of species in the oral cavity was significantly higher when compared with either level in the esophagus, while the yields obtained by brush and biopsy sampling were highly correlated. Hence, the normal human esophagus is colonized with a resident bacterial flora of its own, which has similarities to that of the oral mucosa. There are diverse species that make up this flora, although in relatively low amounts. The most frequent inhabitants of the esophagus are streptococci, with an occurrence rate in brush samples and biopsies of 95-98%. Comparative studies of patients with eosinophilic esophagitis and gastroesophageal reflux disease are warranted.

Miconazole mucoadhesive tablets: a novel delivery system

Oropharyngeal candidiasis (OPC) is among the most common opportunistic infections observed in persons infected with human immunodeficiency virus. A once-daily miconazole 50 mg mucoadhesive buccal tablet (MBT) is a novel delivery system with potent in vitro activity against many Candida species, including some that may be resistant to other azoles. MBT, although more expensive, offers an effective, safe, and well-tolerated topical treatment option for OPC that is administered as a convenient once-daily dose.

Oral candidiasis and angular cheilitis

Candidiasis, an often encountered oral disease, has been increasing in frequency. Most commonly caused by the overgrowth of Candida albicans, oral candidiasis can be divided into several categories including acute and chronic forms, and angular cheilitis. Risk factors for the development of oral candidiasis include immunosuppression, wearing of dentures, pharmacotherapeutics, smoking, infancy and old age, endocrine dysfunction, and decreased salivation. Oral candidiasis may be asymptomatic. More frequently, however, it is physically uncomfortable, and the patient may complain of burning mouth, dysgeusia, dysphagia, anorexia, and weight loss, leading to nutritional deficiency and impaired quality of life. A plethora of antifungal treatments are available. The overall prognosis of oral candidiasis is good, and rarely is the condition life threatening with invasive or recalcitrant disease.

Development and validation of an in vivo Candida albicans biofilm denture model

The most common form of oral candidiasis, denture-associated stomatitis, involves biofilm growth on an oral prosthetic surface. Cells in this unique environment are equipped to withstand host defenses and survive antifungal therapy. Studies of the biofilm process on dentures have primarily been limited to in vitro models. We developed a rodent acrylic denture model and characterized the Candida albicans and mixed oral bacterial flora biofilm formation, architecture, and drug resistance in vivo, using time course quantitative culture experiments, confocal microscopy, scanning electron microscopy, and antifungal susceptibility assays. We also examined the utility of the model for measurement of C. albicans gene expression and tested the impact of a specific gene product (Bcr1p) on biofilm formation. Finally, we assessed the mucosal host response to the denture biofilm and found the mucosal histopathology to be consistent with that of acute human denture stomatitis, demonstrating fungal invasion and neutrophil infiltration. This current oral denture model mimics human denture stomatitis and should be useful for testing the impact of gene disruption on biofilm formation, studying the impact of anti-infectives, examining the biology of mixed Candida-oral bacterial flora biofilm infections, and characterizing the host immunologic response to this disease process.

Oesophageal candidiasis in elderly patients: risk factors, prevention and management

This article reviews risk factors, prevention and management of oesophageal candidiasis (OC) in the elderly. Putative risk factors for OC in the elderly include old age itself, malignant disease, antibacterial and corticosteroid use, chronic obstructive pulmonary disease, acid suppression treatment, oesophageal dysmotility and other local factors, diabetes mellitus and HIV/AIDS. We have found evidence for a risk association between OC in the elderly and malignant disease (both haematological and non-haematological), antibacterial therapy and corticosteroid (including inhaled corticosteroids) use. We also found evidence of an association between OC in the elderly and oesophageal dysmotility or HIV/AIDS, but little direct evidence of an association between diabetes or old age per se. The literature on OC in the elderly is not large. The published series evaluating OC in this age group are small in size, often do not contain controls and mostly contain only limited information about the age of the patients. Prevention of OC is mainly the avoidance of exposure to the risk factors wherever possible. Specific measures such as highly active antiretroviral therapy in AIDS, prophylactic fluconazole when receiving chemotherapy for malignancy, using spacing devices, mouth rinsing soon after inhalation of corticosteroids and avoiding the use of cortiocosteroids just before bedtime are useful. OC is often responsive to a 2- to 3-week course of oral fluconazole, but resistance may be encountered in AIDS or in the presence of uncorrected anatomical factors in the oesophagus. Itraconazole solution, voriconazole or caspofungin may be used in refractory cases. Use of amphotericin B is restricted because of its narrow therapeutic index.