Superficial Mucosal Infections Research Articles

The bacillithiol pathway is required for biofilm formation in Staphylococcus aureus

Staphylococcus aureus is a major human pathogen that can cause infections that range from superficial skin and mucosal infections to life threatening disseminated infections. S. aureus can attach to medical devices and host tissues and form biofilms that allow the bacteria to evade the host immune system and provide protection from antimicrobial agents. To counter host-generated oxidative and nitrosative stress mechanisms that are part of the normal host responses to invading pathogens, S. aureus utilizes low molecular weight (LMW) thiols, such as bacillithiol (BSH). Additionally, S. aureus synthesizes its own nitric oxide (NO), which combined with its downstream metabolites may also protect the bacteria against specific host responses. We have previously shown that LMW thiols are required for biofilm formation in Mycobacterium smegmatis and Pseudomonas aeruginosa. Here, we show that the S. aureus bshC mutant strain, which is defective in the last step of the BSH pathway and lacks BSH, is impaired in biofilm formation. We also identify a possible S-nitrosobacillithiol reductase (BSNOR), similar in sequence to an S-nitrosomycothiol reductase found in M. smegmatis and show that the putative S. aureus bsnoR mutant strain has reduced levels of BSH and decreased biofilm formation. Our studies also show that NO plays an important role in biofilm formation and that acidified sodium nitrite severely reduces biofilm thickness. These studies provide insight into the roles of oxidative and nitrosative stress mechanisms on biofilm formation and indicate that BSH and NO are key players in normal biofilm formation in S. aureus.

Fluconazole resistance in non-albicans Candida species in the United States, 2012-2021

Background:Candida spp can cause a variety of infections known as candidiasis, ranging from severe invasive infections to superficial mucosal infections of the mouth and vagina. Fluconazole, a triazole antifungal, is commonly prescribed to treat candidiasis but increasing fluconazole resistance is a growing concern for several Candida spp. Although C. albicans has historically been the most common cause of candidiasis, other species are increasingly common and antifungal resistance is more prevalent in these non-albicans species, including C. glabrata, C. parapsilosis, and C. tropicalis, which were the focus of this analysis. Methods: We used the PINC AI healthcare data (PHD) database to examine fluconazole resistance for inpatient isolates between 2012 and 2021 from 187 US acute-care hospitals with at least 1 Candida spp culture with a fluconazole susceptibility result over the entire period. We calculated annual percentage fluconazole resistance for C. glabrata, C. tropicalis, and C. parapsilosis isolates using the clinical laboratory interpretation for resistance. Results: We identified 4,264 C. glabrata, 2,482 C. parapsilosis, and 2,283 C. tropicalis isolates between 2012 and 2021 with susceptibility results. The percentage of C. glabrata isolates resistant to fluconazole doubled between 2020 and 2021 (14.6% vs 29.3%) (Fig. 1a). The percentage of C. parapsilosis isolates resistant to fluconazole steadily increased since 2017 (Fig. 1b), with an 82% increase in 2021 compared with 2020 (3.8% in 2020 vs 6.9% in 2021). Fluconazole resistance among C. tropicalis isolates varied over the years, with a 0.3% decrease in 2021 from 2020 (Fig. 1c). Of hospitals reporting at least 1 result each year 2020–2021, 44% observed an increase in the proportion of C. glabrata isolates resistant to fluconazole in 2021 compared to 2020. Conclusions: Our analysis highlights a concerning increase in fluconazole resistance among C. glabrata and C. parapsilosis isolates in 2021 compared with previous years. Further investigation of the observed increases in fluconazole resistance among these Candida spp could provide further insight on potential drivers of resistance or limitations in reported results from large databases. More analyses are needed to understand rates, sites of Candida infections, and risk factors (eg, antifungal exposure) associated with resistance.Disclosures: None

Competitiveness during Dual-Species Biofilm Formation of Fusarium oxysporum and Candida albicans and a Novel Treatment Strategy.

During an infection, a single or multispecies biofilm can develop. Infections caused by non-dermatophyte molds, such as Fusarium spp. and yeasts, such as Candida spp., are particularly difficult to treat due to the formation of a mixed biofilm of the two species. Fusarium oxysporum is responsible for approximately 20% of human fusariosis, while Candida albicans is responsible for superficial mucosal and dermal infections and for disseminated bloodstream infections with a mortality rate above 40%. This study aims to investigate the interactions between C. albicans and F. oxysporum dual-species biofilm, considering variable formation conditions. Further, the ability of the WMR peptide, a modified version of myxinidin, to eradicate the mixed biofilm when used alone or in combination with fluconazole (FLC) was tested, and the efficacy of the combination of WMR and FLC at low doses was assessed, as well as its effect on the expression of some biofilm-related adhesin and hyphal regulatory genes. Finally, in order to confirm our findings in vivo and explore the synergistic effect of the two drugs, we utilized the Galleria mellonella infection model. We concluded that C. albicans negatively affects F. oxysporum growth in mixed biofilms. Combinatorial treatment by WMR and FLC significantly reduced the biomass and viability of both species in mature mixed biofilms, and these effects coincided with the reduced expression of biofilm-related genes in both fungi. Our results were confirmed in vivo since the synergistic antifungal activity of WMR and FLC increased the survival of infected larvae and reduced tissue invasion. These findings highlight the importance of drug combinations as an alternative treatment for C. albicans and F. oxysporum mixed biofilms.

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

ABSTRACTThe 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.

Candida auris: the most talked about multidrug-resistant emerging fungal pathogen

Currently Candida auris is the most talked about multidrug-resistant emerging fungal pathogen. It can cause difficult-to-control nosocomial outbreaks worldwide, being highly contagious, and poses serious challenges to public health authorities. A wide spectrum of infections, ranging from superficial mucosal infections, candidemia to disseminated deep-seated disease, having been reported from more than 40 countries, including Australia. Outbreaks are associated with high mortality rates due to rapid transmission and challenges in prevention, control, and treatment. It is shows a high multidrug-resistance (with 90% of isolates resistant to fluconazole), and is extremely tolerant to conditions which usually limit fungal transmission, including commonly used disinfectants. Whole genome analysis has revealed five different closely related clades (named after the geographical areas they have been first encoundered) with distinct clonal lineages. Its environmental niche remained a mystery until recently when it was found in India in association with costal aquatic environments.

Prevalence of Candida infection in Covid-19 pandemic: A study from a tertiary care center in Central India

Background: Corona virus disease 2019 (COVID-19) infections may be associated with a wide range of bacterial and fungal co-infections. Candida and mucor are the common fungus encountered during this pandemic. Candida is one of the commonly encountered opportunistic fungi that cause superficial mucosal infections usually, but can invade tissue and produce life threatening infections. Candida species recognized as one of the major agent of hospital Acquired (nosocomial) fungal infections. Keeping this in background the current study was conducted. Aims and Objective: To estimate the prevalence of candida infection in tertiary care hospital of Indore. Materials and Methods: The present study was done in the period of one and half year. During this period all received clinical specimens like urine, sputum; high vaginal swab and pus suspected for fungal infection from Covid as well as non-Covid patients were processed according to standard protocol. The specimen was subjected to preliminary tests like wet mount, Gram’s stain, culture on sabourads dextrose agar (SDA) and Hichrome agar, germ tube test, sugar assimilation test and culture on Cornmeal agar (dalmau technique) for candida species were done. For statistical analysis Chi-square test was performed and p ≤ 0.05 was considered statistically significant. Results: The prevalence of Candidiasis was 0.86%. Non-albicans candida (65.9%) isolates was more than Candida albicans (34.07%). Among non-albicans species, C. tropicalis was 27.4% followed by C. glabrata 16.29%, C. krusei 15.55%,C. parapsilosis 5.92% and C. lusitenia 0.74% were the major isolates. Males were affected more than the females. In both the genders maximum patients were from the age group of >60 years. Maximum number of Candida isolates was from blood followed by urine, pus, sputum, vaginal swab and aural swab. Most common risk factors for candidiasis noted in this study was diabetes mellitus in both Covid as well as non-Covid patients. Conclusion: Non albicans candida are gradually increasing in India. Speciation of candida play an important role in preliminary treatment because different species is intrinsically resistant to different antifungal drugs and have different antifungal susceptibility pattern.

Predictive Nephrotoxicity Profiling of a Novel Antifungal Small Molecule in Comparison to Amphotericin B and Voriconazole.

Background and Purpose Candida albicans is the major fungal species associated with superficial mucosal infections such as oral candidiasis as well as systemic mycoses with high morbidity and mortality. On top of the rising drug resistance, currently available antifungal agents have significant adverse effects. Nephrotoxicity is the major treatment complication associated with antifungal agents.Recently, we discovered a novel antifungal small molecule SM21 with promising antifungal activity. The present study aimed to comparatively evaluate the in vivo and in vitro nephrotoxicity of SM21 comparing with Amphotericin B and voriconazole.Experimental ApproachNephrotoxicity of SM21 and its analogue were comparatively evaluated with Amphotericin B (AmB) and voriconazole. Immortalized human kidney proximal tubule epithelial cells (HK-2) were used for in vitro analysis of nephrotoxicity using cytotoxicity assays and qPCR gene expression analysis (Kim-1/HAVcr-1, CASP3). Sprague Dawley (SD) rat model was used to evaluate the nephrotoxicity in vivo using classical (SCr and BUN) and next-generation kidney injury urinary biomarkers (Kim-1, CLU, ALB, NGAL, β2M, and Cys C) alongside histopathological and immunohistochemical standards.Key ResultsAmB treatment showed a stronger cytotoxic impact on HK-2 viability and gene expression of cell death markers (Kim-1/HAVcr-1, CASP3) compared with SM21 and SM21 analogue in vitro (P < 0.01). In vivo data further demonstrated that SM21 did not significantly increase classical as well as novel nephrotoxic biomarkers, and minimal renal tubular necrosis and abnormalities were observed (15 mg kg−1 BW/day).Conclusions and ImplicationsSM21 had a significantly better safety profile in terms of nephrotoxicity with no major tubular epithelial abnormalities observed in kidney cells and no augmentation of kidney injury biomarkers compared to AmB. Kim-1 and CLU were the most sensitive biomarkers for detection of AmB-induced kidney damage. Future clinical trials should consider inclusion of these novel biomarkers as early indicators of acute kidney injury in antifungal-induced nephrotoxicity.

Molecular and genetic basis of azole antifungal resistance in the opportunistic pathogenic fungus Candida albicans.

Candida albicans is an opportunistic yeast and the major human fungal pathogen in the USA, as well as in many other regions of the world. Infections with C. albicans can range from superficial mucosal and dermatological infections to life-threatening infections of the bloodstream and vital organs. The azole antifungals remain an important mainstay treatment of candidiasis and therefore the investigation and understanding of the evolution, frequency and mechanisms of azole resistance are vital to improving treatment strategies against this organism. Here the organism C. albicans and the genetic changes and molecular bases underlying the currently known resistance mechanisms to the azole antifungal class are reviewed, including up-regulated expression of efflux pumps, changes in the expression and amino acid composition of the azole target Erg11 and alterations to the organism's typical sterol biosynthesis pathways. Additionally, we update what is known about activating mutations in the zinc cluster transcription factor (ZCF) genes regulating many of these resistance mechanisms and review azole import as a potential contributor to azole resistance. Lastly, investigations of azole tolerance in C. albicans and its implicated clinical significance are reviewed.

Influenza A Reinfection in Sequential Human Challenge: Implications for Protective Immunity and "Universal" Vaccine Development.

Identification of correlates of protection against human influenza A virus infection is important in development of broadly protective ("universal") influenza vaccines. Certain assumptions underlie current vaccine developmental strategies, including that infection with a particular influenza A virus should offer long-term or lifelong protection against that strain, preventing reinfection. In this study we report observations made when 7 volunteers participated in sequential influenza challenge studies where they were challenged intranasally using the identical influenza A(H1N1)pdm09 virus approximately 1 year apart. We evaluate and describe the outcomes of these 7 rechallenge participants and discuss what these results may suggest about correlates of protection and development of more broadly protective influenza vaccines. Seven participants were enrolled in 2 viral challenge studies at 7.5- to 18.5-month intervals. Both challenge studies used the identical lot of influenza A (H1N1)pdm09 virus administered intranasally. We evaluated pre- and postchallenge hemagglutination inhibition, neuraminidase inhibition, and stalk antibody titers; peripheral blood leukocyte host gene expression response profiles; daily viral detection via nasal wash; and clinical signs and symptoms. At least 3 of 7 participants demonstrated confirmed laboratory evidence of sequential infection, with 5 of 7 demonstrating clinical evidence. The data presented in this report demonstrate that sequential infection with the identical influenza A virus can occur and suggest it may not be rare. These data raise questions about immune memory responses in an acute superficial respiratory mucosal infection and their implications in development of broadly protective influenza vaccines. Further investigation of these observations is warranted. NCT01646138; NCT01971255.

Candida glabrata: A Lot More Than Meets the Eye

Candida glabrata is an opportunistic human fungal pathogen that causes superficial mucosal and life-threatening bloodstream infections in individuals with a compromised immune system. Evolutionarily, it is closer to the non-pathogenic yeast Saccharomyces cerevisiae than to the most prevalent Candida bloodstream pathogen, C. albicans. C. glabrata is a haploid budding yeast that predominantly reproduces clonally. In this review, we summarize interactions of C. glabrata with the host immune, epithelial and endothelial cells, and the ingenious strategies it deploys to acquire iron and phosphate from the external environment. We outline various attributes including cell surface-associated adhesins and aspartyl proteases, biofilm formation and stress response mechanisms, that contribute to the virulence of C. glabrata. We further discuss how, C. glabrata, despite lacking morphological switching and secreted proteolytic activity, is able to disarm macrophage, dampen the host inflammatory immune response and replicate intracellularly.

Glabridin triggers over-expression of apoptosis inducing factor (AIF) gene in Candida albicans.

Background and Purpose: Candida albicans is a prevalent human fungal pathogen that can cause a wide spectrum of diseases, from superficial mucosal infections to systemic disorders, in patients with impaired immunity. Glabridin is a pyranoisoflavan originally extracted from root extract of Glycyrrhiza glabra. Glabridin can also mediate apoptosis in yeast cells by changing the mitochondrial membrane potential, activation of caspase-like proteases, and DNA cleavage. The aim of this study was to investigate the mechanism of action of glabridin in C. albicans.Materials and Methods: Candida albicans ATCC14053 was applied as the standard strain. Total RNA was extracted from the isolate under glabridin-treated and untreated conditions. To evaluate the alternations in the apoptosis inducing factor (AIF) gene expression, real-time polymerase chain reaction (real-time -PCR) was performed, and the obtained data were analyzed using REST software.Results: Expression of the AIF gene was represented as the ratio of expression relative to the reference gene. According to the REST® output, the expression of the AIF gene increased significantly (P<0.05) under the glabridin-treated condition.Conclusion:Our results suggested that glabridin may induce apoptosis through the caspase-independent route and might be considered as an anti-Candida agent.

Common Child and Adolescent Cutaneous Infestations and Fungal Infections

Cutaneous infections and infestations are common among children and adolescents. Ectoparasitic infestations affect individuals across the globe. Head lice, body lice, scabies, and infestations with bed bugs are seen in individuals who reside in both resource poor areas and in developed countries. Superficial cutaneous and mucosal candida infections occur throughout the life cycle. Dermatophyte infections of keratin-containing skin and skin structures result in tinea capitis (scalp), tinea corporis (body), tinea pedis (foot), and tinea unguium (nails). Less frequent endemic fungal infections such as blastomycosis, coccidiodomycosis, and histoplasmosis may present with skin findings. This article will describe the epidemiology and transmission of these conditions as well as their clinical manifestations. The approach to diagnosis will be addressed as well as primary prevention and current therapies.

Antifungal defense of probiotic Lactobacillus rhamnosus GG is mediated by blocking adhesion and nutrient depletion.

Candida albicans is an inhabitant of mucosal surfaces in healthy individuals but also the most common cause of fungal nosocomial blood stream infections, associated with high morbidity and mortality. As such life-threatening infections often disseminate from superficial mucosal infections we aimed to study the use of probiotic Lactobacillus rhamnosus GG (LGG) in prevention of mucosal C. albicans infections. Here, we demonstrate that LGG protects oral epithelial tissue from damage caused by C. albicans in our in vitro model of oral candidiasis. Furthermore, we provide insights into the mechanisms behind this protection and dissect direct and indirect effects of LGG on C. albicans pathogenicity. C. albicans viability was not affected by LGG. Instead, transcriptional profiling using RNA-Seq indicated dramatic metabolic reprogramming of C. albicans. Additionally, LGG had a significant impact on major virulence attributes, including adhesion, invasion, and hyphal extension, whose reduction, consequently, prevented epithelial damage. This was accompanied by glucose depletion and repression of ergosterol synthesis, caused by LGG, but also due to blocked adhesion sites. Therefore, LGG protects oral epithelia against C. albicans infection by preventing fungal adhesion, invasion and damage, driven, at least in parts, by metabolic reprogramming due to nutrient limitation caused by LGG.

An Antifungal Mechanism of Protolichesterinic Acid from the Lichen Usnea albopunctata Lies in the Accumulation of Intracellular ROS and Mitochondria-Mediated Cell Death Due to Apoptosis in Candida tropicalis

Candida species causes superficial and life-threatening systemic infections and are difficult to treat due to the resistance of these organism to various clinically used drugs. Protolichesterinic acid is a well-known lichen compound. Although the antibacterial activity of protolichesterinic acid has been reported earlier, the antifungal property and its mechanism of action are still largely unidentified. The goal of the present investigation is to explore the anticandidal activity and mechanism of action of protolichesterinic acid, especially against Candida tropicalis. The Minimum Inhibitory Concentration (MIC) value was established through microdilution techniques against four Candida species and out of four species tested, C. tropicalis showed a significant effect (MIC: 2 μg/ml). In the morphological interference assay, we observed the enhanced inhibition of hyphae when the cells were treated with protolichesterinic acid. Time-kill assay demonstrated that the maximum rate of killing was recorded between 2 and 6 h. C. tropicalis exposed to protolichesterinic acid exhibited an increased ROS production, which is one of the key factors of fungal death. The rise in ROS was due to the dysfunction of mitochondria caused by protolichesterinic acid. We confirmed that protolichesterinic acid-induced dysfunction of mitochondria in C. tropicalis. The damage of cell membrane due to protolichesterinic acid treatment was confirmed by the influx of propidium iodide and was further confirmed by the release of potassium ions. The treatment of protolichesterinic acid also triggered calcium ion signaling. Moreover, it commenced apoptosis which is clearly evidenced by Annexin V and propidium iodide staining. Interestingly protolichesterinic acid recorded excellent immunomodulatory property when tested against lymphocytes. Finally protolichesterinic acid showed low toxicity toward a normal human cell line Foreskin (FS) normal fibroblast. In in vivo test, protolichesterinic acid significantly enhanced the survival of C. tropicalis infected Caenorhabditis elegans. This investigation proposes that the protolichesterinic acid induces apoptosis in C. tropicalis via the enhanced accumulation of intracellular ROS and mitochondrial damage, which leads fungal cell death via apoptosis. Our work revealed a new key aspect of mechanisms of action of protolichesterinic acid in Candida species. This article is the first study on the antifungal and mechanism of action of protolichesterinic acid in Candida species.

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions.

ABSTRACT The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host’s arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival.

Synergistic Effects and Mechanisms of Budesonide in Combination with Fluconazole against Resistant Candida albicans.

Candida albicans is an important opportunistic pathogen, causing both superficial mucosal infections and life-threatening systemic diseases in the clinic. The emergence of drug resistance in Candida albicans has become a noteworthy phenomenon due to the extensive use of antifungal agents and the development of biofilms. This study showed that budesonide potentiates the antifungal effect of fluconazole against fluconazole-resistant Candida albicans strains both in vitro and in vivo. In addition, our results demonstrated, for the first time, that the combination of fluconazole and budesonide can reverse the resistance of Candida albicans by inhibiting the function of drug transporters, reducing the formation of biofilms, promoting apoptosis and inhibiting the activity of extracellular phospholipases. This is the first study implicating the effects and mechanisms of budesonide against Candida albicans alone or in combination with fluconazole, which may ultimately lead to the identification of new potential antifungal targets.

Water quality and antifungal susceptibility of opportunistic yeast pathogens from rivers.

Yeasts from water sources have been associated with diseases ranging from superficial mucosal infections to life threatening diseases. The aim of this study was to determine the water quality as well as diversity and antifungal susceptibility of yeasts from two rivers. Yeast levels and physico-chemical parameter data were analyzed by principal component analysis to determine correlations between physico-chemical data and yeast levels. Yeast morphotypes were identified by biochemical tests and 26S rRNA gene sequencing. Disk diffusion antifungal susceptibility tests were conducted. Physico-chemical parameters of the water were within target water quality range (TWQR) for livestock farming. For irrigational use, total dissolved solids and nitrates were not within the TWQR. Yeast levels ranged between 27 ± 10 and 2,573 ± 306 cfu/L. Only non-pigmented, ascomycetous yeasts were isolated. Saccharomyces cerevisiae and Candida glabrata were most frequently isolated. Several other opportunistic pathogens were also isolated. A large number of isolates were resistant to azoles, especially fluconazole, but also to other antifungal classes. Candida species were resistant to almost all the antifungal classes. These water sources are used for recreation and religious as well as for watering livestock and irrigation. Of particular concern is the direct contact of individuals with opportunistic yeast, especially the immune-compromised. Resistance of these yeast species to antifungal agents is a further health concern.

Transcriptomics Analysis of Candida albicans Treated with Huanglian Jiedu Decoction Using RNA-seq.

Candida albicans is the major invasive fungal pathogen of humans, causing diseases ranging from superficial mucosal infections to disseminated, systemic infections that are often life-threatening. Resistance of C. albicans to antifungal agents and limited antifungal agents has potentially serious implications for management of infections. As a famous multiherb prescription in China, Huanglian Jiedu Decoction (HLJJD, Orengedokuto in Japan) is efficient against Trichophyton mentagrophytes and C. albicans. But the antifungal mechanism of HLJDD remains unclear. In this study, by using RNA-seq technique, we performed a transcriptomics analysis of gene expression changes for C. albicans under the treatment of HLJDD. A total of 6057 predicted protein-encoding genes were identified. By gene expression analysis, we obtained a total of 735 differentially expressed genes (DEGs), including 700 upregulated genes and 35 downregulated genes. Genes encoding multidrug transporters such as ABC transporter and MFS transporter were identified to be significantly upregulated. Meanwhile, by pathway enrichment analysis, we identified 26 significant pathways, in which pathways of DNA replication and transporter activity were mainly involved. These results might provide insights for the inhibition mechanism of HLJDD against C. albicans.

Noninvasive Colonic Phaeohyphomycosis Caused by Exophiala Oligosperma in a Patient With Crohnʼs Disease

Introduction:Exophiala oligosperma is an uncommon fungal pathogen which can cause infection in immunocompromised patients. The majority of these infections are cutaneous, but fatal systemic infections have been reported. There are no reported cases of E. oligosperma causing colonic infection in the literature. To the best of our knowledge, this is a first reported case of an E. oligosperma induced non-invasive colonic phaeohyphomycosis in an immunocompromised patient with Crohn's disease treated successfully with voricanozole. Case Report: A 27 year old female with Crohn's disease on adalimumab and prednisone presented with persistent fever for three weeks. Index Crohn's symptoms were improving since initiation of adalimumab but diarrhea continued. The patient had no abdominal tenderness. Labs were remarkable for only mild anemia. After extensive work up, only colitis was noted on an abdominal computed tomography (CT) scan. A colonoscopy was done to attempt to further assess source of fever which showed worsened sigmoid colitis with pseudopolyps. Random biopsies showed inflammation. Multiple tissue samples cultured grew black mold with speciation consistent with E. oligosperma. Tissue biopsies did not show invasive fungal elements. Adalimumab was discontinued and patient was started on voricanozole. Fever resolved and the patient reported improvement in diarrhea after starting antifungal therapy. Discussion:E. oligosperma is a fungal strain that was indentified in 2003 by de Hoog et al.There are only six reported cases of phaeohyphomycosis associated with E. oligosperma in the literature. Cutaneous infections are more common with this pathogen but invasive infections are reported, including prosthetic valve endocarditis, dialysis-associated peritonitis, and disseminated infections. We describe a case of noninvasive colonic phaeohyphomycosis associated with E. oligosperma manifested by fever and gastrointestinal symptoms. Gross appearance of colon mucosa can look inflamed or darkly pigmented. Tissue culture is often needed for diagnosis. Histological finding of granulation suggests invasive infection. Superficial colonic mucosal infection can be treated with voricanozole; however, invasive phaeohyphomycosis usually requires surgical resection.

Dressed to impress: impact of environmental adaptation on the Candida albicans cell wall.

Summary C andida albicans is an opportunistic fungal pathogen of humans causing superficial mucosal infections and life‐threatening systemic disease. The fungal cell wall is the first point of contact between the invading pathogen and the host innate immune system. As a result, the polysaccharides that comprise the cell wall act as pathogen associated molecular patterns, which govern the host–pathogen interaction. The cell wall is dynamic and responsive to changes in the external environment. Therefore, the host environment plays a critical role in regulating the host–pathogen interaction through modulation of the fungal cell wall. This review focuses on how environmental adaptation modulates the cell wall structure and composition, and the subsequent impact this has on the innate immune recognition of C . albicans.