scholarly journals Biofilm Formed by Candida haemulonii Species Complex: Structural Analysis and Extracellular Matrix Composition

2020 ◽  
Vol 6 (2) ◽  
pp. 46 ◽  
Author(s):  
Lívia S. Ramos ◽  
Thaís P. Mello ◽  
Marta H. Branquinha ◽  
André L. S. Santos
Keyword(s):  
Extracellular Matrix ◽  
Species Complex ◽  
Multidrug Resistant ◽  
Matrix Composition ◽  
Candida Spp ◽  
Candida Haemulonii ◽  
Complex Structural ◽  
Main Components ◽  
Inert Surfaces ◽  
Virulence Attribute

Candida haemulonii species complex (C. haemulonii, C. duobushaemulonii, and C. haemulonii var. vulnera) has emerged as opportunistic, multidrug-resistant yeasts able to cause fungemia. Previously, we showed that C. haemulonii complex formed biofilm on polystyrene. Biofilm is a well-known virulence attribute of Candida spp. directly associated with drug resistance. In the present study, the architecture and the main extracellular matrix (ECM) components forming the biofilm over polystyrene were investigated in clinical isolates of the C. haemulonii complex. We also evaluated the ability of these fungi to form biofilm on catheters used in medical arena. The results revealed that all fungi formed biofilms on polystyrene after 48 h at 37 °C. Microscopic analyses demonstrated a dense network of yeasts forming the biofilm structure, with water channels and ECM. Regarding ECM, proteins and carbohydrates were the main components, followed by nucleic acids and sterols. Mature biofilms were also detected on late bladder (siliconized latex), nasoenteric (polyurethane), and nasogastric (polyvinyl chloride) catheters, with the biomasses being significantly greater than on polystyrene. Collectively, our results demonstrated the ability of the C. haemulonii species complex to form biofilm on different types of inert surfaces, which is an incontestable virulence attribute associated with devices-related candidemia in hospitalized individuals.

scholarly journals Increasing Prevalence of Multidrug-Resistant Candida haemulonii Species Complex among All Yeast Cultures Collected by a Reference Laboratory over the Past 11 Years

2020 ◽  
Vol 6 (3) ◽  
pp. 110 ◽  
Author(s):  
Soraia Lopes Lima ◽  
Elaine Cristina Francisco ◽  
João Nóbrega de Almeida Júnior ◽  
Daniel Wagner de Castro Lima Santos ◽  
Fabiane Carlesse ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Species Complex ◽  
Antifungal Susceptibility ◽  
Its Region ◽  
Multidrug Resistant ◽  
Sensu Stricto ◽  
Culture Collection ◽  
Reference Laboratory ◽  
Yeast Cultures ◽  
Candida Haemulonii

There is worldwide concern with the increasing rates of infections due to multiresistant Candida isolates reported in tertiary medical centers. We checked for historical trends in terms of prevalence rates and antifungal susceptibility of the Candida haemulonii species complex in our yeast stock culture collected during the last 11 years. The isolates were identified by sequencing the rDNA internal transcribed spacer (ITS) region, and antifungal susceptibility tests for amphotericin B, voriconazole, fluconazole, anidulafungin, and 5-fluorocytosine were performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method. A total of 49 isolates were identified as Candida haemulonii sensu stricto (n = 21), followed by C. haemulonii var. vulnera (n = 15) and C. duobushaemulonii (n = 13), including 38 isolates cultured from patients with deep-seated Candida infections. The prevalence of the C. haemulonii species complex increased from 0.9% (18 isolates among 1931) in the first period (December 2008 to June 2013) to 1.7% (31 isolates among 1868) in the second period (July 2014 to December 2019) of analysis (p = 0.047). All isolates tested exhibited high minimum inhibition concentrations for amphotericin B and fluconazole, but they remained susceptible to 5-fluorocytosine and anidulafungin. We were able to demonstrate the increased isolation of the multiresistant Candida haemulonii species complex in our culture collection, where most isolates were cultured from patients with deep-seated infections.

scholarly journals Insights into the Multi-Azole Resistance Profile in Candida haemulonii Species Complex

2020 ◽  
Vol 6 (4) ◽  
pp. 215
Author(s):  
Laura Nunes Silva ◽  
Lívia de Souza Ramos ◽  
Simone Santiago Carvalho Oliveira ◽  
Lucas Barros Magalhães ◽  
Eamim Daidrê Squizani ◽  
...  
Keyword(s):  
Species Complex ◽  
Fungal Pathogens ◽  
Rhodamine 6G ◽  
Efflux Pump ◽  
Antifungal Susceptibility ◽  
Cross Resistance ◽  
Azole Resistance ◽  
Candida Spp ◽  
Resistance Profile ◽  
Candida Haemulonii

The Candida haemulonii complex (C. duobushaemulonii, C. haemulonii, and C. haemulonii var. vulnera) is composed of emerging, opportunistic human fungal pathogens able to cause invasive infections with high rates of clinical treatment failure. This fungal complex typically demonstrates resistance to first-line antifungals, including fluconazole. In the present work, we have investigated the azole resistance mechanisms expressed in Brazilian clinical isolates forming the C. haemulonii complex. Initially, 12 isolates were subjected to an antifungal susceptibility test, and azole cross-resistance was detected in almost all isolates (91.7%). In order to understand the azole resistance mechanistic basis, the efflux pump activity was assessed by rhodamine-6G. The C. haemulonii complex exhibited a significantly higher rhodamine-6G efflux than the other non-albicans Candida species tested (C. tropicalis, C. krusei, and C. lusitaneae). Notably, the efflux pump inhibitors (Phe-Arg and FK506) reversed the fluconazole and voricolazole resistance phenotypes in the C. haemulonii species complex. Expression analysis indicated that the efflux pump (ChCDR1, ChCDR2, and ChMDR1) and ERG11 genes were not modulated by either fluconazole or voriconazole treatments. Further, ERG11 gene sequencing revealed several mutations, some of which culminated in amino acid polymorphisms, as previously reported in azole-resistant Candida spp. Collectively, these data point out the relevance of drug efflux pumps in mediating azole resistance in the C. haemulonii complex, and mutations in ERG11p may contribute to this resistance profile.

Surface, adhesiveness and virulence aspects of Candida haemulonii species complex

2020 ◽  
Vol 58 (7) ◽  
pp. 973-986 ◽  
Author(s):  
Lívia S Ramos ◽  
Simone S C Oliveira ◽  
Laura N Silva ◽  
Marcela Q Granato ◽  
Diego S Gonçalves ◽  
...  
Keyword(s):  
Species Complex ◽  
Galleria Mellonella ◽  
Fungal Infections ◽  
Neutral Lipids ◽  
Clinical Manifestations ◽  
Cell Surface Hydrophobicity ◽  
Candida Spp ◽  
Murine Macrophages ◽  
Candida Haemulonii

Abstract The emerging opportunistic pathogens comprising the Candida haemulonii complex (C. haemulonii [Ch], C. duobushaemulonii [Cd] and C. haemulonii var. vulnera[Chv]) are notable for their intrinsic antifungal resistance. Different clinical manifestations are associated with these fungal infections; however, little is known about their biology and potential virulence attributes. Herein, we evaluated some surface properties of 12 clinical isolates of Ch (n = 5), Cd (n = 4) and Chv (n = 3) as well as their virulence on murine macrophages and Galleria mellonella larvae. Scanning electron microscopy demonstrated the presence of homogeneous populations among the species of the C. haemulonii complex, represented by oval yeasts with surface irregularities able to form aggregates. Cell surface hydrophobicity was isolate-specific, exhibiting high (16.7%), moderate (25.0%) and low (58.3%) hydrophobicity. The isolates had negative surface charge, except for one. Mannose/glucose- and N-acetylglucosamine-containing glycoconjugates were evidenced in considerable amounts in all isolates; however, the surface expression of sialic acid was poorly detected. Cd isolates presented significantly higher amounts of chitin than Ch and Chv. Membrane sterol and lipid bodies, containing neutral lipids, were quite similar among all fungi studied. All isolates adhered to inert surfaces in the order: polystyrene > poly-L-lysine-coated glass > glass. Likewise, they interacted with murine macrophages in a quite similar way. Regarding in vivo virulence, the C. haemulonii species complex were able to kill at least 80% of the larvae after 120 hours. Our results evidenced the ability of C. haemulonii complex to produce potential surface-related virulence attributes, key components that actively participate in the infection process described in Candida spp.

scholarly journals Origins, potency, and heterogeneity of skeletal muscle fibro-adipogenic progenitors—time for new definitions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Osvaldo Contreras ◽  
Fabio M. V. Rossi ◽  
Marine Theret
Keyword(s):  
Extracellular Matrix ◽  
Muscle Development ◽  
Striated Muscle ◽  
Body Movement ◽  
Well Being ◽  
Lineage Tracing ◽  
Extracellular Matrix Components ◽  
Main Components ◽  
Muscle Homeostasis ◽  
Activated Fibroblasts

AbstractStriated muscle is a highly plastic and regenerative organ that regulates body movement, temperature, and metabolism—all the functions needed for an individual’s health and well-being. The muscle connective tissue’s main components are the extracellular matrix and its resident stromal cells, which continuously reshape it in embryonic development, homeostasis, and regeneration. Fibro-adipogenic progenitors are enigmatic and transformative muscle-resident interstitial cells with mesenchymal stem/stromal cell properties. They act as cellular sentinels and physiological hubs for adult muscle homeostasis and regeneration by shaping the microenvironment by secreting a complex cocktail of extracellular matrix components, diffusible cytokines, ligands, and immune-modulatory factors. Fibro-adipogenic progenitors are the lineage precursors of specialized cells, including activated fibroblasts, adipocytes, and osteogenic cells after injury. Here, we discuss current research gaps, potential druggable developments, and outstanding questions about fibro-adipogenic progenitor origins, potency, and heterogeneity. Finally, we took advantage of recent advances in single-cell technologies combined with lineage tracing to unify the diversity of stromal fibro-adipogenic progenitors. Thus, this compelling review provides new cellular and molecular insights in comprehending the origins, definitions, markers, fate, and plasticity of murine and human fibro-adipogenic progenitors in muscle development, homeostasis, regeneration, and repair.

scholarly journals Susceptibility of the Candida haemulonii Complex to Echinocandins: Focus on Both Planktonic and Biofilm Life Styles and a Literature Review

2020 ◽  
Vol 6 (4) ◽  
pp. 201
Author(s):  
Lívia S. Ramos ◽  
Laura N. Silva ◽  
Marta H. Branquinha ◽  
André L. S. Santos
Keyword(s):  
Literature Review ◽  
Therapeutic Potential ◽  
Multidrug Resistant ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Published Data ◽  
Life Styles ◽  
Fungal Isolates ◽  
Candida Haemulonii ◽  
Almost All

Candida haemulonii complex (C. haemulonii, C. duobushaemulonii and C. haemulonii var. vulnera) is well-known for its resistance profile to different available antifungal drugs. Although echinocandins are the most effective class of antifungal compounds against the C. haemulonii species complex, clinical isolates resistant to caspofungin, micafungin and anidulafungin have already been reported. In this work, we present a literature review regarding the effects of echinocandins on this emergent fungal complex. Published data has revealed that micafungin and anidulafungin were more effective than caspofungin against the species forming the C. haemulonii complex. Subsequently, we investigated the susceptibilities of both planktonic and biofilm forms of 12 Brazilian clinical isolates of the C. haemulonii complex towards caspofungin and micafungin (anidulafungin was unavailable). The planktonic cells of all the fungal isolates were susceptible to both of the test echinocandins. Interestingly, echinocandins caused a significant reduction in the biofilm metabolic activity (viability) of almost all fungal isolates (11/12, 91.7%). Generally, the biofilm biomasses were also affected (reduction range 20–60%) upon exposure to caspofungin and micafungin. This is the first report of the anti-biofilm action of echinocandins against the multidrug-resistant opportunistic pathogens comprising the C. haemulonii complex, and unveils the therapeutic potential of these compounds.

scholarly journals Multiscale molecular profiling of pathological bone resolves sexually dimorphic control of extracellular matrix composition

2021 ◽  
Vol 14 (3) ◽  
pp. dmm048116 ◽  
Author(s):  
Aikta Sharma ◽  
Alice Goring ◽  
Peter B. Johnson ◽  
Roger J. H. Emery ◽  
Eric Hesse ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Collagen Fibre ◽  
Matrix Composition ◽  
Label Free ◽  
Fibre Number ◽  
Backscattered Electron ◽  
Matrix Mineralisation

ABSTRACTCollagen assembly during development is essential for successful matrix mineralisation, which determines bone quality and mechanocompetence. However, the biochemical and structural perturbations that drive pathological skeletal collagen configuration remain unclear. Deletion of vascular endothelial growth factor (VEGF; also known as VEGFA) in bone-forming osteoblasts (OBs) induces sex-specific alterations in extracellular matrix (ECM) conformation and mineralisation coupled to vascular changes, which are augmented in males. Whether this phenotypic dimorphism arises as a result of the divergent control of ECM composition and its subsequent arrangement is unknown and is the focus of this study. Herein, we used murine osteocalcin-specific Vegf knockout (OcnVEGFKO) and performed ex vivo multiscale analysis at the tibiofibular junction of both sexes. Label-free and non-destructive polarisation-resolved second-harmonic generation (p-SHG) microscopy revealed a reduction in collagen fibre number in males following the loss of VEGF, complemented by observable defects in matrix organisation by backscattered electron scanning electron microscopy. This was accompanied by localised divergence in collagen orientation, determined by p-SHG anisotropy measurements, as a result of OcnVEGFKO. Raman spectroscopy confirmed that the effect on collagen was linked to molecular dimorphic VEGF effects on collagen-specific proline and hydroxyproline, and collagen intra-strand stability, in addition to matrix carbonation and mineralisation. Vegf deletion in male and female murine OB cultures in vitro further highlighted divergence in genes regulating local ECM structure, including Adamts2, Spp1, Mmp9 and Lama1. Our results demonstrate the utility of macromolecular imaging and spectroscopic modalities for the detection of collagen arrangement and ECM composition in pathological bone. Linking the sex-specific genetic regulators to matrix signatures could be important for treatment of dimorphic bone disorders that clinically manifest in pathological nano- and macro-level disorganisation.This article has an associated First Person interview with the first author of the paper.

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