scholarly journals Trained Innate Immunity Induced by Vaccination with Low-Virulence Candida Species Mediates Protection against Several Forms of Fungal Sepsis via Ly6G + Gr-1 + Leukocytes

mBio ◽  
2021 ◽  
Author(s):  
Elizabeth A. Lilly ◽  
Breah E. Bender ◽  
Shannon Esher Righi ◽  
Paul L. Fidel ◽  
Mairi C. Noverr
Keyword(s):  
Innate Immunity ◽  
Candida Albicans ◽  
Bloodstream Infection ◽  
Candida Species ◽  
Content Type ◽  
Cytokine Responses ◽  
Fungal Sepsis ◽  
Intravenous Inoculation

Trained innate immunity (TII) is induced following immunization with live attenuated microbes and represents a clinically important strategy to enhance innate defenses. TII was initially demonstrated following intravenous inoculation with low-virulence Candida albicans , with protection against a subsequent lethal C. albicans intravenous bloodstream infection (BSI) mediated by monocytes with enhanced cytokine responses.

scholarly journals Fungemia Surveillance in Denmark Demonstrates Emergence of Non-albicans Candida Species and Higher Antifungal Usage and Resistance Rates than in Other Nations

2018 ◽  
Vol 56 (4) ◽  
pp. e01907-17 ◽  
Author(s):  
Mariana Castanheira
Keyword(s):  
Candida Albicans ◽  
Candida Species ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Fungal Species ◽  
Azole Resistance ◽  
Content Type ◽  
Fungal Organisms ◽  
Echinocandin Resistance ◽  
Resistance Rates

ABSTRACT Recent changes in the occurrence of fungal species and the difficulties in performing reference antifungal susceptibility testing highlight the importance of surveillance of fungal organisms and antifungal resistance rates. K. M. T. Astvad et al. report results from recent (2012 to 2015) fungemia surveillance in Denmark and compare the results to previous data (2004 to 2011), showing a decrease in Candida albicans infections accompanied by an increase in C. glabrata and C. dubliniensis infections (J Clin Microbiol 56:e01564-17, 2018, https://doi.org/10.1128/JCM.01564-17). Azole resistance among C. tropicalis and C. parapsilosis isolates and echinocandin resistance in C. krusei isolates were higher in Denmark than in other regions. Interestingly, the usage of antifungals is higher in Denmark than in other Nordic countries.

scholarly journals Myeloperoxidase is required for neutrophil extracellular trap formation: implications for innate immunity

Blood ◽  
2011 ◽  
Vol 117 (3) ◽  
pp. 953-959 ◽  
Author(s):  
Kathleen D. Metzler ◽  
Tobias A. Fuchs ◽  
William M. Nauseef ◽  
Dominique Reumaux ◽  
Joachim Roesler ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Candida Albicans ◽  
Host Defense ◽  
Candida Species ◽  
Neutrophil Extracellular Traps ◽  
Neutrophil Extracellular Trap ◽  
Extracellular Traps ◽  
Microbial Infections ◽  
Dependent Inhibition ◽  
Extracellular Trap

AbstractThe granule enzyme myeloperoxidase (MPO) plays an important role in neutrophil antimicrobial responses. However, the severity of immunodeficiency in patients carrying mutations in MPO is variable. Serious microbial infections, especially with Candida species, have been observed in a subset of completely MPO-deficient patients. Here we show that neutrophils from donors who are completely deficient in MPO fail to form neutrophil extracellular traps (NETs), indicating that MPO is required for NET formation. In contrast, neutrophils from partially MPO-deficient donors make NETs, and pharmacological inhibition of MPO only delays and reduces NET formation. Extracellular products of MPO do not rescue NET formation, suggesting that MPO acts cell-autonomously. Finally, NET-dependent inhibition of Candida albicans growth is compromised in MPO-deficient neutrophils. The inability to form NETs may contribute in part to the host defense defects observed in completely MPO-deficient individuals.

scholarly journals Intra- and Interlaboratory Agreement in Assessing theIn VitroActivity of Micafungin against Common and Rare Candida Species with the EUCAST, CLSI, and Etest Methods

2016 ◽  
Vol 60 (10) ◽  
pp. 6173-6178 ◽  
Author(s):  
J. Meletiadis ◽  
E. Geertsen ◽  
I. Curfs-Breuker ◽  
J. F. Meis ◽  
J. W. Mouton
Keyword(s):  
Candida Albicans ◽  
Candida Species ◽  
Continuous Monitoring ◽  
The Other ◽  
Interlaboratory Comparisons ◽  
Content Type ◽  
Resistant Strains ◽  
Resistance Rates ◽  
High Mics

ABSTRACTThe emergence of resistant strains among common and rareCandidaspecies necessitates continuous monitoring of thein vitrosusceptibilities of those isolates. We therefore assessed thein vitroactivities of micafungin against 1,099 molecularly identified isolates belonging to 5 common and 20 rareCandidaspecies by the EUCAST, CLSI, and Etest methods, assessing both the intralaboratory agreement and the interlaboratory agreement for two centers. The median micafungin EUCAST MICs were as follows, from the lowest to the highest: forCandida albicans, 0.004 mg/liter; forC. glabrata, 0.016 mg/liter; forC. tropicalis, 0.031 mg/liter; forC. krusei, 0.125 mg/liter; forC. parapsilosis, 2 mg/liter. Among rareCandidaspecies, high MICs were found forC. guilliermondii,C. lipolytica,C. orthopsilosis,C. metapsilosis, andC. fermentati.No resistant isolates were found by the CLSI method, whereas resistance rates of 1 to 2% were found by the EUCAST method. Overall, the EUCAST method resulted in MICs 1 to 2 dilutions higher than those found by the CLSI and Etest methods. The intra- and interlaboratory agreement between methods was >92%, except for the interlaboratory agreement between the EUCAST and CLSI methods (81%), where 17 to 31% of the differences were >2 2-fold dilutions forC. albicans,C. glabrata,C. tropicalis, and other rareCandidaspecies and <6% forC. parapsilosisandC. krusei. For the other interlaboratory comparisons, the EUCAST method resulted in higher MICs than the Etest method for all species, but <7% of these differences were >2 2-fold dilutions. Overall, the CLSI method resulted in lower MICs than the Etest method, with 11% of all isolates demonstrating >2 2-fold-dilution differences (6 to 20% forC. albicans,C. tropicalis, and rareCandidaspecies; <5% forC. glabrata,C. krusei, andC. parapsilosis) and smaller differences found after 24 h. Despite these differences, categorical agreement was excellent (>97%), with only 1 to 2% very major errors between the EUCAST method and the other two methods.

scholarly journals Interplay between Candida albicans and the Mammalian Innate Host Defense

2012 ◽  
Vol 80 (4) ◽  
pp. 1304-1313 ◽  
Author(s):  
Shih-Chin Cheng ◽  
Leo A. B. Joosten ◽  
Bart-Jan Kullberg ◽  
Mihai G. Netea
Keyword(s):  
Innate Immunity ◽  
Candida Albicans ◽  
Host Defense ◽  
High Mortality ◽  
Fungal Pathogen ◽  
Immunocompromised Patients ◽  
Healthy Individuals ◽  
Content Type ◽  
At Risk Populations ◽  
Host Innate Immunity

ABSTRACTCandida albicansis both the most common fungal commensal microorganism in healthy individuals and the major fungal pathogen causing high mortality in at-risk populations, especially immunocompromised patients. In this review, we summarize the interplay between the host innate system andC. albicans, ranging from how the host recognizes, responds, and clearsC. albicansinfection to howC. albicansevades, dampens, and escapes from host innate immunity.

scholarly journals Rate ofFKSMutations among Consecutive Candida Isolates Causing Bloodstream Infection

2015 ◽  
Vol 59 (12) ◽  
pp. 7465-7470 ◽  
Author(s):  
Ryan K. Shields ◽  
M. Hong Nguyen ◽  
Ellen G. Press ◽  
Richard Cumbie ◽  
Eileen Driscoll ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Bloodstream Infection ◽  
Hot Spots ◽  
Candida Glabrata ◽  
Susceptibility Testing ◽  
Mutation Rates ◽  
Broth Microdilution ◽  
Content Type ◽  
Clinical Breakpoints ◽  
Resistance Rates

ABSTRACTPreciseFKSmutation rates amongCandidaspecies are undefined because studies have not systematically screened consecutive, disease-causing isolates. The Sensititre YeastOne (SYO) assay measures echinocandin MICs againstCandidawith less variability than reference broth microdilution methods. However, clinical breakpoint MICs may overstate caspofungin nonsusceptibility compared to other agents. Our objectives were to determineCandidaFKSmutation rates by studying consecutive bloodstream isolates and to determine if discrepant susceptibility results were associated withFKSmutations.FKShot spots were sequenced in echinocandin-intermediate and -resistant isolates and those from patients with breakthrough candidemia or ≥3 days of prior echinocandin exposure. Overall, 453 isolates from 384 patients underwent susceptibility testing; 16% were echinocandin intermediate or resistant. Intermediate susceptibility rates were higher forCandida glabratathan for other species (P< 0.0001) and higher for caspofungin than for other agents (P< 0.0001). Resistance rates were similar between agents.FKSmutations were detected in 5% of sequenced isolates and 2% of isolates overall. Corresponding rates amongC. glabrataisolates were 8% and 4%, respectively. AmongCandida albicansisolates, rates were 5% and <1%, respectively. Mutations occurred exclusively with prior echinocandin exposure and were not detected in other species. Isolates with discrepant susceptibility results did not harborFKSmutations. Mutation rates among isolates resistant to ≥2, 1, and 0 agents were 75%, 13%, and 0%, respectively. In conclusion,FKSmutations were uncommon among non-C. glabrataspecies, even with prior echinocandin exposure. Discrepancies in echinocandin susceptibility by SYO testing were not driven by mutations and likely reflect imprecise caspofungin clinical breakpoints.

scholarly journals The Case for an Expanded Concept of Trained Immunity

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Antonio Cassone
Keyword(s):  
Innate Immunity ◽  
Candida Albicans ◽  
Epithelial Cells ◽  
Nk Cells ◽  
Inflammatory Diseases ◽  
Living Cells ◽  
Content Type ◽  
Trained Immunity ◽  
Innate Immunity Cells ◽  
Expanded Concept

ABSTRACTTrained immunity was originally proposed as a program of innate immunity memory by innate immunity cells of hematopoietic origin such as the monocytes/macrophages and the NK cells. Here I discuss some old and new data justifying this program and some specific, still unanswered, questions it raises regarding the model fungusCandida albicansand the chronic, inflammatory vulvovaginal disease it causes. Building upon this well-established program, the recent reports that epithelial cells of mammals can also acquire memory from previous stimulations, and the apparent intrinsic ability of many living cells from bacteria to mammals to learn from experience, I suggest an expansion of the concept of trained immunity to include all cells of different lineages with the potential of memorizing previous microbial encounters. This expansion would better fit the complexity of innate immunity and the role it plays in infectious and inflammatory diseases.

scholarly journals The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Danelle R. Weakland ◽  
Sara N. Smith ◽  
Bailey Bell ◽  
Ashootosh Tripathi ◽  
Harry L. T. Mobley
Keyword(s):  
Serratia Marcescens ◽  
Bloodstream Infection ◽  
Iron Acquisition ◽  
Gene Clusters ◽  
Clinical Isolates ◽  
Wild Type ◽  
Serratia Plymuthica ◽  
Content Type ◽  
Cas Assay ◽  
Essential Nutrient

ABSTRACT Serratia marcescens is a bacterium frequently found in the environment, but over the last several decades it has evolved into a concerning clinical pathogen, causing fatal bacteremia. To establish such infections, pathogens require specific nutrients; one very limited but essential nutrient is iron. We sought to characterize the iron acquisition systems in S. marcescens isolate UMH9, which was recovered from a clinical bloodstream infection. Using RNA sequencing (RNA-seq), we identified two predicted siderophore gene clusters (cbs and sch) that were regulated by iron. Mutants were constructed to delete each iron acquisition locus individually and in conjunction, generating both single and double mutants for the putative siderophore systems. Mutants lacking the sch gene cluster lost their iron-chelating ability as quantified by the chrome azurol S (CAS) assay, whereas the cbs mutant retained wild-type activity. Mass spectrometry-based analysis identified the chelating siderophore to be serratiochelin, a siderophore previously identified in Serratia plymuthica. Serratiochelin-producing mutants also displayed a decreased growth rate under iron-limited conditions created by dipyridyl added to LB medium. Additionally, mutants lacking serratiochelin were significantly outcompeted during cochallenge with wild-type UMH9 in the kidneys and spleen after inoculation via the tail vein in a bacteremia mouse model. This result was further confirmed by an independent challenge, suggesting that serratiochelin is required for full S. marcescens pathogenesis in the bloodstream. Nine other clinical isolates have at least 90% protein identity to the UMH9 serratiochelin system; therefore, our results are broadly applicable to emerging clinical isolates of S. marcescens causing bacteremia.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

scholarly journals Novel Aggregation Properties of Candida albicans Secreted Aspartyl Proteinase Sap6 Mediate Virulence in Oral Candidiasis

2015 ◽  
Vol 83 (7) ◽  
pp. 2614-2626 ◽  
Author(s):  
Rohitashw Kumar ◽  
Darpan Saraswat ◽  
Swetha Tati ◽  
Mira Edgerton
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Oral Candidiasis ◽  
Oral Microbiome ◽  
Proteinase Activity ◽  
Adhesion Properties ◽  
Content Type ◽  
Oral Epithelial Cells ◽  
Oral Epithelial ◽  
Cell Cell

Candida albicans, a commensal fungus of the oral microbiome, causes oral candidiasis in humans with localized or systemic immune deficiencies. Secreted aspartic proteinases (Saps) are a family of 10 related proteases and are virulence factors due to their proteolytic activity, as well as their roles in adherence and colonization of host tissues. We found that mice infected sublingually withC. albicanscells overexpressing Sap6 (SAP6OE and a Δsap8strain) had thicker fungal plaques and more severe oral infection, while infection with the Δsap6strain was attenuated. These hypervirulent strains had highly aggregative colony structurein vitroand higher secreted proteinase activity; however, the levels of proteinase activity ofC. albicansSaps did not uniformly match their abilities to damage cultured oral epithelial cells (SCC-15 cells). Hyphal induction in cells overexpressing Sap6 (SAP6OE and Δsap8cells) resulted in formation of large cell-cell aggregates. These aggregates could be produced in germinated wild-type cells by addition of native or heat-inactivated Sap6. Sap6 bound only to germinated cells and increasedC. albicansadhesion to oral epithelial cells. The adhesion properties of Sap6 were lost upon deletion of its integrin-binding motif (RGD) and could be inhibited by addition of RGD peptide or anti-integrin antibodies. Thus, Sap6 (but not Sap5) has an alternative novel function in cell-cell aggregation, independent of its proteinase activity, to promote infection and virulence in oral candidiasis.

scholarly journals Dectin-2-Targeted Antifungal Liposomes Exhibit Enhanced Efficacy

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Suresh Ambati ◽  
Emma C. Ellis ◽  
Jianfeng Lin ◽  
Xiaorong Lin ◽  
Zachary A. Lewis ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Aspergillus Fumigatus ◽  
Effective Dose ◽  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Antifungal Drugs ◽  
Extracellular Matrices ◽  
Content Type ◽  
Order Of Magnitude ◽  
Life Threatening

ABSTRACT Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus cause life-threatening candidiasis, cryptococcosis, and aspergillosis, resulting in several hundred thousand deaths annually. The patients at the greatest risk of developing these life-threatening invasive fungal infections have weakened immune systems. The vulnerable population is increasing due to rising numbers of immunocompromised individuals as a result of HIV infection or immunosuppressed individuals receiving anticancer therapies and/or stem cell or organ transplants. While patients are treated with antifungals such as amphotericin B, all antifungals have serious limitations due to lack of sufficient fungicidal effect and/or host toxicity. Even with treatment, 1-year survival rates are low. We explored methods of increasing drug effectiveness by designing fungicide-loaded liposomes specifically targeted to fungal cells. Most pathogenic fungi are encased in cell walls and exopolysaccharide matrices rich in mannans. Dectin-2 is a mammalian innate immune membrane receptor that binds as a dimer to mannans and signals fungal infection. We coated amphotericin-loaded liposomes with monomers of Dectin-2’s mannan-binding domain, sDectin-2. sDectin monomers were free to float in the lipid membrane and form dimers that bind mannan substrates. sDectin-2-coated liposomes bound orders of magnitude more efficiently to the extracellular matrices of several developmental stages of C. albicans, C. neoformans, and A. fumigatus than untargeted control liposomes. Dectin-2-coated amphotericin B-loaded liposomes reduced the growth and viability of all three species more than an order of magnitude more efficiently than untargeted control liposomes and dramatically decreased the effective dose. Future efforts focus on examining pan-antifungal targeted liposomal drugs in animal models of fungal diseases. IMPORTANCE Invasive fungal diseases caused by Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus have mortality rates ranging from 10 to 95%. Individual patient costs may exceed $100,000 in the United States. All antifungals in current use have serious limitations due to host toxicity and/or insufficient fungal cell killing that results in recurrent infections. Few new antifungal drugs have been introduced in the last 2 decades. Hence, there is a critical need for improved antifungal therapeutics. By targeting antifungal-loaded liposomes to α-mannans in the extracellular matrices secreted by these fungi, we dramatically reduced the effective dose of drug. Dectin-2-coated liposomes loaded with amphotericin B bound 50- to 150-fold more strongly to C. albicans, C. neoformans, and A. fumigatus than untargeted liposomes and killed these fungi more than an order of magnitude more efficiently. Targeting drug-loaded liposomes specifically to fungal cells has the potential to greatly enhance the efficacy of most antifungal drugs.

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