scholarly journals Effects of Echinocandins in Combination with Nikkomycin Z against Invasive Candida albicans Bloodstream Isolates and the fks Mutants

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Yuk-Yam Cheung ◽  
Mamie Hui
Keyword(s):  
Candida Albicans ◽  
Therapeutic Potential ◽  
Synergistic Effects ◽  
Rank Test ◽  
Content Type ◽  
Log Rank Test ◽  
Echinocandin Resistance ◽  
Nikkomycin Z

ABSTRACT We evaluated the in vitro and in vivo effects of nikkomycin Z combined with an echinocandin (anidulafungin or micafungin) against two Candida albicans isolates and their lab-derived echinocandin-resistant fks mutants with FKS1 S645Y and FKS1 S645P. Synergistic effects were observed in all tested strains (fractional inhibitory concentration index, <0.5). Enhanced survival was observed in an immunocompromised murine model (log-rank test, P < 0.02). Our study demonstrated the therapeutic potential of nikkomycin Z-echinocandin combinations in managing echinocandin resistance.

scholarly journals Elevated Cell Wall Chitin in Candida albicans Confers Echinocandin ResistanceIn Vivo

2011 ◽  
Vol 56 (1) ◽  
pp. 208-217 ◽  
Author(s):  
Keunsook K. Lee ◽  
Donna M. MacCallum ◽  
Mette D. Jacobsen ◽  
Louise A. Walker ◽  
Frank C. Odds ◽  
...  
Keyword(s):  
Weight Loss ◽  
Cell Wall ◽  
Candida Albicans ◽  
Point Mutations ◽  
Low Frequency ◽  
Normal Cells ◽  
Content Type ◽  
Echinocandin Resistance

ABSTRACTCandida albicanscells with increased cell wall chitin have reduced echinocandin susceptibilityin vitro. The aim of this study was to investigate whetherC. albicanscells with elevated chitin levels have reduced echinocandin susceptibilityin vivo. BALB/c mice were infected withC. albicanscells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully treated with caspofungin, as indicated by reduced kidney fungal burdens, reduced weight loss, and decreasedC. albicansdensity in kidney lesions. In contrast, mice infected with high-chitinC. albicanscells were less susceptible to caspofungin, as they had higher kidney fungal burdens and greater weight loss during early infection. Cells recovered from mouse kidneys at 24 h postinfection with high-chitin cells had 1.6-fold higher chitin levels than cells from mice infected with chitin-normal cells and maintained a significantly reduced susceptibility to caspofungin when testedin vitro. At 48 h postinfection, caspofungin treatment induced a further increase in chitin content ofC. albicanscells harvested from kidneys compared to saline treatment. Some of the recovered clones had acquired, at a low frequency, a point mutation inFKS1resulting in a S645Y amino acid substitution, a mutation known to confer echinocandin resistance. This occurred even in cells that had not been exposed to caspofungin. Our results suggest that the efficacy of caspofungin againstC. albicanswas reducedin vivodue to either elevation of chitin levels in the cell wall or acquisition ofFKS1point mutations.

scholarly journals The Synergistic Effect of Azoles and Fluoxetine against Resistant Candida albicans Strains Is Attributed to Attenuating Fungal Virulence

2016 ◽  
Vol 60 (10) ◽  
pp. 6179-6188 ◽  
Author(s):  
Wenrui Gu ◽  
Dongmei Guo ◽  
Liuping Zhang ◽  
Dongmei Xu ◽  
Shujuan Sun
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Synergistic Effects ◽  
Mechanism Study ◽  
Content Type ◽  
Expression Levels ◽  
Time Kill ◽  
Gene Expression Levels

ABSTRACTThis study evaluated the synergistic effects of the selective serotonin reuptake inhibitor, fluoxetine, in combination with azoles againstCandida albicansbothin vitroandin vivoand explored the underlying mechanism. MICs, sessile MICs, and time-kill curves were determined for resistantC. albicans.Galleria mellonellawas used as a nonvertebrate model for determining the efficacy of the drug combinations againstC. albicansin vivo. For the mechanism study, gene expression levels of theSAPgene family were determined by reverse transcription (RT)-PCR, and extracellular phospholipase activities were detectedin vitroby the egg yolk agar method. The combinations resulted in synergistic activity againstC. albicansstrains, but the same effect was not found for the non-albicans Candidastrains. For the biofilms formed over 4, 8, and 12 h, synergism was seen for the combination of fluconazole and fluoxetine. In addition, the time-kill curves confirmed the synergism dynamically. The results of theG. mellonellastudies agreed with thein vitroanalysis. In the mechanism study, we observed that fluconazole plus fluoxetine caused downregulation of the gene expression levels ofSAP1toSAP4and weakened the extracellular phospholipase activities of resistantC. albicans. The combinations of azoles and fluoxetine showed synergistic effects against resistantC. albicansmay diminish the virulence properties ofC. albicans.

scholarly journals ZN148 Is a Modular Synthetic Metallo-β-Lactamase Inhibitor That Reverses Carbapenem Resistance in Gram-Negative Pathogens In Vivo

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Ørjan Samuelsen ◽  
Ove Alexander Høgmoen Åstrand ◽  
Christopher Fröhlich ◽  
Adam Heikal ◽  
Susann Skagseth ◽  
...  
Keyword(s):  
Active Site ◽  
Therapeutic Potential ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Functional Space ◽  
Bactericidal Effect ◽  
Gram Negative ◽  
Content Type

ABSTRACT Carbapenem-resistant Gram-negative pathogens are a critical public health threat and there is an urgent need for new treatments. Carbapenemases (β-lactamases able to inactivate carbapenems) have been identified in both serine β-lactamase (SBL) and metallo-β-lactamase (MBL) families. The recent introduction of SBL carbapenemase inhibitors has provided alternative therapeutic options. Unfortunately, there are no approved inhibitors of MBL-mediated carbapenem-resistance and treatment options for infections caused by MBL-producing Gram-negatives are limited. Here, we present ZN148, a zinc-chelating MBL-inhibitor capable of restoring the bactericidal effect of meropenem and in vitro clinical susceptibility to carbapenems in >98% of a large international collection of MBL-producing clinical Enterobacterales strains (n = 234). Moreover, ZN148 was able to potentiate the effect of meropenem against NDM-1-producing Klebsiella pneumoniae in a murine neutropenic peritonitis model. ZN148 showed no inhibition of the human zinc-containing enzyme glyoxylase II at 500 μM, and no acute toxicity was observed in an in vivo mouse model with cumulative dosages up to 128 mg/kg. Biochemical analysis showed a time-dependent inhibition of MBLs by ZN148 and removal of zinc ions from the active site. Addition of exogenous zinc after ZN148 exposure only restored MBL activity by ∼30%, suggesting an irreversible mechanism of inhibition. Mass-spectrometry and molecular modeling indicated potential oxidation of the active site Cys221 residue. Overall, these results demonstrate the therapeutic potential of a ZN148-carbapenem combination against MBL-producing Gram-negative pathogens and that ZN148 is a highly promising MBL inhibitor that is capable of operating in a functional space not presently filled by any clinically approved compound.

scholarly journals The Novel Arylamidine T-2307 MaintainsIn VitroandIn VivoActivity against Echinocandin-Resistant Candida albicans

2014 ◽  
Vol 59 (2) ◽  
pp. 1341-1343 ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Laura K. Najvar ◽  
Annette W. Fothergill ◽  
Rosie Bocanegra ◽  
Marcos Olivo ◽  
...  
Keyword(s):  
Body Weight ◽  
Candida Albicans ◽  
Invasive Candidiasis ◽  
Placebo Control ◽  
The Novel ◽  
Content Type ◽  
Fungal Burden ◽  
Potential Use

ABSTRACTWe evaluated thein vitroandin vivoactivities of the investigational arylamidine T-2307 against echinocandin-resistantCandida albicans. T-2307 demonstrated potentin vitroactivity, and daily subcutaneous doses between 0.75 and 6 mg/kg of body weight significantly improved survival and reduced fungal burden compared to placebo control and caspofungin (10 mg/kg/day) in mice with invasive candidiasis caused by an echinocandin-resistant strain. Thus, T-2307 may have potential use in the treatment of echinocandin-resistantC. albicansinfections.

scholarly journals Antimicrobial Photodynamic Inactivation Inhibits Candida albicans Virulence Factors and ReducesIn VivoPathogenicity

2012 ◽  
Vol 57 (1) ◽  
pp. 445-451 ◽  
Author(s):  
Ilka Tiemy Kato ◽  
Renato Araujo Prates ◽  
Caetano Padial Sabino ◽  
Beth Burgwyn Fuchs ◽  
George P. Tegos ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Virulence Factors ◽  
Sodium Dodecyl ◽  
Systemic Infection ◽  
Tube Formation ◽  
Photodynamic Inactivation ◽  
Content Type ◽  
Daughter Cells

ABSTRACTThe objective of this study was to evaluate whetherCandida albicansexhibits altered pathogenicity characteristics following sublethal antimicrobial photodynamic inactivation (APDI) and if such alterations are maintained in the daughter cells.C. albicanswas exposed to sublethal APDI by using methylene blue (MB) as a photosensitizer (0.05 mM) combined with a GaAlAs diode laser (λ 660 nm, 75 mW/cm2, 9 to 27 J/cm2).In vitro, we evaluated APDI effects onC. albicansgrowth, germ tube formation, sensitivity to oxidative and osmotic stress, cell wall integrity, and fluconazole susceptibility.In vivo, we evaluatedC. albicanspathogenicity with a mouse model of systemic infection. Animal survival was evaluated daily. Sublethal MB-mediated APDI reduced the growth rate and the ability ofC. albicansto form germ tubes compared to untreated cells (P< 0.05). Survival of mice systemically infected withC. albicanspretreated with APDI was significantly increased compared to mice infected with untreated yeast (P< 0.05). APDI increasedC. albicanssensitivity to sodium dodecyl sulfate, caffeine, and hydrogen peroxide. The MIC for fluconazole forC. albicanswas also reduced following sublethal MB-mediated APDI. However, none of those pathogenic parameters was altered in daughter cells ofC. albicanssubmitted to APDI. These data suggest that APDI may inhibit virulence factors and reducein vivopathogenicity ofC. albicans. The absence of alterations in daughter cells indicates that APDI effects are transitory. The MIC reduction for fluconazole following APDI suggests that this antifungal could be combined with APDI to treatC. albicansinfections.

scholarly journals The Disruption of the β-Catenin/TCF-1/STAT3 Signaling Axis by 4-Acetylantroquinonol B Inhibits the Tumorigenesis and Cancer Stem-Cell-Like Properties of Glioblastoma Cells, In Vitro and In Vivo

Cancers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 491 ◽  
Author(s):  
Heng-Wei Liu ◽  
Yu-Kai Su ◽  
Oluwaseun Bamodu ◽  
Dueng-Yuan Hueng ◽  
Wei-Hwa Lee ◽  
...  
Keyword(s):  
Poor Prognosis ◽  
Migration And Invasion ◽  
Rank Test ◽  
Lower Grade ◽  
Aberrant Expression ◽  
Stat3 Signaling ◽  
Log Rank Test ◽  
Signaling Axis

Background: Glioblastoma (GBM), a malignant form of glioma, is characterized by resistance to therapy and poor prognosis. Accumulating evidence shows that the initiation, propagation, and recurrence of GBM is attributable to the presence of GBM stem cells (GBM-CSCs). Experimental approach: Herein, we investigated the effect of 4-Acetylantroquinonol B (4-AAQB), a bioactive isolate of Antrodia cinnamomea, on GBM cell viability, oncogenic, and CSCs-like activities. Results: We observed that aberrant expression of catenin is characteristic of GBM, compared to other glioma types (p = 0.0001, log-rank test = 475.2), and correlates with poor prognosis of GBM patients. Lower grade glioma and glioblastoma patients (n = 1152) with low catenin expression had 25% and 21.5% better overall survival than those with high catenin expression at the 5 and 10-year time-points, respectively (p = 3.57e-11, log-rank test = 43.8). Immunohistochemistry demonstrated that compared with adjacent non-tumor brain tissue, primary and recurrent GBM exhibited enhanced catenin expression (~10-fold, p < 0.001). Western blot analysis showed that 4-AAQB significantly downregulated β-catenin and dysregulated the catenin/LEF1/Stat3 signaling axis in U87MG and DBTRG-05MG cells, dose-dependently. 4-AAQB–induced downregulation of catenin positively correlated with reduced Sox2 and Oct4 nuclear expression in the cells. Furthermore, 4-AAQB markedly reduced the viability of U87MG and DBTRG-05MG cells with 48 h IC50 of 9.2 M and 12.5 M, respectively, effectively inhibited the nuclear catenin, limited the migration and invasion of GBM cells, with concurrent downregulation of catenin, vimentin, and slug; similarly, colony and tumorsphere formation was significantly attenuated with reduced expression of c-Myc and KLF4 proteins. Conclusions: Summarily, we show for the first time that 4-AAQB suppresses the tumor-promoting catenin/LEF1/Stat3 signaling, and inhibited CSCs-induced oncogenic activities in GBM in vitro, with in vivo validation; thus projecting 4-AAQB as a potent therapeutic agent for anti-GBM target therapy.

scholarly journals In VitroandIn VivoActivities of Zinc Linolenate, a Selective Antibacterial Agent againstHelicobacter pylori

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Yanqiang Huang ◽  
Xudong Hang ◽  
Xueqing Jiang ◽  
Liping Zeng ◽  
Jia Jia ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Therapeutic Potential ◽  
Combined Therapy ◽  
Peptic Ulcers ◽  
Current Standard ◽  
Gastric Diseases ◽  
Content Type ◽  
H Pylori

ABSTRACTHelicobacter pyloriis a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment forH. pyloriinfection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment ofH. pyloriinfection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates ofH. pyloriin vitrowith no development of resistance during continuous serial passaging. The mechanisms of ZnLla action againstH. pyloriinvolved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistantH. pyloriinfection, ZnLla showedin vivokilling efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla forH. pyloriprovides an attractive candidate for novel targeted anti-H. pyloritreatment.

scholarly journals Targeting Fibronectin To Disrupt In Vivo Candida albicans Biofilms

2016 ◽  
Vol 60 (5) ◽  
pp. 3152-3155 ◽  
Author(s):  
Jeniel E. Nett ◽  
Jonathan Cabezas-Olcoz ◽  
Karen Marchillo ◽  
Deane F. Mosher ◽  
David R. Andes
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Drug Targets ◽  
Venous Catheter ◽  
Surface Adhesion ◽  
Inhibitory Protein ◽  
Content Type ◽  
Novel Target

ABSTRACTNew drug targets are of great interest for the treatment of fungal biofilms, which are routinely resistant to antifungal therapies. We theorized that the interaction ofCandida albicanswith matricellular host proteins would provide a novel target. Here, we show that an inhibitory protein (FUD) targetingCandida-fibronectin interactions disrupts biofilm formationin vitroandin vivoin a rat venous catheter model. The peptide appears to act by blocking the surface adhesion ofCandida, halting biofilm formation.

scholarly journals Symbiotic Relationship between Streptococcus mutans and Candida albicans Synergizes Virulence of Plaque BiofilmsIn Vivo

2014 ◽  
Vol 82 (5) ◽  
pp. 1968-1981 ◽  
Author(s):  
Megan L. Falsetta ◽  
Marlise I. Klein ◽  
Punsiri M. Colonne ◽  
Kathleen Scott-Anne ◽  
Stacy Gregoire ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Bacterial Pathogen ◽  
Single Species ◽  
Content Type ◽  
3 Dimensional ◽  
Biofilm Development

ABSTRACTStreptococcus mutansis often cited as the main bacterial pathogen in dental caries, particularly in early-childhood caries (ECC).S. mutansmay not act alone;Candida albicanscells are frequently detected along with heavy infection byS. mutansin plaque biofilms from ECC-affected children. It remains to be elucidated whether this association is involved in the enhancement of biofilm virulence. We showed that the ability of these organisms together to form biofilms is enhancedin vitroandin vivo. The presence ofC. albicansaugments the production of exopolysaccharides (EPS), such that cospecies biofilms accrue more biomass and harbor more viableS. mutanscells than single-species biofilms. The resulting 3-dimensional biofilm architecture displays sizeableS. mutansmicrocolonies surrounded by fungal cells, which are enmeshed in a dense EPS-rich matrix. Using a rodent model, we explored the implications of this cross-kingdom interaction for the pathogenesis of dental caries. Coinfected animals displayed higher levels of infection and microbial carriage within plaque biofilms than animals infected with either species alone. Furthermore, coinfection synergistically enhanced biofilm virulence, leading to aggressive onset of the disease with rampant carious lesions. Ourin vitrodata also revealed that glucosyltransferase-derived EPS is a key mediator of cospecies biofilm development and that coexistence withC. albicansinduces the expression of virulence genes inS. mutans(e.g.,gtfB,fabM). We also found thatCandida-derived β1,3-glucans contribute to the EPS matrix structure, while fungal mannan and β-glucan provide sites for GtfB binding and activity. Altogether, we demonstrate a novel mutualistic bacterium-fungus relationship that occurs at a clinically relevant site to amplify the severity of a ubiquitous infectious disease.

scholarly journals Oral Administration of the Broad-Spectrum Antibiofilm Compound Toremifene Inhibits Candida albicans and Staphylococcus aureus Biofilm FormationIn Vivo

2014 ◽  
Vol 58 (12) ◽  
pp. 7606-7610 ◽  
Author(s):  
Kaat De Cremer ◽  
Nicolas Delattin ◽  
Katrijn De Brucker ◽  
Annelies Peeters ◽  
Soña Kucharíková ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Broad Spectrum ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Candida Krusei ◽  
Content Type ◽  
And Staphylococcus Aureus

ABSTRACTWe here report on thein vitroactivity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, includingCandida albicans,Candida glabrata,Candida dubliniensis,Candida krusei,Pseudomonas aeruginosa,Staphylococcus aureus, andStaphylococcus epidermidis. We validated thein vivoefficacy of orally administered toremifene againstC. albicans and S. aureusbiofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound.

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