Activity of Metal-Azole Complexes Against Biofilms of Candida albicans and Candida glabrata

2020 ◽  
Vol 26 (14) ◽  
pp. 1524-1531 ◽  
Author(s):  
Livia D. Pereira ◽  
Taissa Vila ◽  
Luana P. Borba-Santos ◽  
Wanderley de Souza ◽  
Maribel Navarro ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Candida Glabrata ◽  
Ex Vivo ◽  
Drug Efficacy ◽  
Ex Vivo Model ◽  
In Vitro Susceptibility ◽  
Poor Patient Compliance ◽  
Nail Infection

Background: Onychomycosis is a chronic nail infection caused by fungi frequently resistant to antifungal treatments. Recalcitrance in nail infections is a result of reduced antifungal penetration due to biofilm formation, combined with poor patient compliance with the treatment, which can be as long as 18 months. Objective: Metal-drug complexation is a widely used strategy to increase drug efficacy. Therefore, the aim of this work was to evaluate the antifungal and anti-biofilm activity of several metal-azole complexes against Candida albicans and Candida glabrata. Methods: Susceptibility assays and scanning electron microscopy were performed to determine the anti-biofilm activity of eight metal-azole complexes in vitro and ex-vivo, using human nail fragments. Results: In vitro susceptibility assays showed that complexation of both Au(I) and Zn(II) to clotrimazole and ketoconazole improved the anti-biofilm activity compared to the azole alone. Using an ex-vivo model of biofilm formation on fragments of human nails, we also demonstrate the improved efficacy of metal-azole complexes against biofilms of C. albicans and C. glabrata that resembles the onychomycosis structure. Noteworthy, biofilms of C. glabrata were more susceptible to the optimized complexes than those of C. albicans. Conclusion: In conclusion, metal-azole complexes used in this work show promising anti-biofilm activity and further clinical studies should confirm its potential for the treatment of Candida-associated onychomycosis.

scholarly journals Efficacies of Fluconazole, Caspofungin, and Amphotericin B in Candida glabrata-Infected p47phox−/− Knockout Mice

2002 ◽  
Vol 46 (5) ◽  
pp. 1240-1245 ◽  
Author(s):  
Justina Y. Ju ◽  
Cynthia Polhamus ◽  
Kieren A. Marr ◽  
Steven M. Holland ◽  
John E. Bennett
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Murine Model ◽  
Knockout Mice ◽  
Candida Glabrata ◽  
Drug Efficacy ◽  
Fungal Burden ◽  
Lethal Infection

ABSTRACT Candida glabrata is the second leading cause of adult candidemia, resulting in high mortality. Amphotericin B is considered the treatment of choice, while the efficacy of fluconazole is controversial and caspofungin efficacy is unknown. To ascertain drug efficacy in vivo, the utility of a murine model of C. glabrata infection was investigated. C. glabrata was found to cause progressive, lethal infection when injected intravenously into C57BL/6 mice with reduced oxidative microbicidal capacity due to knockout of the p47phox gene. Spleen and kidney organ CFU counts were determined in groups of mice 2 days after the mice completed 6 days of daily intraperitoneal drug treatment, which began on the day of infection. Daily injections of fluconazole at 80 mg/kg did not reduce spleen or kidney CFU counts after infection with C. glabrata strains having in vitro fluconazole MICs of 2, 32, or 256 μg/ml compared to saline-treated controls. However, this fluconazole regimen reduced spleen CFU counts in mice infected with Candida albicans, an infection that is known to be responsive to fluconazole. Caspofungin at 5 mg/kg and amphotericin B at 5 mg/kg were both effective in reducing fungal burden in spleens and kidneys of C. glabrata-infected mice. Ten mice treated for 6 days with caspofungin at 1 mg/kg survived for 15 days, though all 10 saline-injected mice died or were so ill that they had to be sacrificed by 96 h postinfection. This murine model provided evidence of the efficacy of amphotericin B and caspofungin but not of fluconazole against C. glabrata infection.

scholarly journals A Combined Phenotypic-Genotypic Predictive Algorithm for In Vitro Detection of Bicarbonate: β-Lactam Sensitization among Methicillin-Resistant Staphylococcus aureus (MRSA)

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1089
Author(s):  
Selvi C. Ersoy ◽  
Warren E. Rose ◽  
Robin Patel ◽  
Richard A. Proctor ◽  
Henry F. Chambers ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Genomic Sequence ◽  
Ex Vivo ◽  
Coding Region ◽  
Ex Vivo Model ◽  
In Vitro Susceptibility ◽  
Predictive Algorithm ◽  
Mrsa Strains

Antimicrobial susceptibility testing (AST) is routinely used to establish predictive antibiotic resistance metrics to guide the treatment of bacterial pathogens. Recently, a novel phenotype termed “bicarbonate (NaHCO3)-responsiveness” was identified in a relatively high frequency of clinical MRSA strains, wherein isolates demonstrate in vitro “susceptibility” to standard β-lactams (oxacillin [OXA]; cefazolin [CFZ]) in the presence of NaHCO3, and in vivo susceptibility to these β-lactams in experimental endocarditis models. We investigated whether a targeted phenotypic-genotypic screening of MRSA could rule in or rule out NaHCO3 susceptibility upfront. We studied 30 well-characterized clinical MRSA bloodstream isolates, including 15 MIC-susceptible to CFZ and OXA in NaHCO3-supplemented Mueller–Hinton Broth (MHB); and 15 MIC-resistant to both β-lactams in this media. Using a two-tiered strategy, isolates were first screened by standard disk diffusion for susceptibility to a combination of amoxicillin-clavulanate [AMC]. Isolates then underwent genomic sequence typing: MLST (clonal complex [CC]); agr; SCCmec; and mecA promoter and coding region. The combination of AMC disk susceptibility testing plus mecA and spa genotyping was able to predict MRSA strains that were more or less likely to be NaHCO3-responsive in vitro, with a high degree of sensitivity and specificity. Validation of this screening algorithm was performed in six strains from the overall cohort using an ex vivo model of endocarditis. This ex vivo model recapitulated the in vitro predictions of NaHCO3-responsiveness vs. nonresponsiveness above in five of the six strains.

scholarly journals Antifungal Activity of Oleylphosphocholine on In Vitro and In Vivo Candida albicans Biofilms

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Michelle Holtappels ◽  
Erwin Swinnen ◽  
Lies De Groef ◽  
Jurgen Wuyts ◽  
Lieve Moons ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Biofilm Formation ◽  
Ex Vivo ◽  
Oral Candidiasis ◽  
Sprague Dawley ◽  
Content Type ◽  
Polyurethane Catheters

ABSTRACT In this study, we investigated the potential antifungal activity of the alkylphospholipid oleylphosphocholine (OlPC), a structural analogue of miltefosine, on in vitro and in vivo Candida albicans biofilm formation. The effect of OlPC on in vitro and in vivo C. albicans biofilms inside triple-lumen polyurethane catheters was studied. In vivo biofilms were developed subcutaneously after catheter implantation on the lower back of Sprague-Dawley rats. Animals were treated orally with OlPC (20 mg/kg of body weight/day) for 7 days. The effect of OlPC on biofilms that developed on the mucosal surface was studied in an ex vivo model of oral candidiasis. The role of OlPC in C. albicans morphogenesis was investigated by using hypha-inducing media, namely, Lee, Spider, and RPMI 1640 media. OlPC displayed activity against both planktonic cells and in vitro C. albicans biofilms. To completely abolish preformed, 24-h-old biofilms, higher concentrations (8, 10, and 13 mg/liter) were needed. Moreover, OlPC was able to reduce C. albicans biofilms formed by caspofungin-resistant clinical isolates and acted synergistically when combined with caspofungin. The daily oral administration of OlPC significantly reduced in vivo C. albicans biofilms that developed subcutaneously. In addition, OlPC decreased biofilm formation on mucosal surfaces. Interestingly, the application of subinhibitory concentrations of OlPC already inhibited the yeast-to-hypha transition, a crucial virulence factor of C. albicans. We document, for the first time, the effects of OlPC on C. albicans cells and suggest the potential use of OlPC for the treatment of C. albicans biofilm-associated infections.

Effects of Two Different Doses of Hirudin on APTT, Determined with Eight Different Reagents

1995 ◽  
Vol 73 (02) ◽  
pp. 219-222 ◽  
Author(s):  
Manuel Monreal ◽  
Luis Monreal ◽  
Rafael Ruiz de Gopegui ◽  
Yvonne Espada ◽  
Ana Maria Angles ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
In Vitro Study ◽  
Ex Vivo Model ◽  
Suitable Candidate ◽  
Significant Prolongation ◽  
High Doses ◽  
Different Doses

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.

Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates on Knee Osteoarthritic Chondrocytes and Cartilage in vitro

2019 ◽  
Vol 20 (11) ◽  
pp. 920-933 ◽  
Author(s):  
Lucía Gato-Calvo ◽  
Tamara Hermida-Gómez ◽  
Cristina R. Romero ◽  
Elena F. Burguera ◽  
Francisco J. Blanco
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Cartilage Explants ◽  
Ex Vivo Model ◽  
Chondrocyte Viability ◽  
Platelet Concentration ◽  
The Absolute ◽  
Anti Inflammatory

Background: Platelet Rich Plasma (PRP) has recently emerged as a potential treatment for osteoarthritis (OA), but composition heterogeneity hampers comparison among studies, with the result that definite conclusions on its efficacy have not been reached. Objective: 1) To develop a novel methodology to prepare a series of standardized PRP releasates (PRP-Rs) with known absolute platelet concentrations, and 2) To evaluate the influence of this standardization parameter on the anti-inflammatory properties of these PRP-Rs in an in vitro and an ex vivo model of OA. Methods: A series of PRPs was prepared using the absolute platelet concentration as the standardization parameter. Doses of platelets ranged from 0% (platelet poor plasma, PPP) to 1.5·105 platelets/µl. PRPs were then activated with CaCl2 to obtain releasates (PRP-R). Chondrocytes were stimulated with 10% of each PRP-R in serum-free culture medium for 72 h to assess proliferation and viability. Cells were co-stimulated with interleukin (IL)-1β (5 ng/ml) and 10% of each PRP-R for 48 h to determine the effects on gene expression, secretion and intra-cellular content of common markers associated with inflammation, catabolism and oxidative stress in OA. OA cartilage explants were co-stimulated with IL-1β (5 ng/ml) and 10% of either PRP-R with 0.75·105 platelets/µl or PRP-R with 1.5·105 platelets/µl for 21 days to assess matrix inflammatory degradation. Results: Chondrocyte viability was not affected, and proliferation was dose-dependently increased. The gene expression of all pro-inflammatory mediators was significantly and dose-independently reduced, except for that of IL-1β and IL-8. Immunoblotting corroborated this effect for inducible NO synthase (NOS2). Secreted matrix metalloproteinase-13 (MMP-13) was reduced to almost basal levels by the PRP-R from PPP. Increasing platelet dosage led to progressive loss to this anti-catabolic ability. Safranin O and toluidine blue stains supported the beneficial effect of low platelet dosage on cartilage matrix preservation. Conclusion: We have developed a methodology to prepare PRP releasates using the absolute platelet concentration as the standardization parameter. Using this approach, the composition of the resulting PRP derived product is independent of the donor initial basal platelet count, thereby allowing the evaluation of its effects objectively and reproducibly. In our OA models, PRP-Rs showed antiinflammatory, anti-oxidant and anti-catabolic properties. Platelet enrichment could favor chondrocyte proliferation but is not necessary for the above effects and could even be counter-productive.

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 Eap1p, an Adhesin That Mediates Candida albicans Biofilm Formation In Vitro and In Vivo

2007 ◽  
Vol 6 (6) ◽  
pp. 931-939 ◽  
Author(s):  
Fang Li ◽  
Michael J. Svarovsky ◽  
Amy J. Karlsson ◽  
Joel P. Wagner ◽  
Karen Marchillo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Adhesion ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Gene Dosage ◽  
Venous Catheter ◽  
Flow Chamber ◽  
Dependent Manner

ABSTRACT Candida albicans is the leading cause of systemic fungal infections in immunocompromised humans. The ability to form biofilms on surfaces in the host or on implanted medical devices enhances C. albicans virulence, leading to antimicrobial resistance and providing a reservoir for infection. Biofilm formation is a complex multicellular process consisting of cell adhesion, cell growth, morphogenic switching between yeast form and filamentous states, and quorum sensing. Here we describe the role of the C. albicans EAP1 gene, which encodes a glycosylphosphatidylinositol-anchored, glucan-cross-linked cell wall protein, in adhesion and biofilm formation in vitro and in vivo. Deleting EAP1 reduced cell adhesion to polystyrene and epithelial cells in a gene dosage-dependent manner. Furthermore, EAP1 expression was required for C. albicans biofilm formation in an in vitro parallel plate flow chamber model and in an in vivo rat central venous catheter model. EAP1 expression was upregulated in biofilm-associated cells in vitro and in vivo. Our results illustrate an association between Eap1p-mediated adhesion and biofilm formation in vitro and in vivo.

scholarly journals Experimental Models to Study COVID-19 Effect in Stem Cells

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 91
Author(s):  
Rishi Man Chugh ◽  
Payel Bhanja ◽  
Andrew Norris ◽  
Subhrajit Saha
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
Drug Efficacy ◽  
Cell Loss ◽  
Experimental Models ◽  
Model Systems ◽  
Virus Infectivity ◽  
Ex Vivo Model ◽  
Global Pandemic ◽  
The Impact

The new strain of coronavirus (severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)) emerged in 2019 and hence is often referred to as coronavirus disease 2019 (COVID-19). This disease causes hypoxic respiratory failure and acute respiratory distress syndrome (ARDS), and is considered as the cause of a global pandemic. Very limited reports in addition to ex vivo model systems are available to understand the mechanism of action of this virus, which can be used for testing of any drug efficacy against virus infectivity. COVID-19 induces tissue stem cell loss, resulting inhibition of epithelial repair followed by inflammatory fibrotic consequences. Development of clinically relevant models is important to examine the impact of the COVID-19 virus in tissue stem cells among different organs. In this review, we discuss ex vivo experimental models available to study the effect of COVID-19 on tissue stem cells.

scholarly journals Considerations to Model Heart Disease in Women with Preeclampsia and Cardiovascular Disease

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 899
Author(s):  
Clara Liu Chung Ming ◽  
Kimberly Sesperez ◽  
Eitan Ben-Sefer ◽  
David Arpon ◽  
Kristine McGrath ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiovascular Disease ◽  
Ex Vivo ◽  
Myocardial Damage ◽  
Cardiovascular Disorder ◽  
Model Systems ◽  
Ex Vivo Model ◽  
Disease Manifestation

Preeclampsia is a multifactorial cardiovascular disorder diagnosed after 20 weeks of gestation, and is the leading cause of death for both mothers and babies in pregnancy. The pathophysiology remains poorly understood due to the variability and unpredictability of disease manifestation when studied in animal models. After preeclampsia, both mothers and offspring have a higher risk of cardiovascular disease (CVD), including myocardial infarction or heart attack and heart failure (HF). Myocardial infarction is an acute myocardial damage that can be treated through reperfusion; however, this therapeutic approach leads to ischemic/reperfusion injury (IRI), often leading to HF. In this review, we compared the current in vivo, in vitro and ex vivo model systems used to study preeclampsia, IRI and HF. Future studies aiming at evaluating CVD in preeclampsia patients could benefit from novel models that better mimic the complex scenario described in this article.

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