Live Candida Albicans Research Articles

PHOTOINACTIVATION OF CANDIDA ALBICANS BIOFILM WITH GREEN LASER MEDIATED BY THE PAPAYA LEAF EXTRACT CHLOROPHYLL

This study aims to activate the effectiveness of Photodynamic Inactivation (PDI) as an antibacterial agent by using a green laser and papaya leaf chlorophyll extract to prevent Candida albicans cell death. Papaya leaf extract chlorophyll is known to have potential as a photosensitizer (PS) through its antimicrobial properties and ability to absorb optimal light photons at a wavelength range of 405–680 nm. Activation of chlorophyll molecules with appropriate light produces Reactive Oxygen Species (ROS), which are toxic to pathogenic microbes such as Candida albicans. The research method involves using PDI with a green laser light source and chlorophyll extract on Candida albicans biofilms. Four main treatment groups were applied, negative control (C-), positive controls with 10% (C1+) and 15% chlorophyll (C2+), irradiation for 60, 120, 180, 240, and 300 seconds (L1–L5), and combinations of irradiation with chlorophyll (L1F1–L5F2, where F1 for 10% chlorophyll and F2 for 15% chlorophyll), with measurements performed three times for each treatment. Living Candida albicans cells were detected using the XTT assay staining method. The results showed a significant decrease in activity in all treatment groups. Maximum activity was achieved in the L5F1 and L5F2 treatment groups with inactivation of 80% (p<0.05) and 83% (p<0.05), respectively. This study concludes that high papaya leaf extract chlorophyll concentrations combined with a green laser effectively inhibit Candida albicans biofilm.

Comparison Study of Phagocytosis Activity among Live Candida albicans, Live and Heat-treated Saccharomyces cerevisiae

Comparison Study of Phagocytosis Activity among Live Candida albicans, Live and Heat-treated Saccharomyces cerevisiae

Spatiotemporal dynamics of calcium signals during neutrophil cluster formation

Neutrophils form cellular clusters or swarms in response to injury or pathogen intrusion. Yet, intracellular signaling events favoring this coordinated response remain to be fully characterized. Here, we show that calcium signals play a critical role during mouse neutrophil clustering around particles of zymosan, a structural fungal component. Pioneer neutrophils recognizing zymosan or live Candida albicans displayed elevated calcium levels. Subsequently, a transient wave of calcium signals in neighboring cells was observed followed by the attraction of neutrophils that exhibited more persistent calcium signals as they reached zymosan particles. Calcium signals promoted LTB4 production while the blocking of extracellular calcium entry or LTB4 signaling abrogated cluster formation. Finally, using optogenetics to manipulate calcium influx in primary neutrophils, we show that calcium signals could initiate recruitment of neighboring neutrophils in an LTB4-dependent manner. Thus, sustained calcium responses at the center of the cluster are necessary and sufficient for the generation of chemoattractive gradients that attract neutrophils in a self-reinforcing process.

LPS Guides Distinct Patterns of Training and Tolerance in Mast Cells.

Mast cells (MCs) are tissue-resident, long lived innate immune cells with important effector and immunomodulatory functions. They are equipped with an eclectic variety of receptors that enable them to sense multiple stimuli and to generate specific responses according on the type, strength and duration of the stimulation. Several studies demonstrated that myeloid cells can retain immunological memory of their encounters – a process termed ‘trained immunity’ or ‘innate immune memory’. As MCs are among the one of first cells to come into contact with the external environment, it is possible that such mechanisms of innate immune memory might help shaping their phenotype and effector functions; however, studies on this aspect of MC biology are still scarce. In this manuscript, we investigated the ability of MCs primed with different stimuli to respond to a second stimulation with the same or different ligands, and determined the molecular and epigenetic drivers of these responses. Our results showed that, while the stimulation with IgE and β-glucan failed to induce either tolerant or trained phenotypes, LPS conditioning was able to induce a profound and long-lasting remodeling of the signaling pathways involved in the response against LPS or fungal pathogens. On one side, LPS induced a strong state of unresponsiveness to secondary LPS stimulation due to the impairment of the PI3K-AKT signaling pathway, which resulted in the reduced activation of NF-κB and the decreased release of TNF-α and IL-6, compared to naïve MCs. On the other side, LPS primed MCs showed an increased release of TNF-α upon fungal infection with live Candida albicans, thus suggesting a dual role of LPS in inducing both tolerance and training phenotypes depending on the secondary challenge. Interestingly, the inhibition of HDAC during LPS stimulation partially restored the response of LPS-primed MCs to a secondary challenge with LPS, but failed to revert the increased cytokine production of these cells in response to C. albicans. These data indicate that MCs, as other innate immune cells, can develop innate immune memory, and that different stimulatory environments can shape and direct MC specific responses towards the dampening or the propagation of the local inflammatory response.

Treatment with Candida albicans biotherapic influences in vitro fungal adhesion to Ma-104 cells

Background: Oral candidiasis is an opportunist fungal infection in humans, mainly caused by Candida albicans. It occurs when the host presents an imbalance in the immune system and Candida spp., normally found in human flora, become able to develop the infection [1]. This disease is very common in HIV patients, and in all individuals that present immunossupression, such as patients treated with chemotherapy. Considering this scenario, the development of new medicines to treat oral candidiasis is mandatory.
 
 Aims: The aim of this study was to evaluate citotoxicity, morphology and quantify the adhesion rates of C. albicans to biotherapic-treated Ma104 cells.
 
 Methodology: The biotherapic was prepared following the Roberto Costa technique and Brazilian Homeopathic Pharmacopeia protocol [2]. Briefly, biotherapic 1X was prepared with 1 mL of aqueous solution containing 108 yeasts of living Candida albicans plus 9 ml of sterile distilled water. This solution was submmited to 100 mechanical succussions. Biotherapic 2X was obtained after addition of 1 ml of 1X solution in 9 ml of sterile distilled water and it was also submitted to 100 mechanical succussions. This procedure was repeated until biotherapic 30X was obtained. As a control, sterile dynamized water (30X) was used. The inhibition of fungal growth induced by biotherapic was evaluated by MTT method after 24 hours of treatment. The morphological aspects of Ma104-biotherapic-treated cells were analyzed by Giemsa staining after 5, 10 and 60 days, and compared with control groups (water 30X and untreated cells). Additionally, Ma104 cells were treated during 5 and 30 days with biotherapic in parallel with respective controls, and the index adhesion of yeast cells was quantified. 
 
 Results: The biotherapic was not able to reduce the viability of treated C. albicans when compared with controls. On the other hand, Ma104 treated cells presented important morphological alterations after 60 days, such as: cytoplasmic vacuoles, halos around the nucleolus and elongation of the plasmatic membrane. These changes were not observed in ,untreated cells nor in ones treated with water 30X. The adhesion index to Ma104 cells was reduced around 27% after 5 and 30 days of treatment when compared to controls. 
 
 Conclusion: These results showed that the biotherapic did not present any citotoxicity, but was able to modify the morphological aspects of Ma-104 cells. Additionally, the interaction between host cells and ethilogic agent is directly influenced by biotherapic treatment, suggesting a promising antifungal potential of this medicine.

The Proteome of Community Living Candida albicans Is Differentially Modulated by the Morphologic and Structural Features of the Bacterial Cohabitants.

Candida albicans is a commensal polymorphic and opportunistic fungus, which usually resides as a small community in the oral cavities of a majority of humans. The latter eco-system presents this yeast varied opportunities for mutualistic interactions with other cohabitant oral bacteria, that synergizes its persistence and pathogenicity. Collectively, these communities live within complex plaque biofilms which may adversely affect the oral health and increase the proclivity for oral candidiasis. The proteome of such oral biofilms with myriad interkingdom interactions are largely underexplored. Herein, we employed limma differential expression analysis, and cluster analysis to explore the proteomic interactions of C. albicans biofilms with nine different common oral bacterial species, Aggregatibacter actinomycetemcomitans, Actinomyces naeslundii, Fusobacterium nucleatum, Enterococcus faecalis, Porphyromonas gingivalis, Streptococcus mutants, Streptococcus sanguinis, Streptococcus mitis, and Streptococcus sobrinus. Interestingly, upon exposure of C. albicans biofilms to the foregoing heat-killed bacteria, the proteomes of the fungus associated with cellular respiration, translation, oxidoreductase activity, and ligase activity were significantly altered. Subsequent differential expression and cluster analysis revealed the subtle, yet significant alterations in the C. albicans proteome, particularly on exposure to bacteria with dissimilar cell morphologies, and Gram staining characteristics.

The Interactions between the Antimicrobial Peptide P-113 and Living Candida albicans Cells Shed Light on Mechanisms of Antifungal Activity and Resistance.

In the absence of proper immunity, such as in the case of acquired immune deficiency syndrome (AIDS) patients, Candida albicans, the most common human fungal pathogen, may cause mucosal and even life-threatening systemic infections. P-113 (AKRHHGYKRKFH), an antimicrobial peptide (AMP) derived from the human salivary protein histatin 5, shows good safety and efficacy profiles in gingivitis and human immunodeficiency virus (HIV) patients with oral candidiasis. However, little is known about how P-113 interacts with Candida albicans or its degradation by Candida-secreted proteases that contribute to the fungi’s resistance. Here, we use solution nuclear magnetic resonance (NMR) methods to elucidate the molecular mechanism of interactions between P-113 and living Candida albicans cells. Furthermore, we found that proteolytic cleavage of the C-terminus prevents the entry of P-113 into cells and that increasing the hydrophobicity of the peptide can significantly increase its antifungal activity. These results could help in the design of novel antimicrobial peptides that have enhanced stability in vivo and that can have potential therapeutic applications.

14-Helical β-Peptides Elicit Toxicity against C. albicans by Forming Pores in the Cell Membrane and Subsequently Disrupting Intracellular Organelles

Synthetic peptidomimetics of antimicrobial peptides (AMPs) are promising antimicrobial drug candidates because they promote membrane disruption and exhibit greater structural and proteolytic stability than natural AMPs. We previously reported selective antifungal 14-helical β-peptides, but the mechanism of antifungal toxicity of β-peptides remains unknown. To provide insight into the mechanism, we studied antifungal β-peptide binding to artificial membranes and living Candida albicans cells. We investigated the ability of β-peptides to interact with and permeate small unilamellar vesicle models of fungal membranes. The partition coefficient supported a pore-mediated mechanism characterized by the existence of a critical β-peptide concentration separating low- and high-partition coefficient regimes. Live cell intracellular tracking of β-peptides showed that β-peptides translocated into the cytoplasm, and then disrupted the nucleus and vacuole sequentially, leading to cell death. This understanding of the mechanisms of antifungal activity will facilitate design and development of peptidomimetic AMPs, including 14-helical β-peptides, for antifungal applications.

Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep‐UV fluorescence imaging study

The interaction of the tryptophan functionalized Ag nanoparticles and live Candida albicans cells was studied by synchrotron excitation deep-ultraviolet (DUV) fluorescence imaging at the DISCO beamline of Synchrotron SOLEIL. DUV imaging showed that incubation of the fungus with functionalized nanoparticles results in significant increase in the fluorescence signal. The analysis of the images revealed that the interaction of the nanoparticles with (pseudo)hyphae polymorphs of the diploid fungus was less pronounced than in the case of yeast cells or budding spores. The changes in the intensity of the fluorescence signals of the cells after incubation were followed in [327–353nm] and [370–410nm] spectral ranges that correspond to the fluorescence of tryptophan in non-polar and polar environment, respectively. As a consequence of the environmental sensitivity of the silver-tryptophan fluorescent nanoprobe, we were able to determine the possible accumulation sites of the nanoparticles. The analysis of the intensity decay kinetics showed that the photobleaching effects were more pronounced in the case of the functionalized nanoparticle treated cells. The results of time-integrated emission in the mentioned spectral ranges suggested that the nanoparticles penetrate the cells, but that the majority of the nanoparticles attach to the cells’ surfaces.

Candida colonization of respiratory tract: to treat or not to treat, will we ever get an answer?

In non-immunocompromised intensive care unit (ICU)patients Candida isolation from various sites is common[1]. The association with the risk of invasive candidiasis(IC) is the rational for the use of predictive scores whichinclude the colonization status.However the meaning of Candida spp. recovery fromthe lung is definitely more intriguing. Apart from ICepisodes occurring in deeply immunosuppressed subjectswho may develop true fungal pneumonia, Candidarespiratory tract (RT) isolation should not be considered amarker of lung infection. This issue was addressed byMeersseman et al. [2] who did not identify any autopsy-proven case of Candida pneumonia among 135 autopsieswith histopathological evidence of bacterial infection andhigh rate of Candida isolation from endotracheal aspirate(EA) and/or bronchoalveolar lavage (BAL) (57 %).However there is growing convincing evidence, basedon animal studies and human observations, that Candidaspp. is not definitely an innocent bystander in the respi-ratory tract of ICU ventilated patients [3–13] (Table 1).Beta-glucan (BG), a component of yeast cell wall, mayact as a lung proinflammatory agent causing alveolarmacrophage and neutrophil dysfunction. Additionally,within the environmental biofilm there is a strong inter-play, through quorum-sensing (QS) molecules, betweenand both Gram-positive and Gram-negativebacteria [14]. Live Candida albicans instillation in ratshas been observed to increase the susceptibility to developexperimental Pseudomonas aeruginosa (PA), Escherichiacoli (Ec), and Staphylococcus aureus (Sa) pneumonia,fostering the production of lung inflammatory cytokines(tumor necrosis factor alpha [TNF-alpha], interleukin-6[IL-6], and interferon-gamma [INF-c]) and inhibitingalveolar macrophage phagocytosis [3, 5]. From a clinicalviewpoint, Candida airway colonization has been shownto be associated with prolonged duration of mechanicalventilation, ICU/hospital length of stay, and increasedmortality [8–11]. One of the first reports of this possiblerelationship dates back to almost 10 years ago, whenAzoulay et al. [6] identified Candida bronchial isolationas an independent risk factor for the development of PAventilator-associated pneumonia (VAP) (9 vs 4.8 % innon-colonized patients, p = 0.048). These data werestrengthened just 1 year later by Nseir et al. [7] whoobserved a protective role of antifungal treatment on PAVAP occurrence in a cohort of patients with Candidatracheobronchial colonization. However, recently, the useof nebulized amphotericin B (NAB) was not able toprovide any clinical improvement, albeit increasing therate of Candida decolonization (adjusted HR 2.2; 95 %CI 1.6–3) [13]. Hence the clinical usefulness of respira-tory tract Candida colonization (CC) eradication inmechanically ventilated patients is still a matter of debateand the paper by Albert et al. [15] in the current issue ofIntensive Care Medicine is the first interventional trialaiming to describe the biochemical and clinical effect ofantifungal treatment in ICU patients with VAP and RTCc. In this double-blind, placebo-controlled, multicenterstudy 60 patients were enrolled: 29 in the placebo groupand 31 in the antifungal strategy group. A comparative

Viable quantitative PCR for assessing the response of Candida albicans to antifungal treatment

Propidium monoazide (PMA) or ethidium bromide monoazide (EMA) treatment has been used before nucleic acid detection methods, such as PCR, to distinguish between live and dead cells using membrane integrity as viability criterion. The performance of these DNA intercalating dyes was compared in many studies utilizing different microorganisms. These studies demonstrated that EMA and PMA differ in their abilities to identify nonviable cells from mixed cell populations, depending on the microorganism and the nature of the sample. Due to this heterogeneity, both dyes were used in the present study to specifically distinguish dead from live Candida albicans cells using viable quantitative PCR (qPCR). The viable qPCR was optimized, and the best results were obtained when pre-treating the cells for 10min in the dark with 25μM EMA followed by continuous photoactivation for 15min. The suitability of this technique to distinguish clotrimazole- and fluconazole-treated C. albicans cells from untreated cells was then assessed. Furthermore, the antifungal properties of two commercial essential oils (Thymus vulgaris and Matricaria chamomilla) were evaluated. The viable qPCR method was determined to be a feasible technique for assessing the viability of C. albicans after drug treatment and may help to provide a rapid diagnostic and susceptibility testing method for fungal infections, especially for patients treated with antifungal therapies.

Cell surface shaving of Candida albicans biofilms, hyphae, and yeast form cells

We used a brief trypsin treatment followed by peptide separation and identification using nano-LC followed by off-line MS/MS to identify the surface proteins on live Candida albicans organisms growing in biofilms and planktonic yeast cells and hyphae. One hundred thirty-one proteins were present in at least two of the three replicates of one condition and distributed in various combinations of the three growth conditions. Both previously reported and new surface proteins were identified and these were distributed between covalently attached proteins and noncovalently attached proteins of the cell wall.

Scavenger receptors and β-glucan receptors participate in the recognition of yeasts by murine macrophages

ObjectivesNumerous receptors have been implicated in recognition of pathogenic fungi by macrophages, including the β-glucan receptor dectin-1. The role of scavenger receptors (SRs) in anti-fungal immunity is not well characterized.MethodsWe studied uptake of unopsonized Saccharomycetes cerevisiae (zymosan) and live Candida albicans yeasts as well as zymosan-stimulated H2O2 production in J774 macrophage-like cells and peritoneal exudate macrophages (PEMs). The role of different receptors was assessed with the use of competitive ligands, transfected cells and receptor-deficient macrophages.ResultsThe uptake of zymosan by untreated J774 cells was mediated approximately half by SRs and half by a β-glucan receptor which was distinct from dectin-1 and not linked to stimulation of H2O2 production. Ligands of β-glucan receptors and of SRs also inhibited uptake of C. albicans by macrophages (J774 cells and PEMs). In macrophages pretreated with a CpG motif-containing oligodeoxynucleotide (CpG-ODN) the relative contribution of SRs to yeast uptake increased and that of β-glucan receptors decreased. Whereas the class A SR MARCO participated in the uptake of both zymosan and C. albicans by CpG-ODN-pretreated, but not untreated macrophages, the related receptor SR-A/CD204 was involved in the uptake of zymosan, but not of C. albicans. The reduction of zymosan-stimulated H2O2 production observed in DS-pretreated J774 cells and in class A SRs-deficient PEMs suggest that class A SRs mediate part of this process.ConclusionsOur results revealed that SRs belong to a redundant system of receptors for yeasts. Binding of yeasts to different receptors in resting versus CpG-ODN-pre-exposed macrophages may differentially affect polarization of adaptive immune responses.

The classical CD14++CD16− monocytes, but not the patrolling CD14+CD16+ monocytes, promote Th17 responses to Candida albicans

In the present study, we investigated the functional differences between cluster of differentiation (CD)14(++) CD16(-) and CD14(+) CD16(+) monocytes during anti-Candida host defense. CD14(++) CD16(-) are the "classical" monocytes and represent the majority of circulating monocytes in humans, while CD14(+) CD16(+) monocytes patrol the vasculature for maintenance of tissue integrity and repair. Both monocyte subsets inhibited the germination of live Candida albicans, and there was no difference in their capacity to phagocytose and kill Candida. Although production of IL-6 and IL-10 induced by C. albicans was found to be similar between monocyte subsets, IL-1β and prostaglandin E2 (PGE2) production was higher in CD14(++) CD16(-) compared with CD14(+) CD16(+) monocytes. In line with the increased production of IL-1β and PGE2, central mediators for inducing Th17 responses, CD14(++) CD16(-) monocytes induced greater Th17 responses upon stimulation with heat-killed C. albicans yeast. The percentage of cells that expressed mannose receptor (MR) was higher in the CD14(++) CD16(-) monocyte subset, and MR-specific stimulation induced higher Th17 responses only in co-cultures of CD14(++) CD16(-) monocytes and CD4 lymphocytes. In conclusion, both monocyte subsets have potent innate antifungal properties, but only CD14(++) CD16(-) monocytes are capable of inducing a potent Th17 response to C. albicans, an important component of antifungal host defense.

Specific inhibition of Candida albicans growth in vitro by antibodies from experimental Candida keratitis mice

To investigate the role of humoral immunity in the response to experimental keratitis, Balb/c mice were primed by one of three protocols: i) intranasal inhalation of live Candida spores; ii) subcutaneous injection of heat-inactivated spores; or iii) induction and healing of primary CaK. Experimental murine CaK was then induced in the three groups of primed mice and one group of unprimed mice by intrastromal injection of live Candida albicans spores. Totally 30 mice were included in each group. Sera collected after CaK induction were subjected to serial dilution and their effects on fungal growth and survival were tested as an assay for fungicidal activity in vitro. Corneas removed at various stages of disease were examined histologically, and fungal loads were determined using quantitative real-time PCR. Compared to corneas from mice with primary CaK, all corneas from CaK mice that had been previously primed exhibited milder histological disruptions that were faster to resolve, contained higher immunoglobulin and IFNγ titers, and had lower pathogen load ( P < 0.05). Infiltration of pro-Inflammatory cells, which comprised mainly leukocytes other than lymphocytes, also initiated earlier in the primed mice compared to the controls (at day 3 versus day 7 respectively), and this should be due to differential production of cytokines. Sera from primed CaK mice exhibited stronger fungicidal activity and this was relatively specific for the original pathogen. Based on these findings, we proposed that the humoral response elicited by CaK plays important role in host protection against secondary C. albicans infections, and this might be achieved by pathogen-specific inhibition of fungal survival and/or growth.

DIFFERENTIAL EFFECTS OF IL-17 PATHWAY IN DISSEMINATED CANDIDIASIS AND ZYMOSAN-INDUCED MULTIPLE ORGAN FAILURE

The role of the IL-17 pathway in antifungal host defense is controversial. Several studies suggested that IL-17 is crucial for the protection against Candida infection, whereas other studies reported that IL-17 may contribute to inflammatory pathology and worsening of fungal disease. To address these discrepancies, we assessed the differential role of IL-17 pathway in two models of fungal sepsis: intravenous infection with live Candida albicans, in which fungal growth is the main cause of mortality, and zymosan-induced multiple organ failure, in which the inflammatory pathology drives the mortality. First, IL-17 receptor-deficient (IL-17RA) mice showed increased mortality and higher fungal loads in the kidneys in the model of disseminated candidiasis, partly caused by lower neutrophil recruitment in the IL-17RA mice. Second, IL-17RA mice were not protected against the multiorgan failure induced by zymosan. These data demonstrate that IL-17 does not have a major contribution to the inflammatory pathology leading to organ failure in fungal sepsis and support the concept that the IL-17 pathway is protective in antifungal host defense.

WHAT'S NEW IN SHOCK, OCTOBER 2010?

WHAT'S NEW IN SHOCK, OCTOBER 2010?

Differential effects of IL-17 pathway in disseminated candidiasis and zymosan-induced multiple organ failure

The role of the IL-17 pathway in fungal sepsis remains controversial. Several studies suggested that IL-17 is crucial for the protection against Candida sepsis, while other studies reported that IL-17 may contribute to inflammatory pathology and worsening of fungal disease. To address these discrepancies, we assessed the differential role of IL-17 pathway in two models of fungal sepsis: intravenous infection with live Candida albicans, in which fungal growth is the main cause of mortality, and zymosan-induced multiple organ failure in which the inflammatory pathology drives the mortality.

Research on the Inactivation Effect of Low-Temperature Plasma on Candida Albicans

A dielectric barrier discharge was used to generate low-temperature plasma to treat Candida albicans. When the gap spacing was 3 mm, the killing log value (KLV) of the plasma on Candida albicans within 20 s of exposure was more than five, and for 4 and 5 mm gap spacing, the KLV within 25 s was more than five. With the extension of exposure time, the decrease in velocity of the number of living Candida albicans was fastest for the gap spacing of 3 mm, and then for 4 and 5 mm spacing. With 60 s of electric field treatment, as the applied voltage increases, the survival number of Candida albicans has no significant difference from that of the control sample. As for the inactivation mechanism of plasma on Candida albicans on the molecular microbiology side, transmission electron microscopic examination and the results of protein, nucleic acid and K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> detection in the extracellular environment showed that the plasma destroyed the outer structure of Candida albicans. Cytoplasm was also released, which caused Candida albicans to be dead. On the plasma physics side, the role of the electric field during Candida albicans inactivation by plasma is considered negligible. Therefore, charged particles and reactive species in plasma might play a dominant role in the process of destroying the outer structure of Candida albicans.

Phagocytosis Assay Based on Living Candida albicans for the Detection of Effects of Chemicals on Macrophage Function

Phagocytosis is the first step of defense against infections from the innate immune system, as it is the process of internalization of pathogens by cells with phagocytic activity, such as macrophages, which is followed by pathogen killing and destruction. Thus, phagocytosis assays are used as assays for one function of the innate immune system. As fungal infections are of increasing relevance and phagocytic mechanisms are dependent on the pathogenic organism and its viability, we established a microtiter plate phagocytosis assay based on viable, fluorescence‐labeled Candida albicans. The distinction between internalized yeast cells and cells attached to macrophages was done via quenching of FITC—fluorescence by trypan blue, and the remaining fluorescence was quantified and used as indicator of the phagocytosis efficiency. As a proof of principle we showed that compounds acting on the dynamics of the actin cytoskeleton of the macrophages reduced the phagocytosis efficiency in a concentration dependent manner.