Evaluation of Potential Probiotic Properties and In Vivo Safety of Lactic Acid Bacteria and Yeast Strains Isolated from Traditional Home-Made Kefir.

Probiotics are known for their health-promoting resources and are considered as beneficial microorganisms. The current study focuses on the isolation, and on a complete in vitro and in vivo characterization, of yeast and lactic acid bacteria acquired from traditional homemade kefir in order to assess their potentiality as probiotic candidates. In particular, the isolates Pichia kudriavzevii Y1, Lactococcus lactis subsp. hordniae LAB1 and Lactococcus lactis subsp. lactis LAB2 were subjected to in vitro characterization to evaluate their suitability as probiotics. Resistance to acid and bile salts, auto-aggregation, co-aggregation, hydrophobicity, and biofilm production capability were examined, as well as their antioxidant activity. A safety assessment was also conducted to confirm the non-pathogenic nature of the isolates, with hemolysis assay and antibiotic resistance assessment. Moreover, mortality in the invertebrate model Galleria mellonella was evaluated. Current findings showed that P. kudriavzevii exhibited estimable probiotic properties, placing them as promising candidates for functional foods. Both lactic acid bacteria isolated in this work could be classified as potential probiotics with advantageous traits, including antimicrobial activity against enteric pathogens and good adhesion ability on intestinal cells. This study revealed that homemade kefir could be a beneficial origin of different probiotic microorganisms that may enhance health and wellness.

A metabolomics footprinting approach using GC-MS to study inhibitory effects of the fungal metabolite diplopyrone C against nosocomial pathogen biofilms.

Seen initially as wonder drugs, the widespread and often inappropriate use of antibiotics led to the development of microbial resistances. As a result, a true emergency has arisen, and a significant need has emerged to discover and develop new safe and valuable antibiotics. The captivating chemical structure of the fungal metabolite diplopyrone C has caught our attention as an excellent candidate for a circumstantial study aimed at revealing its antimicrobial and antibiofilm activities. In this work, we describe the full analytical strategy from the isolation/identification to the evaluation of the metabolomics effect on target microorganisms of this fungal metabolite. Our results show interesting antimicrobial and antibiofilm activities of diplopyrone C against two frequently isolated nosocomial pathogens (i.e., the fungus Candida albicans and the gram-negative bacterium Klebsiella pneumoniae). Moreover, a GC-MS based metabolomics footprinting approach gave an insight into the uptake and excretion of metabolites from and into the culture medium as a response to the presence of this active substance. The workflow employed in this study is suitable to exploit natural resources for the search of lead compounds for drug development.

A Preliminary Evaluation on the Antifungal Efficacy of VT-1161 against Persister Candida albicans Cells in Vulvovaginal Candidiasis.

Persister cells are a small fraction of the microbial population that survive lethal concentrations of antimicrobial agents. Candida albicans causes vaginal candidiasis, including recurrent vulvovaginal candidiasis, and may survive common antifungal treatments. The triazole VT-1161 is an antifungal agent that specifically targets fungal CYP51, as opposed to the human CYP enzyme. This work illustrates a new role of VT-1161 in eradicating the biofilm created from the persister cells of a primary biofilm of a clinical vaginal isolate of C. albicans. Antifungal activity was determined by the minimum inhibitory concentration (MIC), and the primary biofilm was treated with amphotericin B to obtain persister cells that were able to form a new biofilm. Results obtained using the new azole VT-1161 showed that VT-1161 not only eradicated a secondary biofilm formed from the persister-derived biofilm and counteracted the adhesion of C. albicans in vitro to human cells but also ameliorated C. albicans-induced infection in vivo in Galleria mellonella larvae, suggesting that it could be proposed as an alternative therapeutic strategy for the treatment of recurrent candidiasis.

Early consequences of the phospholamban mutation PLN-R14del+/- in a transgenic mouse model.

AIMS: The heterozygous phospholamban (PLN) mutation R14del (PLN R14del+/- ) is associated with a severe arrhythmogenic cardiomyopathy (ACM) developing in the adult. "Superinhibition" of SERCA2a by PLN R14del is widely assumed to underlie the pathogenesis, but alternative mechanisms such abnormal energy metabolism have also been reported. This work aims to (1) to evaluate Ca2+ dynamics and energy metabolism in a transgenic (TG) mouse model of the mutation prior to cardiomyopathy development; (2) to test whether they are causally connected. METHODS: Ca2+ dynamics, energy metabolism parameters, reporters of mitochondrial integrity, energy, and redox homeostasis were measured in ventricular myocytes of 8-12 weeks-old, phenotypically silent, TG mice. Mutation effects were compared to pharmacological PLN antagonism and analyzed during modulation of sarcoplasmic reticulum (SR) and cytosolic Ca2+ compartments. Transcripts and proteins of relevant signaling pathways were evaluated. RESULTS: The mutation was characterized by hyperdynamic Ca2+ handling, compatible with a loss of SERCA2a inhibition by PLN. All components of energy metabolism were depressed; myocyte energy charge was preserved under quiescence but reduced during stimulation. Cytosolic Ca2+ buffering or SERCA2a blockade reduced O2 consumption with larger effect in the mutant. Signaling changes suggest cellular adaptation to perturbed Ca2+ dynamics and response to stress. CONCLUSIONS: (1) PLN R14del+/- loses its ability to inhibit SERCA2a, which argues against SERCA2a superinhibition as a pathogenetic mechanism; (2) depressed energy metabolism, its enhanced dependency on Ca2+ and activation of signaling responses point to an early involvement of metabolic stress in the pathogenesis of this ACM model.

Extracellular Vesicles from a Biofilm of a Clinical Isolate of Candida albicans Negatively Impact on Klebsiella pneumoniae Adherence and Biofilm Formation.

The opportunistic human fungal pathogen Candida albicans produces and releases into the surrounding medium extracellular vesicles (EVs), which are involved in some processes as communication between fungal cells and host-pathogen interactions during infection. Here, we have conducted the isolation of EVs produced by a clinical isolate of C. albicans during biofilm formation and proved their effect towards the ability of the Gram-negative bacterial pathogen Klebsiella pneumoniae to adhere to HaCaT cells and form a biofilm in vitro. The results represent the first evidence of an antagonistic action of fungal EVs against bacteria.

Patient-specific primary and pluripotent stem cell-derived stromal cells recapitulate key aspects of arrhythmogenic cardiomyopathy.

Primary cardiac mesenchymal stromal cells (C-MSCs) can promote the aberrant remodeling of cardiac tissue that characterizes arrhythmogenic cardiomyopathy (ACM) by differentiating into adipocytes and myofibroblasts. These cells' limitations, including restricted access to primary material and its manipulation have been overcome by the advancement of human induced pluripotent stem cells (hiPSCs), and their ability to differentiate towards the cardiac stromal population. C-MSCs derived from hiPSCs make it possible to work with virtually unlimited numbers of cells that are genetically identical to the cells of origin. We performed in vitro experiments on primary stromal cells (Primary) and hiPSC-derived stromal cells (hiPSC-D) to compare them as tools to model ACM. Both Primary and hiPSC-D cells expressed mesenchymal surface markers and possessed typical MSC differentiation potentials. hiPSC-D expressed desmosomal genes and proteins and shared a similar transcriptomic profile with Primary cells. Furthermore, ACM hiPSC-D exhibited higher propensity to accumulate lipid droplets and collagen compared to healthy control cells, similar to their primary counterparts. Therefore, both Primary and hiPSC-D cardiac stromal cells obtained from ACM patients can be used to model aspects of the disease. The choice of the most suitable model will depend on experimental needs and on the availability of human source samples.

A Re-Purposing Strategy: Sub-Lethal Concentrations of an Eicosanoid Derived from the Omega-3-Polyunsaturated Fatty Acid Resolvin D1 Affect Dual Species Biofilms.

The fungal species Candida parapsilosis and the bacterial species Staphylococcus aureus may be responsible for hospital-acquired infections in patients undergoing invasive medical interventions or surgical procedures and often coinfect critically ill patients in complicating polymicrobial biofilms. The efficacy of the re-purposing therapy has recently been reported as an alternative to be used. PUFAs (polyunsaturated fatty acids) may be used alone or in combination with currently available traditional antimicrobials to prevent and manage various infections overcoming antimicrobial resistance. The objectives of the study were to evaluate the effects of Resolvin D1 (RvD1) as an antimicrobial on S. aureus and C. parapsilosis, as well as the activity against the mixed biofilm of the same two species. Microdilution assays and time-kill growth curves revealed bacterial and fungal inhibition at minimum concentration values between 5 and 10 µg mL-1. In single-species structures, an inhibition of 55% and 42% was reported for S. aureus and C. parapsilosis, respectively. Moreover, RvD1 demonstrated an eradication capacity of 60% and 80% for single- and mixed-species biofilms, respectively. In association with the inhibition activity, a downregulation of genes involved in biofilm formation as well as ROS accumulation was observed. Eradication capability was confirmed also on mature mixed biofilm grown on silicone platelets as shown by scanning electron microscopy (SEM). In conclusion, RvD1 was efficient against mono and polymicrobial biofilms in vitro, being a promising alternative for the treatment of mixed bacterial/fungal infections.

Candida Biofilm Eye Infection: Main Aspects and Advance in Novel Agents as Potential Source of Treatment.

Fungi represent a very important cause of microbial eye infections, especially in tropical and developing countries, as they could cause sight-threating disease, such as keratitis and ocular candidiasis, resulting in irreversible vision loss. Candida species are among the most frequent microorganisms associated with fungal infection. Although Candida albicans is still the most frequently detected organism among Candida subspecies, an important increase in non-albicans species has been reported. Mycotic infections often represent an important diagnostic-clinical problem due to the difficulties in performing the diagnosis and a therapeutic problem due to the limited availability of commercial drugs and the difficult penetration of antifungals into ocular tissues. The ability to form biofilms is another feature that makes Candida a dangerous pathogen. In this review, a summary of the state-of-the-art panorama about candida ocular pathology, diagnosis, and treatment has been conducted. Moreover, we also focused on new prospective natural compounds, including nanoparticles, micelles, and nanocarriers, as promising drug delivery systems to better cure ocular fungal and biofilm-related infections. The effect of the drug combination has also been examined from the perspective of increasing efficacy and improving the course of infections caused by Candida which are difficult to fight.

Impaired Plakophilin-2 in obesity breaks cell cycle dynamics to breed adipocyte senescence.

Plakophilin-2 (PKP2) is a key component of desmosomes, which, when defective, is known to promote the fibro-fatty infiltration of heart muscle. Less attention has been given to its role in adipose tissue. We report here that levels of PKP2 steadily increase during fat cell differentiation, and are compromised if adipocytes are exposed to a pro-inflammatory milieu. Accordingly, expression of PKP2 in subcutaneous adipose tissue diminishes in patients with obesity, and normalizes upon mild-to-intense weight loss. We further show defective PKP2 in adipocytes to break cell cycle dynamics and yield premature senescence, a key rheostat for stress-induced adipose tissue dysfunction. Conversely, restoring PKP2 in inflamed adipocytes rewires E2F signaling towards the re-activation of cell cycle and decreased senescence. Our findings connect the expression of PKP2 in fat cells to the physiopathology of obesity, as well as uncover a previously unknown defect in cell cycle and adipocyte senescence due to impaired PKP2.

Effect of Escin Alone or in Combination with Antifungal Agents on Resistant Candida glabrata Biofilms: Mechanisms of Action.

Nowadays, the increase in antimicrobial-resistant fungi (AMR) is certainly a major health concern, and the development of alternative therapeutic strategies has become crucial. Natural products have been used to treat various infections, and their chemical properties contribute to the performance of their biological activities, such as antifungal action. The various virulence factors and mechanisms of resistance to antifungals contribute to making Candida glabrata one of the most frequent agents of candidiasis. Here we investigate the in vitro and in vivo activity of ß-escin against Candida glabrata. The ß-escin MICs were determined for a reference strain and two clinical isolates of C. glabrata. Furthermore, growth kinetics assays and biofilm inhibition/eradication assays (crystal violet) were performed. The differences in the expression of some anti-biofilm-associated genes were analyzed during biofilm inhibition treatment so that reactive oxygen species could be detected. The efficacy of ß-escin was evaluated in combination with fluconazole, ketoconazole, and itraconazole. In addition, a Galleria mellonella infection model was used for in vivo treatment assays. Results have shown that ß-escin had no toxicity in vitro or in vivo and was able to inhibit or destroy biofilm formation by downregulating some important genes, inducing ROS activity and affecting the membrane integrity of C. glabrata cells. Furthermore, our study suggests that the combination with azoles can have synergistic effects against C. glabrata biofilm. In summary, the discovery of new antifungal drugs against these resistant fungi is crucial and could potentially lead to the development of future treatment strategies.

Omics Analyses of Stromal Cells from ACM Patients Reveal Alterations in Chromatin Organization and Mitochondrial Homeostasis.

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder characterized by ventricular arrhythmias, contractile dysfunctions and fibro-adipose replacement of myocardium. Cardiac mesenchymal stromal cells (CMSCs) participate in disease pathogenesis by differentiating towards adipocytes and myofibroblasts. Some altered pathways in ACM are known, but many are yet to be discovered. We aimed to enrich the understanding of ACM pathogenesis by comparing epigenetic and gene expression profiles of ACM-CMSCs with healthy control (HC)-CMSCs. Methylome analysis identified 74 differentially methylated nucleotides, most of them located on the mitochondrial genome. Transcriptome analysis revealed 327 genes that were more expressed and 202 genes that were less expressed in ACM- vs. HC-CMSCs. Among these, genes implicated in mitochondrial respiration and in epithelial-to-mesenchymal transition were more expressed, and cell cycle genes were less expressed in ACM- vs. HC-CMSCs. Through enrichment and gene network analyses, we identified differentially regulated pathways, some of which never associated with ACM, including mitochondrial functioning and chromatin organization, both in line with methylome results. Functional validations confirmed that ACM-CMSCs exhibited higher amounts of active mitochondria and ROS production, a lower proliferation rate and a more pronounced epicardial-to-mesenchymal transition compared to the controls. In conclusion, ACM-CMSC-omics revealed some additional altered molecular pathways, relevant in disease pathogenesis, which may constitute novel targets for specific therapies.

Prevalence, Resistance Patterns and Biofilm Production Ability of Bacterial Uropathogens from Cases of Community-Acquired Urinary Tract Infections in South Italy.

Community-acquired urinary tract infections represent the most common infectious diseases in the community setting. Knowing the antibiotic resistance patterns of uropathogens is crucial for establishing empirical treatment. The aim of the current study is to determine the incidence of the causative agents of UTIs and their resistance profiles. Patients of all ages and both sexes were enrolled in the study, and admitted to San Ciro Diagnostic Center in Naples between January 2019 and Jun 2020. Bacterial identification and antibiotic susceptibility testing were carried out using Vitek 2 system. Among the 2741 urine samples, 1702 (62.1%) and 1309 (37.9%) were negative and positive for bacterial growth, respectively. Of 1309 patients with infection, 760 (73.1%) were females and 279 (26.9%) were males. The greatest number of positive cases were found in the in the elderly (>61 years). Regarding uropathogens, 1000 (96.2%) were Gram-negative while 39 (3.8%) were Gram-positive strains. The three most isolated pathogenic strains were Escherichia coli (72.2%), Klebsiella pneumoniae (12.4%), and Proteus mirabilis (9.0%). Strong biofilm formation ability was observed in about 30% of the tested isolates. The low resistance rates recorded against nitrofurantoin, fosfomycin, piperacillin-tazobactam, and gentamicin could suggest them as the most appropriate therapies for CA-UTIs.

Anti-Biofilm Activity of Phenyllactic Acid against Clinical Isolates of Fluconazole-Resistant Candida albicans.

Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region, and is responsible for 85% to 90% of vulvovaginal candidiasis (VVC) cases. The development of drug resistance in C. albicans isolates after long-term therapy with fluconazole is an important complication to solve and new therapeutic strategies are required to target this organism and its pathogenicity. In the present study, phenyllactic acid (PLA) an important broad-spectrum antimicrobial compound was investigated for its antifungal and antivirulence activities against clinical isolates of C. albicans. Previously characterized strains of C. albicans isolates from women with VVC and C. albicans ATCC90028 were used to evaluate the antimicrobial and time dependent killing assay activity of PLA showing a MIC 7.5 mg mL-1 and a complete reduction of viable Candida cells detected by killing kinetics after 4 h of treatment with PLA. Additionally, PLA significantly reduced the biomass and the metabolic activity of C. albicans biofilms and impaired biofilm formation also with changes in ERG11, ALS3, and HWP1 genes expression as detected by qPCR. PLA eradicated pre-formed biofilms as showed also with confocal laser scanning microscopy (CLSM) observations. Furthermore, the compound prolonged the survival rate of Galleria mellonella infected by C. albicans isolates. These results indicate that PLA is a promising candidate as novel and safe antifungal agents for the treatment of vulvovaginal candidiasis.

VT-1161-A Tetrazole for Management of Mono- and Dual-Species Biofilms.

VT-1161 is a novel tetrazole antifungal agent with high specificity for fungal CYP51 (compared to human CYP enzymes) which has been proven to have fewer adverse effects and drug-drug interaction profiles due to fewer off-target inhibitors. In this study, we evaluated the anti-biofilm potential of VT-1161 against mono- and dual-species biofilms of Candida albicans, Klebsiella pneumoniae and Staphylococcus aureus. VT-1161 inhibited planktonic growth of all three strains, with an MIC value of 2 µg mL-1 for C. albicans and 0.5 µg mL-1 for K. pneumoniae and S. aureus, and killed 99.9% of the microbial populations, indicating a cytocidal action. Additionally, VT-1161 showed an excellent anti-biofilm action, since it inhibited mono-microbial biofilms by 80% at 0.5 µg mL-1, and dual-species biofilms of C. albicans/K. pneumoniae and C. albicans/S. aureus by 90% at the same concentration. Additionally, the eradication of mature biofilms after 24 h of VT-1161 exposure was excellent, reaching 90% at 2 µg mL-1 for both mono- and dual-species biofilms. In such mixed biofilms, the use of VT-1161 was revealed to be an alternative treatment because it was able to reduce the number of cells of each species during both inhibition and eradication. Since long-term therapy is necessary for most fungal biofilm infections due to their recurrence and obstinacy, VT-1161 showed low cytotoxicity against normal human cell lines and also against the invertebrate model Caenorhabditis elegans. Considering the excellent anti-biofilm potential and its GRAS (generally recognized as safe) status, VT-1161 may find use in the prevention or therapeutic treatment of mono- or poly-microbial biofilms.

Synthesis of temporin L hydroxamate-based peptides and evaluation of their coordination properties with iron(III ).

Ferric iron is an essential nutrient for bacterial growth. Pathogenic bacteria synthesize iron-chelating entities known as siderophores to sequestrate ferric iron from host organisms in order to colonize and replicate. The development of antimicrobial peptides (AMPs) conjugated to iron chelators represents a promising strategy for reducing the iron availability, inducing bacterial death, and enhancing simultaneously the efficacy of AMPs. Here we designed, synthesized, and characterized three hydroxamate-based peptides Pep-cyc1, Pep-cyc2, and Pep-cyc3, derived from a cyclic temporin L peptide (Pep-cyc) developed previously by some of us. The Fe3+ complex formation of each ligand was characterized by UV-visible spectroscopy, mass spectrometry, and IR and NMR spectroscopies. In addition, the effect of Fe3+ on the stabilization of the α-helix conformation of hydroxamate-based peptides and the cotton effect were examined by CD spectroscopy. Moreover, the antimicrobial results obtained in vitro on some Gram-negative strains (K. pneumoniae and E. coli) showed the ability of each peptide to chelate efficaciously Fe3+ obtaining a reduction of MIC values in comparison to their parent peptide Pep-cyc. Our results demonstrated that siderophore conjugation could increase the efficacy and selectivity of AMPs used for the treatment of infectious diseases caused by Gram-negative pathogens.

Myxinidin-Derived Peptide against Biofilms Caused by Cystic Fibrosis Emerging Pathogens.

Chronic lung infections in cystic fibrosis (CF) patients are triggered by multidrug-resistant bacteria such as Pseudomonas aeruginosa, Achromobacter xylosoxidans, and Stenotrophomonas maltophilia. The CF airways are considered ideal sites for the colonization and growth of bacteria and fungi that favor the formation of mixed biofilms that are difficult to treat. The inefficacy of traditional antibiotics reinforces the need to find novel molecules able to fight these chronic infections. Antimicrobial peptides (AMPs) represent a promising alternative for their antimicrobial, anti-inflammatory, and immunomodulatory activities. We developed a more serum-stable version of the peptide WMR (WMR-4) and investigated its ability to inhibit and eradicate C. albicans, S. maltophilia, and A. xylosoxidans biofilms in both in vitro and in vivo studies. Our results suggest that the peptide is able better to inhibit than to eradicate both mono and dual-species biofilms, which is further confirmed by the downregulation of some genes involved in biofilm formation or in quorum-sensing signaling. Biophysical data help to elucidate its mode of action, showing a strong interaction of WMR-4 with lipopolysaccharide (LPS) and its insertion in liposomes mimicking Gram-negative and Candida membranes. Our results support the promising therapeutic application of AMPs in the treatment of mono- and dual-species biofilms during chronic infections in CF patients.

Polystyrene Microplastics Exacerbate Candida albicans Infection Ability In Vitro and In Vivo.

Plastic pollution is an important environmental problem, and microplastics have been shown to have harmful effects on human and animal health, affecting immune and metabolic physiological functions. Further, microplastics can interfere with commensal microorganisms and exert deleterious effects on exposure to pathogens. Here, we compared the effects of 1 µm diameter polystyrene microplastic (PSMPs) on Candida albicans infection in both in vitro and in vivo models by using HT29 cells and Galleria mellonella larvae, respectively. The results demonstrated that PSMPs could promote Candida infection in HT29 cells and larvae of G. mellonella, which show immune responses similar to vertebrates. In this study, we provide new experimental evidence for the risk to human health posed by PSMPs in conjunction with Candida infections.

A model for microbial interactions and metabolomic alterations in Candida glabrata-Staphylococcus epidermidis dual-species biofilms.

The fungus Candida glabrata and the bacterium Staphylococcus epidermidis are important biofilm-forming microorganisms responsible of nosocomial infections in patients. In addition to causing single-species disease, these microorganisms are also involved in polymicrobial infections leading to an increased antimicrobial resistance. To expand knowledge about polymicrobial biofilms, in this study we investigate the formation of single- and dual-species biofilms of these two opportunistic pathogens employing several complementary approaches. First, biofilm biomass, biofilm metabolic activity and the microbial composition in single- and dual-species biofilms were assessed and compared. Then, the expression of three genes of C. glabrata and three genes of S. epidermidis positively related to the process of biofilm formation was evaluated. Although S. epidermidis is a stronger biofilm producer than C. glabrata, both biological and genetic data indicate that S. epidermidis growth is inhibited by C. glabrata which dominates the dual-species biofilms. To better understand the mechanisms of the interactions between the two microorganisms, a broad GC-MS metabolomic dataset of extracellular metabolites for planktonic, single- and dual-species biofilm cultures of C. glabrata and S. epidermidis was collected. As demonstrated by Partial Least Squares Discriminant Analysis (PLS-DA) of GC-MS metabolomic data, planktonic cultures, single- and dual-species biofilms can be sharply differentiated from each other by the nature and levels of an assortment of primary and secondary metabolites secreted in the culture medium. However, according to our data, 2-phenylethanol (secreted by C. glabrata) and the synergistically combined antifungal activity of 3-phenyllactic acid and of the cyclic dipeptide cyclo-(l-Pro-l-Trp) (secreted by S. epidermidis) play a major role in the race of the two microorganisms for predominance and survival.

Undesired Effect of Vancomycin Prolonged Treatment: Enhanced Biofilm Production of the Nosocomial Pathogen Candida auris.

Fungal infections are often consequent to prolonged antibiotic treatments. Vancomycin (Van) is the first-choice antibiotic in the treatment of Staphylococcus aureus infections associated with colonization of catheter surfaces. We demonstrate the direct effect of Van in promoting the formation of the biofilm of the emergent yeast pathogen Candida auris, developed in the conventional polystyrene microwell plate model, as well as on silicone surfaces (22 and 28% increase in total biomass, respectively) and on an S. aures biofilm, residual after vancomycin treatment, where C. auris achieved 99% of the mixed biofilm population. The effect of Van was assessed also in vivo, in the Galleria mellonella infection model, which showed higher mortality when infected with the yeast pathogen in the presence of the antibiotic. This evidence enhances awareness of the potential risk associated with prolonged antibiotic use in promoting fungal infections.

The Arylamidine T-2307 as a Novel Treatment for the Prevention and Eradication of Candida tropicalis Biofilms.

Candida tropicalis is an emerging pathogen with a high mortality rate due to its virulence factors, including biofilm formation, that has important repercussions on the public health system. The ability of C. tropicalis to form biofilms, which are potentially more resistant to antifungal drugs and the consequent increasing antimicrobial resistance, highlights an urgent need for the development of novel antifungal. The present study analyzed the antibiofilm capacity of the arylamidine T-2307 on two strains of Candida tropicalis. Antimicrobial activity and time-killing assays were performed to evaluate the anticandidal effects of T-2307, the antibiofilm ability on biomass inhibition and eradication was evaluated by the crystal violet (CV) method. Furthermore, in Galleria mellonella infected larvae an increased survival after pre-and post- treatment with T-2307 was observed. The MTT test was used to determine the viability of immortalized human prostate epithelial cells (PNT1A) after exposure to different concentrations of T-2307. Levels of interleukin IL-4, IL-8, IL-10 were quantified after Candida infection of PNT1A cells and treatment. Active doses of T-2307 did not affect the viability of PNT1A cells, and drug concentrations of 0.005 or 0.01 µg mL-1 inhibited the secretion of inflammatory cytokines. Taken together, these results provide new information on T-2307, indicating this drug as a new and promising alternative therapeutic option for the treatment of Candida infections.