Effects of bioconversion by Battus polydamas on the chemical composition of Aristolochia spp. and evaluation of antimicrobial activity and biocompatibility.

Aristolochia plants are emblematic from an ethnopharmacological viewpoint and are know to possess numerous biological properties, including antiseptic. However, the medicinal potential of these species is debatable because of their representative chemical constituents, aristolochic acids (AAs) and aristolactams (ALs), which are associated, for instance, with nephropathy and cancer. These contrasting issues have stimulated the development of approaches intended to detoxification of aristoloquiaceous biomasses, among which is included the bioconversion method using larvae of the specialist phytophagous insect Battus polydamas, previously shown to be viable for chemical diversification and to reduce toxicity. Thus, eleven Aristolochia spp. were bioconverted, and the antimicrobial activities of the plant methanolic extracts and its respective bioconversion products were evaluated. The best results were found for Aristolochia esperanzae, Aristolochia gibertii, and Aristolochia ringens against Bacillus cereus, with MIC ranging from 7.8 to 31.25 µg/mL. These three species were selected for chemical, antioxidant, cytotoxic, hemolytic, and mutagenic analyses. Chemical analysis revealed 65 compounds, 21 of them possible bioconversion products. The extracts showed potential to inhibit the formation and degradation of B. cereus biofilms. Extracts of A. gibertii and its bioconverted biomass showed antioxidant activity comparable to dibutylhydroxytoluene (BHT) standard. Bioconversion decreased the hemolytic activity of A. esperanzae and the cytotoxicities of A. esperanzae and A. gibertii. None of the extracts was found to be mutagenic. The bioactivities of the fecal extracts were maintained, and biocompatibility was improved. Therefore, the results obtained in this study reveal positive expectations about the natural detoxification process of the Aristolochia species.

Detection of 2-ethyl-1-hexanol and its modulating effect in biofilm of Fusarium oxysporum.

In immunocompetent individuals, Fusarium spp. stands out as the causative agent of onychomycosis, among the non-dermatophyte molds. Despite evidence indicating that Fusarium oxysporum organizes itself in the form of a biofilm causing onychomycosis, there is little literature on the etiopathogenesis of the biofilm on the nail, specifically the signaling molecules present, known as quorum sensing (QS). Thus, this study detected the presence of a molecule related to QS from the ex vivo biofilm of F. oxysporum on human nail and investigated its effect on preformed biofilm in vitro. The detection and physicochemical characterization of a QS molecule, from the extracellular matrix (ECM), was carried out by Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflectance (ATR) accessory and by headspace gas chromatography coupled to mass spectrometry (GC-MS) analyses. Determination of viable cells, cell activity, total biomass, ECM components and scanning electron microscopy (SEM) were performed to evaluate the influence of the QS molecule on the in vitro biofilm of F. oxysporum. The beginning, in the ex vivo biofilm of F. oxysporum on human nails, the volatile organic compound 2-ethyl-1-hexanol (2EH) was detected as a component of QS. Thereafter in vitro analyses, synthetic 2EH was able to modulate the biofilm by stimulating its filament, increasing total biomass and ECM production in terms of total carbohydrates, but with a reduction in total proteins and nucleic acids. We thus evidence, for the first time, the presence of 2EH in the biofilm of F. oxysporum, developed on the human nail, and the in vitro action of this compound as a QS molecule.

Stilbenes, phenanthrenes and antiproliferative activity of Cattleya intermedia.

The phytochemical study of Cattleya intermedia (Orchidaceae) led to the isolation of two new stilbenoids and one new 9,10-dihydrophenanthrene, 4',5-dihydroxy-2',3-dimethoxy-dihydrostilbene (1), 3,6'-dihydroxy-4'-methoxy-dihydrostilbene (2) and 1,2,6-trihydroxy-3,8-dimethoxy-9,10-dihydrophenanthrene (3), named cattleymediol, cattleyol and phenanmediol, respectively, in addition to other five known compounds (4-8). The structural elucidations of the isolated compounds were carried out through the analyses of the one-dimensional 1H,1³C and NOE NMR spectra, and the 2D HSQC, HMBC, COSY and NOESY spectra, besides high-resolution mass spectrometry. In addition to this, the crude extract and its main fractions were analysed by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-QTOF-MS/MS), leading to the putative identification of several other compounds, including flavonoids and organic acids derivatives. Finally, the main fractions of the crude extract, and the pure compounds cattleymediol (1) and lusiantridine (7), had their antiproliferative activities evaluated against human cancerous HeLa and non-cancerous VERO cells.

Antibacterial and immunological properties of piperine evidenced by preclinical studies: a systematic review.

Aim: To review in vitro, in vivo, and in silico studies examining the antibacterial and immunomodulatory properties of piperine (PPN). Methods: This systematic review followed PRISMA guidelines, and five databases were searched. Results: A total of 40 articles were included in this study. Six aspects of PPN activity were identified, including antibacterial spectrum, association with antibiotics, efflux pump inhibition, biofilm effects, protein target binding, and modulation of immune functions/virulence factors. Most studies focused on Mycobacterium spp. and Staphylococcus aureus. Cell lineages and in vivo models were employed to study PPN antibacterial effects. Conclusion: We highlight PPN as a potential adjuvant in the treatment of bacterial infections. PPN possesses several antibacterial properties that need further exploration to determine the mechanisms behind its pharmacological activity.

Impact of invasive fungal infections in men from a state in southern Brazil: A geospatial analysis.

OBJECTIVE: To analyse the records of male hospitalisation for fungal infections, including their spatial distribution and the main invasive epidemiological and sociodemographic characteristics in the State of Paraná, Brazil. METHODS: Spatial analysis based on data from male admission records for invasive fungal infections (IFIs) in the State of Paraná, from 2015 to 2019. Data were taken from the hospital records obtained in the Hospital Information System of the Unified Health System, being collected, georeferenced and analysed to infer the existence of autocorrelation with the hospitalisation rates in the state. RESULTS: From 2015 to 2019, there were 385 cases of IFIs in men, being more prevalent in white individuals aged 61-70 years. We observed that the metropolitan, southeast, central-eastern, north-central, northwestern and western regions formed high-high clusters, with regions with a high number of registered cases. In the regression, there was an association with socioeconomic and demographic factors that showed a correlation with the rates of hospitalisation for IFIs. CONCLUSION: The study draws attention to Paraná as an endemic region for paracoccidioidomycosis, in addition to presenting high rates of nosocomial fungal infections. We also emphasise the importance of compulsory notification in the state and in the country to gain greater control over the incidence and prevalence of cases and to incentivise the creation of public policies for the prevention of IFIs.

Ascending renal infection following experimental candiduria by Candida tropicalis in immunocompromised mice.

The present study evaluated renal infection resulting from the implantation of C. tropicalis in the bladder of immunosuppressed mice. Yeasts were implanted in two manners: planktonic and via preformed biofilm on a small catheter fragment (SCF). Renal histopathology and cultures was performed 72 and 144 h after cystotomy was carried out in mice from three groups: group I contained non-contaminated mice implanted with a sterile SCF; group II mice received a sterile SCF plus a yeast suspension containing 1 × 107 yeasts/mL in a planktonic form; group III mice were implanted with a SCF containing preformed C. tropicalis biofilm. Viable yeasts were found in the kidneys of mice from both groups II and III. However, after 72 h the planktonic cells (group II) invaded more quickly than the sessile cells (group III). Over a longer period (144 h), group III exhibited a more invasive infection (50% of the animals presented renal infection and the renal fungal load was 3.2 log10 CFU/g tissue) than in group II, where yeasts were not found. C. tropicalis introduced into the bladder in two ways (in planktonic or biofilm form) were able to reach the kidney and establish a renal fungal infection, causing interstitial disorders. The data of the present study therefore support the hypothesis of an ascending pathway for renal infections by C. tropicalis. Furthermore, the biofilm resulted in a greater and progressive risk of renal infection, attributed to the slow detachment of the yeasts.

In Vitro and Ex Vivo Biofilm-Forming Ability of Rhinocladiella similis and Trichophyton rubrum Isolated from a Mixed Onychomycosis Case.

Infections caused by biofilm-forming agents have important implications for world health. Mixed infections, caused by more than one etiological agent, are also an emerging problem, especially regarding the standardization of effective diagnosis and treatment methods. Cases of mixed onychomycosis (OM) have been reported; however, studies on the microbial interactions between the different fungi in biofilms formed on nails are still scarce. We describe a case of mixed OM caused by the dermatophyte Trichophyton rubrum and the black yeast-like fungus Rhinocladiella similis. Identical growths of both fungi were observed in more than 50 cultures from different nail samples. Additionally, both species were able to form organized single and mixed biofilms, reinforcing the participation of both fungi in the etiology of this OM case. R. similis seemed to grow faster during the process, suggesting that T. rubrum benefits from biofilm development when in combination. Moreover, the biofilm of the Rhinocladiella isolate exhibited exacerbated production of the extracellular matrix, which was not observed with that of a Rhinocladiella reference strain, suggesting that the isolate had natural abilities that were possibly perfected during development in the nail of the patient.

Candida palmioleophila: A New Emerging Threat in Brazil?

Human activity directly or indirectly causes climate change, promoting changes in the composition of the atmosphere. This change is beyond the variation of the natural climate. In this manner, climate change could create an environmental pressure which is enough to trigger new fungal diseases. In addition to climate alterations, the onset of the COVID-19 pandemic has also been associated with the emergence of fungal pathogens. Fungi showed that an inability to grow at high temperatures limits the capacity of fungi to infect mammals. However, fungi can develop thermotolerance, gradually adapting to rising temperatures due to climate change, and generating a greater number of disease-causing organisms. In the present study, we reported the detection and identification of Candida palmioleophila isolates recovered from raw sewage samples in Niteroi city, Rio de Janeiro State, Brazil, during a monitoring program for measuring SARS-CoV-2 presence and concentration. Using polyphasic taxonomy to identify the species and evaluating some virulence aspects of this species, such as biofilm formation and extracellular enzyme production, our data highlight this species as a possible emerging pathogen in Brazil, especially in the pandemic context.

Case of Mixed Infection of Toenail Caused by Candida parapsilosis and Exophiala dermatitidis and In Vitro Effectiveness of Propolis Extract on Mixed Biofilm.

Onychomycosis is a chronic fungal nail infection caused by several filamentous and yeast-like fungi, such as the genus Candida spp., of great clinical importance. Black yeasts, such as Exophiala dermatitidis, a closely related Candida spp. species, also act as opportunistic pathogens. Fungi infectious diseases are affected by organisms organized in biofilm in onychomycosis, making treatment even more difficult. This study aimed to evaluate the in vitro susceptibility profile to propolis extract and the ability to form a simple and mixed biofilm of two yeasts isolated from the same onychomycosis infection. The yeasts isolated from a patient with onychomycosis were identified as Candida parapsilosis sensu stricto and Exophiala dermatitidis. Both yeasts were able to form simple and mixed (in combination) biofilms. Notably, C. parapsilosis prevailed when presented in combination. The susceptibility profile of propolis extract showed action against E. dermatitidis and C. parapsilosis in planktonic form, but when the yeasts were in mixed biofilm, we only observed action against E. dermatitidis, until total eradication.

Challenges and perspectives in research and teaching of host pathogen interaction topics: new post-pandemic times to Brazil and other South American countries.

Here is our proposal to improve learning in biomedical sciences for graduate and undergraduate courses with a broad vision integrating disciplines such as molecular cell biology, biochemistry, and biophysics around concepts of pathogen interaction within vertebrate and invertebrate hosts. Our paradigm is based on the possibility offered by the pandemic to have remote activities that give access to students and researchers from different places in Brazil and Latin American countries to discuss science. A multidisciplinary view of host-pathogen interaction allows us to understand better the mechanisms involved in the pathology of diseases, as well as to formulate broad strategies for the diagnosis, treatment, and control of thereof. The approach to integrating heterogeneous groups in science involves the critical analysis of national scientific resource distribution, where only some have the possibilities to conduct competitive scientific research. Solid theoretical training, contact, collaboration with groups of excellence, and training within a multidisciplinary network are our proposals for a permanent platform of scientific strengthening and dissemination for Latin America. Here we will review the concept of host-pathogen interaction, the type of institutions where it is taught and researched, new trends in active teaching methodologies, and the current political context in science.

Fungal quorum-sensing molecules and antiseptics: A promising strategy for biofilm modulation?

New strategies to control fungal biofilms are essential, especially those that interfere in the biofilm organization process and cellular communication, known as quorum sensing. The effect of antiseptics and quorum-sensing molecules (QSMs) have been considered with regard to this; however, little has been elucidated, particularly because studies are often restricted to the action of antiseptics and QSMs against a few fungal genera. In this review, we discuss progress reported in the literature thus far and analyze, through in silico methods, 13 fungal QSMs with regard to their physicochemical, pharmacological, and toxicity properties, including their mutagenicity, tumorigenicity, hepatotoxicity, and nephrotoxicity. From these in silico analyses, we highlight 4-hydroxyphenylacetic acid and tryptophol as having satisfactory properties and, thus, propose that these should be investigated further as antifungal agents. We also recommend future in vitro approaches to determine the association of QSMs with commonly used antiseptics as potential antibiofilm agents.

Polycaprolactone nanofibers colonized by HeLa cells: an alternative for in vitro investigation of fungal infection.

Introduction: In vitro 3D equivalent tissues can be used for studies of fungal infections. Objectives: To develop 3D electrospun nanofibers using polycaprolactone (PCL) colonized by HeLa cells as a possible in vitro model for the investigation of fungal infection. Materials & methods: A PCL solution was synthesized and electrospun. HeLa cells were cultured on the nanostructured PCL scaffolds, forming a 3D structure. Physicochemical, biological and Candida albicans infection assays were performed in this model. Results: The nanostructured PCL scaffolds showed favorable physicochemical characteristics and allowed the colonization of HeLa cells, which showed indications of extracellular matrix production. Conclusions: Fungal infection was evidenced in the 3D nanostructured PCL scaffolds, being viable, economical and compatible to study fungal infections in vitro.

Hospital Trichosporon asahii isolates with simple architecture biofilms and high resistance to antifungals routinely used in clinical practice.

Infections by Trichosporon spp. are increasing worldwide and its treatment remains a challenge. Colonization of medical devices has been considered as a predisposing factor for trichosporonosis, which is related to fungal biofilm production. Thus, this study aimed to evaluate the ability of six hospital T. asahii isolates to form biofilm on abiotic surface, as well as to investigate the impact of three classic antifungals on both planktonic and biofilm forms. The fungal identification was based on macro and micromorphological characteristics, biochemical tests and confirmation by mass spectrometry assisted by the flight time desorption/ionization matrix (MALDI-TOF MS). Antifungal susceptibility assay of planktonic cells showed inhibitory and fungicidal concentrations ranging from 2.5 to 10 µg/mL for voriconazole, 2 to 8 µg/mL for fluconazole, and 1 to 4 µg/mL for amphotericin B. All T. asahii strains were able to form biofilms on the polystyrene microplates surface within 24 h, showing a simple architecture when compared with Candida spp. biofilm. On the other hand, the same antifungals did not show action in neither the inhibition of biofilm formation nor on the formed biofilm. Concluding, the present study reinforced the relevance of the MALDI-TOF MS methodology for a safe identification of T. asahii. Classic antifungals were active on the planktonic form, but not on the biofilms. All isolates formed biofilms on the polystyrene microplates and showed a simple architecture.

Challenges and perspectives in research and teaching of host pathogen interaction topics: new post-pandemic times to Brazil and other South American countries

Here is our proposal to improve learning in biomedical sciences for graduate and undergraduate courses with a broad vision integrating disciplines such as molecular cell biology, biochemistry, and biophysics around concepts of pathogen interaction within vertebrate and invertebrate hosts. Our paradigm is based on the possibility offered by the pandemic to have remote activities that give access to students and researchers from different places in Brazil and Latin American countries to discuss science. A multidisciplinary view of host-pathogen interaction allows us to understand better the mechanisms involved in the pathology of diseases, as well as to formulate broad strategies for the diagnosis, treatment, and control of thereof. The approach to integrating heterogeneous groups in science involves the critical analysis of national scientific resource distribution, where only some have the possibilities to conduct competitive scientific research. Solid theoretical training, contact, collaboration with groups of excellence, and training within a multidisciplinary network are our proposals for a permanent platform of scientific strengthening and dissemination for Latin America. Here we will review the concept of host-pathogen interaction, the type of institutions where it is taught and researched, new trends in active teaching methodologies, and the current political context in science.

Challenges and perspectives in research and teaching of host pathogen interaction topics: new post-pandemic times to Brazil and other South American countries

Here is our proposal to improve learning in biomedical sciences for graduate and undergraduate courses with a broad vision integrating disciplines such as molecular cell biology, biochemistry, and biophysics around concepts of pathogen interaction within vertebrate and invertebrate hosts. Our paradigm is based on the possibility offered by the pandemic to have remote activities that give access to students and researchers from different places in Brazil and Latin American countries to discuss science. A multidisciplinary view of host-pathogen interaction allows us to understand better the mechanisms involved in the pathology of diseases, as well as to formulate broad strategies for the diagnosis, treatment, and control of thereof. The approach to integrating heterogeneous groups in science involves the critical analysis of national scientific resource distribution, where only some have the possibilities to conduct competitive scientific research. Solid theoretical training, contact, collaboration with groups of excellence, and training within a multidisciplinary network are our proposals for a permanent platform of scientific strengthening and dissemination for Latin America. Here we will review the concept of host-pathogen interaction, the type of institutions where it is taught and researched, new trends in active teaching methodologies, and the current political context in science.

Efficacy of Propolis Gel on Mature Biofilm Formed by Neocosmospora keratoplastica Isolated from Onychomycosis.

This article describes Neocosmospora keratoplastica as an etiological onychomycosis agent. Ex vivo studies were initially performed to demonstrate the ability of this species to grow and form a well-organized characteristic biofilm on sterilized healthy nails. Based on the history of excellent results, both for antifungal and antibiofilm, of propolis resin gum, we evaluated its activity using artificially formed biofilm. In vitro, the minimal biofilm eradication concentration of the propolis extract (PE) was 375 µg of total polyphenol content (TPC) per mL, while for the propolis gel (PG) it was 450 µg of TPC per mL. In biofilm exposed to the propolis products, a decrease in hyphae and conidia was evident, accompanied by a disorganization of the extracellular matrix. Additionally, this low concentration of PE was able to significantly reduce the number of colony-forming units and the metabolic activity. Furthermore, the treatment of a 15-year nail infection due to N. keratoplastica was carried out exclusively using a topical treatment with a gel containing propolis (30%) with a daily dosage. This treatment achieved complete remission of the onychomycosis in 12 months. It is important to point out that some inconveniences previously reported by other patients treated with propolis extract were eliminated, increasing adherence to treatment.

In vitro ability of Fusarium keratoplasticum to form biofilms in venous catheter.

Fusarium keratoplasticum is a common specie in human infections and is responsible for many diseases affecting immunocompetent and immunocompromised patients. This study aimed to evaluate the ability of Fusarium keratoplasticum to form biofilm in venous catheters (VC), focusing on the development of maturation and dispersion over time (24, 48, 72, 96 and 120 h) and the evaluation amphotericin B (AB) susceptibility in planktonic cells and after 96 h of biofilm formation. F. keratoplasticum was able to form a biofilm in VC with maturation most likely between 48 and 72 h, according to colony count and total biomass results. The dispersion process supposedly occurred from 72 to 96 h, when we observed a decrease in the parameter's colony count, total biomass and mitochondrial metabolic activity. The planktonic cells of F. keratoplasticum were susceptible to AB, however, there was no inhibition of the F. keratoplasticum strain biofilm in any of the AB concentrations, with the growth of the fungus recovering after 48 h in contact with AB. Thus, our findings suggest that in addition to forming a biofilm on VC, F. keratoplasticum becomes AB-resistant, highlighting the concern of this fungus on medical devices.

Farnesol modulation of Rhodotorula mucilaginosa in biofilm and planktonic forms.

Biofilms are important to the virulence of human pathogenic fungi, and some molecules have been found to play key roles in the growth and regulation of fungal biofilms. Farnesol, one of these molecules, is well-described for some microorganisms but is still scarcely known for Rhodotorula spp. This study aimed to evaluate the influence of farnesol on the biofilm of R. mucilaginosa. Initially, screening with 0.2 mM to 2.1 mM of farnesol was evaluated against planktonic forms. A concentration of this compound was then chosen and evaluated for its effect on biofilm in formation and on preformed biofilm after 24, 48 and 72 hours. The impact of farnesol was evaluated by colony-forming units (CFU) counts, determination of metabolic activity and quantification of total biomass. In the presence of 0.9 mM, farnesol was able to decrease the CFU number, at 48 hours, when the biofilm was in formation, although it did not affect the preformed biofilms. Thus, our results show that farnesol exerts a modulating activity during biofilm formation for R. mucilaginosa, with this compound reducing the metabolic activity and total biomass of the biofilms.

Mixed Fungal Biofilms: From Mycobiota to Devices, a New Challenge on Clinical Practice.

Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that allow the evaluation of fungal morphology and the identification of the etiologic agent of mycosis. Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that enable the examination of the fungi for further identification of the etiological agent of the mycosis. The isolation of fungi from pure cultures is typically recommended, as when more than one species is identified, the second agent is considered a contaminant. Fungi mostly survive in highly organized communities that provoke changes in phenotypic profile, increase resistance to antifungals and environmental stresses, and facilitate evasion from the immune system. Mixed fungal biofilms (MFB) harbor more than one fungal species, wherein exchange can occur that potentialize the effects of these virulence factors. However, little is known about MFB and their role in infectious processes, particularly in terms of how each species may synergistically contribute to the pathogenesis. Here, we review fungi present in MFB that are commensals of the human body, forming the mycobiota, and how their participation in MFB affects the maintenance of homeostasis. In addition, we discuss how MFB are formed on both biotic and abiotic surfaces, thus being a significant reservoir of microorganisms that have already been associated in infectious processes of high morbidity and mortality.

Plants of the Phytolaccaceae family with antimicrobial activity: A systematic review.

Phytolaccaceae is a plant family of the order Caryophyllales, which includes species used in traditional medicine to treat diseases. The purpose of this study was to investigate Phytolaccaceae family plants with potential antimicrobial action, through a systematic review. The study was conducted following the criteria of PRISMA protocol. The search was performed in the electronic databases PubMed, Web of Science, Scopus, and LILACS, in March 2021. The search strategy used free descriptors and terms, limiting articles to the English language, regardless of publication year. The risk of bias and the quality of publications were based on the CONSORT checklist, modified for in vitro studies and SYRCLE's RoB tool for in vivo study. Five independent judges performed quality assessments of publications and risk of bias analysis. Ninety-five publications were retrieved from the databases and, after screening and eligibility criteria, 22 articles remained, from 1998 to 2019. In the selected studies, the plants were obtained from eight countries. In vivo and in vitro studies of extracts from the Phytolaccaceae family plants, evaluating antibacterial (8 publications), antifungal (8), anti-Trypanosoma (2), anti-Leishmania (2), antiviral (1), and antiamoebic (1) activities, are included. The plant species identified belong to genera Petiveria, Phytolacca, Gallesia, Trichostigma, and Seguieria. The risk of bias in the 22 publications both in vitro and in vitro was suboptimal. The evidence obtained showed that the Phytolaccaceae family, a source of plants with antimicrobial action, can serve as a basis for the creation of new herbal medicines, expanding the possibility of treatment for infectious diseases and stimulating their preservation and biodiversity. However, more high-quality studies are needed to establish the clinical efficacy of the plant.