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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.

Chromoblastomycosis (CBM) is a neglected human implantation mycosis caused by several dematiaceous fungal species. Currently available therapy is usually associated with physical methods, especially surgery, and with high refractoriness. Therefore, drug discovery for CBM is essential. Drug repositioning is a strategy used to facilitate the discovery of new treatments for several diseases. The aim of this study was to discover substances with antifungal activity against CBM agents from a collection of drugs previously approved for use in human diseases. A screening was performed with the NIH Clinical Collection against Fonsecaea pedrosoi . Ten substances, with clinical applicability in CBM, inhibited fungal growth by at least 60%. The minimum inhibitory concentration (MIC) of these substances was determined against other CBM agents, and the benzimidazoles albendazole, mebendazole and thiabendazole presented the lowest MIC values. The selectivity index, based on MIC and cytotoxicity of these substances, revealed albendazole to be more selective. To investigate a possible synergism of this benzimidazole with itraconazole and terbinafine, the chequerboard method was used. All interactions were classified as indifferent. Our current results suggest that benzimidazoles have repositioning potential against CBM agents. Albendazole seems to be the most promising, since it presented the highest selectivity against all dematiaceous fungi tested.

Leishmaniasis is a group of infectious-parasitic diseases with high mortality rates, and endemic in many regions of the globe. The currently available drugs present serious problems such as high toxicity, costs, and the emergence of drug resistance. This has stimulated research into new antileishmania drugs based on natural products and their derivatives. β-Ocimene is a monoterpene found naturally in the essential oils of many plant species which presents antileishmanial activity, and which has not yet been evaluated for its potential to inhibit the etiological agent of leishmaniasis. The aim of this work was to evaluate the activity of β-ocimene against Leishmania amazonensis , its cytotoxicity, and potential mechanisms of action. β-Ocimene presented direct activity against the parasite, with excellent growth inhibition of promastigotes (IC 50 = 2.78 μM) and axenic amastigotes (EC 50 = 1.12 μM) at concentrations non-toxic to RAW 264.7 macrophages (CC 50 = 114.5 µM). The effect is related to changes in membrane permeability and resulting abnormalities in the parasitic cell shape. These were, respectively, observed in membrane integrity and atomic force microscopy assays. β-Ocimene was also shown to act indirectly, with greater activity against intra-macrophagic amastigotes (EC 50 = 0.89 μM), increasing TNF-α, nitric oxide (NO), and reactive oxygen species (ROS), with lysosomal effects, as well as promoting decreases in IL-10 and IL-6. Against intra-macrophagic amastigote forms the selectivity index was higher than the reference drugs, being 469.52 times more selective than meglumine antimoniate, and 42.88 times more selective than amphotericin B. Our results suggest that β-ocimene possesses promising in vitro antileishmania activity and is a potential candidate for investigation in in vivo assays.

Chagas disease (CD) is an old neglected problem that affects more than 6 million people through 21 endemic countries in Latin America. Despite being responsible for more than 12 thousand deaths per year, the disease disposes basically of two drugs for its treatment, the nitroimidazole benznidazole and the nitrofuran nifurtimox. However, these drugs have innumerous limitations that greatly reduce the chances of cure. In Brazil, for example, only benznidazole is available to treat CD patients. Therefore, some proof-of-concept phase II clinical trials focused on improving the current treatment with benznidazole, also comparing it with repositioned drugs or combining them. Indeed, repositioning already marketed drugs in view of combating neglected tropical diseases is a very interesting approach in the context of decreased time for approval, better treatment options and low cost for development and implementation. After the introduction of human immunodeficiency virus aspartyl peptidase inhibitors (HIV-PIs) in the treatment of acquired immune deficiency syndrome (AIDS), the prevalence and incidence of parasitic, fungal and bacterial co-infections suffered a marked reduction, making these HIV-PIs attractive for drug repositioning. In this line, the present perspective presents the promising and beneficial data concerning the effects of HIV-PIs on the clinically relevant forms of Trypanosoma cruzi (i.e., trypomastigotes and amastigotes) and also highlights the ultrastructural and physiological targets for the HIV-PIs on this parasite. Therefore, we raise the possibility that HIV-PIs could be considered as alternative treatment options in the struggle against CD.

Biofilms are highly-organized microbial communities attached to a biotic or an abiotic surface, surrounded by an extracellular matrix secreted by the biofilm-forming cells. The majority of fungal pathogens contribute to biofilm formation within tissues or biomedical devices, leading to serious and persistent infections. The clinical significance of biofilms relies on the increased resistance to conventional antifungal therapies and suppression of the host immune system, which leads to invasive and recurrent fungal infections. While different features of yeast biofilms are well-described in the literature, the structural and molecular basis of biofilm formation of clinically related filamentous fungi has not been fully addressed. This review aimed to address biofilm formation in clinically relevant filamentous fungi.

In the present perspective, some parallels are drawn between a career as a scientist in Brazil and the ability of microorganisms to form a biofilm. Do these connections really exist? Definitely the answer is YES. Over billions of years, microbial biofilms have evolved in order to form a cohesive, well-structured, organized and dynamic community, which is characterized by its resistant/resilient profile to several environmental stressors. Adapting to constant change is a necessary attribute for survival and perpetuation of all live organisms, which are key signatures present in the hereditary molecule. Brazilian scientists are faced with many stressful situations along their journey in academia, which requires constant adaptability, reorganization and, above all, resilience. Can we take some lessons from what we know about the biofilm lifestyle developed by microorganisms? The answer is yes!

The chemical composition and biological properties of citronella essential oil were modified by enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella ( Cymbopogon winterianus ) essential oil, into geranyl (99%) and citronellyl (98%) cinnamates was obtained after 48 hours of reaction using a molar ratio of 3:1 (cinnamic acid/alcohol), lipase concentration (Novozym 435) of 15% (w/w) and 70 °C. The esterified oil showed higher antimicrobial activity against Staphylococcus aureus bacteria resistant to oxacillin and penicillin and also greater larvicidal activity against Aedes aegypti larvae compared to unesterified oil. The results concerning the evaluation of toxicity against Artemia salina and cytotoxicity against monkey kidney epithelial cells also showed the superiority of the esterified oil.

Over the past decades, several advances in cancer cell biology have led to relevant details about a phenomenon called the 'Warburg effect'. Currently, it has been accepted that the Warburg effect is not compatible with all cancer cells, and thus the process of aerobic glycolysis is now challenged by the knowledge of a large number of cells presenting mitochondrial function. The energy metabolism of cancer cells is focused on the bioenergetic and biosynthetic pathways in order to meet the requirements of rapid proliferation. Changes in the metabolism of carbohydrates, amino acids and lipids have already been reported for cancer cells and this might play an important role in cancer progression. To the best of our knowledge, these changes are mainly attributed to genetic reprogramming which leads to the transformation of a healthy into a cancerous cell. Indeed, several enzymes that are highly relevant for cellular energy are targets of oncogenes (e.g. PI3K, HIF1, and Myc) and tumor suppressor proteins (e.g. p53). As a consequence of extensive studies on cancer cell metabolism, some new therapeutic strategies have appeared that aim to interrupt the aberrant metabolism, in addition to influencing genetic reprogramming in cancer cells. In this review, we present an overview of cancer cell metabolism (carbohydrate, amino acid, and lipid), and also describe oncogenes and tumor suppressors that directly affect the metabolism. We also discuss some of the potential therapeutic candidates which have been designed to target and disrupt the main driving forces associated with cancer cell metabolism and proliferation., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Klebsiella pneumoniae appears as one of the most prevalent pathogens among cancer patients. The present study investigates the clinical, epidemiological and microbiological aspects related to infections caused by K. pneumoniae in cancer patients treated at an oncology referral center in the state of Pará, Amazon region, Brazil. Between July 2017 to July 2019, an epidemiological, observational, cross-sectional study, with a descriptive and analytical approach was conducted, including patients with confirmed diagnosis of cancer who acquired infection by K. pneumoniae 72 h after hospital admission. K. pneumoniae isolates included in the study were obtained from different clinical materials (blood, urine, catheter tip and bladder catheter, orotracheal secretions, oncological and surgical wounds). Antimicrobial susceptibility testing and molecular detection of the carbapenemase-encoding genes were performed. A high prevalence of MDR K. pneumoniae isolates was observed, including two colistin-resistant isolates and seven isolates harboring bla KPC-1 gene. To conclude, our findings provide the firsts insights into the epidemiology and infection by K. pneumoniae in the state of Pará, Brazil, and may be useful on treatment guidance and establishment of strategies to control the spread of resistance strains of K. pneumoniae in the region.

Background: Calpains are present in almost all organisms and comprise a family of calcium-dependent cysteine peptidases implicated in crucial cellular functions. Trypanosoma cruzi, the causative agent of Chagas disease, presents an expansion on this gene family with unexplored biological properties., Objectives: Here, we searched for calpains in the T. cruzi genome, evaluated the mRNA levels, calpain activity and the protein expression and determined the cellular localisation in all three parasite life cycle forms., Methods/findings: Sixty-three calpain sequences were identified in T. cruzi CL Brener genome, with fourteen domain arrangements. The comparison of calpain mRNA abundance by quantitative polymerase chain reaction (qPCR) revealed seven up-regulated sequences in amastigotes and/or bloodstream trypomastigotes and five in epimastigotes. Western Blotting analysis revealed seven different molecules in the three parasite forms, and one amastigote-specific, while no proteolytic activity could be detected. Flow cytometry assays revealed a higher amount of intracellular calpains in amastigotes and/or trypomastigotes in comparison to epimastigotes. Finally, ultrastructural analysis revealed the presence of calpains in the cytoplasm, vesicular and plasma membranes of the three parasite forms, and in the paraflagellar rod in trypomastigotes., Conclusion: Calpains are differentially expressed and localised in the T. cruzi life cycle forms. This study adds data on the calpain occurrence and expression pattern in T. cruzi.

The Candida haemulonii complex ( C. duobushaemulonii , C. haemulonii , and C. haemulonii var. vulnera ) is composed of emerging, opportunistic human fungal pathogens able to cause invasive infections with high rates of clinical treatment failure. This fungal complex typically demonstrates resistance to first-line antifungals, including fluconazole. In the present work, we have investigated the azole resistance mechanisms expressed in Brazilian clinical isolates forming the C. haemulonii complex. Initially, 12 isolates were subjected to an antifungal susceptibility test, and azole cross-resistance was detected in almost all isolates (91.7%). In order to understand the azole resistance mechanistic basis, the efflux pump activity was assessed by rhodamine-6G. The C. haemulonii complex exhibited a significantly higher rhodamine-6G efflux than the other non- albicans Candida species tested ( C. tropicalis , C. krusei , and C. lusitaneae ). Notably, the efflux pump inhibitors (Phe-Arg and FK506) reversed the fluconazole and voricolazole resistance phenotypes in the C. haemulonii species complex. Expression analysis indicated that the efflux pump ( ChCDR1 , ChCDR2 , and ChMDR1 ) and ERG11 genes were not modulated by either fluconazole or voriconazole treatments. Further, ERG11 gene sequencing revealed several mutations, some of which culminated in amino acid polymorphisms, as previously reported in azole-resistant Candida spp. Collectively, these data point out the relevance of drug efflux pumps in mediating azole resistance in the C. haemulonii complex, and mutations in ERG11p may contribute to this resistance profile.

Microbial interactions may impact patient's diagnosis, prognosis and treatment. Sporotrichosis is a hyperendemic neglected zoonosis in Brazil, caused by Sporothrix brasiliensis. Four pairs of clinical isolates of Sporothrix were recovered from four diseased cats (CIM01-CIM04, two isolates per animal) raising the possibility of coinfection in a sporotrichosis hyperendemic area, Brazil. Each isolate of the pair had distinct pigmentation in mycological culture, and was designated as "Light" or "Dark", for low and high pigmentation, respectively. Dark isolates reacted strongly with monoclonal antibodies to melanin (p ≤ 0.05) by both ELISA and FACS quantitation, and displayed a ring pattern with some regions exhibiting higher punctuated labeling at cell wall by immunofluorescence. In turn, Light isolates reacted less intensely, with few and discrete punctuated labeling at the cell wall. PCR identified all isolates as S. brasiliensis, MAT1-2 idiomorph. Sequencing of β-tubulin and calmodulin genes followed by phylogenetic analysis placed all eight isolates within the same cluster as others from the Brazilian hyperendemic area. The ability of these strains to stimulate cytokine production by human PBMCs (Peripheral blood mononuclear cells) was also analyzed. CIM01 and CIM03 Light and Dark isolates showed similar cytokine profiles to the control strain, while CIM02 and CIM04 behaved differently (p < 0.001), suggesting that differences in the surface of the isolates can influence host-fungus interaction. MICs for amphotericin B, terbinafine, caspofungin, micafungin, itraconazole, fluconazole, and voriconazole were obtained (CLSI M38-A2/M27-A3). Pairwise comparisons showed distinct MICs between Sporothrix Light and Dark isolates, higher than at least two-fold dilutions, to at least one of the antifungals tested. Isolates from the same pair displayed discrepancies in relation to fungistatic or fungicidal drug activity, notably after itraconazole exposure. Since S. brasiliensis Light and Dark isolates show disparate phenotypic parameters it is quite possible that coinfection represents a common occurrence in the hyperendemic area, with potential clinical implications on feline sporotrichosis dynamics. Alternatively, future studies will address if this specie may have, as reported for other fungi, broad phenotypic plasticity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Biofilm formation is the preferred mode of growth lifestyle for many microorganisms, including bacterial and fungal human pathogens. Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces. Microbial biofilms cause problems in the hospital environment, generating high healthcare costs and prolonged patient stay, which can result in further secondary microbial infections and various health complications. Consequently, both public and private investments must be made to ensure better patient management, as well as to find novel therapeutic strategies to circumvent the resistance and resilience profiles arising from biofilm-associated microbial infections. In this work, we present a general overview of microbial biofilm formation and its relevance within the biomedical context.

BACKGROUND Scedosporium/Lomentospora species are opportunistic mould pathogens, presenting notable antifungal resistance. OBJECTIVES/METHODS We analysed the conidia and germinated conidia of S. apiospermum (Sap), S. aurantiacum (Sau), S. minutisporum (Smi) and L. prolificans (Lpr) by scanning electron microscopy and exposition of surface molecules by fluorescence microscopy. FINDINGS Conidia of Sap, Smi and Sau had oval, ellipsoidal and cylindrical shape, respectively, with several irregularities surrounding all surface areas, whereas Lpr conidia were rounded with a smooth surface. The germination of Sap occurred at the conidial bottom, while Smi and Sau germination primarily occurred at the centre of the conidial cell, and Lpr germination initiated at any part of the conidial surface. The staining of N-acetylglucosamine-containing molecules by fluorescein-labelled WGA primarily occurred during the germination of all studied fungi and in the conidial scars, which is the primary location of germination. Calcofluor white, which recognises the polysaccharide chitin, strongly stained the conidial cells and, to a lesser extent, the germination. Both mannose-rich glycoconjugates (evidenced by fluoresceinated-ConA) and cell wall externally located polypeptides presented distinct surface locations and expression according to both morphotypes and fungal species. In contrast, sialic acid and galactose-containing structures were not detected at fungal surfaces. MAIN CONCLUSIONS The present study demonstrated the differential production/exposition of surface molecules on distinct morphotypes of Scedosporium/Lomentospora species.