Photodynamic inhibition was more efficient in promoting cell death than the antifungal cyclopiroxolamine against T. rubrum. ROS, ONOO· and NO· were important in the fungicidal activity of aPI. A suggested mechanism for this activity is that TBO is excited by LED light (630 nm), reacts with biomolecules and increases the availability of transition electrons and substrates for nitric oxide synthase, thereby increasing the oxidative and nitrosative bursts in the fungal cell.

and are environmental fungi that cause cryptococcosis, which is usually treated with amphotericin B and fluconazole. However, therapeutic failure is increasing because of the emergence of resistant strains. Because these species are constantly isolated from vegetal materials and the usage of agrochemicals is growing, we postulate that pesticides could be responsible for the altered susceptibility of these fungi to clinical drugs. Therefore, we evaluated the influence of the pesticide tebuconazole on the susceptibility to clinical drugs, morphophysiology, and virulence of and strains. The results showed that tebuconazole exposure caused cross-resistance (CR) between the agrochemical and clinical azoles (fluconazole, itraconazole, and ravuconazole) but not with amphotericin B. In some strains, CR was observed even after the exposure ceased. Further, tebuconazole exposure changed the morphology, including formation of pseudohyphae in H99, and the surface charge of the cells. Although the virulence of both species previously exposed to tebuconazole was decreased in mice, the tebuconazole-exposed colonies recovered from the lungs were more resistant to azole drugs than the nonexposed cells. This CR was confirmed when fluconazole was not able to reduce the fungal burden in the lungs of mice. The tolerance to azoles could be due to increased expression of the gene in both species and of efflux pump genes ( and ) in Our study data support the idea that agrochemical usage can significantly affect human pathogens present in the environment by affecting their resistance to clinical drugs.

Influenza A virus (IAV) infects millions of people annually and predisposes to secondary bacterial infections. Inhalation of fungi within the Cryptococcus complex causes pulmonary disease with secondary meningo-encephalitis. Underlying pulmonary disease is a strong risk factor for development of C. gattii cryptococcosis though the effect of concurrent infection with IAV has not been studied. We developed an in vivo model of Influenza A H1N1 and C. gattii co-infection. Co-infection resulted in a major increase in morbidity and mortality, with severe lung damage and a high brain fungal burden when mice were infected in the acute phase of influenza multiplication. Furthermore, IAV alters the host response to C. gattii, leading to recruitment of significantly more neutrophils and macrophages into the lungs. Moreover, IAV induced the production of type 1 interferons (IFN-α4/β) and the levels of IFN-γ were significantly reduced, which can be associated with impairment of the immune response to Cryptococcus during co-infection. Phagocytosis, killing of cryptococci and production of reactive oxygen species (ROS) by IAV-infected macrophages were reduced, independent of previous IFN-γ stimulation, leading to increased proliferation of the fungus within macrophages. In conclusion, IAV infection is a predisposing factor for severe disease and adverse outcomes in mice co-infected with C. gattii.

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Exposure to pyraclostrobin induces cross-resistance with clinical antifungals in Cryptococcus  Non-azole agrochemical exposure increases expression of efflux pumps in C. gattii  Pyraclostrobin-exposed yeasts are less virulent than non-exposed ones in mice  Fluconazole is not able to treat cryptococcosis by pyraclostrobin-exposed cells.  Agrochemicals jeopardize animal and human health by influencing fungal resistance. *Highlights (for review : 3 to 5 bullet points (maximum 85 characters including spaces per bullet point) From the environment to the host: how non-azole agrochemical exposure affects the antifungal susceptibility and virulence of Cryptococcus gattii

Antimicrobial peptides (AMPs) are currently being investigated as potential sources of novel therapeutics against an increasing number of microorganisms resistant to conventional antibiotics. The conjugation of an AMP to other bioactive compounds is an interesting approach for the development of new derivatives with increased antimicrobial efficiency and broader spectra of action. In this work, the synthesis of a new peptide−coumarin conjugate via copper(I)-catalyzed azide−alkyne cycloaddition is described. The conjugate was assayed for in vitro cytotoxicity and displayed antifungal activity against Cryptococcus gattii and Cryptococcus neoformans. Additionally, the conjugate exhibited increased antifungal efficacy when compared with the individual peptide, coumarin, or triazole moieties. Treatment of C. gattii with the peptide−coumarin conjugate enhanced the production of reactive oxygen species, suggesting that the oxidative burst plays an important role in the mechanism of action of the conjugate. KEYWORDS: Antimicrobial peptide, copper(I)-catalyzed azide−alkyne cycloaddition, coumarin, cryptococcosis, reactive oxygen species A ntimicrobial peptides (AMPs) are small molecular weight proteins with antimicrobial activity against bacteria, viruses, and fungi. 1 AMPs are currently being investigated as potential sources of novel therapeutic antimicrobial agents because of their broad-spectrum activity and low susceptibility for developing resistance. 2 Ubiquicidin (UBI) is an antimicrobial peptide, which was first isolated from murine macrophages and then found at low concentrations (as a first line of defense) inside human airway epithelial cells, activated macrophages, and in human colon mucosa. UBI is a cationic peptide consisting of 59 amino acid residues. It is not expected to be immunogenic to humans since it is of human origin. 3 UBI 1−59 and some of its fragments have been shown to be microbicidal against a broad spectrum of pathogens. Of particular interest is the fragment UBI 31−38 (Figure 1), which is relatively small, easily synthesized, and exhibits antibacterial activity toward methicillin resistant Staphylococcus aureus. 4 Peptides open up new perspectives in drug design by providing an entire range of highly selective and nontoxic pharmaceuticals. With growing applications of their synthesis and bioactivity, considerable attention has been focused on the research of peptide-based derivatives. 5 Coumarins form an important class of benzopyrones, which are found in nature. Many coumarins and their derivatives possess antimicrobial, anti-inflammatory, and anticancer properties. 6 Research on coumarin compounds as antifungal agents has shown that structural modification of the coumarin skeleton (i.e., the benzene ring, lactone ring, or both) results in derivatives, which possess potent antifungal activity when compared to clinically used antifungal drugs. 7 Therefore, numerous efforts have focused on the development of coumarins as potential drugs. 8 The copper(I)-catalyzed azide−alkyne cyclo...