1,721,017 research outputs found
Antimicrobial peptides with antiprotozoal activity: Current state and future perspectives
No full textFrom Pichia anomala killer toxin through killer antibodies to killer peptides for a comprehensive anti-infective strategy
No full textDissection of the structural features and fungicidal activity of an antibody-derived peptide
No full textThe activity of a mammalian proline-rich peptide against Gram-negative bacteria, including drug-resistant strains, relies on a nonmembranolytic mode of action
No full textBackground: A peptide of 2,733 Da named SP-E, previously isolated from pig saliva and already described for its antifungal activity and absence of toxicity against mammalian cells, is characterized by a high content of proline residues (70% of entire sequence), that confer structural features probably related to peptide activity. Purpose: The aim of this study was to evaluate the activity of SP-E against Gram-negative bacteria, including drug-resistant clinical isolates. Methods: SP-E and shorter fragments of the same peptide were tested in vitro against the selected bacteria by colony forming unit assays. Scanning electron microscopy and confocal microscopy were also applied. SP-E potential therapeutic activity was evaluated in vivo in a Galleria mellonella model of bacterial infection. Results: SP-E proved to be active against the tested bacteria with EC50 values in the micro-molar range. Though maintaining antibacterial properties, the shorter peptides showed lower activity in respect to the parental molecule. Kinetics of killing action and nonmembranolytic internalization within Escherichia coli and Pseudomonas aeruginosa cells strongly suggested a cytosolic mechanism of action involving one or more intracellular molecular targets. A single injection of SP-E exerted a therapeutic effect in G. mellonella larvae infected with P. aeruginosa. Conclusion: The biological properties of SP-E strongly back this peptide as a new promising multitasking antimicrobial molecule. © 2018 Ciociola et al
Antibodies as unlimited source of anti-infective, anti-tumor and immunomodulatory peptides
No full textScreening of thiosemicarbazones as antimycotic drugs
No full textFungal infections have become a problem of increasing importance over the past last decades, especially in patients with immunological impairment, due to HIV infections, organ transplantations or cancer therapy. The most frequently diagnosed fungal infections are caused by pathogens of the genera Candida, Cryptococcus and Aspergillus. Current treatments use a limited number of antifungal drugs and the increased resistance to these molecules is now a great problem in medicine. Is then important to select and develop new antifungal therapeutics.
Thiosemicarbazones have received great interest because of their chemical and biological activities, such as antibacterial, antivirus, antiamoebic, and antitumor activities in human pharmacology. In order to test if an antifungal activity is associated to some of these molecules we screened 16 different thiosemicarbazone molecules, against a panel of fungal pathogens. Two of these compounds showed interesting activity. Results will be here presented
Analisi dell’attività fungicida di un peptide derivato dalla regione costante di immunoglobuline M umane
No full textEffect of different wavelengths and dyes on Candida albicans: In vivo study using Galleria mellonella as an experimental model
Full text linkBackground Studies on photodynamic inactivation against microorganisms had a great development in recent years. The aim of this work was to test the application of different laser wavelengths with or without different photosensitizing dyes on Candida albicans cells in vitro and in photodynamic therapy protocols in vivo in larvae of Galleria mellonella. Methods Laser application was realized on C. albicans cells suspended in saline solution or cultured on solid medium for the in vitro study, and in a model of G. mellonella candidal infection for the in vivo study. Three wavelengths (650, 405, and 532 nm) were used in continuous mode with different values of applied fluences: 10, 20 and 30 J/cm2 for the in vitro study and 10 J/cm2 for the in vivo study, without and with photosensitizing dyes. Results No growth inhibition was obtained on yeast cells in saline solution without photosensitizers. The maximum inhibition of growth (100%) was obtained with 405 nm diode laser and curcumin at any used fluence. No growth inhibition was observed for yeast cells cultured on solid medium after laser application without dyes. An inhibition was observed after laser application when curcumin and erythrosine were added to the medium. The survival curves of G. mellonella larvae infected with C. albicans with or without the different dyes and after laser application showed a statistically significant difference (p < 0.001) in comparison with the proper control groups. Conclusions These results show the efficacy of photodynamic inactivation exploiting a suitable combination of light and dyes against C. albicans and the potential of photodynamic therapy for the treatment of candidal infections
Anaflatoxin B1 as the Paradigm of a New Class of Vaccines Based on “Mycotoxoids”
No full textMycotoxicoses are a group of important diseases caused by human and animal dietary, respiratory, and dermal exposure to mycotoxins, fungal secondary metabolites that exert toxic effects in minimum concentration. Human exposure result mainly from consumption of plant-based foods containing mycotoxins and animal-derived foods, such as milk, meat and eggs, containing mycotoxins residues and metabolites (carry
over).
Aflatoxins (AF) are among the most relevant mycotoxins of medical interest due to their high toxic, carcinogenic and immunosuppressive properties for humans and animals. AFs are the most intensively studied mycotoxins in dairy industry as the excretion of AFM1 in milk is a relevant public health concern.
Other than prevention of mycotoxin exposure, there are currently no known prophylactic measures for mycotoxicoses and no therapeutic treatments are available. Thus, the production of a vaccine able to induce specific neutralizing antibodies would be of great social, scientific and economic interests.
Mycotoxins are non proteinaceous, low molecular weight haptens. Their use as conjugate immunogens should be carefully evaluated owing to the toxic properties of the molecule that might be released. Potential vaccine candidates could be protein conjugates of “mycotoxoids”, chemically detoxified forms of mycotoxins still maintaining the ability to induce antibodies reactive with the parent molecule.
The present review gives an overview of overall aspects of immunization against mycotoxins, with emphasis on Anaflatoxin B1 as a paradigm of “mycotoxoid” which has been used in immunization protocols to prevent AFB1 carry over as AFM1 in milk
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