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1.
Int J Mol Sci ; 25(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38791486

RESUMO

Periodontal diseases, including gingivitis and periodontitis, are among the most prevalent diseases in humans. Gingivitis is the mildest form of periodontal disease, characterized by inflammation of the gingiva caused by the accumulation of dental plaque. Salivary diagnostics are becoming increasingly popular due to the variation in saliva composition in response to pathological processes. We used a metabolomics approach to investigate whether a specific saliva metabolic composition could indicate preclinical stage of gingivitis. 1H-NMR spectroscopy was used to obtain the salivary metabolite profiles of 20 healthy subjects. Univariate/multivariate statistical analysis evaluated the whole saliva metabolite composition, and the Full-Mouth Bleeding Score (FMBS) was employed as a classification parameter. Identifying a signature of specific salivary metabolites could distinguish the subjects with high FMBS scores but still within the normal range. This set of metabolites may be due to the enzymatic activities of oral bacteria and be associated with the early stages of gingival inflammation. Although this analysis is to be considered exploratory, it seems feasible to establish an FMBS threshold that distinguishes between the absence and presence of early inflammatory alterations at the salivary level.


Assuntos
Gengivite , Voluntários Saudáveis , Saliva , Humanos , Saliva/metabolismo , Feminino , Masculino , Projetos Piloto , Adulto , Gengivite/metabolismo , Gengivite/diagnóstico , Metabolômica/métodos , Hemorragia Gengival/metabolismo , Metaboloma , Adulto Jovem , Pessoa de Meia-Idade , Biomarcadores/metabolismo
2.
Environ Microbiol ; 24(12): 6453-6462, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36086955

RESUMO

Recent pandemic infection caused by SARS-CoV-2 (COVID-19) led the scientific community to investigate the possible causes contributing to the physiopathology of this disease. In this context, analyses of the intestinal microbiota highlighted possible correlation between host-associated bacterial communities and development of the COVID-19. Nevertheless, a detailed investigation of the role of the human microbiota in the severity of the symptoms of this disease is still lacking. This study performed a comprehensive meta-analysis of 323 faecal samples from public and novel Italian data sets based on the shotgun metagenomic approach. In detail, the comparative analyses revealed possible differences in the microbial biodiversity related to the individual health status, highlighting a species richness decrease in COVID-19 patients with a severe prognosis. Moreover, healthy subjects resulted characterized by a higher abundance of protective and health-supporting bacterial species, while patients affected by COVID-19 disease displayed a significant increase of opportunistic pathogen bacteria involved in developing putrefactive dysbiosis. Furthermore, prediction of the microbiome functional capabilities suggested that individuals affected by COVID-19 subsist in an unbalanced metabolism characterized by an overrepresentation of enzymes involved in the protein metabolism at the expense of carbohydrates oriented pathways, which can impact on disease severity and in excessive systemic inflammation.


Assuntos
COVID-19 , Microbioma Gastrointestinal , Humanos , SARS-CoV-2 , Disbiose/microbiologia , Pandemias , Bactérias/genética
3.
Int J Mol Sci ; 22(20)2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34681564

RESUMO

The synthetic peptide T11F (TCRVDHRGLTF), with sequence identical to a fragment of the constant region of human IgM, and most of its alanine-substituted derivatives proved to possess a significant candidacidal activity in vitro. In this study, the therapeutic efficacy of T11F, D5A, the derivative most active in vitro, and F11A, characterized by a different conformation, was investigated in Galleria mellonella larvae infected with Candida albicans. A single injection of F11A and D5A derivatives, in contrast with T11F, led to a significant increase in survival of larvae injected with a lethal inoculum of C. albicans cells, in comparison with infected animals treated with saline. Peptide modulation of host immunity upon C. albicans infection was determined by hemocyte analysis and larval histology, highlighting a different immune stimulation by the studied peptides. F11A, particularly, was the most active in eliciting nodule formation, melanization and fat body activation, leading to a better control of yeast infection. Overall, the obtained data suggest a double role for F11A, able to simultaneously target the fungus and the host immune system, resulting in a more efficient pathogen clearance.


Assuntos
Candida albicans/patogenicidade , Candidíase/tratamento farmacológico , Mariposas/microbiologia , Peptídeos/administração & dosagem , Animais , Candida albicans/efeitos dos fármacos , Candidíase/imunologia , Modelos Animais de Doenças , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Humanos , Imunoglobulina M/química , Larva/microbiologia , Viabilidade Microbiana/efeitos dos fármacos , Mariposas/imunologia , Peptídeos/química , Peptídeos/farmacologia , Análise de Sobrevida , Resultado do Tratamento
4.
Intervirology ; 61(4): 166-173, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30654366

RESUMO

BACKGROUND/AIMS: New antivirals are needed to supplement or replace currently used drugs. The aim of this study was to evaluate the antiviral activity of synthetic peptides derived from physiological proteins. METHODS: Vero cell monolayers were infected with herpes simplex virus 1, vesicular stomatitis virus, adenovirus, and coxsackievirus B5 strains in the presence of different concentrations of the selected peptides and viral yield was determined by plaque reduction assays to evaluate the antiviral activity of the peptides. Virucidal activity was evaluated by determining the residual infectivity of viral suspensions treated for 1 h with the peptides at the same concentrations as in the viral yield assays. RESULTS: Among the investigated peptides, the killer peptide proved to exert a considerable antiviral activity against herpes simplex virus, attributable to a direct effect on virus particles, while its derivative K10S showed to be effective against the four investigated virus strains only at the highest concentration tested, yet, the inhibitory effects were only partial. CONCLUSION: Overall, initial evidence is provided on the antiviral activity of several peptides, as well as of their derivatives. Further investigation is warranted to ascertain the mechanism of action in order to develop new potential antiviral drugs.


Assuntos
Antivirais/farmacologia , Peptídeos/farmacologia , Adenoviridae/efeitos dos fármacos , Animais , Chlorocebus aethiops , Enterovirus Humano B/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Peptídeos/genética , Células Vero , Vesiculovirus/efeitos dos fármacos , Carga Viral , Ensaio de Placa Viral
5.
Int J Mol Sci ; 19(12)2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30487461

RESUMO

The synthetic peptide T11F (TCRVDHRGLTF), derived from the constant region of human IgM antibodies, proved to exert a significant activity in vitro against yeast strains, including multidrug resistant isolates. Alanine substitution of positively charged residues led to a decrease in candidacidal activity. A more dramatic reduction in activity resulted from cysteine replacement. Here, we investigated the conformational properties of T11F and its alanine-substituted derivatives by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. Peptide interaction with Candida albicans cells was studied by confocal and scanning electron microscopy. T11F and most of its derivatives exhibited CD spectra with a negative band around 200 nm and a weaker positive band around 218 nm suggesting, together with NMR coupling constants, the presence of a polyproline II (PPII) helix, a conformational motif involved in a number of biological functions. Analysis of CD spectra revealed a critical role for phenylalanine in preserving the PPII helix. In fact, only the F11A derivative presented a random coil conformation. Interestingly, the loss of secondary structure influenced the rate of killing, which turned out to be significantly reduced. Overall, the obtained results suggest that the PPII conformation contributes in characterising the cell penetrating and fungicidal properties of the investigated peptides.


Assuntos
Anticorpos/química , Peptídeos Penetradores de Células/química , Fungicidas Industriais/química , Peptídeos/química , Candida albicans/efeitos dos fármacos , Peptídeos Penetradores de Células/farmacologia , Dicroísmo Circular , Fungicidas Industriais/farmacologia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Ressonância Magnética Nuclear Biomolecular , Peptídeos/farmacologia
6.
Int J Mol Sci ; 19(4)2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29642388

RESUMO

In cells derived from several types of cancer, a transcriptional program drives high consumption of glutamine (Gln), which is used for anaplerosis, leading to a metabolic addiction for the amino acid. Low or absent expression of Glutamine Synthetase (GS), the only enzyme that catalyzes de novo Gln synthesis, has been considered a marker of Gln-addicted cancers. In this study, two human cell lines derived from brain tumors with oligodendroglioma features, HOG and Hs683, have been shown to be GS-negative. Viability of both lines depends from extracellular Gln with EC50 of 0.175 ± 0.056 mM (Hs683) and 0.086 ± 0.043 mM (HOG), thus suggesting that small amounts of extracellular Gln are sufficient for OD cell growth. Gln starvation does not significantly affect the cell content of anaplerotic substrates, which, consistently, are not able to rescue cell growth, but causes hindrance of the Wnt/ß-catenin pathway and protein synthesis attenuation, which is mitigated by transient GS expression. Gln transport inhibitors cause partial depletion of intracellular Gln and cell growth inhibition, but do not lower cell viability. Therefore, GS-negative human oligodendroglioma cells are Gln-auxotrophic but do not use the amino acid for anaplerosis and, hence, are not Gln addicted, exhibiting only limited Gln requirements for survival and growth.


Assuntos
Glutamato-Amônia Ligase/deficiência , Glutamina/metabolismo , Oligodendroglioma/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Glutamato-Amônia Ligase/genética , Glutamato-Amônia Ligase/metabolismo , Humanos , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
7.
Antimicrob Agents Chemother ; 60(4): 2435-42, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26856836

RESUMO

Synthetic peptides encompassing sequences related to the complementarity-determining regions of antibodies or derived from their constant region (Fc peptides) were proven to exert differential antimicrobial, antiviral, antitumor, and/or immunomodulatory activitiesin vitroand/orin vivo, regardless of the specificity and isotype of the parental antibody. Alanine substitution derivatives of these peptides exhibited unaltered, increased, or decreased candidacidal activitiesin vitro The bioactive IgG-derived Fc N10K peptide (NQVSLTCLVK) spontaneously self-assembles, a feature previously recognized as relevant for the therapeutic activity of another antibody-derived peptide. We evaluated the contribution of each residue to the peptide self-assembling capability by circular-dichroism spectroscopy. The interaction of the N10K peptide and its derivatives withCandida albicanscells was studied by confocal, transmission, and scanning electron microscopy. The apoptosis and autophagy induction profiles in yeast cells treated with the peptides were evaluated by flow cytometry, and the therapeutic efficacy against candidal infection was studied in aGalleria mellonellamodel. Overall, the results indicate a critical role for some residues in the self-assembly process and a correlation of that capability with the candidacidal activities of the peptidesin vitroand their therapeutic effectsin vivo.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Regiões Determinantes de Complementaridade/farmacologia , Imunoglobulina G/farmacologia , Peptídeos/farmacologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Antifúngicos/síntese química , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Regiões Determinantes de Complementaridade/química , Humanos , Imunoglobulina G/química , Larva/efeitos dos fármacos , Larva/microbiologia , Testes de Sensibilidade Microbiana , Mariposas/efeitos dos fármacos , Mariposas/microbiologia , Peptídeos/síntese química , Fosfatidilserinas/análise , Fosfatidilserinas/metabolismo , Relação Estrutura-Atividade , Análise de Sobrevida
8.
J Pept Sci ; 21(5): 370-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25756615

RESUMO

Synthetic peptides, representative of sequences related to the complementarity determining regions and constant region of antibodies, proved to exert in vitro, ex vivo and/or in vivo antimicrobial, antiviral, anti-tumour and/or immunomodulatory activities, conceivably mediated by different mechanisms of action and regardless of the specificity and isotype of the belonging immunoglobulin. Antibody-derived peptides can show intrinsic properties of self-aggregation in ß structures, able to assemble on molecular targets and dissociate spontaneously, leading to the formation of hydrogels. Whilst the self-assembled state may provide protection against proteases and the slow kinetic of dissociation assures a release of the active form over time, the receptor affinity is responsible for targeted delivery. Peptides derived from single amino acid substitution of bioactive antibody fragments, adopted as surrogates of natural point mutations, displayed further differential biological activities. Overall, these observations allow to envisage that antibodies could represent an unlimited source of new anti-infective and anti-tumour peptides.


Assuntos
Anticorpos Monoclonais/química , Peptídeos/química , Peptídeos/farmacologia , Substituição de Aminoácidos , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anticorpos Monoclonais/genética , Antineoplásicos/química , Antineoplásicos/farmacologia , Humanos , Hidrogéis/química , Modelos Moleculares , Estrutura Secundária de Proteína
9.
Biochim Biophys Acta ; 1828(3): 1066-74, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23274276

RESUMO

A proline-rich peptide of 2733Da, isolated from pig parotid granule preparations was tested against different pathogenic fungi. It showed interesting antifungal activity towards a clinical isolate of Cryptococcus neoformans, with an EC(50) of 2.2µM. Neither cytotoxic nor haemolytic effects were observed towards mammalian cells. Circular dichroism and infrared spectroscopic studies showed that the peptide adopted a combination of polyproline type-II, ß-turn and unordered conformations at physiological temperatures. Temperature dependent experiments evidenced a tendency to adopt a polyproline-II helix conformation. From experiments with lipid vesicles, Neutral Red Uptake (NRU), haemolytic assays, and confocal microscopy studies, it could be hypothesized that the peptide may exert its antifungal effect by interacting with an intracellular target rather than through membrane damage.


Assuntos
Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Peptídeos/química , Prolina/química , Saliva/metabolismo , Células 3T3 , Animais , Antifúngicos/análise , Dicroísmo Circular , Cryptococcus neoformans/metabolismo , Relação Dose-Resposta a Droga , Eritrócitos/citologia , Hemólise , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Microscopia Confocal/métodos , Conformação Proteica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Suínos , Temperatura , Raios Ultravioleta
10.
Med Mycol ; 52(4): 350-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24625672

RESUMO

In order to overcome the limitations inherent in current pharmacological treatments for Malassezia pachydermatis, the cause of otitis externa in dogs, the efficacy of a killer decapeptide (KP) was evaluated in vitro and in vivo. Sixteen dogs with naturally occurring M. pachydermatis otitis externa were enrolled, and the in vitro fungicidal activity of KP was evaluated using yeasts recovered from these animals. The therapeutic activity was evaluated in four groups of four animals each. The dogs were topically treated with KP (150 µl, 2 mg/ml) three times per week (group A) or every day (group B), treated with a scramble peptide every day (group C), or left untreated (group D). Assessment of clinical signs (pruritus, erythema, and lichenification and/or hyperpigmentation), expressed as mean of the total clinical index score (mTCIS), the population size of M. pachydermatis at the cytological examination (mean number of yeast cells at 40× magnification [mYC]), and culture testing (mean number of log10 CFU/swab [mCFU]), were conducted daily from the first day of treatment (T0) until two consecutive negative cultures (mCFU ≤ 2). KP showed an in vitro fungicidal effect against M. pachydermatis isolates, with an MFC90 value of 1 µg/ml. The mTCIS, mYC and mCFU were negative only in animals in group B after T8. Daily administration of KP for 8 days was safe and effective in controlling both clinical signs and the population size of M. pachydermatis causing otitis externa, thus offering an alternative to the currently available therapeutic or prophylactic protocols for recurrent cases of Malassezia otitis in dogs.


Assuntos
Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Dermatomicoses/veterinária , Malassezia/efeitos dos fármacos , Otite/veterinária , Administração Tópica , Animais , Peptídeos Catiônicos Antimicrobianos/efeitos adversos , Contagem de Colônia Microbiana , Dermatomicoses/microbiologia , Cães , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Malassezia/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Otite/microbiologia , Resultado do Tratamento
11.
Sci Prog ; 97(Pt 3): 215-33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25549407

RESUMO

Antibodies (Abs) are emerging as an important class of therapeutic agents for the treatment of various human diseases, often conjugated to drugs or toxic substances. In recent years, the incidence of cancer and infectious diseases has increased dramatically making it imperative to discover new effective therapeutic molecules. Among these, small peptides are arousing great interest. Synthetic peptides, representative of variable and constant region fragments of Abs, were proved to exert in vitro, ex vivo and/or in vivo anti-microbial, anti-viral, anti-tumour and/or immunomodulatory activities, mediated by different mechanisms of action and regardless of the specificity and isotype of the Ab. Some of these synthetic peptides possess the ability to spontaneously and reversibly self-assemble in an organised network of fibril-like structure. Ab fragments may represent a novel model of targeted anti-infective and anti-tumour auto-delivering drugs.


Assuntos
Anti-Infecciosos/farmacologia , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Anti-Infecciosos/química , Anti-Infecciosos/uso terapêutico , Anticorpos Monoclonais/química , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Sítios de Ligação de Anticorpos , Linhagem Celular Tumoral , Dicroísmo Circular , Indústria Farmacêutica , Humanos , Modelos Moleculares , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/uso terapêutico , Relação Estrutura-Atividade
12.
Antibiotics (Basel) ; 13(8)2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39199983

RESUMO

Bacterial resistance to ß-lactam antibiotics, particularly new generation cephalosporins, is a major public health concern. In Escherichia coli, resistance to these antibiotics is mainly mediated by extended-spectrum ß-lactamases (ESBL), which complicates a range of health-threatening infections. These infections may also be biofilm-related, making them more difficult to treat because of the higher tolerance to conventional antibiotics and the host immune response. In this study, we tested as potential new drug candidates against biofilm-forming ESBL-producing E. coli four antimicrobial peptides previously shown to have antifungal properties. The peptides proved to be active in vitro at micromolar concentrations against both sensitive and ESBL-producing E. coli strains, effectively killing planktonic cells and inhibiting biofilm formation. Quantitative fluorescence intensity analysis of three-dimensional reconstructed confocal laser scanning microscopy (CLSM) images of mature biofilm treated with the most active peptide showed significant eradication and a reduction in viable bacteria, while scanning electron microscopy (SEM) revealed gross morphological alterations in treated bacteria. The screening of the investigated peptides for antibacterial and antibiofilm activity led to the selection of a leading candidate to be further studied for developing new antimicrobial drugs as an alternative treatment against microbial infections, primarily associated with biofilms.

13.
Lasers Med Sci ; 28(4): 1131-5, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23053244

RESUMO

A bactericidal effect has been reported by the use of near-infrared laser light on both Gram-positive and Gram-negative bacteria. The aim of this study was to evaluate the effect of Nd:YAG laser on Actinomyces israelii, filamentous bacteria causing cervicofacial actinomycosis. Experiments were realized on bacterial cells in saline suspension or streaked on Mueller-Hinton (MH) agar plates with or without India ink. Laser application was performed in Eppendorf tubes with different powers and frequencies for 40 s; bacterial suspensions were then streaked on agar plates and incubated at 35 °C in proper conditions for 5 days before colony enumeration. A reduction of colony number variable from 60.13 to 100 % for powers of 2, 4, and 6 W at 25-50 Hz of frequency was observed in comparison with growth control. For agar plates, laser application was performed with different powers at 50 Hz for 60 s. A growth inhibition was observed after 5 days of incubation on MH plates with powers of 6 W and on MH-ink plates with all applied powers. This preliminary study showed a bactericidal effect caused by Nd:YAG laser application worthy to be evaluated in further experiments in vivo.


Assuntos
Actinomyces/efeitos da radiação , Lasers de Estado Sólido , Actinomyces/crescimento & desenvolvimento , Actinomyces/patogenicidade , Actinomicose Cervicofacial/microbiologia , Actinomicose Cervicofacial/radioterapia , Carga Bacteriana , Humanos , Lasers de Estado Sólido/uso terapêutico , Terapia com Luz de Baixa Intensidade/métodos
14.
Antibiotics (Basel) ; 12(3)2023 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-36978339

RESUMO

Antimicrobial resistance is a major public health concern worldwide. Albeit to a lesser extent than bacteria, fungi are also becoming increasingly resistant to antifungal drugs. Moreover, due to the small number of antifungal classes, therapy options are limited, complicating the clinical management of mycoses. In this view, antimicrobial peptides (AMPs) are a potential alternative to conventional drugs. Among these, Proline-rich antimicrobial peptides (PrAMPs), almost exclusively of animal origins, are of particular interest due to their peculiar mode of action. In this study, a search for new arginine- and proline-rich peptides from plants has been carried out with a bioinformatic approach by sequence alignment and antimicrobial prediction tools. Two peptide candidates were tested against planktonic cells and biofilms of Candida albicans and Candida glabrata strains, including resistant isolates. These peptides showed similar potent activity, with half-maximal effective concentration values in the micromolar range. In addition, some structural and functional features, revealing peculiar mechanistic behaviors, were investigated.

15.
Microbiol Spectr ; : e0219423, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37728335

RESUMO

The human organism is inhabited by trillions of microorganisms, known as microbiota, which are considered to exploit a pivotal role in the regulation of host health and immunity. Recent investigations have suggested a relationship between the composition of the human microbiota and COVID-19 infection, highlighting a possible role of bacterial communities in the modulation of the disease severity. In this study, we performed a shotgun metagenomics analysis to explore and compare the nasopharyngeal microbiota of 38 hospitalized Italian patients with and without COVID-19 infection during the third and fourth pandemic waves. In detail, the metagenomic analysis combined with specific correlation analyses suggested a positive association of several microbial species, such as S. parasanguinis and P. melaninogenica, with the severity of COVID-19 infection. Furthermore, the comparison of the microbiota composition between the nasopharyngeal and their respective fecal samples highlighted an association between these different compartments represented by a sharing of several bacterial species. Additionally, lipidomic and deep-shotgun functional analyses of the fecal samples suggested a metabolic impact of the microbiome on the host's immune response, indicating the presence of key metabolic compounds in COVID-19 patients, such as lipid oxidation end products, potentially related to the inflammatory state. Conversely, the patients without COVID-19 displayed enzymatic patterns associated with the biosynthesis and degradation of specific compounds like lysine (synthesis) and phenylalanine (degradation) that could positively impact disease severity and contribute to modulating COVID-19 infection. IMPORTANCE The human microbiota is reported to play a major role in the regulation of host health and immunity, suggesting a possible impact on the severity of COVID-19 disease. This preliminary study investigated the possible correlation between nasopharyngeal microbiota and COVID-19 infection. In detail, the analysis of the nasopharyngeal microbiota of hospitalized Italian patients with and without COVID-19 infection suggested a positive association of several microbial species with the severity of the disease and highlighted a sharing of several bacteria species with the respective fecal samples. Moreover, the metabolic analyses suggested a possible impact of the microbiome on the host's immune response and the disease severity.

16.
J Fungi (Basel) ; 8(7)2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35887478

RESUMO

The ubiquitous commensal Candida albicans, part of the human microbiota, is an opportunistic pathogen able to cause a wide range of diseases, from cutaneous mycoses to life-threatening infections in immunocompromised patients. Candida albicans adapts to different environments and survives long-time starvation. The ability to switch from yeast to hyphal morphology under specific environmental conditions is associated with its virulence. Using hydrogen nuclear magnetic resonance spectroscopy, we profiled the intracellular and extracellular metabolome of C. albicans kept in water, yeast extract-peptone-dextrose (YPD), and M199 media, at selected temperatures. Experiments were carried out in hypoxia to mimic a condition present in most colonized niches and fungal infection sites. Comparison of the intracellular metabolites measured in YPD and M199 at 37 °C highlighted differences in specific metabolic pathways: (i) alanine, aspartate, glutamate metabolism, (ii) arginine and proline metabolism, (iii) glycerolipid metabolism, attributable to the diverse composition of the media. Moreover, we hypothesized that the subtle differences in the M199 metabolome, observed at 30 °C and 37 °C, are suggestive of modifications propaedeutic to a subsequent transition from yeast to hyphal form. The analysis of the metabolites' profiles of C. albicans allows envisaging a molecular model to better describe its ability to sense and adapt to environmental conditions.

17.
J Oral Microbiol ; 14(1): 2103282, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35923899

RESUMO

The recent COVID-19 pandemic prompted a rapid-growing interest in the investigation of the human microbiota of the upper airways. In fact, the resident microbial community of this body district may have an influence on the onset of SARS-CoV-2 infection and its clinical course in terms of presence, symptom severity, and outcomes. However, several microbiological methodologies are available to study the human microbiota, reflecting the extensive fragmentation of methodological approaches. We investigate the impact of two critical steps that can induce biases in the downstream analyses, i.e. sampling method and microbial DNA extraction kit employed. We observed major discrepancies regarding the total amount of prokaryotic DNA that could be retrieved from a biological sample and the proportion between bacterial DNA and human host DNA. Moreover, shotgun DNA sequencing and taxonomic profile reconstruction also revealed correlations between sampling methods and the procedures applied for microbial DNA extraction. Based on all the data collected in this study, we formulate indications regarding the most efficient and reliable methodological procedures for the metagenomic analyses of the upper airways' microbiota to maximize accuracy and reproducibility.

18.
Antonie Van Leeuwenhoek ; 99(1): 35-41, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20714805

RESUMO

"Antibiobodies", antibodies (Abs) with antibiotic activity, internal image of a Pichia anomala killer toxin (PaKT) characterized by microbicidal activity against microorganisms expressing ß-glucans cell-wall receptors (PaKTRs), were produced by idiotypic vaccination with a PaKT-neutralizing monoclonal Ab (PaKT-like Abs) or induced by a protein-conjugated ß-glucan. Human natural PaKT-like Abs (PaKTAbs) were found in the vaginal fluid of women infected with KT-sensitive microorganisms. Monoclonal and recombinant PaKT-like Abs, and PaKTAbs proved to be protective against experimental candidiasis, cryptococcosis and aspergillosis. A killer decapeptide (KP), synthesized from the sequence of a recombinant PaKT-like Ab or produced in transgenic plants, showed a microbicidal activity in vitro, neutralized by ß-glucans, a therapeutic effect in vivo, against experimental mucosal and systemic mycoses, and a prophylactic role in planta, against phytopathogenic microorganisms, respectively. KP showed fungicidal properties against all the defective mutants of a Saccharomyces cerevisiae library, inclusive of strains recognized to be resistant to conventional antifungal drugs. KP inhibited in vitro, ex vivo and/or in vivo HIV-1 and Influenza A virus replication, owing to down-regulation of CCR5 co-receptors, physical block of the gp120-receptor interaction and reduction in the synthesis of glycoproteins, HA and M1 in particular. KP modulated the expression of costimulatory and MHC molecules on murine dendritic cells, improving their capacity to induce lymphocyte proliferation. KP, proven to be devoid of cytotoxicity on human cells, showed self-assembly-releasing hydrogel-like properties, catalyzed by ß 1,3 glucan. PaKT's biotechnological derivatives may represent the prototypes of novel antifungal vaccines and anti-infective drugs characterized by different mechanisms of action.


Assuntos
Anti-Infecciosos/farmacologia , Produtos Biológicos/farmacologia , Fatores Imunológicos/farmacologia , Fatores Matadores de Levedura/farmacologia , Pichia/metabolismo , Animais , Células Dendríticas/efeitos dos fármacos , Feminino , Vacinas Fúngicas/imunologia , Fungos/efeitos dos fármacos , Humanos , Camundongos , Vírus/efeitos dos fármacos
19.
Microorganisms ; 9(1)2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33435157

RESUMO

Mycoses still represent relevant opportunistic infections worldwide, although overshadowed in recent years by other severe and more widespread infections. Moreover, deep-seated mycoses are often accompanied by unacceptably high mortality rates. Etiologic agents include endogenous components of the mycobiota, Candida and Malassezia species above all, and exogenous species, both yeasts and filamentous fungi. Old and new fungal pathogens are increasingly characterized by resistance to the existing antifungal agents, making imperative the search for effective and safe new therapeutics. Among the candidate molecules proposed in recent decades, synthetic peptides derived from the complementarity determining and constant regions of diverse antibodies (Abs), as well as the translated products of Ab-encoding genes, have proved of considerable interest. Their anti-infective activities, regardless of the specificity and isotype of the originating Ab, will be briefly presented and discussed in the light of their different mechanisms of action. Intriguing suggestions on the possible function of Abs after their half-life will be presented, following the recent detection, in human serum, of an antimicrobial Ab-derived peptide. Overall, Abs could represent a source of biologically active, highly flexible peptides, devoid of detectable toxicity, which can be easily synthesized and manipulated to be used, alone or in association with already available drugs, for new anti-infective strategies.

20.
Toxins (Basel) ; 13(9)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34564659

RESUMO

Possible implications and applications of the yeast killer phenomenon in the fight against infectious diseases are reviewed, with particular reference to some wide-spectrum killer toxins (KTs) produced by Wickerhamomyces anomalus and other related species. A perspective on the applications of these KTs in the medical field is provided considering (1) a direct use of killer strains, in particular in the symbiotic control of arthropod-borne diseases; (2) a direct use of KTs as experimental therapeutic agents; (3) the production, through the idiotypic network, of immunological derivatives of KTs and their use as potential anti-infective therapeutics. Studies on immunological derivatives of KTs in the context of vaccine development are also described.


Assuntos
Anti-Infecciosos/toxicidade , Anti-Infecciosos/uso terapêutico , Doenças Transmissíveis/tratamento farmacológico , Citotoxinas/uso terapêutico , Fatores Matadores de Levedura/toxicidade , Fatores Matadores de Levedura/uso terapêutico , Saccharomycetales/química , Humanos , Desenvolvimento de Vacinas
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