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1.
J Bacteriol ; 206(5): e0007124, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38629875

RESUMO

Bovine mastitis is a frequent infection in lactating cattle, causing great economic losses. Staphylococcus aureus represents the main etiological agent, which causes recurrent and persistent intramammary infections because conventional antibiotics are ineffective against it. Mastoparan-like peptides are multifunctional molecules with broad antimicrobial potential, constituting an attractive alternative. Nevertheless, their toxicity to host cells has hindered their therapeutic application. Previously, our group engineered three mastoparan-L analogs, namely mastoparan-MO, mastoparan-R1, and [I5, R8] MP, to improve cell selectivity and potential. Here, we were interested in comparing the antibacterial efficacy of mastoparan-L and its analogs against bovine mastitis isolates of S. aureus strains, making a correlation with the physicochemical properties and structural arrangement changes promoted by the sequence modifications. As a result, the analog's hemolytic and/or antimicrobial activity was balanced. All the peptides displayed α-helical folding in hydrophobic and membrane-mimetic environments, as determined by circular dichroism. The peptide [I5, R8] MP stood out for its enhanced selectivity and antibacterial features related to mastoparan-L and the other derivatives. Biophysical approaches revealed that [I5, R8] MP rapidly depolarizes the bacterial membrane of S. aureus, causing cell death by subsequent membrane disruption. Our results demonstrated that the [I5, R8] MP peptide could be a starting point for the development of peptide-based drugs for the treatment of bovine mastitis, with the advantage of no residue in milk, which would help reduce the use of classical antibiotics.IMPORTANCEStaphylococcus aureus is a leading cause of mastitis, the world's most important dairy cattle disease. The multidrug resistance and zoonotic potential of S. aureus, besides the likelihood of antibiotic residues in milk, are of critical concern to public and animal health. Antimicrobial peptides offer a novel antimicrobial strategy. Here, we demonstrate that [I5, R8] MP is a potent and selective peptide, which acts on S. aureus by targeting the bacterial membrane. Therefore, understanding the physicochemical determinants and the modes of action of this class of antimicrobials opens novel prospects for peptide development with enhanced activities in the bovine mastitis context.


Assuntos
Antibacterianos , Peptídeos e Proteínas de Sinalização Intercelular , Mastite Bovina , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas , Staphylococcus aureus , Animais , Bovinos , Mastite Bovina/microbiologia , Mastite Bovina/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Feminino , Antibacterianos/farmacologia , Antibacterianos/química , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/tratamento farmacológico , Peptídeos/farmacologia , Peptídeos/química , Venenos de Vespas/farmacologia , Venenos de Vespas/química
2.
J Antimicrob Chemother ; 79(1): 112-122, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37966053

RESUMO

BACKGROUND: The synthetic antimicrobial peptide, PaDBS1R1, has been reported as a powerful anti-Klebsiella pneumoniae antimicrobial. However, there is only scarce knowledge about whether K. pneumoniae could develop resistance against PaDBS1R1 and which resistance mechanisms could be involved. OBJECTIVES: Identify via label-free shotgun proteomics the K. pneumoniae resistance mechanisms developed against PaDBS1R1. METHODS: An adaptive laboratory evolution experiment was performed to obtain a PaDBS1R1-resistant K. pneumoniae lineage. Antimicrobial susceptibility was determined through microdilution assay. Modifications in protein abundances between the resistant and sensitive lineages were measured via label-free quantitative shotgun proteomics. Enriched Gene Ontology terms and KEGG pathways were identified through over-representation analysis. Data are available via ProteomeXchange with identifier PXD033020. RESULTS: K. pneumoniae ATCC 13883 parental strain challenged with increased subinhibitory PaDBS1R1 concentrations allowed the PaDBS1R1-resistant K. pneumoniae lineage to emerge. Proteome comparisons between PaDBS1R1-resistant K. pneumoniae and PaDBS1R1-sensitive K. pneumoniae under PaDBS1R1-induced stress conditions enabled the identification and quantification of 1702 proteins, out of which 201 were differentially abundant proteins (DAPs). The profiled DAPs comprised 103 up-regulated proteins (adjusted P value < 0.05, fold change ≥ 2) and 98 down-regulated proteins (adjusted P value < 0.05, fold change ≤ 0.5). The enrichment analysis suggests that PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery could be relevant resistance mechanisms against PaDBS1R1. CONCLUSIONS: Based on experimental evolution and a label-free quantitative shotgun proteomic approach, we showed that K. pneumoniae developed resistance against PaDBS1R1, whereas PhoPQ-guided LPS modifications and CpxRA-dependent folding machinery appear to be relevant resistance mechanisms against PaDBS1R1.


Assuntos
Anti-Infecciosos , Infecções por Klebsiella , Humanos , Antibacterianos/farmacologia , Klebsiella pneumoniae/genética , Peptídeos Antimicrobianos , Proteômica , Lipopolissacarídeos , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana
3.
Biochemistry ; 58(36): 3802-3812, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31448597

RESUMO

Antimicrobial peptides (AMPs) represent alternative strategies to combat the global health problem of antibiotic resistance. However, naturally occurring AMPs are generally not sufficiently active for use as antibiotics. Optimized synthetic versions incorporating additional design principles are needed. Here, we engineered amino-terminal Cu(II) and Ni(II) (ATCUN) binding motifs, which can enhance biological function, into the native sequence of two AMPs, CM15 and citropin1.1. The incorporation of metal-binding motifs modulated the antimicrobial activity of synthetic peptides against a panel of carbapenem-resistant enterococci (CRE) bacteria, including carbapenem-resistant Klebsiella pneumoniae (KpC+) and Escherichia coli (KpC+). Activity modulation depended on the type of ATCUN variant utilized. Membrane permeability assays revealed that the in silico selected lead template, CM15, and its ATCUN analogs increased bacterial cell death. Mass spectrometry, circular dichroism, and molecular dynamics simulations indicated that coordinating ATCUN derivatives with Cu(II) ions did not increase the helical tendencies of the AMPs. CM15 ATCUN variants, when combined with Meropenem, streptomycin, or chloramphenicol, showed synergistic effects against E. coli (KpC+ 1812446) biofilms. Motif addition also reduced the hemolytic activity of the wild-type AMP and improved the survival rate of mice in a systemic infection model. The dependence of these bioactivities on the particular amino acids of the ATCUN motif highlights the possible use of size, charge, and hydrophobicity to fine-tune AMP biological function. Our data indicate that incorporating metal-binding motifs into peptide sequences leads to synthetic variants with modified biological properties. These principles may be applied to augment the activities of other peptide sequences.


Assuntos
Antibacterianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Proteínas de Transporte/uso terapêutico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Transporte/química , Proteínas de Transporte/farmacologia , Quelantes/química , Quelantes/farmacologia , Quelantes/uso terapêutico , Cobre/química , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Hemólise/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Conformação Proteica em alfa-Hélice , Engenharia de Proteínas , Pseudomonas aeruginosa/efeitos dos fármacos
4.
Microb Pathog ; 135: 103605, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31228542

RESUMO

Biofilm-related infections represent an enormous clinical challenge nowadays. In this context, diverse studies are underway to develop effective antimicrobial agents targeting bacterial biofilms. Here, we describe the antibacterial and anti-biofilm activities of a short, cationic peptide named R5F5, obtained from sliding-window analysis based on a peptide (PcDBS1R5) derived from Plasmodium chabaudi. Ten fragments were generated (R5F1 to F10) and submitted to initial antibacterial assays against Pseudomonas aeruginosa. As a result, R5F5 showed the highest antimicrobial activity. We therefore carried out further antibacterial and anti-biofilm assays against P. aeruginosa and Klebsiella pneumoniae carbapenemase-producing bacterial strains. R5F5 revealed selective anti-biofilm activity, as the peptide inhibited >60% biofilm formation in all cases from 8 to 64 µg·mL-1. Moreover, R5F5 was not hemolytic against mice erythrocytes at 640 µg mL-1. Cytotoxic effects on human lung fibroblast cells were not detected at 160 µg·mL-1. Structural studies revealed that R5F5 presents random coil conformations in water and 50% 2,2,2-trifluoroethanol (TFE)/water (v/v), whereas amphipathic, extended conformations were observed in contact with sodium dodecyl sulfate (SDS) micelles. Thus, here we report a novel peptide with selective anti-biofilm activity against susceptible and resistant bacterial strains, with no toxicity toward mammalian cells and that adopts a stable structure in anionic environment.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Proteínas de Bactérias , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Simulação de Dinâmica Molecular , Plasmodium chabaudi/química , beta-Lactamases
5.
Int J Mol Sci ; 20(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581426

RESUMO

The advent of multidrug resistance among pathogenic bacteria has attracted great attention worldwide. As a response to this growing challenge, diverse studies have focused on the development of novel anti-infective therapies, including antimicrobial peptides (AMPs). The biological properties of this class of antimicrobials have been thoroughly investigated, and membranolytic activities are the most reported mechanisms by which AMPs kill bacteria. Nevertheless, an increasing number of works have pointed to a different direction, in which AMPs are seen to be capable of displaying non-lytic modes of action by internalizing bacterial cells. In this context, this review focused on the description of the in vitro and in vivo antibacterial and antibiofilm activities of non-lytic AMPs, including indolicidin, buforin II PR-39, bactenecins, apidaecin, and drosocin, also shedding light on how AMPs interact with and further translocate through bacterial membranes to act on intracellular targets, including DNA, RNA, cell wall and protein synthesis.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Bactérias/metabolismo , Glicopeptídeos/metabolismo , Insetos , Biossíntese de Proteínas
6.
Microbiology (Reading) ; 164(11): 1383-1393, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30277857

RESUMO

Antimicrobial peptides (AMPs) have attracted considerable attention because of their multiple and complex mechanisms of action toward resistant bacteria. However, reports have increasingly highlighted how bacteria can escape AMP administration. Here, the molecular mechanisms involved in Escherichia coli resistance to magainin I were investigated through comparative transcriptomics. Sub-inhibitory concentrations of magainin I were used to generate four experimental groups, including magainin I-susceptible E. coli, in the absence (C) and presence of magainin I (CM); and magainin I-resistant E. coli in the absence (R) and presence of magainin I (RM). The total RNA from each sample was extracted; cDNA libraries were constructed and further submitted for Illumina MiSeq sequencing. After RNA-seq data pre-processing and functional annotation, a total of 103 differentially expressed genes (DEGs) were identified, mainly related to bacterial metabolism. Moreover, down-regulation of cell motility and chaperone-related genes was observed in CM and RM, whereas cell communication, acid tolerance and multidrug efflux pump genes (ABC transporter, major facilitator and resistance-nodulation cell division superfamilies) were up-regulated in these same groups. DEGs from the C and R groups are related to basal levels of expression of homeostasis-related genes compared to CM and RM, suggesting that the presence of magainin I is required to change the transcriptomics panel in both C and R E. coli strains. These findings show the complexity of E. coli resistance to magainin I through the rearrangement of several metabolic pathways involved in bacterial physiology and drug response, also providing information on the development of novel antimicrobial strategies targeting resistance-related transcripts and proteins herein described.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Fenômenos Fisiológicos Bacterianos/genética , Farmacorresistência Bacteriana/genética , Metabolismo Energético/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Transcriptoma/genética , Transportadores de Cassetes de Ligação de ATP/biossíntese , Proteínas de Bactérias/biossíntese , DNA Complementar/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Escherichia coli/metabolismo , Perfilação da Expressão Gênica , RNA/análise
7.
Biochim Biophys Acta ; 1858(7 Pt A): 1488-98, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27063608

RESUMO

Recently, several peptides have been studied regarding the defence process against pathogenic microorganisms, which are able to act against different targets, with the purpose of developing novel bioactive compounds. The present work focuses on the structural and functional evaluation of the palindromic antimicrobial peptide Pa-MAP2, designed based on the peptide Pa-MAP from Pleuronectes americanus. For a better structural understanding, molecular modelling analyses were carried out, together with molecular dynamics and circular dichroism, in different media. Antibacterial activity against Gram-negative and positive bacteria was evaluated, as well as cytotoxicity against human erythrocytes, RAW 264.7, Vero and L6 cells. In silico docking experiments, lipid vesicle studies, and atomic force microscopy (AFM) imaging were carried out to explore the activity of the peptide. In vivo studies on infected mice were also done. The palindromic primary sequence favoured an α-helix structure that was pH dependent, only present on alkaline environment, with dynamic N- and C-terminals that are stabilized in anionic media. Pa-MAP2 only showed activity against Gram-negative bacteria, with a MIC of 3.2 µM, and without any cytotoxic effect. In silico, lipid vesicles and AFM studies confirm the preference for anionic lipids (POPG, POPS, DPPE, DPPG and LPS), with the positively charged lysine residues being essential for the initial electrostatic interaction. In vivo studies showed that Pa-MAP2 increases to 100% the survival rate of mice infected with Escherichia coli. Data here reported indicated that palindromic Pa-MAP2 could be an alternative candidate for use in therapeutics against Gram-negative bacterial infections.


Assuntos
Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Infecções por Escherichia coli/tratamento farmacológico , Peptidomiméticos/química , Alanina/química , Sequência de Aminoácidos , Animais , Antibacterianos/síntese química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Colesterol/química , Eritrócitos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/mortalidade , Linguado/metabolismo , Humanos , Lipopolissacarídeos/química , Camundongos , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Peptidomiméticos/síntese química , Peptidomiméticos/farmacologia , Fosfatidilcolinas/química , Fosfatidilgliceróis/química , Fosfatidilserinas/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Análise de Sobrevida , Lipossomas Unilamelares/química , Células Vero
8.
Front Chem ; 12: 1382954, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38873409

RESUMO

N-capping (N-cap) and C-capping (C-cap) in biologically active peptides, including specific amino acids or unconventional group motifs, have been shown to modulate activity against pharmacological targets by interfering with the peptide's secondary structure, thus generating unusual scaffolds. The insertion of capping motifs in linear peptides has been shown to prevent peptide degradation by reducing its susceptibility to proteolytic cleavage, and the replacement of some functional groups by unusual groups in N- or C-capping regions in linear peptides has led to optimized peptide variants with improved secondary structure and enhanced activity. Furthermore, some essential amino acid residues that, when placed in antimicrobial peptide (AMP) capping regions, are capable of complexing metals such as Cu2+, Ni2+, and Zn2+, give rise to the family known as metallo-AMPs, which are capable of boosting antimicrobial efficacy, as well as other activities. Therefore, this review presents and discusses the different strategies for creating N- and C-cap motifs in AMPs, aiming at fine-tuning this class of antimicrobials.

9.
Trends Microbiol ; 32(7): 624-627, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38777700

RESUMO

Many factors contribute to bacterial membrane stabilization, including steric effects between lipids, membrane spontaneous curvature, and the difference in the number of neighboring molecules. This forum provides an overview of the physicochemical properties associated with membrane curvature and how this parameter can be tuned to design more effective antimicrobial peptides.


Assuntos
Peptídeos Antimicrobianos , Bactérias , Membrana Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/química , Membrana Celular/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Antibacterianos/farmacologia , Antibacterianos/química , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo
10.
FEBS J ; 291(5): 865-883, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37997610

RESUMO

Mastoparans are cationic peptides with multifunctional pharmacological properties. Mastoparan-R1 and mastoparan-R4 were computationally designed based on native mastoparan-L from wasps and have improved therapeutic potential for the control of bacterial infections. Here, we evaluated whether these peptides maintain their activity against Escherichia coli strains under a range of salt concentrations. We found that mastoparan-R1 and mastoparan-R4 preserved their activity under the conditions tested, including having antibacterial activities at physiological salt concentrations. The overall structure of the peptides was investigated using circular dichroism spectroscopy in a range of solvents. No significant changes in secondary structure were observed (random coil in aqueous solutions and α-helix in hydrophobic and anionic environments). The three-dimensional structures of mastoparan-R1 and mastoparan-R4 were elucidated through nuclear magnetic resonance spectroscopy, revealing amphipathic α-helical segments for Leu3-Ile13 (mastoparan-R1) and Leu3-Ile14 (mastoparan-R4). Possible membrane-association mechanisms for mastoparan-R1 and mastoparan-R4 were investigated through surface plasmon resonance and leakage studies with synthetic POPC and POPC/POPG (4:1) lipid bilayers. Mastoparan-L had the highest affinity for both membrane systems, whereas the two analogs had weaker association, but improved selectivity for lysing anionic membranes. This finding was also supported by molecular dynamics simulations, in which mastoparan-R1 and mastoparan-R4 were found to have greater interactions with bacteria-like membranes compared with model mammalian membranes. Despite having a few differences in their functional and structural profiles, the mastoparan-R1 analog stood out with the highest activity, greater bacteriostatic potential, and selectivity for lysing anionic membranes. This study reinforces the potential of mastoparan-R1 as a drug candidate.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular , Peptídeos , Animais , Peptídeos/farmacologia , Venenos de Vespas/farmacologia , Escherichia coli , Cloreto de Sódio , Computadores , Mamíferos
11.
Chem Biol Drug Des ; 104(1): e14588, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39048531

RESUMO

Diverse computational approaches have been widely used to assist in designing antimicrobial peptides with enhanced activities. This tactic has also been used to address the need for new treatment alternatives to combat resistant bacterial infections. Herein, we have designed eight variants from a natural peptide, pro-adrenomedullin N-terminal 20 peptide (PAMP), using an in silico pattern insertion approach, the Joker algorithm. All the variants show an α-helical conformation, but with differences in the helix percentages according to circular dichroism (CD) results. We found that the C-terminal portion of PAMP may be relevant for its antimicrobial activities, as revealed by the molecular dynamics, CD, and antibacterial results. The analogs showed variable antibacterial potential, but most were not cytotoxic. Nevertheless, PAMP2 exhibited the most potent activities against human and animal-isolated bacteria, showing cytotoxicity only at a substantially higher concentration than its minimal inhibitory concentration (MIC). Our results suggest that the enhanced activity in the profile of PAMP2 may be related to their particular physicochemical properties, along with the adoption of an amphipathic α-helical arrangement with the conserved C-terminus portion. Finally, the peptides designed in this study can constitute scaffolds for the design of improved sequences.


Assuntos
Adrenomedulina , Dicroísmo Circular , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Humanos , Adrenomedulina/química , Adrenomedulina/farmacologia , Sequência de Aminoácidos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Animais , Simulação por Computador , Precursores de Proteínas/química , Precursores de Proteínas/farmacologia , Precursores de Proteínas/metabolismo , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Estrutura Secundária de Proteína
12.
Drug Discov Today ; 28(2): 103444, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36400344

RESUMO

Macrophage intracellular infections are difficult to treat because conventional antibiotics tend to have poor penetration of mammalian cells. As a consequence, the immune response is affected and bacteria remain protected inside macrophages. The use of antimicrobial peptides (AMPs) is one of the alternatives developed as new treatments because of their broad spectrum of action. To improve drug delivery into the intracellular space, extracellular vesicles (EVs) have emerged as an innovative strategy for drug delivery. In particular, apoptotic bodies (ApoBDs) are EVs that exhibit attraction to macrophages, which makes them a promising means of improving AMP delivery to treat macrophage intracellular infections. Here, we review important aspects that should be taken into account when developing ApoBD-AMP conjugates.


Assuntos
Infecções Bacterianas , Vesículas Extracelulares , Animais , Peptídeos Antimicrobianos , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Antibacterianos/uso terapêutico , Bactérias , Mamíferos
13.
Travel Med Infect Dis ; 52: 102557, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36805033

RESUMO

Patients with respiratory viral infections are more likely to develop co-infections leading to increased fatality. Mucormycosis is an epidemic amidst the COVID-19 pandemic that conveys a 'double threat' to the global health fraternity. Mucormycosis is caused by the Mucorales group of fungi and exhibits acute angioinvasion generally in immunocompromised patients. The most familiar foci of infections are sinuses (39%), lungs (24%), and skin tissues (19%) where the overall dissemination occurs in 23% of cases. The mortality rate in the case of disseminated mucormycosis is found to be 96%. Symptoms are mostly nonspecific and often resemble other common bacterial or fungal infections. Currently, COVID-19-associated mucormycosis (CAM) is being reported from a number of countries such as the USA, Turkey, France, Mexico, Iran, Austria, UK, Brazil, and Italy, while India is the hotspot for this deadly co-infection, accounting for approximately 28,252 cases up to June 8, 2021. It strikes patients within 12-18 days after COVID-19 recovery, and nearly 80% require surgery. Nevertheless, the mortality rate can reach 94% if the diagnosis is delayed or remains untreated. Sometimes COVID-19 is the sole predisposing factor for CAM. Therefore, this study may provide a comprehensive resource for clinicians and researchers dealing with fungal infections, intending to link the potential translational knowledge and prospective therapeutic challenges to counter this opportunistic pathogen.


Assuntos
COVID-19 , Coinfecção , Mucormicose , Humanos , Mucormicose/epidemiologia , Pandemias , Brasil , Coinfecção/epidemiologia
14.
ACS Omega ; 8(20): 17856-17868, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37251186

RESUMO

Antibiotic-resistant bacterial infections have increased the prevalence of sepsis and septic shock mortality worldwide and have become a global concern. Antimicrobial peptides (AMPs) show remarkable properties for developing new antimicrobial agents and host response modulatory therapies. A new series of AMPs derived from pexiganan (MSI-78) were synthesized. The positively charged amino acids were segregated at their N- and C-termini, and the rest of the amino acids created a hydrophobic core surrounded by positive charges and were modified to simulate the lipopolysaccharide (LPS). The peptides were investigated for their antimicrobial activity and LPS-induced cytokine release inhibition profile. Various biochemical and biophysical methods were used, including attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, microscale thermophoresis (MST), and electron microscopy. Two new AMPs, MSI-Seg-F2F and MSI-N7K, preserved their neutralizing endotoxin activity while reducing toxicity and hemolytic activity. Combining all of these properties makes the designed peptides potential candidates to eradicate bacterial infection and detoxify LPS, which might be useful for sepsis treatment.

15.
Front Bioinform ; 3: 1216362, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37521317

RESUMO

Antimicrobial peptides (AMPs) are components of natural immunity against invading pathogens. They are polymers that fold into a variety of three-dimensional structures, enabling their function, with an underlying sequence that is best represented in a non-flat space. The structural data of AMPs exhibits non-Euclidean characteristics, which means that certain properties, e.g., differential manifolds, common system of coordinates, vector space structure, or translation-equivariance, along with basic operations like convolution, in non-Euclidean space are not distinctly established. Geometric deep learning (GDL) refers to a category of machine learning methods that utilize deep neural models to process and analyze data in non-Euclidean settings, such as graphs and manifolds. This emerging field seeks to expand the use of structured models to these domains. This review provides a detailed summary of the latest developments in designing and predicting AMPs utilizing GDL techniques and also discusses both current research gaps and future directions in the field.

16.
RSC Adv ; 13(31): 21345-21364, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37465579

RESUMO

The intricate, tightly controlled mechanism of wound healing that is a vital physiological mechanism is essential to maintaining the skin's natural barrier function. Numerous studies have focused on wound healing as it is a massive burden on the healthcare system. Wound repair is a complicated process with various cell types and microenvironment conditions. In wound healing studies, novel therapeutic approaches have been proposed to deliver an effective treatment. Nanoparticle-based materials are preferred due to their antibacterial activity, biocompatibility, and increased mechanical strength in wound healing. They can be divided into six main groups: metal NPs, ceramic NPs, polymer NPs, self-assembled NPs, composite NPs, and nanoparticle-loaded hydrogels. Each group shows several advantages and disadvantages, and which material will be used depends on the type, depth, and area of the wound. Better wound care/healing techniques are now possible, thanks to the development of wound healing strategies based on these materials, which mimic the extracellular matrix (ECM) microenvironment of the wound. Bearing this in mind, here we reviewed current studies on which NPs have been used in wound healing and how this strategy has become a key biotechnological procedure to treat skin infections and wounds.

17.
Peptides ; 157: 170865, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36038014

RESUMO

The gut microbiota presents essential functions in the immune response. The gut epithelium acts as a protective barrier and, therefore, can produce several antimicrobial peptides (AMPs) that can act against pathogenic microorganisms, including bacteria. Several factors cause a disturbance in gut microbiota, including the exacerbated and erroneous use of antibiotics. Antibiotic therapy has been closely related to bacterial resistance and is also correlated with undesired side-effects to the host, including the eradication of commensal bacteria. Consequently, this results in gut microbiota imbalance and inflammatory bowel diseases (IBD) development. In this context, AMPs in the gut epithelium play a restructuring role for gut microbiota. Some naturally occurring AMPs are selective for pathogenic bacteria, thus preserving the health microbiota. Therefore, AMPs produced by the host's epithelial cells represent effective molecules in treating gut bacterial infections. Bearing this in mind, this review focused on describing the importance of the host's AMPs in gut microbiota modulation and their role as anti-infective agents against pathogenic bacteria.


Assuntos
Anti-Infecciosos , Infecções Bacterianas , Microbioma Gastrointestinal , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Peptídeos Antimicrobianos , Bactérias , Humanos
18.
Microbiol Resour Announc ; 11(7): e0037022, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35758757

RESUMO

Streptomyces strains are powerhouses for a diverse range of secondary metabolites, including antibiotics, anticancer and immunosuppressive agents, and enzymes. Here, we report the genome sequence of Streptomyces sp. strain PSAA01, which was isolated from a soil sample taken in Manas National Park, Assam, India, in the eastern Himalayan foothills of India.

19.
Chem Sci ; 13(32): 9410-9424, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36093022

RESUMO

Structural diversity drives multiple biological activities and mechanisms of action in linear peptides. Here we describe an unusual N-capping asparagine-lysine-proline (NKP) motif that confers a hybrid multifunctional scaffold to a computationally designed peptide (PaDBS1R7). PaDBS1R7 has a shorter α-helix segment than other computationally designed peptides of similar sequence but with key residue substitutions. Although this motif acts as an α-helix breaker in PaDBS1R7, the Asn5 presents exclusive N-capping effects, forming a belt to establish hydrogen bonds for an amphipathic α-helix stabilization. The combination of these different structural profiles was described as a coil/N-cap/α-helix scaffold, which was also observed in diverse computational peptide mutants. Biological studies revealed that all peptides displayed antibacterial activities. However, only PaDBS1R7 displayed anticancer properties, eradicated Pseudomonas aeruginosa biofilms, decreased bacterial counts by 100-1000-fold in vivo, reduced lipopolysaccharide-induced macrophages stress, and stimulated fibroblast migration for wound healing. This study extends our understanding of an N-capping NKP motif to engineering hybrid multifunctional peptide drug candidates with potent anti-infective and immunomodulatory properties.

20.
Sci Rep ; 12(1): 15493, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36109567

RESUMO

The main effectors in the innate immune system of Bombyx mori L. are antimicrobial peptides (AMPs). Here, we infected B. mori with varied inoculum sizes of Pseudomonas aeruginosa ATCC 25668 cells to investigate changes in morpho-anatomical responses, physiological processes and AMP production. Ultraviolet-visible spectra revealed a sharp change in λmax from 278 to 285 nm (bathochromic shift) in the hemolymph of infected B. mori incubated for 24 h. Further, Fourier Transform InfraRed studies on the hemolymph extracted from the infected B. mori showed a peak at 1550 cm-1, indicating the presence of α-helical peptides. The peptide fraction was obtained through methanol, acetic acid and water mixture (90:1:9) extraction, followed by peptide purification using Reverse Phase High Performance Liquid Chromatography. The fraction exhibiting antibacterial properties was collected and characterized by Matrix-Assisted Laser Desorption/Ionization-Time of Flight. A linear α-helical peptide with flexible termini (LLKELWTKMKGAGKAVLGKIKGLL) was found, corresponding to a previously described peptide from ant venom and here denominated as Bm-ponericin-L1. The antibacterial activity of Bm-ponericin-L1 was determined against ESKAPE pathogens. Scanning electron microscopy confirmed the membrane disruption potential of Bm-ponericin-L1. Moreover, this peptide also showed promising antibiofilm activity. Finally, cell viability and hemolytic assays revealed that Bm-ponericin-L1 is non-toxic toward primary fibroblasts cell lines and red blood cells, respectively. This study opens up new perspectives toward an alternative approach to overcoming multiple-antibiotic-resistance by means of AMPs through invertebrates' infection with human pathogenic bacteria.


Assuntos
Venenos de Formiga , Anti-Infecciosos , Bombyx , Infecções por Pseudomonas , Animais , Humanos , Antibacterianos/farmacologia , Hemolinfa , Metanol , Peptídeos/química , Infecções por Pseudomonas/tratamento farmacológico , Água
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