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1.
Nat Commun ; 12(1): 5473, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531396

RESUMO

Implant related infections are the most common cause of joint arthroplasty failure, requiring revision surgeries and a new implant, resulting in a cost of $8.6 billion annually. To address this problem, we created a class of coating technology that is applied in the operating room, in a procedure that takes less than 10 min, and can incorporate any desired antibiotic. Our coating technology uses an in situ coupling reaction of branched poly(ethylene glycol) and poly(allyl mercaptan) (PEG-PAM) polymers to generate an amphiphilic polymeric coating. We show in vivo efficacy in preventing implant infection in both post-arthroplasty infection and post-spinal surgery infection mouse models. Our technology displays efficacy with or without systemic antibiotics, the standard of care. Our coating technology is applied in a clinically relevant time frame, does not require modification of implant manufacturing process, and does not change the implant shelf life.


Assuntos
Antibacterianos/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Sistemas Automatizados de Assistência Junto ao Leito , Infecções Relacionadas à Prótese/prevenção & controle , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Endogâmicos C57BL , Polietilenoglicóis/química , Polímeros/química , Próteses e Implantes/microbiologia , Próteses e Implantes/normas , Infecções Relacionadas à Prótese/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Resultado do Tratamento
2.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445281

RESUMO

Bacterial quorum sensing (QS) is a cell-cell communication system that regulates several bacterial mechanisms, including the production of virulence factors and biofilm formation. Thus, targeting microbial QS is seen as a plausible alternative strategy to antibiotics, with potentiality to combat multidrug-resistant pathogens. Many phytochemicals with QS interference activity are currently being explored. Herein, an extract and a compound of bioinspired origin were tested for their ability to inhibit biofilm formation and interfere with the expression of QS-related genes in Pseudomonas aeruginosa and Staphylococcus aureus. The extract, a carboxypyranoanthocyanins red wine extract (carboxypyrano-ant extract), and the pure compound, carboxypyranocyanidin-3-O-glucoside (carboxypyCy-3-glc), did not cause a visible effect on the biofilm formation of the P. aeruginosa biofilms; however, both significantly affected the formation of biofilms by the S. aureus strains, as attested by the crystal violet assay and fluorescence microscopy. Both the extract and the pure compound significantly interfered with the expression of several QS-related genes in the P. aeruginosa and S. aureus biofilms, as per reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results. Indeed, it was possible to conclude that these molecules interfere with QS at distinct stages and in a strain-specific manner. An extract with anti-QS properties could be advantageous because it is easily obtained and could have broad, antimicrobial therapeutic applications if included in topical formulations.


Assuntos
Antocianinas/farmacologia , Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Percepção de Quorum/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Biofilmes/crescimento & desenvolvimento
3.
J Dairy Res ; 88(3): 293-301, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34425921

RESUMO

Staphylococcus aureus is a common pathogen of bovine mastitis which can induce autophagy and inhibit autophagy flux, resulting in intracellular survival and persistent infection. The aim of the current study was to investigate the role of p38α in the autophagy induced by intracellular S. aureus in bovine mammary epithelial cells. An intracellular infection model of MAC-T cells was constructed, and activation of p38α was examined after S. aureus invasion. Through activating/inhibiting p38α by anisomycin/SB203580, the autophagosomes, LC3 and p62 level were analyzed by immunofluorescence and western blot. To further study the detailed mechanism of p38α, phosphorylation of ULK1ser757 was also detected. The results showed that intracellular S. aureus activated p38α, and the activation developed in a time-dependent manner. Inhibition of p38α promoted intracellular S. aureus-induced autophagy flow, up-regulated the ratio of LC3 II/I, reduced the level of p62 and inhibited the phosphorylation of ULK1ser757, whereas the above results were reversed after activation of p38α. The current study indicated that intracellular S. aureus can inhibit autophagy flow by activating p38α in bovine mammary epithelial cells.


Assuntos
Autofagia/fisiologia , Células Epiteliais/microbiologia , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Animais , Bovinos , Linhagem Celular , Ativação Enzimática , Células Epiteliais/fisiologia , Feminino , Glândulas Mamárias Animais/citologia , Mastite Bovina/fisiopatologia
4.
J Immunol ; 207(5): 1448-1455, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34362834

RESUMO

Identification of the receptors involved in innate immune recognition of Staphylococcus aureus, a major cause of morbidity and mortality in humans, is essential to develop alternative strategies to treat infections caused by antibiotic-resistant strains. In the current study, we examine the role of endosomal TLRs, which sense the presence of prokaryotic-type nucleic acids, in anti-staphylococcal host defenses using infection models involving genetically defective mice. Single deficiencies in TLR7, 9, or 13 resulted in mild or no decrease in host defenses. However, the simultaneous absence of TLR7, 9, and 13 resulted in markedly increased susceptibility to cutaneous and systemic S. aureus infection concomitantly with decreased production of proinflammatory chemokines and cytokines, neutrophil recruitment to infection sites, and reduced production of reactive oxygen species. This phenotype was significantly more severe than that of mice lacking TLR2, which senses the presence of staphylococcal lipoproteins. Notably, the combined absence of TLR7, 9, and 13 resulted in complete abrogation of IL-12 p70 and IFN-ß responses to staphylococcal stimulation in macrophages. Taken together, our data highlight the presence of a highly integrated endosomal detection system, whereby TLR7, 9, and 13 cooperate in sensing the presence of staphylococcal nucleic acids. We demonstrate that the combined absence of these receptors cannot be compensated for by cell surface-associated TLRs, such as TLR2, or cytosolic receptors. These data may be useful to devise strategies aimed at stimulating innate immune receptors to treat S. aureus infections.


Assuntos
Endossomos/metabolismo , Glicoproteínas de Membrana/metabolismo , Neutrófilos/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/fisiologia , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo , Receptores Toll-Like/metabolismo , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Humanos , Imunidade Inata , Mediadores da Inflamação/metabolismo , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 7 Toll-Like/genética , Receptor Toll-Like 9/genética , Receptores Toll-Like/genética
5.
J Immunol ; 207(5): 1371-1376, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34380647

RESUMO

Inflammatory cytokine storm is a known cause for acute respiratory distress syndrome. In this study, we have investigated the role of IFN-γ in lethal lung inflammation using a mouse model of postinfluenza methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. To mimic the clinical scenario, animals were treated with antibiotics for effective bacterial control following MRSA superinfection. However, antibiotic therapy alone is not sufficient to improve survival of wild-type animals in this lethal acute respiratory distress syndrome model. In contrast, antibiotics induce effective protection in mice deficient in IFN-γ response. Mechanistically, we show that rather than inhibiting bacterial clearance, IFN-γ promotes proinflammatory cytokine response to cause lethal lung damage. Neutralization of IFN-γ after influenza prevents hyperproduction of TNF-α, and thereby protects against inflammatory lung damage and animal mortality. Taken together, the current study demonstrates that influenza-induced IFN-γ drives a stepwise propagation of inflammatory cytokine response, which ultimately results in fatal lung damage during secondary MRSA pneumonia, despite of antibiotic therapy.


Assuntos
Antibacterianos/uso terapêutico , Inflamação/imunologia , Vírus da Influenza A/fisiologia , Influenza Humana/imunologia , Interferon gama/metabolismo , Pulmão/imunologia , Infecções por Orthomyxoviridae/imunologia , Pneumonia Estafilocócica/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/fisiologia , Animais , Células Cultivadas , Humanos , Influenza Humana/complicações , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/complicações , Pneumonia Estafilocócica/complicações , Infecções Estafilocócicas/complicações , Superinfecção , Fator de Necrose Tumoral alfa
6.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443349

RESUMO

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but to date, their biological activity on skin commensal and/or opportunistic pathogen bacteria has not been reported. In this study, the effects of poly- and oligosaccharide fractions produced by enzyme-assisted extraction and depolymerization were investigated, for the first time in vitro, on cutaneous bacteria: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. At 1000 µg/mL, poly- and oligosaccharide fractions did not affect the growth of the bacteria regarding their generation time. Polysaccharide Ulva sp. fractions at 1000 µg/mL did not alter the bacterial biofilm formation, while oligosaccharide fractions modified S. epidermidis and C. acnes biofilm structures. None of the fractions at 1000 µg/mL significantly modified the cytotoxic potential of S. epidermidis and S. aureus towards keratinocytes. However, poly- and oligosaccharide fractions at 1000 µg/mL induced a decrease in the inflammatory potential of both acneic and non-acneic C. acnes strains on keratinocytes of up to 39.8%; the strongest and most significant effect occurred when the bacteria were grown in the presence of polysaccharide fractions. Our research shows that poly- and oligosaccharide Ulva sp. fractions present notable biological activities on cutaneous bacteria, especially towards C. acnes acneic and non-acneic strains, which supports their potential use for dermo-cosmetic applications.


Assuntos
Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pele/microbiologia , Ulva/química , Bactérias/patogenicidade , Relação Dose-Resposta a Droga , Propionibacteriaceae/efeitos dos fármacos , Propionibacteriaceae/crescimento & desenvolvimento , Propionibacteriaceae/patogenicidade , Propionibacteriaceae/fisiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/fisiologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento , Staphylococcus epidermidis/patogenicidade , Staphylococcus epidermidis/fisiologia , Virulência/efeitos dos fármacos
7.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443363

RESUMO

The antimicrobial properties of herbs from Papaveraceae have been used in medicine for centuries. Nevertheless, mutual relationships between the individual bioactive substances contained in these plants remain poorly elucidated. In this work, phytochemical composition of extracts from the aerial and underground parts of five Papaveraceae species (Chelidonium majus L., Corydalis cava (L.) Schweigg. and Körte, C. cheilanthifolia Hemsl., C. pumila (Host) Rchb., and Fumaria vaillantii Loisel.) were examined using LC-ESI-MS/MS with a triple quadrupole analyzer. Large differences in the quality and quantity of all analyzed compounds were observed between species of different genera and also within one genus. Two groups of metabolites predominated in the phytochemical profiles. These were isoquinoline alkaloids and, in smaller amounts, non-phenolic carboxylic acids and phenolic compounds. In aerial and underground parts, 22 and 20 compounds were detected, respectively. These included: seven isoquinoline alkaloids: protopine, allocryptopine, coptisine, berberine, chelidonine, sanguinarine, and chelerythrine; five of their derivatives as well as non-alkaloids: malic acid, trans-aconitic acid, quinic acid, salicylic acid, trans-caffeic acid, p-coumaric acid, chlorogenic acid, quercetin, and kaempferol; and vanillin. The aerial parts were much richer in phenolic compounds regardless of the plant species. Characterized extracts were studied for their antimicrobial potential against planktonic and biofilm-producing cells of S. aureus, P. aeruginosa, and C. albicans. The impact of the extracts on cellular metabolic activity and biofilm biomass production was evaluated. Moreover, the antimicrobial activity of the extracts introduced to the polymeric carrier made of bacterial cellulose was assessed. Extracts of C. cheilanthifolia were found to be the most effective against all tested human pathogens. Multiple regression tests indicated a high antimicrobial impact of quercetin in extracts of aerial parts against planktonic cells of S. aureus, P. aeruginosa, and C. albicans, and no direct correlation between the composition of other bioactive substances and the results of antimicrobial activity were found. Conclusively, further investigations are required to identify the relations between recognized and unrecognized compounds within extracts and their biological properties.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Produtos Biológicos/farmacologia , Papaveraceae/química , Extratos Vegetais/farmacologia , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Produtos Biológicos/química , Avaliação Pré-Clínica de Medicamentos , Extratos Vegetais/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
8.
Chem Commun (Camb) ; 57(69): 8648-8651, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34369943

RESUMO

We report that Thioflavin T (ThT), the reference fluorogenic probe for amyloid detection, displays photodynamic activity against bacterial biofilms. ThT recognizes key structures of the biofilm matrix, disrupting the complex architecture and efficiently inactivating bacterial cells. We also show that ThT phototherapy synergistically boosts the activity of conventional antimicrobials.


Assuntos
Antibacterianos/farmacologia , Benzotiazóis/farmacologia , Biofilmes/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Luz , Testes de Sensibilidade Microbiana , Staphylococcus aureus/fisiologia
9.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34338626

RESUMO

Introduction. Biofilm formation is a major virulence factor associated with Staphylococcus aureus infections. However, the influence of plasma proteins on biofilm formation of clinical isolates in vitro remains unclear.Hypotheses. We hypothesized that coating surfaces with plasma proteins might induce biofilm formation by S. aureus of different clonal lineages.Aim. To evaluate biofilm production by clinical S. aureus isolates of different clonal lineages isolated in Rio de Janeiro hospitals and investigated the presence of biofilm-associated genes.Methodology. This study assessed biofilm production of 60 S. aureus isolates in polystyrene microtitre plates with and without fibrinogen or fibronectin. The biochemical composition of the biofilm matrices was determined and the biofilm formation on fibrinogen-coated surfaces was also evaluated by confocal laser scanning microscopy. The presence of biofilm-related genes was detected by PCR, and the typing and functionality of agr operon was also evaluated.Results. Most of the isolates (45 %) were weak biofilm producers or non-producers. However, most of them presented a significant increase in biofilm production on plates covered with plasma proteins. There was no significant difference in biofilm formation between methicillin-resistant and -susceptible S. aureus isolates, or between different clonal lineages, except for ST30-IV (weak producers) and ST239-III (strong producers). The fnbB gene was associated with higher biofilm production.Conclusion. An increase in biofilm production in the presence of plasma proteins highlights the importance of investigating biofilm formation by S. aureus clinical isolates under different conditions since this virulence factor contributes to persistent infections and increased resistance to antimicrobials.


Assuntos
Biofilmes/crescimento & desenvolvimento , Fibrinogênio , Fibronectinas , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus/patogenicidade , Adesinas Bacterianas/genética , Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Genes Bacterianos , Genótipo , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/fisiologia , Óperon , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Transativadores/genética
10.
Elife ; 102021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34227939

RESUMO

The normal wound healing process is characterised by proteolytic events, whereas infection results in dysfunctional activations by endogenous and bacterial proteases. Peptides, downstream reporters of these proteolytic actions, could therefore serve as a promising tool for diagnosis of wounds. Using mass-spectrometry analyses, we here for the first time characterise the peptidome of human wound fluids. Sterile post-surgical wound fluids were found to contain a high degree of peptides in comparison to human plasma. Analyses of the peptidome from uninfected healing wounds and Staphylococcus aureus -infected wounds identify unique peptide patterns of various proteins, including coagulation and complement factors, proteases, and antiproteinases. Together, the work defines a workflow for analysis of peptides derived from wound fluids and demonstrates a proof-of-concept that such fluids can be used for analysis of qualitative differences of peptide patterns from larger patient cohorts, providing potential biomarkers for wound healing and infection.


Assuntos
Líquidos Corporais/metabolismo , Espectrometria de Massas/métodos , Fragmentos de Peptídeos/análise , Proteômica/métodos , Infecções Estafilocócicas/fisiopatologia , Cicatrização/fisiologia , Humanos , Peso Molecular , Staphylococcus aureus/fisiologia
11.
Methods Mol Biol ; 2341: 31-36, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264458

RESUMO

Staphylococcus aureus interacts with fibrinogen in plasma to form macroscopic clumps of cells. A simple and rapid slide agglutination test using rabbit plasma has been employed in clinical labs to distinguish S. aureus from most coagulase-negative Staphylococci. The method described here is a quantitative clumping assay in which S. aureus cells are mixed with either plasma or purified fibrinogen, and clumps are allowed to sediment out of solution. Clearing of the overlying solution is monitored over time by measuring the optical density at 600 nm and comparing these values to the initial turbidity. This simple assay can be used to study regulation and expression of various cell wall-anchored adhesins.


Assuntos
Testes de Aglutinação/métodos , Fibrinogênio/metabolismo , Staphylococcus aureus/fisiologia , Coagulase/metabolismo , Humanos , Técnicas In Vitro
12.
Methods Mol Biol ; 2341: 69-78, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264462

RESUMO

Most Staphylococcus aureus strains can grow as a multicellular biofilm, a phenotype of utmost importance to clinical infections such as endocarditis, osteomyelitis, and implanted medical device infection. As biofilms are inherently more tolerant to the host immune system and antibiotics, understanding the S. aureus genes and regulatory circuits that contribute to biofilm development is an active and on-going field of research. This chapter details a high-throughput and standardized way to grow S. aureus biofilms using a classical microtiter plate assay. Biofilms can be quantified using crystal violet or by confocal microscopy imaging and COMSTAT analysis.


Assuntos
Biofilmes/crescimento & desenvolvimento , Violeta Genciana/farmacologia , Staphylococcus aureus/fisiologia , Técnicas Bacteriológicas , Microscopia Confocal , Espectrofotometria
13.
Methods Mol Biol ; 2341: 95-101, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264465

RESUMO

Quantifying fluorescent markers in cell populations using flow cytometry has been a powerful technological advance. Fluorescent properties of cyanine dyes coupled with flow cytometry allow investigators to monitor the membrane potential (MP), an important component of the proton motive force (PMF). MP (or ΔΨ) is the electrical potential across the cell membrane. The other component of the PMF is ΔpH, or the difference in interior and exterior proton concentrations. MP plays a critical role in bacterial physiology. In Staphylococcus aureus, MP is required for generation of ATP, regulating autolytic activity, maintaining ion homeostasis, and resistance to some classes of antibiotics. This protocol exploits unique spectral and physical properties of the cyanine-based molecule diethyloxacarbocyanine iodide, or DiOC, and flow cytometry technology to quantify MP in S. aureus. This assay has been used by researchers to define the electron transport chain of S. aureus as well as determine how intrinsic and extrinsic factors affect MP.


Assuntos
Membrana Externa Bacteriana/fisiologia , Staphylococcus aureus/fisiologia , Autólise , Carbocianinas/química , Corantes/química , Citometria de Fluxo , Potenciais da Membrana , Força Próton-Motriz
14.
Methods Mol Biol ; 2341: 117-125, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264467

RESUMO

Secreted bacterial proteins are difficult to identify directly from an infection site due to a limited amount of bacteria and presence of a large quantity of host proteins. Here we describe a rat model of orthopedic implant that allows us to harvest bacterial biofilm materials sufficient for identification of bacterial proteins in the biofilm matrix by liquid chromatography-tandem MS (GeLC-MS/MS) analysis.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Infecções Relacionadas à Prótese/microbiologia , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/fisiologia , Animais , Cromatografia Líquida , Modelos Animais de Doenças , Masculino , Próteses e Implantes/microbiologia , Ratos , Staphylococcus aureus/metabolismo , Espectrometria de Massas em Tandem
15.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199748

RESUMO

BACKGROUND: Psoriasis, a chronic inflammatory disease affecting 2-3% of the population, is characterised by epidermal hyperplasia, a sustained pro-inflammatory immune response and is primarily a T-cell driven disease. Previous work determined that Connexin26 is upregulated in psoriatic tissue. This study extends these findings. METHODS: Biopsies spanning psoriatic plaque (PP) and non-involved tissue (PN) were compared to normal controls (NN). RNA was isolated and subject to real-time PCR to determine gene expression profiles, including GJB2/CX26, GJB6/CX30 and GJA1/CX43. Protein expression was assessed by immunohistochemistry. Keratinocytes and fibroblasts were isolated and used in 3D organotypic models. The pro-inflammatory status of fibroblasts and 3D cultures was assessed via ELISA and RnD cytokine arrays in the presence or absence of the connexin channel blocker Gap27. RESULTS: Connexin26 expression is dramatically enhanced at both transcriptional and translational level in PP and PN tissue compared to NN (>100x). In contrast, CX43 gene expression is not affected, but the protein is post-translationally modified and accumulates in psoriatic tissue. Fibroblasts isolated from psoriatic patients had a higher inflammatory index than normal fibroblasts and drove normal keratinocytes to adopt a "psoriatic phenotype" in a 3D-organotypic model. Exposure of normal fibroblasts to the pro-inflammatory mediator peptidoglycan, isolated from Staphylococcus aureus enhanced cytokine release, an event protected by Gap27. CONCLUSION: dysregulation of the connexin26:43 expression profile in psoriatic tissue contributes to an imbalance of cellular events. Inhibition of connexin signalling reduces pro-inflammatory events and may hold therapeutic benefit.


Assuntos
Conexinas/genética , Regulação da Expressão Gênica , Psoríase/genética , Adulto , Idoso , Biópsia , Conexinas/metabolismo , Conexinas/farmacologia , Epiderme/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Células HaCaT , Humanos , Mediadores da Inflamação , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/patologia , Pessoa de Meia-Idade , Modelos Biológicos , Oligopeptídeos/farmacologia , Peptidoglicano/isolamento & purificação , Fosforilação , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Psoríase/patologia , Staphylococcus aureus/fisiologia , Adulto Jovem
16.
Inorg Chem ; 60(15): 11058-11069, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34255500

RESUMO

In this work, the synthesis, structural and photophysical characterization of six phosphorescent H2O-soluble Pt(II) complexes are reported while addressing their emission maxima, photoluminescence quantum yields (ΦL), lifetimes (τ), aggregation tendency, and microenvironment sensitivity as a function of the substitution pattern on the main tridentate luminophore. Different ancillary ligands, namely, a trisulfonated phosphane and maltohexaose-conjugated pyridines (with or without amide bridges), were introduced and evaluated for the realization of switch-on-photoluminescent labels reporting on the microenvironment sensed in biofilms of Gram+ and Gram- models, namely, Staphylococcus aureus and Escherichia coli. With the aid of confocal luminescence micro(spectro)scopy, we observed that selected complexes specifically interact with the biofilms while leaving planktonic cells unlabeled. By using photoluminescence lifetime imaging microscopy, excited-state lifetimes within S. aureus biofilms were measured. The photoluminescence intensities were drastically boosted, and the excited state lifetimes were significantly prolonged upon binding to the viscous biofilm matrix, mainly due to the suppression of radiationless deactivation pathways upon shielding from physical quenching processes, such as interactions with solvent molecules and 3O2. The best performances were attained for non-aggregating complexes with maltohexaose targeting units and without amide bridges. Notably, in the absence of the maltodextrin, a hydrophobic adamantyl moiety suffices to attain a sizeable labeling capacity. Moreover, photoluminescence studies showed that selected complexes can also effectively interact with E. coli biofilms, where the bacterial cells are able to partially uptake the maltodextrin-based agents. In summary, the herein introduced concepts enable the development of specific biofilm reporters providing spatial resolution as well as lifetime- and spectrum-based readouts. Considering that most theragnostic agents reported so far mainly address metabolically active bacteria at the surface of biofilms but without reaching cells deeply immersed in the matrix, a new platform with a clear structure-property correlation is provided for the early detection of such bacterial arrays.


Assuntos
Biofilmes , Complexos de Coordenação/química , Escherichia coli/fisiologia , Luminescência , Platina/química , Staphylococcus aureus/fisiologia , Microscopia
17.
Int J Mol Sci ; 22(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202218

RESUMO

Periprosthetic joint infections (PJIs) caused by Staphylococcus aureus infection are difficult to treat due to antibiotic resistance. It is known that the biofilms from methicillin-resistant S. aureus (MRSA) promote expansion of myeloid-derived suppressor cells (MDSCs) to suppress T-cell proliferation and benefit bacterial infections. This study finds that GMI, a fungal immunomodulatory peptide isolated from Ganoderma microsporum, suppresses MDSC expansion to promote the proliferation of cytotoxic T cells. The enhancement is likely attributed to increased expression of IL-6 and TNF-α and reduction in ROS expression. Similar beneficial effects of GMI on the suppression of MDSC expansion and IL-6 expression are also observed in the whole blood and reduces the accumulation of MDSCs in the infected bone region in a mouse PJI infection model. This study shows that GMI is potentially useful for treating S. aureus-induced PJIs.


Assuntos
Ganoderma/química , Imunomodulação/efeitos dos fármacos , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Peptídeos/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Animais , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/etiologia , Artrite Infecciosa/metabolismo , Biofilmes/efeitos dos fármacos , Biomarcadores , Biópsia , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Masculino , Camundongos , Células Supressoras Mieloides/metabolismo , Peptídeos/química , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/tratamento farmacológico , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/metabolismo , Espécies Reativas de Oxigênio , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Linfócitos T/metabolismo
18.
Int J Mol Sci ; 22(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34298964

RESUMO

The rapid emergence of drug-resistant bacteria is a major global health concern. Antimicrobial peptides (AMPs) and peptidomimetics have arisen as a new class of antibacterial agents in recent years in an attempt to overcome antibiotic resistance. A library of phenylglyoxamide-based small molecular peptidomimetics was synthesised by incorporating an N-alkylsulfonyl hydrophobic group with varying alkyl chain lengths and a hydrophilic cationic group into a glyoxamide core appended to phenyl ring systems. The quaternary ammonium iodide salts 16d and 17c showed excellent minimum inhibitory concentration (MIC) of 4 and 8 µM (2.9 and 5.6 µg/mL) against Staphylococcus aureus, respectively, while the guanidinium hydrochloride salt 34a showed an MIC of 16 µM (8.5 µg/mL) against Escherichia coli. Additionally, the quaternary ammonium iodide salt 17c inhibited 70% S. aureus biofilm formation at 16 µM. It also disrupted 44% of pre-established S. aureus biofilms at 32 µM and 28% of pre-established E. coli biofilms 64 µM, respectively. A cytoplasmic membrane permeability study indicated that the synthesised peptidomimetics acted via disruption and depolarisation of membranes. Moreover, the quaternary ammonium iodide salts 16d and 17c were non-toxic against human cells at their therapeutic dosages against S. aureus.


Assuntos
Antibacterianos , Biofilmes/efeitos dos fármacos , Escherichia coli/fisiologia , Peptidomiméticos , Staphylococcus aureus/fisiologia , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Peptidomiméticos/síntese química , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Relação Estrutura-Atividade , Compostos de Sulfonilureia/síntese química , Compostos de Sulfonilureia/química , Compostos de Sulfonilureia/farmacologia
19.
Molecules ; 26(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299652

RESUMO

Implantable medical devices (IMDs) are susceptible to microbial adhesion and biofilm formation, which lead to several clinical complications, including the occurrence of implant-associated infections. Polylactic acid (PLA) and its composites are currently used for the construction of IMDs. In addition, chitosan (CS) is a natural polymer that has been widely used in the medical field due to its antimicrobial and antibiofilm properties, which can be dependent on molecular weight (Mw). The present study aims to evaluate the performance of CS-based surfaces of different Mw to inhibit bacterial biofilm formation. For this purpose, CS-based surfaces were produced by dip-coating and the presence of CS and its derivatives onto PLA films, as well surface homogeneity were confirmed by contact angle measurements, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antimicrobial activity of the functionalized surfaces was evaluated against single- and dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. Chitosan-based surfaces were able to inhibit the development of single- and dual-species biofilms by reducing the number of total, viable, culturable, and viable but nonculturable cells up to 79%, 90%, 81%, and 96%, respectively, being their activity dependent on chitosan Mw. The effect of CS-based surfaces on the inhibition of biofilm formation was corroborated by biofilm structure analysis using confocal laser scanning microscopy (CLSM), which revealed a decrease in the biovolume and thickness of the biofilm formed on CS-based surfaces compared to PLA. Overall, these results support the potential of low Mw CS for coating polymeric devices such as IMDs where the two bacteria tested are common colonizers and reduce their biofilm formation.


Assuntos
Biofilmes/efeitos dos fármacos , Quitosana , Implantes Experimentais/microbiologia , Pseudomonas aeruginosa/fisiologia , Staphylococcus aureus/fisiologia , Biofilmes/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Propriedades de Superfície
20.
BMC Infect Dis ; 21(1): 627, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210263

RESUMO

BACKGROUND AND OBJECTIVE: Carriage of virulence factors confers some evolutionary benefit to bacteria, which favors the resistant strains. We aimed to analyze whether antibiotic susceptibility of Staphylococcus aureus strains is affected by agr typing, biofilm formation ability, and virulence profiles. METHODS: A total of 123 S. aureus clinical isolates were subjected to antimicrobial susceptibility testing by disk diffusion method, biofilm formation by microtiter plate method, as well as polymerase chain reaction screening to identify virulence genes and the accessory gene regulator (agr) types I-IV. A P value < 0.05 was considered significant. RESULTS: The most prevalent virulence gene was staphyloxanthin crtN, followed by hemolysin genes, capsular cap8H, toxic shock toxin tst, and enterotoxin sea, respectively. Resistant isolates were more commonly found in the agr-negative group than in the agr-positive group. Isolates of agr type III were more virulent than agr I isolates. Strong biofilm producers showed more antibiotic susceptibility and carried more virulence genes than non-strong biofilm producers. Associations were found between the presence of virulence genes and susceptibility to antibiotics. Carriage of the virulence genes and agr was higher in the inpatients; while, resistance and strong biofilms were more prevalent in the outpatients. CONCLUSION: These findings indicated the presence of several virulence factors, biofilm production capacity, agr types and resistance to antibiotics in clinical S. aureus isolates. Considering the importance of S. aureus for human medicine, an understanding of virulence and resistance relationships would help to reduce the impact of S. aureus infections.


Assuntos
Proteínas de Bactérias , Biofilmes , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/fisiologia , Staphylococcus aureus/patogenicidade , Transativadores , Fatores de Virulência/genética , Toxinas Bacterianas/genética , Farmacorresistência Bacteriana , Enterotoxinas/genética , Exfoliatinas/genética , Feminino , Proteínas Hemolisinas/genética , Humanos , Masculino , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Superantígenos/genética , Xantofilas
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