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1.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360998

RESUMO

Candida albicans, an opportunistic fungus, causes dental caries and contributes to mucosal bacterial dysbiosis leading to a second infection. Furthermore, C.albicans forms biofilms that are resistant to medicinal treatment. To make matters worse, antifungal resistance has spread (albeit slowly) in this species. Thus, it has been imperative to develop novel, antifungal drug compounds. Herein, a peptide was engineered with the sequence of RRFSFWFSFRR-NH2; this was named P19. This novel peptide has been observed to exert disruptive effects on fungal cell membrane physiology. Our results showed that P19 displayed high binding affinity to lipopolysaccharides (LPS), lipoteichoic acids (LTA) and the plasma membrane phosphatidylinositol (PI), phosphatidylserine (PS), cardiolipin, and phosphatidylglycerol (PG), further indicating that the molecular mechanism of P19 was not associated with the receptor recognition, but rather related to competitive interaction with the plasma membrane. In addition, compared with fluconazole and amphotericin B, P19 has been shown to have a lower potential for resistance selection than established antifungal agents.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Oligopeptídeos/farmacologia , Antifúngicos/química , Candida albicans/fisiologia , Cardiolipinas/metabolismo , Membrana Celular/efeitos dos fármacos , Lipopolissacarídeos/metabolismo , Oligopeptídeos/química , Fosfatidilgliceróis/metabolismo , Fosfatidilinositóis/metabolismo , Fosfatidilserinas/metabolismo , Ácidos Teicoicos/metabolismo , Triptofano/química
2.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443608

RESUMO

In order to develop novel bioactive substances with potent activities, some new valine-derived compounds incorporating a 4-(phenylsulfonyl)phenyl fragment, namely, acyclic precursors from N-acyl-α-amino acids and N-acyl-α-amino ketones classes, and heterocycles from the large family of 1,3-oxazole-based compounds, were synthesized. The structures of the new compounds were established using elemental analysis and spectral (UV-Vis, FT-IR, MS, NMR) data, and their purity was checked by reversed-phase HPLC. The newly synthesized compounds were evaluated for their antimicrobial and antibiofilm activities, for toxicity on D. magna, and by in silico studies regarding their potential mechanism of action and toxicity. The 2-aza-3-isopropyl-1-[4-(phenylsulfonyl)phenyl]-1,4-butanedione 4b bearing a p-tolyl group in 4-position exhibited the best antibacterial activity against the planktonic growth of both Gram-positive and Gram-negative strains, while the N-acyl-α-amino acid 2 and 1,3-oxazol-5(4H)-one 3 inhibited the Enterococcus faecium biofilms. Despite not all newly synthesized compounds showing significant biological activity, the general scaffold allows several future optimizations for obtaining better novel antimicrobial agents by the introduction of various substituents on the phenyl moiety at position 5 of the 1,3-oxazole nucleus.


Assuntos
Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Cetonas/síntese química , Cetonas/farmacologia , Oxazóis/síntese química , Oxazóis/farmacologia , Anti-Infecciosos/química , Biofilmes/efeitos dos fármacos , Técnicas de Química Sintética , Cetonas/química , Oxazóis/química , Relação Estrutura-Atividade
3.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361735

RESUMO

Biofilms, the predominant growth mode of microorganisms, pose a significant risk to human health. The protective biofilm matrix, typically composed of exopolysaccharides, proteins, nucleic acids, and lipids, combined with biofilm-grown bacteria's heterogenous physiology, leads to enhanced fitness and tolerance to traditional methods for treatment. There is a need to identify biofilm inhibitors using diverse approaches and targeting different stages of biofilm formation. This review discusses discovery strategies that successfully identified a wide range of inhibitors and the processes used to characterize their inhibition mechanism and further improvement. Additionally, we examine the structure-activity relationship (SAR) for some of these inhibitors to optimize inhibitor activity.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Antibacterianos/biossíntese , Antibacterianos/síntese química , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , GMP Cíclico/antagonistas & inibidores , GMP Cíclico/química , GMP Cíclico/metabolismo , Desenho de Fármacos , Descoberta de Drogas , Farmacorresistência Bacteriana/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/química , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Negativas/patogenicidade , Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/patogenicidade , Lipídeos/antagonistas & inibidores , Lipídeos/química , Testes de Sensibilidade Microbiana , Ácidos Nucleicos/antagonistas & inibidores , Ácidos Nucleicos/química , Ácidos Nucleicos/metabolismo , Polissacarídeos Bacterianos/antagonistas & inibidores , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/isolamento & purificação , Relação Estrutura-Atividade
4.
Molecules ; 26(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34443332

RESUMO

Peptoids (oligo N-substituted glycines) are peptide analogues, which can be designed to mimic host antimicrobial peptides, with the advantage that they are resistant to proteolytic degradation. Few studies on the antimicrobial efficacy of peptoids have focused on Gram negative anaerobic microbes associated with clinical infections, which are commonly recalcitrant to antibiotic treatment. We therefore studied the cytotoxicity and antibiofilm activity of a family of peptoids against the Gram negative obligate anaerobe Fusobacterium nucleatum, which is associated with infections in the oral cavity. Two peptoids, peptoid 4 (NaeNpheNphe)4 and peptoid 9 (NahNspeNspe)3 were shown to be efficacious against F. nucleatum biofilms at a concentration of 1 µM. At this concentration, peptoids 4 and 9 were not cytotoxic to human erythrocytes or primary human gingival fibroblast cells. Peptoids 4 and 9 therefore have merit as future therapeutics for the treatment of oral infections.


Assuntos
Biofilmes/efeitos dos fármacos , Fusobacterium nucleatum/efeitos dos fármacos , Fusobacterium nucleatum/fisiologia , Peptoides/farmacologia , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana/efeitos dos fármacos
5.
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
6.
J Microbiol ; 59(9): 871-878, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34449059

RESUMO

Anti-virulence therapeutic strategies are promising alternatives against drug-resistant pathogens. Outer membrane protein A (OmpA) plays a versatile role in the pathogenesis and antimicrobial resistance of Acinetobacter baumannii. Therefore, OmpA is an innovative target for anti-virulence therapy against A. baumannii. This study aimed to develop a high-throughput screening (HTS) system to discover small molecules inhibiting the ompA promoter activity of A. baumannii and screen chemical compounds using the bacterial growth-based HTS system. The ompA promoter and open reading frame of nptI fusion plasmids that controlled the expression of nptI encoding resistance to kanamycin by the ompA promoter were constructed and then transformed into A. baumannii ATCC 17978. This reporter strain was applied to screen small molecules inhibiting the ompA promoter activity in a chemical library. Of the 7,520 chemical compounds, 15 exhibited ≥ 70% growth inhibition of the report strain cultured in media containing kanamycin. Three compounds inhibited the expression of ompA and OmpA in the outer membrane of A. baumannii ATCC 17978, which subsequently reduced biofilm formation. In conclusion, our reporter strain is useful for large-scale screening of small molecules inhibiting the ompA expression in A. baumannii. Hit compounds identified by the HTS system are promising scaffolds to develop novel therapeutics against A. baumannii.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Biofilmes/efeitos dos fármacos , Regiões Promotoras Genéticas/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/patogenicidade , Acinetobacter baumannii/fisiologia , Proteínas da Membrana Bacteriana Externa/genética , Avaliação Pré-Clínica de Medicamentos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Virulência/efeitos dos fármacos
7.
Molecules ; 26(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34443480

RESUMO

Within this study, new materials were synthesized and characterized based on polysiloxane modified with different ratios of N-acetyl-l-cysteine (NAC) and crosslinked via UV-assisted thiol-ene addition, in order to obtain efficient membranes able to resist bacterial adherence and biofilm formation. These membranes were subjected to in vitro testing for microbial adherence against S. pneumoniae using standardized tests. WISTAR rats were implanted for 4 weeks with crosslinked siloxane samples without and with NAC. A set of physical characterization methods was employed to assess the chemical structure and morphological aspects of the new synthetized materials before and after contact with the microbiological medium.


Assuntos
Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Implantes Cocleares/microbiologia , Otite/tratamento farmacológico , Polímeros/química , Siloxanas/química , Acetilcisteína/química , Acetilcisteína/farmacologia , Acetilcisteína/uso terapêutico , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/uso terapêutico , Implantes Cocleares/efeitos adversos , Polímeros/farmacologia , Polímeros/uso terapêutico , Ratos Wistar , Siloxanas/farmacologia , Siloxanas/uso terapêutico , Streptococcus pneumoniae/efeitos dos fármacos , Compostos de Sulfidrila/química , Propriedades de Superfície
8.
ACS Appl Mater Interfaces ; 13(33): 38979-38989, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433249

RESUMO

Chronic infections caused by Pseudomonas aeruginosa pose severe threats to human health. Traditional antibiotic therapy has lost its total supremacy in this battle. Here, nanoplatforms activated by the clinical microenvironment are developed to treat P. aeruginosa infection on the basis of dynamic borate ester bonds. In this design, the nanoplatforms expose targeted groups for bacterial capture after activation by an acidic infection microenvironment, resulting in directional transport delivery of the payload to bacteria. Subsequently, the production of hyperpyrexia and reactive oxygen species enhances antibacterial efficacy without systemic toxicity. Such a formulation with a diameter less than 200 nm can eliminate biofilm up to 75%, downregulate the level of cytokines, and finally promote lung repair. Collectively, the biomimetic design with phototherapy killing capability has the potential to be an alternative strategy against chronic infections caused by P. aeruginosa.


Assuntos
Antibacterianos/química , Verde de Indocianina/química , Nanocápsulas/química , Fármacos Fotossensibilizantes/química , Polímeros/química , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/radioterapia , Células A549 , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Composição de Medicamentos , Liberação Controlada de Fármacos , Sinergismo Farmacológico , Humanos , Verde de Indocianina/farmacologia , Raios Infravermelhos , Masculino , Metacrilatos/química , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Pseudomonas aeruginosa/efeitos dos fármacos
9.
Molecules ; 26(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34299385

RESUMO

An efficient and simple protocol for the synthesis of a new class of diverse bis(indolyl)pyridines analogues of the marine alkaloid nortopsentin has been reported. A one-pot four-component condensation of 3-cyanocarbomethylindole, various aldehyde, 3-acetylindole, and ammonium acetate in glacial acetic acid led to the formation of 2,6-bis(1H-indol-3-yl)-4-(substituted-phenyl)pyridine-5-carbonitriles. Additionally, 2,6-bis(1H-indol-3-yl)-4-(benzofuran) pyridine-5-carbonitriles were prepared via a one-pot four-component condensation of 3-cyanocarbomethylindole, various N-substituted-indole-3-aldehydes, 2-acetylbenzofuran, and ammonium acetate. The synthesized compounds were evaluated for their ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 6538 and the Gram-negative strain Escherichia coli ATCC 25922. Some of the new compounds showed a marked selectivity against the Gram-positive and Gram-negative strains. Remarkably, five compounds 4b, 7a, 7c, 7d and 8e demonstrated good antibiofilm formation against S. aureus and E. coli. On the other hand, the release of reducing sugars and proteins from the treated bacterial strains over the untreated strains was considered to explain the disruption effect of the selected compound on the contact cells of S. aureus and E. coli. Out of all studied compounds, the binding energies and binding mode of bis-indole derivatives 7c and 7d were theoretically the best thymidylate kinase, DNA gyrase B and DNA topoisomerase IV subunit B inhibitors.


Assuntos
Alcaloides/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Inibidores Enzimáticos/farmacologia , Indóis/química , Biofilmes/efeitos dos fármacos , DNA Girase/química , DNA Topoisomerase IV/antagonistas & inibidores , Inibidores Enzimáticos/química , Simulação de Acoplamento Molecular , Núcleosídeo-Fosfato Quinase/antagonistas & inibidores , Piridinas/química
10.
Photochem Photobiol Sci ; 20(8): 985-996, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275118

RESUMO

Chronic lung infections are among the most diffused human infections, being often associated with multidrug-resistant bacteria. In this framework, the European project "Light4Lungs" aims at synthesizing and testing an inhalable light source to control lung infections by antimicrobial photoinactivation (aPDI), addressing endogenous photosensitizers only (porphyrins) in the representative case of S. aureus and P. aeruginosa. In the search for the best emission characteristics for the aerosolized light source, this work defines and calculates the photo-killing action spectrum for lung aPDI in the exemplary case of cystic fibrosis. This was obtained by applying a semi-theoretical modelling with Monte Carlo simulations, according to previously published methodology related to stomach infections and applied to the infected trachea, bronchi, bronchioles and alveoli. In each of these regions, the two low and high oxygen concentration cases were considered to account for the variability of in vivo conditions, together with the presence of endogenous porphyrins and other relevant absorbers/diffusers inside the illuminated biofilm/mucous layer. Furthermore, an a priori method to obtain the "best illumination wavelengths" was defined, starting from maximizing porphyrin and light absorption at any depth. The obtained action spectrum is peaked at 394 nm and mostly follows porphyrin extinction coefficient behavior. This is confirmed by the results from the best illumination wavelengths, which reinforces the robustness of our approach. These results can offer important indications for the synthesis of the aerosolized light source and definition of its most effective emission spectrum, suggesting a flexible platform to be considered in further applications.


Assuntos
Espectro de Ação , Antibacterianos/química , Antibacterianos/farmacologia , Pulmão/microbiologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Aerossóis , Biofilmes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Porfirinas/química , Porfirinas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação
11.
J Photochem Photobiol B ; 221: 112253, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34271411

RESUMO

Biofilms formed by different bacterial species are likely to play key roles in photocatalytic resistance. This study aims to evaluate the efficacy of a photocatalytic immobilized nanotube system (TiO2-NT) (IS) and suspended nanoparticles (TiO2-NP) (SS) against mono- and dual-species biofilms developed by Gram-negative and Gram-positive strains. Two main factors were corroborated to significantly affect the biofilm resistance during photocatalytic inactivation, i.e., the biofilm-growth conditions and biofilm-forming surfaces. Gram-positive bacteria showed great photosensitivity when forming dual-species biofilms in comparison with the Gram-positive bacteria in single communities. When grown onto TiO2-NT (IS) surfaces for immobilized photocatalytic systems, mono- and dual-species biofilms did not exhibit differences in photocatalytic inactivation according to kinetic constant values (p > 0.05) but led to a reduction of ca. 3-4 log10. However, TiO2-NT (IS) surfaces did affect biofilm colonization as the growth of mono-species biofilms of Gram-negative and Gram-positive bacteria is significantly (p ≤ 0.05) favored compared to co-culturing; although, the photocatalytic inactivation rate did not show initial bacterial concentration dependence. The biofilm growth surface (which depends on the photocatalytic configuration) also favored resistance of mono-species biofilms of Gram-positive bacteria compared to that of Gram-negative in immobilized photocatalytic systems, but opposite behavior was confirmed with suspended TiO2 (p ≤ 0.05). Successful efficacy of immobilized TiO2 for inactivation of mono- and dual-species biofilms was accomplished, making it feasible to transfer this technology into real scenarios in water treatment and food processing.


Assuntos
Biofilmes/efeitos dos fármacos , Titânio/química , Raios Ultravioleta , Biofilmes/efeitos da radiação , Catálise , Listeria monocytogenes/fisiologia , Nanotubos/química , Salmonella typhimurium/fisiologia , Titânio/toxicidade
12.
Methods Mol Biol ; 2341: 153-159, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264471

RESUMO

Biofilms provide an environment in which bacteria can survive adverse conditions such as nutrient or oxygen deficiencies, and antibiotic treatments. Bacterial survival of antibiotic treatments can often result in antimicrobial resistance, which can make treating infections substantially more difficult, increase the burden of healthcare costs, and hinder the healing of infected wounds. As Staphylococcus aureus is a bacterium that commonly causes skin infections, can be found in infected skin wounds, and is prone to developing antimicrobial resistance-especially within a biofilm microenvironment, the study and development of methodologies to treat infected wounds have become an important topic of research. To study the development of bacterial biofilm in a skin wound, this chapter discusses an in vitro model to access biofilm growth in an environment that mimics a human skin wound. This model serves as a tool to study the biofilm growth and efficacy of antibiotic use in an in vitro system that more closely resembles human skin tissue, rather than a polystyrene plate.


Assuntos
Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Infecção dos Ferimentos/microbiologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana , Humanos , Viabilidade Microbiana , Modelos Biológicos , Pele/microbiologia , Staphylococcus aureus/efeitos dos fármacos
13.
Colloids Surf B Biointerfaces ; 206: 111935, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34252691

RESUMO

Silver nanoparticles (AgNPs) could be employed in the combat against COVID-19, yet are associated with toxicities. In this study, biogenic and biocompatible AgNPs using the agro-waste, non-edible Hibiscus sabdariffa stem were synthesized. Under optimized reaction conditions, synthesized green AgNPs were crystalline, face cubic centered, spherical with a diameter of around 17 nm and a surface charge of -20 mV. Their murine lethal dose 50 (LD50) was 4 folds higher than the chemical AgNPs. Furthermore, they were more murine hepato- and nephro-tolerated than chemical counterparts due to activation of Nrf-2 and HO-1 pathway. They exerted an apoptotic anti-ovarian cancer activity with IC50 value 6 times more than the normal cell line. Being functionalized with polydopamine and conjugated to either moxifloxacin or gatifloxacin, the conjugates exerted an augmented antibiofilm activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii biofilms that was significantly higher than antibiotic alone or functionalized AgNPs suggesting a synergistic activity. In conclusion, this study introduced a facile one-pot synthesis of biogenic and biocompatible AgNPs with preferential anti-cancer activity and could be utilized as antibiotic delivery system for a successful eradication of Gram-negative biofilms.


Assuntos
Antibacterianos , Nanopartículas Metálicas , Prata , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Química Verde , Hibiscus , Indóis , Camundongos , Testes de Sensibilidade Microbiana , Polímeros , Prata/farmacologia
14.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34259620

RESUMO

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters.Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity.Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs.Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time-kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation.Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole.Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Contaminação de Equipamentos/prevenção & controle , Fluconazol/farmacologia , Sulfonamidas/farmacologia , Candida/classificação , Candida/fisiologia , Candidíase/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Oxiquinolina/farmacologia , Diálise Renal
15.
Int J Mol Sci ; 22(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299160

RESUMO

Infections with Candida spp. are commonly found in long-time denture wearers, and when under immunosuppression can lead to stomatitis. Imidazolium ionic liquids with an alkyl or alkyloxymethyl chain and a natural (1R,2S,5R)-(-)-menthol substituent possess high antifungal and antiadhesive properties towards C. albicans, C. parapsilosis, C. glabrata and C. krusei. We tested three compounds and found they disturbed fungal plasma membranes, with no significant hemolytic properties. In the smallest hemolytic concentrations, all compounds inhibited C. albicans biofilm formation on acrylic, and partially on porcelain and alloy dentures. Biofilm eradication may result from hyphae inhibition (for alkyl derivatives) or cell wall lysis and reduction of adhesins level (for alkyloxymethyl derivative). Thus, we propose the compounds presented herein as potential anti-fungal denture cleaners or denture fixatives, especially due to their low toxicity towards mammalian erythrocytes after short-term exposure.


Assuntos
Adesinas Bacterianas/metabolismo , Antifúngicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Imidazóis/química , Líquidos Iônicos/química , Mentol/farmacologia , Antipruriginosos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos
16.
Molecules ; 26(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204121

RESUMO

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.


Assuntos
Bactérias/efeitos dos fármacos , Frutas/química , Polifenóis/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Microbiologia de Alimentos , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacologia , Humanos , Nanopartículas , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polifenóis/química
17.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200763

RESUMO

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis(m-hydroxyphenyl)porphyrin (mTHPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with mTHPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates mTHPP inside, and that the composite acquired an overall positive charge. The incorporation of mTHPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the mTHPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.


Assuntos
Antibacterianos/química , Celulose/análogos & derivados , Quitosana/química , Nanocompostos/química , Porfirinas/química , Piridonas/química , Pirróis/química , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Celulose/química , Chlorocebus aethiops , Lasers , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Vero
18.
Ecotoxicol Environ Saf ; 221: 112468, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34198191

RESUMO

The study shows how microalgae biofilm formation and antioxidant responses to the production of reactive oxygen species (ROS) is alter by the presences of Lemna minor L., Chlorella vulgaris, and Aphanizomenon flos-aquae. The study involves the cultivation of the biofilm of Chlorella vulgaris and Aphanizomenon flos-aquae in three bioreactors. The condition of growth for the biofilm formation was varied across the three bioreactors to enable the dominance Chlorella vulgaris and Aphanizomenon flos-aquae in one of the bioreactors. Lemna minor L. was also introduce into one of the bioreactors to determine its effect on the biofilm formation. The result obtained shows that C. vulgaris and A. flos-aquae dominate the biofilm, resulting in a high level of H2O2 and O2- (H2O2 was 0.122 ± 0.052 and 0.183 ± 0.108 mmol/L in C. vulgaris and A. flos-aquae, respectively, and O2- was 0.261 ± 0.039 and 0.251 ± 0.148 mmol/L in C. vulgaris and A. flos-aquae, respectively). The study also revealed that the presence of L. minor L. tend to reduce the oxidative stress to the biofilm leading to low production of ROS (H2O2 was 0.086 ± 0.027 and 0.089 ± 0.045 mmol/L in C. vulgaris and A. flos-aquae respectively, and O2- was 0.185 ± 0.044 and 0.161 ± 0.065 mmol/L in C. vulgaris and A. flos-aquae respectively). The variation in the ability of the biofilm of C. vulgaris and A. flos-aquae to respond via chlorophyll, carotenoid, flavonoid, anthocyanin, superoxide dismutase, peroxidase, catalase, glutathione reductase activities, antioxidant reducing power, phosphomolybdate activity, DPPH reduction activity, H2O2 scavenging activity, lipid content and organic carbon also supports the fact that the presence of biomass of microalgae and aquatic macrophytes tend to affect the process of microalgae biofilm formation and the ability of the biofilm to produce antioxidant. This high nutrient utilization leads to the production of biomass which can be used for biofuel production and other biotechnological products.


Assuntos
Aphanizomenon/fisiologia , Araceae/fisiologia , Biofilmes , Chlorella vulgaris/fisiologia , Microalgas/fisiologia , Antioxidantes/farmacologia , Biofilmes/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio
19.
J Chem Phys ; 154(20): 204201, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34241187

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen implicated in both acute and chronic diseases, which resists antibiotic treatment, in part by forming physical and chemical barriers such as biofilms. Here, we explore the use of confocal Raman imaging to characterize the three-dimensional (3D) spatial distribution of alkyl quinolones (AQs) in P. aeruginosa biofilms by reconstructing depth profiles from hyperspectral Raman data. AQs are important to quorum sensing (QS), virulence, and other actions of P. aeruginosa. Three-dimensional distributions of three different AQs (PQS, HQNO, and HHQ) were observed to have a significant depth, suggesting 3D anisotropic shapes-sheet-like rectangular solids for HQNO and extended cylinders for PQS. Similar to observations from 2D imaging studies, spectral features characteristic of AQs (HQNO or PQS) and the amide I vibration from peptide-containing species were found to correlate with the PQS cylinders typically located at the tips of the HQNO rectangular solids. In the QS-deficient mutant lasIrhlI, a small globular component was observed, whose highly localized nature and similarity in size to a P. aeruginosa cell suggest that the feature arises from HHQ localized in the vicinity of the cell from which it was secreted. The difference in the shapes and sizes of the aggregates of the three AQs in wild-type and mutant P. aeruginosa is likely related to the difference in the cellular response to growth conditions, environmental stress, metabolic levels, or other structural and biochemical variations inside biofilms. This study provides a new route to characterizing the 3D structure of biofilms and shows the potential of confocal Raman imaging to elucidate the nature of heterogeneous biofilms in all three spatial dimensions. These capabilities should be applicable as a tool in studies of infectious diseases.


Assuntos
Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Quinolonas/farmacologia , Biofilmes/crescimento & desenvolvimento , Microscopia Confocal , Quinolonas/química , Análise Espectral Raman
20.
Int J Biol Macromol ; 185: 620-628, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216663

RESUMO

Mandarin (Citrus reticulata L.) essential oil (MEO) reportedly displays excellent antimicrobial properties. In this study, MEO was loaded into chitosan nanoparticles (CSNPs). The characteristics, antibacterial properties and benefit in pork preservation of MEO-CSNPs were evaluated. The MEO-CSNPs displayed an excellent encapsulation efficiency (EE) (67.32%-82.35%), the particle size values of 131.3 nm-161.9 nm, and the absolute zeta potential values above 30 mV. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, and thermogravimetric analysis (TGA) revealed that the MEO was incorporated into CSNPs without requiring a chemical reaction, the antibacterial activity of the MEO remained. Furthermore, the damage of MEO-chitosan nanoemulsions (MEO-CSs) to the cell membranes of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was confirmed by the change of bacterial cell morphology. The anti-biofilm assays verified that the MEO-CSs substantially inhibited biofilm formation and destroyed the mature biofilms. MEO-CSs were also applied to pork, proving a great potential for pork preservation. This study provides a potential approach for developing and utilizing MEO-CSs as natural antimicrobial agents in the food industry.


Assuntos
Quitosana/química , Citrus/química , Conservação de Alimentos/métodos , Óleos Voláteis/farmacologia , Carne de Porco , Animais , Membrana Externa Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Nanopartículas , Óleos Voláteis/química , Tamanho da Partícula , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Suínos , Termogravimetria , Difração de Raios X
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