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1.
Microb Pathog ; 195: 106837, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39103128

RESUMO

Microbial resistance to drugs continues to be a global public health issue that demands substantial investment in research and development of new antimicrobial agents. Essential oils (EO) have demonstrated satisfactory and safe antimicrobial action, being used in pharmaceutical, cosmetic, and food formulations. In order to improve solubility, availability, and biological action, EO have been converted into nanoemulsions (NE). This review identified scientific evidence corroborating the antimicrobial action of nanoemulsions of essential oils (NEEO) against antibiotic-resistant pathogens. Using integrative review methodology, eleven scientific articles evaluating the antibacterial or antifungal assessment of NEEO were selected. The synthesis of evidence indicates that NEEO are effective in combating multidrug-resistant microorganisms and in the formation of their biofilms. Factors such as NE droplet size, chemical composition of essential oils, and the association of NE with antibiotics are discussed. Furthermore, NEEO showed satisfactory results in vitro and in vivo evaluations against resistant clinical isolates, making them promising for the development of new antimicrobial and antivirulence drugs.


Assuntos
Bactérias , Biofilmes , Emulsões , Óleos Voláteis , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Emulsões/química , Emulsões/farmacologia , Biofilmes/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Humanos , Anti-Infecciosos/farmacologia , Antifúngicos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fungos/efeitos dos fármacos , Nanopartículas/química , Animais
2.
Chem Biodivers ; : e202401604, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39145539

RESUMO

This study aims to investigate the essential oil from leaves of Eugenia pohliana (EOEP) in regard to its chemical composition, antimicrobial and drug-enhancing activity, as well as the reduction of fungal virulence capacity. Chemical characterization using GC-MS showed as major components the sesquiterpenes δ-cadinene, Epi-α-Muurolol, and bicyclogermacrene. The results of antibacterial tests indicated that Staphylococcus aureus was more sensitive to EOEP, that also enhanced the efficacy of gentamicin, erythromycin, and norfloxacin. EOEP exhibited antifungal properties against Candida albicans, in addition to potentiating the effectiveness of fluconazole against Candida tropicalis. It showed anti-virulence effects in all fungal strains. These findings underscore E. pohliana as a potential candidate for the prospection of novel therapeutic agents to treat infectious diseases caused by resistant microbes.

3.
Plants (Basel) ; 13(14)2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39065498

RESUMO

Propolis is a complex mixture formed from exudates that bees collect from plants and then mix with beeswax and their own salivary enzymes. Chilean propolis is characterized by the presence of phenolic compounds, which are considered responsible for the biological activities. The endemic species Escallonia pulverulenta (Ruiz and Pav.) Pers. [Escalloniaceae] is a recognized source of exudate to produce propolis. This study reports for the first time the chemical profile and antibacterial activity of E. pulverulenta exudate and leaves, as well as two samples of Chilean propolis. Palynological and morphological analysis showed the presence of E. pulverulenta as one of the main species in the propolis samples. UPLC-MS/MS analyses enabled the identification of phenolic acids in the leaves and in the propolis. Conversely, flavonoids are mainly present in exudates and propolis. Quercetin is the most abundant flavonol in the exudate, with similar concentrations in the propolis samples. Nevertheless, the main compound present in both samples of propolis was the flavanone pinocembrin. The antibacterial results obtained for exudate and propolis have shown a similar behavior, especially in the inhibition of Streptococcus pyogenes. These results show the importance of the exudates collected by the bees in the chemical composition and antibacterial capacity of propolis.

4.
Antibiotics (Basel) ; 13(7)2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39061319

RESUMO

Calcium hydroxide represents the most commonly used intracanal dressing between sessions; however, it may not be effective against all types of microorganisms. Several compounds of plant origin have attracted increasing attention from researchers in recent years. The objective of this study was to evaluate the cytocompatibility and antimicrobial activity of calcium hydroxide associated with the essential oil of Cyperus articulatus and the new bioceramic intracanal medicament Bio-C Temp®. Five experimental groups were designed: group Ca-C. articulatus essential oil; group CHPG-calcium hydroxide associated with propylene glycol; group CHCa-essential oil of C. articulatus associated with calcium hydroxide; and group U-UltraCal® XS; group BCT-Bio-C Temp®. The control group was a culture medium. Cytocompatibility was assessed by the methyltetrazolium (MTT) assay after exposure of the Saos-2 human osteoblast-like cell line to dilutions of commercial products/associations for 24 h and 72 h. The antimicrobial activity against mature Enterococcus faecalis biofilm was evaluated by the crystal violet assay. All commercial products/associations showed a cell viability similar to or even higher than the control group (p > 0.05) for both periods evaluated. C. articulatus essential oil associated or not with calcium hydroxide showed better antibiofilm capacity. C. articulatus associated or not with calcium hydroxide showed superior cytocompatibility and antimicrobial capacity, representing a promissory intracanal medicament.

5.
Antibiotics (Basel) ; 13(7)2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39061356

RESUMO

In response to the steady increase in antimicrobial-resistant strains, the World Health Organisation has emphasised the need to investigate new antimicrobial agents and alternative therapies that improve the spectrum of activity and reduce the dose required, thus improving safety. This study focused on the characterisation of Acanthospermum australe essential oil and green-synthesis silver nanoparticles (AgNP), evaluating their cytotoxicity in human cells, antimicrobial activity and synergistic effect against pathogens causing skin infections. The main components of the essential oil were germacrene A (24.07%), γ-cadinene (21.47%) and trans-caryophyllene (14.97%). Spherical AgNP with a diameter of 15 ± 3 nm were synthesised. The essential oil showed antimicrobial activity against dermatophytes and Malassezia globosa, while AgNP were found to be active against bacteria, yeasts and dermatophytes. Both compounds were found to be primarily non-cytotoxic at the concentrations required to inhibit microbial growth. Furthermore, the combined use of essential oil and AgNP showed a synergistic antimicrobial effect against dermatophytes and M. globosa. In conclusion, the results suggest that the combined use of bioactive compounds from natural sources, such as essential oil and biogenic AgNP, has the potential to improve antimicrobial efficacy against specific skin pathogens, particularly Microsporum canis, Nannizzia gypsea and M. globosa.

6.
Nat Prod Res ; : 1-5, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39001699

RESUMO

In the present study, chemical characterisation, thermal analysis and antibacterial activity of honeys from Melipona spp. with occurrence in Caatinga biome of Brazil. The honeys presented pH from 4.07 to 4.14, density of 1.41 g/cm3 and °Brix value of 79.90. The thermogravimetry (TG) analysis presented six-seven events and differential thermal analysis (DTA) presented three-four endothermic peaks. HPLC fingerprint revealed a predominant presence of gallic acid and vanillin. Antioxidant activity evaluated using in vitro 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging with IC50 values in the range of 14.5404 to 15.2454 mg/mL. The honeys also showed antimicrobial activities against Staphylococcus aureus and Pseudomonas aeruginosa using a modified agar diffusion and microdilution method. The results of the present study demonstrate that the honey from stingless bees by Caatinga biome indicate polyphenol compounds, antioxidant activity and in vitro antimicrobial potential. The analytical methos permitted of fingerprint of samples.

7.
Biomed Chromatogr ; 38(10): e5971, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39079937

RESUMO

Drug biotransformation studies emerges as an alternative to pharmacological investigations of metabolites, development of new drug candidates with reduced investment and most efficient production. The present study aims to evaluate the capacity of biotransformation of rifampicin by the filamentous fungus Aspergillus niger ATCC 9029. After incubation for 312 h, the drug was metabolized to two molecules: an isomer (m/z 455) and the rifampicin quinone (m/z 821). The monitoring of metabolite formation was performed by high-performance liquid chromatography, followed by their identification through ultra-high-performance liquid chromatography coupled to tandem mass spectrometer. In vitro antimicrobial activity of the proposed metabolites was evaluated against Staphylococus aureus microorganism, resulting in the loss of inhibitory activity when compared with the standards, with minimum inhibitory concentration of 7.5 µg/ml. The significant biotransformation power of the ATCC 9029 strain of A. niger was confirmed in this study, making this strain a candidate for pilot studies in fermentation tanks for the enzymatic metabolization of the antimicrobial rifampicin. The unprecedented result allows us to conclude that the prospect of new biotransforming strains in species of anemophilic fungi is a promising choice.


Assuntos
Aspergillus niger , Biotransformação , Testes de Sensibilidade Microbiana , Rifampina , Espectrometria de Massas em Tandem , Aspergillus niger/metabolismo , Aspergillus niger/efeitos dos fármacos , Rifampina/farmacologia , Rifampina/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/metabolismo , Anti-Infecciosos/farmacologia , Anti-Infecciosos/metabolismo , Anti-Infecciosos/química
8.
J Toxicol Environ Health A ; 87(20): 824-835, 2024 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-38984907

RESUMO

Dental caries is a highly prevalent oral disease affecting billions of individuals globally. The disease occurs chemically as a result of breakdown of the tooth surface attributed to metabolic activity in colonizing biofilm. Biofilms, composed of exopolysaccharides and proteins, protect bacteria like Streptococcus mutans, which is notable for its role in tooth decay due to its acid-producing abilities. While various antimicrobial agents may prevent biofilm formation, these drugs often produce side effects including enamel erosion and taste disturbances. This study aimed to examine utilization of the Mentha piperita essential oil as a potential antibiofilm activity agent against S. mutans. M. piperita oil significantly (1) reduced bacterial biofilm, (2) exhibited a synergistic effect when combined with chlorhexidine, and (3) did not induce cell toxicity. Chemical analysis identified the essential oil with 99.99% certainty, revealing menthol and menthone as the primary components, constituting approximately 42% and 26%, respectively. Further, M. piperita oil eradicated preformed biofilms and inhibited biofilm formation at sub-inhibitory concentrations. M. piperita oil also interfered with bacterial quorum sensing communication and did not produce any apparent cell toxicity in immortalized human keratinocytes (HaCaT). M. piperita represented an alternative substance for combating S. mutans and biofilm formation and a potential combination option with chlorhexidine to minimize side effects. An in-situ performance assessment requires further studies.


Assuntos
Biofilmes , Mentha piperita , Óleos Voláteis , Percepção de Quorum , Streptococcus mutans , Streptococcus mutans/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Mentha piperita/química , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Humanos , Percepção de Quorum/efeitos dos fármacos , Óleos de Plantas/farmacologia , Óleos de Plantas/química , Antibacterianos/farmacologia
9.
Odontology ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39046588

RESUMO

To evaluate the microstructural characterization, mechanical properties and antimicrobial activity of acrylic resins incorporated with different concentrations of reduced graphene oxide (rGO). Specimens were made of self-cured and heat-cured acrylic resins for the control group and concentrations of 0.5%, 1%, and 3%. The microstructural characterization was evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDS). For mechanical testing, flexural strength, and Knoop hardness tests were performed. Microbiological evaluations were performed by colony forming units (CFU) analysis, tetrazolium salt reduction (XTT), and SEM images. The modified acrylic resins showed increased mechanical properties at low concentrations (p < 0.05) and with reduced S. mutans (p < 0.05). Reduced graphene oxide interfered with the mechanical performance and microbiological properties of acrylic resins depending on the concentration of rGO, and type of polymerization and microorganism evaluated. The incorporation of graphene compounds into acrylic resins is an alternative to improve the antimicrobial efficacy and performance of the material.

10.
Artigo em Inglês | MEDLINE | ID: mdl-39080213

RESUMO

New wound dressings based on polymeric membranes have been widely exploited for clinical applications to assist in the healing process and prevent additional complications (e.g., bacterial infections). Here we propose the development of a new production method of polymeric membranes based on chitosan, incorporating glycolic extract of Aloe vera with joint synthesis of silver nanoparticles for use as a new bioactive dressing. The membranes were obtained by casting technique, and their morphological, physicochemical characteristics, degree of swelling, degradation profile and antimicrobial activity evaluated. Morphological analyzes confirmed the synthesis and presence of silver nanoparticles in the polymeric membrane. The chemical compatibility between the materials was demonstrated through thermal analysis (TGA and DSC) combined with ATR-FTIR tests, showing the complexation of the membranes (Mb-Ch-Ex.Av-NPs). All membranes were characterized as hydrophilic material (with a contact angle (Ó©) < 90°); however, the highest degree of swelling was obtained for the chitosan. (Mb-Ch) membrane (69.91 ± 5.75%) and the lowest for Mb-Ch-Ex.Av-NPs (26.62 ± 8.93%). On the other hand, the degradation profile was higher for Mb-Ch-Ex.Av-NPs (77.85 ± 7.51%) and lower for Mb-Ch (57.60 ± 2.29%). The manufactured bioactive dressings showed activity against Escherichia coli and Staphylococcus aureus. Our work confirmed the development of translucent and flexible chitosan-based membranes, incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for use as a new bioactive dressing, with proven antimicrobial activity.

11.
Bol. latinoam. Caribe plantas med. aromát ; 23(4): 636-644, jul. 2024. graf, tab
Artigo em Inglês | LILACS | ID: biblio-1538072

RESUMO

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.


Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.


Assuntos
Óleos Voláteis/química , Extratos Vegetais/química , Asteraceae/química , Anti-Infecciosos/química , Antioxidantes/química , Bactérias/efeitos dos fármacos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Cromatografia Gasosa , Folhas de Planta/química , Monoterpenos/análise , Equador , Hidrocarbonetos/análise , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia
12.
Front Pharmacol ; 15: 1415659, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38910894

RESUMO

Introduction: Lung cancer is the most commonly diagnosed and the main cause of cancer death, usually related to cigarette smoking. Furthermore, the microbiota of people exposed to cigarette smoke can be modified, making it difficult to eliminate opportunistic microorganisms. The leaves of Eugenia pyriformis are a by-product of fruit production and, to date, there have been no studies addressing the antiproliferative, anti-inflammatory, and antimicrobial activities. Objective: Investigate the antimicrobial, Nitric Oxide (NO)-production inhibition, and antiproliferative activities of the essential oil from E. pyriformis leaves and its possible effect on the treatment and prevention of damage caused by tobacco. Methods: The essential oil (EO) was obtained by hydrodistillation (3 h). Its chemical composition was investigated by GC-MS. It was proposed to investigate antiproliferative activity against human tumor cell lines, namely, breast adenocarcinoma (MCF-7), lung (NCI-H460), cervical (HeLa), and hepatocellular (HepG2) carcinomas. A non-tumor primary culture from pig liver (PLP2) was also tested. The EO capacity to inhibit nitric oxide (NO) production was evaluated by a lipopolysaccharide stimulated murine macrophage cell line. Antibacterial and antifungal activities against opportunistic pathogens were investigated against seven strains of bacteria and eight fungi. Results: The results indicated the presence of 23 compounds in the essential oil, the majority were spathulenol (45.63%) and ß-caryophyllene oxide (12.72%). Leaf EO provided 50% inhibition of nitric oxide production at a concentration of 92.04 µg mL-1. The EO also demonstrated antiproliferative activity against all human tumor cell lines studied, with GI50 values comprised between 270.86 and 337.25 µg mL-1. The essential oil showed antimicrobial potential against the bacteria Listeria monocytogenes (Murray et al.) Pirie (NCTC 7973) and Salmonella Typhimurium ATCC 13311 (MIC 1870 µg mL-1) and fungi Aspergillus versicolor ATCC 11730, Aspergillus ochraceus ATCC 12066, Penicillium ochrochloron ATCC 90288, Penicillium verrucosum var. cyclopium (Westling) Samson, Stolk & Hadlok (food isolate) (MIC 1870 µg mL-1) and Trichoderma viride Pers. IAM 5061 (1,400 µg mL-1). Conclusion: The demonstrated anti-inflammatory, antiproliferative, and antimicrobial activities in the leaves of E. pyriformis can add value to the production chain of this plant, being a possible option for preventing and combating cancer, including lung cancer.

13.
Cell ; 187(14): 3761-3778.e16, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38843834

RESUMO

Novel antibiotics are urgently needed to combat the antibiotic-resistance crisis. We present a machine-learning-based approach to predict antimicrobial peptides (AMPs) within the global microbiome and leverage a vast dataset of 63,410 metagenomes and 87,920 prokaryotic genomes from environmental and host-associated habitats to create the AMPSphere, a comprehensive catalog comprising 863,498 non-redundant peptides, few of which match existing databases. AMPSphere provides insights into the evolutionary origins of peptides, including by duplication or gene truncation of longer sequences, and we observed that AMP production varies by habitat. To validate our predictions, we synthesized and tested 100 AMPs against clinically relevant drug-resistant pathogens and human gut commensals both in vitro and in vivo. A total of 79 peptides were active, with 63 targeting pathogens. These active AMPs exhibited antibacterial activity by disrupting bacterial membranes. In conclusion, our approach identified nearly one million prokaryotic AMP sequences, an open-access resource for antibiotic discovery.


Assuntos
Peptídeos Antimicrobianos , Aprendizado de Máquina , Microbiota , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/genética , Humanos , Animais , Antibacterianos/farmacologia , Camundongos , Metagenoma , Bactérias/efeitos dos fármacos , Bactérias/genética , Microbioma Gastrointestinal/efeitos dos fármacos
14.
Int J Biol Macromol ; 275(Pt 1): 133457, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945335

RESUMO

Essential oils show several biological properties, such as antimicrobial activity, but have limitations regarding their availability and stability. To maximize their antimicrobial effect and protection against environmental conditions, Pickering-type emulsions were used to vehiculate oregano essential oil (OEO) using cellulose nanofibers (CNF) as emulsion stabilizer. Enzymatic hydrolysis was used to produce CNF from a food industry waste (cassava peel), obtaining an environmentally sustainable emulsion stabilizer. It was evaluated how the different properties of the nanofibers affected the stability of the emulsions. Furthermore, the composition of the dispersed phase was varied (different ratios of OEO and sunflower oil-SO) in view of the target application in biodegradable active coatings. Even at very low concentration (0.01 % w/w), CNF was able to form kinetically stable emulsions with small droplet sizes using oil mixtures (OEO + SO). The stabilization mechanism was not purely Pickering, as there was a reduction in interfacial tension. Excellent antimicrobial activity was observed against bacteria and the fungus Alternaria alternata, demonstrating the ability to apply these emulsions in active systems such as coatings and films. An improvement in the stability of emulsions was observed when using a mixture of oils, which is extremely advantageous considering costs and stability to heat treatments, since the desired antimicrobial activity is maintained for the final application.


Assuntos
Anti-Infecciosos , Celulose , Emulsões , Nanofibras , Óleos Voláteis , Origanum , Nanofibras/química , Emulsões/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Celulose/química , Celulose/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Origanum/química , Alternaria/efeitos dos fármacos
15.
Artigo em Inglês | MEDLINE | ID: mdl-38904883

RESUMO

Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia are considered emerging pathogens classified as a public health problem due to extensive antimicrobial resistance. Therefore, the discovery of new therapeutic strategies has become crucial. This study aimed to evaluate the antimicrobial activity of gallic acid and methyl gallate against non-fermenting bacteria. The study included five clinical isolates of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia. The minimum inhibitory concentrations of gallic acid and methyl gallate were determined by the broth microdilution method. Growth curves, metabolic activity, and biofilm formation of each bacterial strain in the presence or absence of phenolic compounds were performed. Finally, the therapeutic efficacy of the compounds was evaluated using an in vivo model. Gallic acid and methyl gallate showed antibacterial activity against bacterial strains in a concentration range of 64 to 256 µg/mL, both compounds reduced bacterial growth and metabolic activity of the strains, even at subinhibitory concentrations. Only, methyl gallate exhibited activity to inhibit the formation of bacterial biofilms. Moreover, gallic acid and methyl gallate increased larval survival by up to 60% compared to 30% survival of untreated larvae in a bacterial infection model in Galleria mellonella. Our results highlight the potential of gallic acid and methyl gallate as therapeutic alternatives for infections by emerging non-fermentative bacteria.

16.
Molecules ; 29(12)2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38930909

RESUMO

In this work, a group of ten sesquiterpene drimanes, including polygodial (1), isopolygodial (2), and drimenol (3) obtained from the bark of Drimys winteri F. and seven synthetic derivatives, were tested in vitro against a unique panel of bacteria, fungi, and oomycetes with standardized procedures against bacterial strains K. pneumoniae, S. tiphy, E. avium, and E. coli. The minimum inhibitory concentrations and bactericidal activities were evaluated using standardized protocols. Polygodial (1) was the most active compound, with MBC 8 µg/mL and MIC 16 µg/mL in E. avium; MBC 16 µg/mL and MIC 32 µg/mL in K. pneumoniae; MBC 64 µg/mL and MIC 64 µg/mL in S. typhi; and MBC 8 µg/mL and MIC 16 µg/mL and MBC 32 µg/mL and MIC 64 µg/mL in E. coli, respectively. The observed high potency could be attributed to the presence of an aldehyde group at the C8-C9 position. The antifungal activity of 1 from different microbial isolates has been evaluated. The results show that polygodial affects the growth of normal isolates and against filamentous fungi and oomycetes with MFC values ranging from 8 to 64 µg/mL. Sesquiterpene drimanes isolated from this plant have shown interesting antimicrobial properties.


Assuntos
Anti-Infecciosos , Drimys , Testes de Sensibilidade Microbiana , Sesquiterpenos , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Drimys/química , Sesquiterpenos Policíclicos/farmacologia , Sesquiterpenos Policíclicos/química , Antibacterianos/farmacologia , Antibacterianos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Escherichia coli/efeitos dos fármacos , Fungos/efeitos dos fármacos , Bactérias/efeitos dos fármacos
17.
Heliyon ; 10(11): e32029, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38868038

RESUMO

This study aimed to incorporate ß-AgVO3 and rGO into self-curing (SC) and heat-curing (HC) acrylic resins and to evaluate their physicochemical, mechanical, and antimicrobial properties while correlating them with the characterized material structure. Acrylic resin samples were prepared at 0 % (control), 0.5 %, 1 %, and 3 % for both nanoparticles. The microstructural characterization was assessed by scanning electron microscopy (SEM) (n = 1) and energy dispersive X-ray spectroscopy (EDS) (n = 1). The physicochemical and mechanical tests included flexural strength (n = 10), Knoop hardness (n = 10), roughness (n = 10), wettability (n = 10), sorption (n = 10), solubility (n = 10), porosity (n = 10), and color evaluation (n = 10). The microbiological evaluation was performed by counting colony-forming units (CFU/mL) and cell viability (n = 8). The results showed that the ß-AgVO3 samples showed lower counts of Candida albicans, Pseudomonas aeruginosa, and Streptococcus mutans due to their promising physicochemical properties. The mechanical properties were maintained with the addition of ß-AgVO3. The rGO samples showed higher counts of microorganisms due to the increase in physicochemical properties. It can be concluded that the incorporation of ß-AgVO3 into acrylic resins could be an alternative to improve the antimicrobial efficacy and performance of the material.

18.
Braz J Microbiol ; 55(3): 2539-2545, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38789904

RESUMO

Pediococcus pentosaceus ST65ACC is a bacteriocinogenic lactic acid bacteria (LAB) isolated from Brazilian artisanal cheese that is capable of inhibiting different food pathogens, mainly Listeria monocytogenes. The production of bacteriocins can be influenced by several growth conditions, such as temperature, pH, and medium composition. This study aimed to evaluate the effect of different culture media on the production of bacteriocins and antimicrobial activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The strains were inoculated alone and in coculture in four different media: BHI broth, MRS broth, meat broth, and reconstituted skim milk (RSM) 10% (w/v). The culture media were then incubated at 37 °C for 96 h, and count analysis, pH measurement, and bacteriocin production were performed at 0, 24, 48, 72 and 96 h. L. monocytogenes was inhibited to nondetectable levels in coculture with P. pentosaceus ST65ACC in MRS broth within 96 h, consistent with the high production of bacteriocin throughout the analysis period (3,200-12,800 AU/mL). However, lower inhibitory activities of P. pentosaceus ST65ACC on L. monocytogenes Scott A were recorded in BHI, RSM, and meat broth, with low or no production of bacteriocins at the analyzed times. The composition of these culture media may have repressed the production and activity of bacteriocins and, consequently, the antagonist activity of P. pentosaceus ST65ACC on L. monocytogenes Scott A. The results showed that the antimicrobial activity was more effective in MRS broth, presenting greater production of bacteriocins and less variability when compared to the other media analyzed.


Assuntos
Bacteriocinas , Meios de Cultura , Listeria monocytogenes , Pediococcus pentosaceus , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Meios de Cultura/química , Bacteriocinas/biossíntese , Bacteriocinas/farmacologia , Bacteriocinas/metabolismo , Pediococcus pentosaceus/metabolismo , Antibiose , Queijo/microbiologia , Antibacterianos/farmacologia , Concentração de Íons de Hidrogênio , Microbiologia de Alimentos , Brasil
19.
Braz J Microbiol ; 55(3): 2285-2292, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38744770

RESUMO

OBJECTIVE: To evaluate the antimicrobial activity of Brazilian honeys against oral microorganisms. DESIGN: Organic honeys (OH-1 to OH-8) were diluted (%-w/v) and sterilized by filtration. Antimicrobial activity was defined by determining MIC and CBM against oral Streptococcus. The component responsible for the antimicrobial action was defined by a catalase assay. Antibiofilm activity was evaluated against the monospecies biofilm of Streptococcus mutans  (ATCC 700610). RESULTS: OHs showed antimicrobial activity principally OH-1, OH-2, OH-3, and OH-7 with MIC values ​​ranging between 10 and 25%. The mechanism of action occurs mainly by hydrogen peroxide produced by honey enzymes. OH-1, OH-2, and OH-7 showed total biofilm destruction at low concentrations. CONCLUSION: Brazilian honeys have promising antimicrobial and antibiofilm activity with the potential to control oral microbiota.


Assuntos
Antibacterianos , Biofilmes , Mel , Testes de Sensibilidade Microbiana , Boca , Biofilmes/efeitos dos fármacos , Mel/análise , Brasil , Boca/microbiologia , Antibacterianos/farmacologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/fisiologia , Humanos , Streptococcus/efeitos dos fármacos , Streptococcus/fisiologia
20.
Chem Biodivers ; 21(7): e202400687, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38702295

RESUMO

Rhizophora extracts have several potential biological activities, and their metabolites can be used in the pharmaceutical industry. Extracts of Rhizophora species obtained from mangroves have shown prospective activity against Staphylococcus aureus. This study aimed to investigate the chemical profile of Rhizophora mangle leaves from fringe, basin, and transition mangrove zones and their bactericidal/bacteriostatic potential against S. aureus. R. mangle leaves were collected monthly in 2018 from litterfall in three different zones of the mangrove of Guaratiba State Reserve: fringe, basin, and transition. Extracts were prepared from the material collected in October and December for LC-HRMS/MS analysis, and dereplication was performed using a molecular library search and the classical molecular networking GNPS platform. The minimum inhibitory concentrations (MICs) of the aqueous extract of R. mangle against S. aureus were determined. No S. aureus growth was observed compared to the control for extracts collected from September to December. Different compounds were annotated in each region, yet a marked presence of phenolic compounds was noted, among them glycosylated flavonoid derivatives of quercetin and kaempferol. The results suggest bactericidal/bacteriostatic activity for extracts of R. mangle leaves collected in 2018 from three mangrove forest zones.


Assuntos
Antibacterianos , Testes de Sensibilidade Microbiana , Extratos Vegetais , Folhas de Planta , Rhizophoraceae , Staphylococcus aureus , Rhizophoraceae/química , Rhizophoraceae/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química
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