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1.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361759

RESUMO

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), ß-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 µg/mL, a scavenging capacity SC50 of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC50 of 146 ± 20 µg/mL.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Croton/química , Inibidores Enzimáticos/química , Óleos Voláteis/química , Folhas de Planta/química , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/isolamento & purificação , Alcenos/química , Alcenos/isolamento & purificação , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Monoterpenos Cicloexânicos/química , Monoterpenos Cicloexânicos/isolamento & purificação , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Sesquiterpenos Monocíclicos/química , Sesquiterpenos Monocíclicos/isolamento & purificação , Picratos/antagonistas & inibidores , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/isolamento & purificação , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/isolamento & purificação , Ácidos Sulfônicos/antagonistas & inibidores , alfa-Glucosidases/química
2.
Biochem Biophys Res Commun ; 575: 36-41, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34455219

RESUMO

Air spaces and material surfaces in a pathogen-contaminated environment can often be a source of infection to humans, and disinfection has become a common intervention focused on reducing the contamination levels. In this study, we examined the efficacy of SAIW, a unique electrolyzed water with chlorine-free, high pH, high concentration of dissolved hydrogen, and low oxygen reduction potential, for the inactivation of several viruses and bacteria. Infectivity assays revealed that initial viral titers of enveloped and non-enveloped viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, herpes simplex virus type 1, human coronavirus, feline calicivirus, and canine parvovirus, were reduced by 2.9- to 5.5-log10 within 30 s of SAIW exposure. Similarly, the culturability of three Gram-negative bacteria (Escherichia coli, Salmonella, and Legionella) dropped down by 1.9- to 4.9-log10 within 30 s of SAIW treatment. Mechanistically, treatment with SAIW was found to significantly decrease the binding and subsequent entry efficiencies of SARS-CoV-2 on Vero cells. Finally, we showed that this chlorine-free electrolytic ion water had no acute inhalation toxicity in mice, demonstrating that SAIW holds promise for a safer antiviral and antibacterial disinfectant.


Assuntos
Anti-Infecciosos/farmacologia , Desinfetantes/farmacologia , Desinfecção/métodos , SARS-CoV-2/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos , Água/farmacologia , Animais , Calicivirus Felino/efeitos dos fármacos , Calicivirus Felino/crescimento & desenvolvimento , Chlorocebus aethiops , Contagem de Colônia Microbiana , Eletrólise , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/crescimento & desenvolvimento , Humanos , Concentração de Íons de Hidrogênio , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/crescimento & desenvolvimento , Legionella/efeitos dos fármacos , Legionella/crescimento & desenvolvimento , Camundongos , Parvovirus Canino/efeitos dos fármacos , Parvovirus Canino/crescimento & desenvolvimento , SARS-CoV-2/crescimento & desenvolvimento , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Pele/efeitos dos fármacos , Células Vero , Carga Viral
3.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360723

RESUMO

The emergence of multidrug-resistant bacteria is a worldwide health problem. Antimicrobial peptides have been recognized as potential alternatives to conventional antibiotics, but still require optimization. The proline-rich antimicrobial peptide Bac7(1-16) is active against only a limited number of Gram-negative bacteria. It kills bacteria by inhibiting protein synthesis after its internalization, which is mainly supported by the bacterial transporter SbmA. In this study, we tested two different lipidated forms of Bac7(1-16) with the aim of extending its activity against those bacterial species that lack SbmA. We linked a C12-alkyl chain or an ultrashort cationic lipopeptide Lp-I to the C-terminus of Bac7(1-16). Both the lipidated Bac-C12 and Bac-Lp-I forms acquired activity at low micromolar MIC values against several Gram-positive and Gram-negative bacteria. Moreover, unlike Bac7(1-16), Bac-C12, and Bac-Lp-I did not select resistant mutants in E. coli after 14 times of exposure to sub-MIC concentrations of the respective peptide. We demonstrated that the extended spectrum of activity and absence of de novo resistance are likely related to the acquired capability of the peptides to permeabilize cell membranes. These results indicate that C-terminal lipidation of a short proline-rich peptide profoundly alters its function and mode of action and provides useful insights into the design of novel broad-spectrum antibacterial agents.


Assuntos
Antibacterianos , Peptídeos Catiônicos Antimicrobianos , Escherichia coli/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Lipoilação , Antibacterianos/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia
4.
Molecules ; 26(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361848

RESUMO

The industrial processing of crude propolis generates residues. Essential oils (EOs) from propolis residues could be a potential source of natural bioactive compounds to replace antibiotics and synthetic antioxidants in pig production. In this study, we determined the antibacterial/antioxidant activity of EOs from crude organic propolis (EOP) and from propolis residues, moist residue (EOMR), and dried residue (EODR), and further elucidated their chemical composition. The EOs were extracted by hydrodistillation, and their volatile profile was tentatively identified by GC-MS. All EOs had an antibacterial effect on Escherichia coli and Lactobacillus plantarum as they caused disturbances on the growth kinetics of both bacteria. However, EODR had more selective antibacterial activity, as it caused a higher reduction in the maximal culture density (D) of E. coli (86.7%) than L. plantarum (46.9%). EODR exhibited mild antioxidant activity, whereas EOMR showed the highest antioxidant activity (ABTS = 0.90 µmol TE/mg, FRAP = 463.97 µmol Fe2+/mg) and phenolic content (58.41 mg GAE/g). Each EO had a different chemical composition, but α-pinene and ß-pinene were the major compounds detected in the samples. Interestingly, specific minor compounds were detected in a higher relative amount in EOMR and EODR as compared to EOP. Therefore, these minor compounds are most likely responsible for the biological properties of EODR and EOMR. Collectively, our findings suggest that the EOs from propolis residues could be resourcefully used as natural antibacterial/antioxidant additives in pig production.


Assuntos
Antibacterianos , Antioxidantes , Escherichia coli/crescimento & desenvolvimento , Lactobacillus plantarum/crescimento & desenvolvimento , Óleos Voláteis , Própole/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia
5.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361717

RESUMO

The development of bio-based nanocomposites is of high scientific and industrial interest, since they offer excellent advantages in creating functional materials. However, dispersion and distribution of the nanomaterials inside the polymer matrix is a key challenge to achieve high-performance functional nanocomposites. In this context, for better dispersion, biobased triethyl citrate (TEC) as a dispersing agent in a liquid-assisted extrusion process was used to prepare the nanocomposites of poly (lactic acid) (PLA) and chitin nanocrystals (ChNCs). The aim was to identify the effect of the TEC content on the dispersion of ChNCs in the PLA matrix and the manufacturing of a functional nanocomposite. The nanocomposite film's optical properties; microstructure; migration of the additive and nanocomposites' thermal, mechanical and rheological properties, all influenced by the ChNC dispersion, were studied. The microscopy study confirmed that the dispersion of the ChNCs was improved with the increasing TEC content, and the best dispersion was found in the nanocomposite prepared with 15 wt% TEC. Additionally, the nanocomposite with the highest TEC content (15 wt%) resembled the mechanical properties of commonly used polymers like polyethylene and polypropylene. The addition of ChNCs in PLA-TEC15 enhanced the melt viscosity, as well as melt strength, of the polymer and demonstrated antibacterial activity.


Assuntos
Antibacterianos/síntese química , Quitina/química , Citratos/química , Nanocompostos/química , Nanopartículas/química , Poliésteres/química , Antibacterianos/farmacologia , Módulo de Elasticidade , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Reologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração , Viscosidade
6.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445410

RESUMO

Development of novel therapeutics to treat antibiotic-resistant infections, especially those caused by ESKAPE pathogens, is urgent. One of the most critical pathogens is P. aeruginosa, which is able to develop a large number of factors associated with antibiotic resistance, including high level of impermeability. Gram-negative bacteria are protected from the environment by an asymmetric Outer Membrane primarily composed of lipopolysaccharides (LPS) at the outer leaflet and phospholipids in the inner leaflet. Based on a large hemi-synthesis program focusing on amphiphilic aminoglycoside derivatives, we extend the antimicrobial activity of 3',6-dinonyl neamine and its branched isomer, 3',6-di(dimethyloctyl) neamine on clinical P. aeruginosa, ESBL, and carbapenemase strains. We also investigated the capacity of 3',6-homodialkyl neamine derivatives carrying different alkyl chains (C7-C11) to interact with LPS and alter membrane permeability. 3',6-Dinonyl neamine and its branched isomer, 3',6-di(dimethyloctyl) neamine showed low MICs on clinical P. aeruginosa, ESBL, and carbapenemase strains with no MIC increase for long-duration incubation. In contrast from what was observed for membrane permeability, length of alkyl chains was critical for the capacity of 3',6-homodialkyl neamine derivatives to bind to LPS. We demonstrated the high antibacterial potential of the amphiphilic neamine derivatives in the fight against ESKAPE pathogens and pointed out some particular characteristics making the 3',6-dinonyl- and 3',6-di(dimethyloctyl)-neamine derivatives the best candidates for further development.


Assuntos
Compostos Alílicos/farmacologia , Antibacterianos/farmacologia , Framicetina/química , Bactérias Gram-Negativas/crescimento & desenvolvimento , Lipopolissacarídeos/metabolismo , Compostos Alílicos/síntese química , Compostos Alílicos/química , Antibacterianos/síntese química , Antibacterianos/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/metabolismo , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismo
7.
Molecules ; 26(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34443699

RESUMO

Three α,α-difluorophosphonate derivatives of fosmidomycin were synthesized from diethyl 1,1-difluorobut-3-enylphosphonate and were evaluated on Escherichia coli. Two of them are among the best 1-deoxy-d-xylulose 5-phosphate reductoisomerase inhibitors, with IC50 in the nM range, much better than fosmidomycin, the reference compound. They also showed an enhanced antimicrobial activity against E. coli on Petri dishes in comparison with the corresponding phosphates and the non-fluorinated phosphonate.


Assuntos
Antibacterianos/farmacologia , Fosfomicina/análogos & derivados , Ácidos Hidroxâmicos/farmacologia , Aldose-Cetose Isomerases/antagonistas & inibidores , Aldose-Cetose Isomerases/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Fosfomicina/síntese química , Fosfomicina/química , Fosfomicina/farmacologia , Testes de Sensibilidade Microbiana
8.
Biomolecules ; 11(8)2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34439812

RESUMO

Intra-amniotic infections (IAI) are one of the reasons for preterm birth. High mobility group box 1 (HMGB1) is a nuclear protein with various physiological functions, including tissue healing. Its excessive extracellular release potentiates inflammatory reaction and can revert its action from beneficial to detrimental. We infected the amniotic fluid of a pig on the 80th day of gestation with 1 × 104 colony forming units (CFUs) of E. coli O55 for 10 h, and evaluated the appearance of HMGB1, receptor for glycation endproducts (RAGE), and Toll-like receptor (TLR) 4 in the amniotic membrane and fluid. Sham-infected amniotic fluid served as a control. The expression and release of HMGB1 were evaluated by Real-Time PCR, immunofluorescence, immunohistochemistry, and ELISA. The infection downregulated HMGB1 mRNA expression in the amniotic membrane, changed the distribution of HMGB1 protein in the amniotic membrane, and increased its level in amniotic fluid. All RAGE mRNA, protein expression in the amniotic membrane, and soluble RAGE level in the amniotic fluid were downregulated. TLR4 mRNA and protein expression and soluble TLR4 were all upregulated. HMGB1 is a potential target for therapy to suppress the exaggerated inflammatory response. This controlled expression and release can, in some cases, prevent the preterm birth of vulnerable infants. Studies on suitable animal models can contribute to the development of appropriate therapy.


Assuntos
Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Proteína HMGB1/genética , Complicações Infecciosas na Gravidez/veterinária , RNA Mensageiro/genética , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor 4 Toll-Like/genética , Âmnio/imunologia , Âmnio/microbiologia , Âmnio/patologia , Líquido Amniótico/imunologia , Líquido Amniótico/microbiologia , Animais , Modelos Animais de Doenças , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Feminino , Regulação da Expressão Gênica , Proteína HMGB1/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Gravidez , Complicações Infecciosas na Gravidez/genética , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologia , Nascimento Prematuro/prevenção & controle , RNA Mensageiro/imunologia , Receptor para Produtos Finais de Glicação Avançada/imunologia , Transdução de Sinais , Suínos , Receptor 4 Toll-Like/imunologia
9.
Biomed Res Int ; 2021: 9940591, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381841

RESUMO

This study is aimed at identifying the chemical composition of the essential oil extracted from the Syzygium aromaticum seeds, as well as investigating its biological activities, insecticide effect, and allelopathic properties. The extraction yield was about 14.3 and 7.14% for grounded and ungrounded seeds, respectively. The GC-MS analysis allowed the identification of 17 heterogeneous compounds, including eugenol (68.7-87.4%), as major compound, cyperene (20.5-7.2%), phenethyl isovalerate (6.4-3.6%), and cis-thujopsene (1.9-0.8%), respectively, for grounded and ungrounded seeds. Concerning the antibacterial activity, the diameter of the inhibition zone reached 35 mm when the essential oil extracted from grounded seeds was applied against Escherichia coli. Regarding the antioxidant activity via the DPPH radical scavenging test, the IC50 varied from 1.2 ± 0.1 to 2.8 ± 0.5 µg/mL. With respect to reducing power, the efficient concentration EC50 ranged from 32 to 50 µg/mL. The essential oil exhibited also an allelopathic effect against seeds of Hyoscyamus niger, as well as an insecticide effect against Sitophilus oryzae with a DL50 value of 252.4 µL/L air. These findings enhance the use of this spice as a natural food preservative and encourage its use in several fields, including pharmaceutical, cosmetics, agriculture, and therapy, that could be a strategic way to guarantee the consumer's health.


Assuntos
Antibacterianos/química , Antioxidantes/química , Inseticidas/química , Óleos Voláteis/química , Syzygium/química , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Inocuidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Hyoscyamus/efeitos dos fármacos , Hyoscyamus/crescimento & desenvolvimento , Inseticidas/isolamento & purificação , Inseticidas/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Óleos Vegetais/química , Óleos Vegetais/isolamento & purificação , Sementes/química , Gorgulhos/efeitos dos fármacos , Gorgulhos/crescimento & desenvolvimento
10.
Elife ; 102021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34382933

RESUMO

N1-methylation of G37 is required for a subset of tRNAs to maintain the translational reading-frame. While loss of m1G37 increases ribosomal +1 frameshifting, whether it incurs additional translational defects is unknown. Here, we address this question by applying ribosome profiling to gain a genome-wide view of the effects of m1G37 deficiency on protein synthesis. Using E coli as a model, we show that m1G37 deficiency induces ribosome stalling at codons that are normally translated by m1G37-containing tRNAs. Stalling occurs during decoding of affected codons at the ribosomal A site, indicating a distinct mechanism than that of +1 frameshifting, which occurs after the affected codons leave the A site. Enzyme- and cell-based assays show that m1G37 deficiency reduces tRNA aminoacylation and in some cases peptide-bond formation. We observe changes of gene expression in m1G37 deficiency similar to those in the stringent response that is typically induced by deficiency of amino acids. This work demonstrates a previously unrecognized function of m1G37 that emphasizes its role throughout the entire elongation cycle of protein synthesis, providing new insight into its essentiality for bacterial growth and survival.


Assuntos
Escherichia coli/genética , Mudança da Fase de Leitura do Gene Ribossômico , Expressão Gênica , Biossíntese de Proteínas/fisiologia , RNA de Transferência/genética , RNA de Transferência/metabolismo , Aminoácidos/genética , Aminoácidos/metabolismo , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Metilação , Biossíntese de Proteínas/genética , Especificidade por Substrato
11.
Science ; 373(6556): 813-818, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34385401

RESUMO

A Western-style, high-fat diet promotes cardiovascular disease, in part because it is rich in choline, which is converted to trimethylamine (TMA) by the gut microbiota. However, whether diet-induced changes in intestinal physiology can alter the metabolic capacity of the microbiota remains unknown. Using a mouse model of diet-induced obesity, we show that chronic exposure to a high-fat diet escalates Escherichia coli choline catabolism by altering intestinal epithelial physiology. A high-fat diet impaired the bioenergetics of mitochondria in the colonic epithelium to increase the luminal bioavailability of oxygen and nitrate, thereby intensifying respiration-dependent choline catabolism of E. coli In turn, E. coli choline catabolism increased levels of circulating trimethlamine N-oxide, which is a potentially harmful metabolite generated by gut microbiota.


Assuntos
Colo/fisiologia , Dieta Hiperlipídica , Escherichia coli/metabolismo , Mucosa Intestinal/fisiologia , Metilaminas/metabolismo , Animais , Hipóxia Celular , Colina/administração & dosagem , Colina/metabolismo , Colo/citologia , Metabolismo Energético , Células Epiteliais/fisiologia , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Fezes/microbiologia , Microbioma Gastrointestinal , Inflamação , Mucosa Intestinal/metabolismo , Masculino , Metilaminas/sangue , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Nitratos/metabolismo , Obesidade , Consumo de Oxigênio
12.
Transfusion ; 61 Suppl 1: S80-S89, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269444

RESUMO

BACKGROUND: Collection of non-leukoreduced citrate-phosphate-dextrose-adenine (CPDA-1) whole blood is performed in walking blood banks. Blood collected under field conditions may have increased risk of bacterial contamination. This study was conducted to examine the effects of WBC reduction and storage temperature on growth of Escherichia coli (ATCC® 25922™) in CPDA-1 whole blood. METHODS: CPDA-1 whole blood of 450 ml from 10 group O donors was inoculated with E. coli. Two hours after inoculation, the test bags were leukoreduced with a platelet-sparing filter. The control bags remained unfiltered. Each whole blood bag was then split into three smaller bags for further storage at 2-6°C, 20-24°C, or 33-37°C. Bacterial growth was quantified immediately, 2 and 3 h after inoculation, on days 1, 3, 7, and 14 for all storage temperatures, and on days 21 and 35 for storage at 2-6°C. RESULTS: Whole blood was inoculated with a median of 19.5 (range 12.0-32.0) colony-forming units per ml (CFU/ml) E. coli. After leukoreduction, a median of 3.3 CFU/ml (range 0.0-33.3) E. coli remained. In the control arm, the WBCs phagocytized E. coli within 24 h at 20-24°C and 33-37°C in 9 of 10 bags. During storage at 2-6°C, a slow self-sterilization occurred over time with and without leukoreduction. CONCLUSIONS: Storage at 20-24°C and 33-37°C for up to 24 h before leukoreduction reduces the risk of E. coli-contamination in CPDA-1 whole blood. Subsequent storage at 2-6°C will further reduce the growth of E. coli.


Assuntos
Preservação de Sangue , Segurança do Sangue , Infecções por Escherichia coli/microbiologia , Escherichia coli/crescimento & desenvolvimento , Procedimentos de Redução de Leucócitos , Adenina/química , Preservação de Sangue/métodos , Citratos/química , Escherichia coli/isolamento & purificação , Glucose/química , Humanos , Temperatura
13.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299005

RESUMO

Nanoparticles can interact with the complement system and modulate the inflammatory response. The effect of these interactions on the complement activity strongly depends on physicochemical properties of nanoparticles. The interactions of silver nanoparticles with serum proteins (particularly with the complement system components) have the potential to significantly affect the antibacterial activity of serum, with serious implications for human health. The aim of the study was to assess the influence of graphite oxide (GO) nanocomposites (GO, GO-PcZr(Lys)2-Ag, GO-Ag, GO-PcZr(Lys)2) on the antibacterial activity of normal human serum (NHS), serum activity against bacteria isolated from alveoli treated with nanocomposites, and nanocomposite sensitivity of bacteria exposed to serum in vitro (using normal human serum). Additionally, the in vivo cytotoxic effect of the GO compounds was determined with application of a Galleria mellonella larvae model. GO-PcZr(Lys)2, without IR irradiation enhance the antimicrobial efficacy of the human serum. IR irradiation enhances bactericidal activity of serum in the case of the GO-PcZr(Lys)2-Ag sample. Bacteria exposed to nanocomposites become more sensitive to the action of serum. Bacteria exposed to serum become more sensitive to the GO-Ag sample. None of the tested GO nanocomposites displayed a cytotoxicity towards larvae.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Grafite/química , Nanopartículas Metálicas/química , Nanocompostos/química , Óxidos/química , Soro/efeitos dos fármacos , Animais , Antibacterianos/química , Anti-Infecciosos/química , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/efeitos da radiação , Humanos , Raios Infravermelhos , Larva/efeitos dos fármacos , Larva/efeitos da radiação , Lepidópteros/efeitos dos fármacos , Lepidópteros/efeitos da radiação , Nanopartículas Metálicas/administração & dosagem , Nanocompostos/administração & dosagem , Soro/microbiologia , Prata/química
14.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200430

RESUMO

The virus-host interaction requires a complex interplay between the phage strategy of reprogramming the host machinery to produce and release progeny virions, and the host defense against infection. Using RNA sequencing, we investigated the phage-host interaction to resolve the phenomenon of improved lytic development of P1vir phage in a DksA-deficient E. coli host. Expression of the ant1 and kilA P1vir genes in the wild-type host was the highest among all and most probably leads to phage virulence. Interestingly, in a DksA-deficient host, P1vir genes encoding lysozyme and holin are downregulated, while antiholins are upregulated. Gene expression of RepA, a protein necessary for replication initiating at the phage oriR region, is increased in the dksA mutant; this is also true for phage genes responsible for viral morphogenesis and architecture. Still, it seems that P1vir is taking control of the bacterial protein, sugar, and lipid metabolism in both, the wild type and dksA- hosts. Generally, bacterial hosts are reacting by activating their SOS response or upregulating the heat shock proteins. However, only DksA-deficient cells upregulate their sulfur metabolism and downregulate proteolysis upon P1vir infection. We conclude that P1vir development is enhanced in the dksA mutant due to several improvements, including replication and virion assembly, as well as a less efficient lysis.


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófagos/patogenicidade , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Interações entre Hospedeiro e Microrganismos/genética , Transcriptoma , Proteínas de Bactérias/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/virologia , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Virulência
15.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201173

RESUMO

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.


Assuntos
Biofilmes/crescimento & desenvolvimento , Carbonatos/química , Ciprofloxacina/farmacologia , Escherichia coli/crescimento & desenvolvimento , Magnetismo , Nanocompostos/administração & dosagem , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacos
16.
Molecules ; 26(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206375

RESUMO

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs-ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis's spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).


Assuntos
Antibacterianos , Carvão Vegetal , Escherichia coli/crescimento & desenvolvimento , Química Verde , Nanopartículas Metálicas/química , Prata , Staphylococcus aureus/crescimento & desenvolvimento , Têxteis , Aloe/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Carvão Vegetal/química , Carvão Vegetal/farmacologia , Extratos Vegetais/química , Prata/química , Prata/farmacologia
17.
Nat Commun ; 12(1): 4415, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285228

RESUMO

Complex dynamical fluctuations, from intracellular noise, brain dynamics or computer traffic display bursting dynamics consistent with a critical state between order and disorder. Living close to the critical point has adaptive advantages and it has been conjectured that evolution could select these critical states. Is this the case of living cells? A system can poise itself close to the critical point by means of the so-called self-organized criticality (SOC). In this paper we present an engineered gene network displaying SOC behaviour. This is achieved by exploiting the saturation of the proteolytic degradation machinery in E. coli cells by means of a negative feedback loop that reduces congestion. Our critical motif is built from a two-gene circuit, where SOC can be successfully implemented. The potential implications for both cellular dynamics and behaviour are discussed.


Assuntos
Engenharia Celular/métodos , Proteínas de Escherichia coli/metabolismo , Escherichia coli/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica , Engenharia Genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Retroalimentação Fisiológica , Modelos Genéticos , Proteólise , Análise de Célula Única
18.
Nat Microbiol ; 6(8): 981-990, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34183814

RESUMO

The bacterial SOS response represents a paradigm of gene networks controlled by a master transcriptional regulator. Self-cleavage of the SOS repressor LexA induces a wide range of cell functions that are critical for survival and adaptation when bacteria experience stress conditions1 including DNA repair2, mutagenesis3,4, horizontal gene transfer5-7, filamentous growth and the induction of bacterial toxins8-12, toxin-antitoxin systems13, virulence factors6,14 and prophages15-17. SOS induction is also implicated in biofilm formation and antibiotic persistence11,18-20. Considering the fitness burden of these functions, it is surprising that the expression of LexA-regulated genes is highly variable across cells10,21-23 and that cell subpopulations induce the SOS response spontaneously even in the absence of stress exposure9,11,12,16,24,25. Whether this reflects a population survival strategy or a regulatory inaccuracy is unclear, as are the mechanisms underlying SOS heterogeneity. Here, we developed a single-molecule imaging approach based on a HaloTag fusion to directly monitor LexA in live Escherichia coli cells, demonstrating the existence of three main states of LexA: DNA-bound stationary molecules, free LexA and degraded LexA species. These analyses elucidate the mechanisms by which DNA binding and degradation of LexA regulate the SOS response in vivo. We show that self-cleavage of LexA occurs frequently throughout the population during unperturbed growth, rather than being restricted to a subpopulation of cells. This causes substantial cell-to-cell variation in LexA abundances. LexA variability underlies SOS gene-expression heterogeneity and triggers spontaneous SOS pulses, which enhance bacterial survival in anticipation of stress.


Assuntos
Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Resposta SOS em Genética , Serina Endopeptidases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica , Proteólise , Serina Endopeptidases/química , Serina Endopeptidases/genética , Imagem Individual de Molécula
19.
Biomed Res Int ; 2021: 9981915, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34124267

RESUMO

Antibacterial activity of ethanolic and aqueous extracts of two medicinal plants including Oxalis corniculata (EtOc, AqOc) and Artemisia annua (EtAa, AqAa) as well as A. annua essential oil (EoAa) was investigated on multi-drug resistance (MDR) E. coli. Microdilution and agar well diffusion methods were used to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) as well as the inhibition zone. The phytconstituents of these products were analyzed using Reverse-phase High- performance liquid chromatography (RP-HPLC) and gas chromatography-mass spectrometry (GC-mass). The order of bacteriostatic and bacteriocide rate of the products can be shown as follows: EoAa>AqOc>EtAa = AqAa>EtOc, but the bactericidal effect of A. annua extracts is higher than of O. corniculata based on the MIC/MBC ratio and the order is as follows: EoAa>EtAa = AqAa>EtOc>AqOc. The most potent product, i.e. EoAa with a 56.7% inhibition of all isolates, has the potential to substitute 13 used antibiotics including oxacillin, amoxicillin, ampicillin, amoxicillin-clavulanic acid, tetracycline, streptomycin, ciprofloxacin, ceftriaxone, cefazolin, cefuroxime, cefotaxime, ceftazidime and cefixime (P <0.05). Different terpenoids were detected and measured in EoAa and catechin flavonoids in extracts of both plants, quercetin in extracts of O. corniculata but it was only possible to detect chlorogenic acid polyphenol in AqAa. Due to the antibacterial activities of the studied products, more effective than some antibiotics and their edible consumption, these products can be suggested as an alternative to some antibiotics and food preservatives to fight against MDR E. coli.


Assuntos
Antibacterianos , Artemisia annua/química , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/crescimento & desenvolvimento , Oxalidaceae/química , Extratos Vegetais , Plantas Medicinais/química , Antibacterianos/química , Antibacterianos/farmacologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia
20.
Methods Mol Biol ; 2323: 249-265, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086286

RESUMO

Research on RNA function and therapeutic potential is dominated by the use of chemoengineered RNA mimics. Recent efforts have led to the establishment of novel technologies for the production of recombinant or bioengineered RNA molecules, which should better recapitulate the structures, functions and safety profiles of natural RNAs because both are produced and folded in living cells. Herein, we describe a robust approach for reproducible fermentation production of bioengineered RNA agents (BERAs) carrying warhead miRNAs, siRNAs, aptamers, or other forms of small RNAs, based upon an optimal hybrid tRNA/pre-miRNA carrier. Target BERA/sRNAs are readily purified by fast protein liquid chromatography (FPLC) to a high degree of homogeneity (>97%). This approach offers a consistent high-level expression (>30% of total bacterial RNAs) and large-scale production of ready-to-use BERAs (multiple to tens milligrams from 1 L bacterial culture).


Assuntos
Bioengenharia/métodos , MicroRNAs/isolamento & purificação , RNA Bacteriano/isolamento & purificação , RNA de Transferência/isolamento & purificação , RNA não Traduzido/isolamento & purificação , RNA/isolamento & purificação , Sequência de Bases , Cromatografia por Troca Iônica/métodos , Clonagem Molecular/métodos , Contaminação de Medicamentos , Eletroforese em Gel de Poliacrilamida , Endotoxinas/análise , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Fermentação , MicroRNAs/biossíntese , MicroRNAs/genética , Desnaturação de Ácido Nucleico , Plasmídeos/genética , Reação em Cadeia da Polimerase/métodos , RNA/biossíntese , RNA/genética , RNA Bacteriano/biossíntese , RNA Bacteriano/genética , RNA de Transferência/biossíntese , RNA de Transferência/genética , RNA não Traduzido/genética
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