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1.
Braz. j. oral sci ; 20: e213867, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1254427

RESUMO

Aim: This study aimed to compare the microbiological potential and gustatory perception of essential oils (EO) mouthrinses containing and not containing alcohol. Methods: Twenty healthy adult volunteers rinsed with 10mL of the following test solutions: EO with alcohol, EO without alcohol, or a control solution (saline solution with mint essence). A washout period of at least seven days was adopted after a single-use protocol of the respective solution. All participants used all three tested substances. Antimicrobial potential was assessed by counting salivary total viable bacteria both before and after each rinse. Gustatory perception was evaluated using the Visual Analogue Scale (VAS). Multiple comparisons were performed with the Wilcoxon test, using Bonferroni correction. Results: Both EO solutions presented a higher antimicrobial potential in comparison to the control solution (p<0.017). However, no significant difference in antimicrobial potential was observed between EO containing or not containing alcohol (p=0.218). VAS of EO with alcohol (median: 2.7) was similar to control solution (median: 1.6) (p=0.287). A better gustatory perception was observed of the EO without alcohol (median 7.6) when compared to the control solution (p<0.0001). When EO groups were compared, EO without alcohol also demonstrated a significantly better gustatory perception (p=0.001). Conclusion: Mouthrinse containing EO without alcohol presented a better taste perception when compared to the EO with alcohol, but no difference was observed in the antimicrobial potential of both EO solutions after a single rinse protocol


Assuntos
Humanos , Masculino , Feminino , Bactérias , Óleos Voláteis , Álcoois , Percepção Gustatória , Antissépticos Bucais
2.
Appl Microbiol Biotechnol ; 105(13): 5309-5324, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34215905

RESUMO

The xylose oxidative pathway (XOP) has been engineered in microorganisms for the production of a wide range of industrially relevant compounds. However, the performance of metabolically engineered XOP-utilizing microorganisms is typically hindered by D-xylonic acid accumulation. It acidifies the media and perturbs cell growth due to toxicity, thus curtailing enzymatic activity and target product formation. Fortunately, from the growing portfolio of genetic tools, several strategies that can be adapted for the generation of efficient microbial cell factories have been implemented to address D-xylonic acid accumulation. This review centers its discussion on the causes of D-xylonic acid accumulation and how to address it through different engineering and synthetic biology techniques with emphasis given on bacterial strains. In the first part of this review, the ability of certain microorganisms to produce and tolerate D-xylonic acid is also tackled as an important aspect in developing efficient microbial cell factories. Overall, this review could shed some insights and clarity to those working on XOP in bacteria and its engineering for the development of industrially applicable product-specialist strains. KEY POINTS: D-Xylonic acid accumulation is attributed to the overexpression of xylose dehydrogenase concomitant with basal or inefficient expression of enzymes involved in D-xylonic acid assimilation. Redox imbalance and insufficient cofactors contribute to D-xylonic acid accumulation. Overcoming D-xylonic acid accumulation can increase product formation among engineered strains. Engineering strategies involving enzyme engineering, evolutionary engineering, coutilization of different sugar substrates, and synergy of different pathways could potentially address D-xylonic acid accumulation.


Assuntos
Engenharia Metabólica , Xilose , Bactérias/genética , Meios de Cultura , Xilose/análogos & derivados
3.
Sensors (Basel) ; 21(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208674

RESUMO

The consumption of water and food contaminated by pathogens is a major cause of numerous diseases and deaths globally. To control pathogen contamination and reduce the risk of illness, a system is required that can quickly detect and monitor target pathogens. We developed a simple and reproducible strategy, termed three-way junction (3WJ)-induced transcription amplification, to detect target nucleic acids by rationally combining 3WJ-induced isothermal amplification with a light-up RNA aptamer. In principle, the presence of the target nucleic acid generates a large number of light-up RNA aptamers (Spinach aptamers) through strand displacement and transcription amplification for 2 h at 37 °C. The resulting Spinach RNA aptamers specifically bind to fluorogens such as 3,5-difluoro-4-hydroxybenzylidene imidazolinone and emit a highly enhanced fluorescence signal, which is clearly distinguished from the signal emitted in the absence of the target nucleic acid. With the proposed strategy, concentrations of target nucleic acids selected from the genome of Salmonellaenterica serovar Typhi (S. Typhi) were quantitatively determined with high selectivity. In addition, the practical applicability of the method was demonstrated by performing spike-and-recovery experiments with S. Typhi in human serum.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Ácidos Nucleicos , Bactérias , Fluorescência , Humanos , Técnicas de Amplificação de Ácido Nucleico , Spinacia oleracea/genética
4.
Huan Jing Ke Xue ; 42(7): 3375-3384, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34212663

RESUMO

A petrochemical wastewater treatment plant (PWWTP) was selected to investigate the distribution and removal of antibiotic-resistant bacteria (ARB) and three forms of antibiotic resistance genes (ARGs), namely intracellular ARGs (iARGs), adsorbed-extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs). Tetracycline, sulfanilamide, and ampicillin ARB were detected with the total absolute concentration of 8.45×102-2.38×105 CFU·mL-1; the absolute concentrations of three types of ARB decreased by 0.04 lg-0.21 lg through anaerobic treatment. The effect of aeration and precipitation treatment on ARB varies with its type, and the absolute concentration of ARB in effluent was 0.12 lg-0.63 lg higher than that in influent. The absolute abundance of aeARGs and iARGs in activated sludge was 1.96×107-3.02×1010 copies·g-1 and 5.22×107-4.15×1010 copies·g-1, respectively; the absolute abundance of feARGs in wastewater was 5.90×108-1.01×1012 copies·L-1. Anaerobic treatment can remove 0.13 lg-0.65 lg aeARGs and 0.04 lg-0.28 lg iARGs, while the removal efficiency of aeARGs and iARGs by aeration and precipitation process was affected by ARGs types and forms. The absolute abundance of feARGs in effluent is 0.06 lg-0.81 lg higher than that in influent. Redundancy analysis showed that the concentration of ARB was significantly positively correlated with chemical oxygen demand (COD), Cl-, and total nitrogen concentration (P<0.05). The abundance of aeARGs was positively correlated with COD and total nitrogen concentration (P<0.05), and both the abundance of iARGs and feARGs are positively correlated with heavy metals concentration (P<0.05). This study confirmed the enrichment risk of ARB and different forms of ARGs in PWWTPs, which provided references for the research and prevention of antibiotic resistance pollution in industrial wastewater.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Antibacterianos/farmacologia , Bactérias , Resistência Microbiana a Medicamentos , Genes Bacterianos , Águas Residuárias/análise
5.
Talanta ; 233: 122549, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215052

RESUMO

Characterization of protein-protein interactions (PPIs) is essential for understanding cellular signal transduction pathways. However, quantitative measurement of the binding strength remains challenging. Building upon the classical bacterial adenylate cyclase two-hybrid (BACTH) system, we previously demonstrated that the relative reporter protein expression (RRPE), defined as the level of reporter expression normalized to that of the interacting protein, is an intrinsic characteristic associated with the binding strength between the two interacting proteins. In this study, we inserted fluorescent protein tdTomato in the chromosome as the reporter protein by CRISPR/Cas9 technology and employed a 12-amino acid tetracysteine (TC) to tag one of the interacting proteins, which can be further labeled by a membrane-permeable biarsenical dye. The combined use of tdTomato and TC-tag offers rapid and high-throughput analysis of the expression levels of both the reporter protein and one of the interacting proteins at the single-cell level by multicolor flow cytometry, which simplifies the quantitative measurement of PPI. The use of the as-developed RRPE-tdTomato-TC-BACTH approach was demonstrated in three demanding applications. First, binding affinities could be correctly ranked for discriminating interaction strengths with a tenfold difference or of the same order of magnitude. We demonstrate that the method is sensitive enough to discriminate affinities with a small difference of 1.4-fold. Moreover, residues involved in PPI can be easily mapped and ranked. Lastly, protein interaction inhibitors can be rapidly screened.


Assuntos
Bactérias , Corantes , Citometria de Fluxo
6.
Talanta ; 233: 122472, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215106

RESUMO

Direct identification of bacteria in blood cultures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is interfered with by a variety of non-bacterial proteins derived from blood cells and culture media. Thus, appropriate pre-treatments are needed for successful identification. Here, the bacteria in blood culture bottles were enriched using co-magnetic beads and processed for MALDI-TOF MS profiling. In this strategy, the Fc-containing mannose-binding lectin-coated Fe3O4 (Fc-MBL@Fe3O4) is incorporated with human IgG-coated Fe3O4 (IgG@Fe3O4) to form co-magnetic beads, which can recognize both Gram-positive and Gram-negative bacteria. Compared to single magnetic beads Fc-MBL@Fe3O4 or IgG@Fe3O4, co-magnetic beads resulted in better bacterial capture efficiency and, therefore, could decrease the false-negative results. Our proposed strategy is much more suitable for enrichment of clinically unknown bacteria from blood culture bottles for MALDI-TOF MS database identification.


Assuntos
Antibacterianos , Hemocultura , Bactérias , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Humanos , Fenômenos Magnéticos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
7.
Mater Sci Eng C Mater Biol Appl ; 127: 112225, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225870

RESUMO

Many medical and chemical applications require the precise supply of antimicrobial components in a controlled manner at the location of mature biofilm deposits. This work reports a facile strategy to fabricate nanoscale metal-organic frameworks (NMOFs) coencapsulating the antibacterial ligand (lysine carbon dots, Lys-CDs) and targeted drug (folic acid, FA) in one pot to improve antibiofilm efficiency against established biofilms. The resulting products are characterized by transmission electron microscopy, field-emission scanning electron microscopy, powder x-ray diffraction, and ultraviolet-visible spectroscopy. The results show that Lys-CDs could coordinate with Zn2+ and the adding of FA inhibits the coordination of Lys-CDs with central ions of Zn. The Lys-CDs and FA are successfully exposed with the NMOFs disintegrating in the acid environment of bacterial metabolites. We are surprised to find a sharp increase of reactive oxygen species (ROS) inside the bacterial cells by FA functionalizing NMOFs, which undoubtedly enhance the antibacterial and antibiofilm activity. The as-synthesized ZIF-8-based nanocomposites also show the peroxidase-like activity in an acid environment, and produce extremely active hydroxyl radicals resulting in the improved antibacterial and antibiofilm activity. The possible mechanisms of antibacterial activities indicate that the presence of FA is significant in the sense of targeting bacteria. This study shows a novel approach to construct acid stimulation supply system which may be helpful for the research of antibiofilms.


Assuntos
Ácido Fólico , Estruturas Metalorgânicas , Antibacterianos/farmacologia , Bactérias , Biofilmes , Espécies Reativas de Oxigênio
8.
Artigo em Inglês | MEDLINE | ID: mdl-34204975

RESUMO

Discovering novel bacterial strains might be the link to unlocking the value in lignocellulosic bio-refinery as we strive to find alternative and cleaner sources of energy. Bacteria display promise in lignocellulolytic breakdown because of their innate ability to adapt and grow under both optimum and extreme conditions. This versatility of bacterial strains is being harnessed, with qualities like adapting to various temperature, aero tolerance, and nutrient availability driving the use of bacteria in bio-refinery studies. Their flexible nature holds exciting promise in biotechnology, but despite recent pointers to a greener edge in the pretreatment of lignocellulose biomass and lignocellulose-driven bioconversion to value-added products, the cost of adoption and subsequent scaling up industrially still pose challenges to their adoption. However, recent studies have seen the use of co-culture, co-digestion, and bioengineering to overcome identified setbacks to using bacterial strains to breakdown lignocellulose into its major polymers and then to useful products ranging from ethanol, enzymes, biodiesel, bioflocculants, and many others. In this review, research on bacteria involved in lignocellulose breakdown is reviewed and summarized to provide background for further research. Future perspectives are explored as bacteria have a role to play in the adoption of greener energy alternatives using lignocellulosic biomass.


Assuntos
Biocombustíveis , Lignina , Bactérias , Biomassa
9.
Int J Mol Sci ; 22(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34205995

RESUMO

The increasing spread of multidrug-resistant pathogenic bacteria is one of the major threats to public health worldwide. Bacteria can acquire antibiotic resistance and virulence genes through horizontal gene transfer (HGT). A novel horizontal gene transfer mechanism mediated by outer membrane vesicles (OMVs) has been recently identified. OMVs are rounded nanostructures released during their growth by Gram-negative bacteria. Biologically active toxins and virulence factors are often entrapped within these vesicles that behave as molecular carriers. Recently, OMVs have been reported to contain DNA molecules, but little is known about the vesicle packaging, release, and transfer mechanisms. The present review highlights the role of OMVs in HGT processes in Gram-negative bacteria.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Membrana Externa Bacteriana/metabolismo , Técnicas de Transferência de Genes , Transferência Genética Horizontal/genética , Bactérias/genética , Bactérias/patogenicidade , Humanos , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
10.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207073

RESUMO

Laccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.


Assuntos
Compostos Heterocíclicos/síntese química , Lacase/química , Lacase/metabolismo , Bactérias/metabolismo , Biocatálise/efeitos dos fármacos , Fungos/metabolismo , Oxirredução/efeitos dos fármacos
12.
Sensors (Basel) ; 21(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: covidwho-1282573

RESUMO

The consumption of water and food contaminated by pathogens is a major cause of numerous diseases and deaths globally. To control pathogen contamination and reduce the risk of illness, a system is required that can quickly detect and monitor target pathogens. We developed a simple and reproducible strategy, termed three-way junction (3WJ)-induced transcription amplification, to detect target nucleic acids by rationally combining 3WJ-induced isothermal amplification with a light-up RNA aptamer. In principle, the presence of the target nucleic acid generates a large number of light-up RNA aptamers (Spinach aptamers) through strand displacement and transcription amplification for 2 h at 37 °C. The resulting Spinach RNA aptamers specifically bind to fluorogens such as 3,5-difluoro-4-hydroxybenzylidene imidazolinone and emit a highly enhanced fluorescence signal, which is clearly distinguished from the signal emitted in the absence of the target nucleic acid. With the proposed strategy, concentrations of target nucleic acids selected from the genome of Salmonellaenterica serovar Typhi (S. Typhi) were quantitatively determined with high selectivity. In addition, the practical applicability of the method was demonstrated by performing spike-and-recovery experiments with S. Typhi in human serum.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Ácidos Nucleicos , Bactérias , Fluorescência , Humanos , Técnicas de Amplificação de Ácido Nucleico , Spinacia oleracea/genética
13.
Molecules ; 26(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199466

RESUMO

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with an incompletely understood pathogenesis. Long-standing colitis is associated with increased risk of colon cancer. Despite the availability of various anti-inflammatory and immunomodulatory drugs, many patients fail to respond to pharmacologic therapy and some experience drug-induced adverse events. Dietary supplements, particularly saffron (Crocus sativus), have recently gained an appreciable attention in alleviating some symptoms of digestive diseases. In our study, we investigated whether saffron may have a prophylactic effect in a murine colitis model. Saffron pre-treatment improved the gross and histopathological characteristics of the colonic mucosa in murine experimental colitis. Treatment with saffron showed a significant amelioration of colitis when compared to the vehicle-treated mice group. Saffron treatment significantly decreased secretion of serotonin and pro-inflammatory cytokines, such as TNF-α, IL-1ß, and IL-6, in the colon tissues by suppressing the nuclear translocation of NF-κB. The gut microbiome analysis revealed distinct clusters in the saffron-treated and untreated mice in dextran sulfate sodium (DSS)-induced colitis by visualization of the Bray-Curtis diversity by principal coordinates analysis (PCoA). Furthermore, we observed that, at the operational taxonomic unit (OTU) level, Cyanobacteria were depleted, while short-chain fatty acids (SCFAs), such as isobutyric acid, acetic acid, and propionic acid, were increased in saffron-treated mice. Our data suggest that pre-treatment with saffron inhibits DSS-induced pro-inflammatory cytokine secretion, modulates gut microbiota composition, prevents the depletion of SCFAs, and reduces the susceptibility to colitis.


Assuntos
Bactérias/classificação , Produtos Biológicos/administração & dosagem , Colite/tratamento farmacológico , Crocus/química , Sulfato de Dextrana/efeitos adversos , Microbiota/efeitos dos fármacos , Administração Oral , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Produtos Biológicos/farmacologia , Colite/induzido quimicamente , Colite/imunologia , Colite/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Filogenia , Profilaxia Pré-Exposição , Serotonina/metabolismo , Resultado do Tratamento
14.
BMC Infect Dis ; 21(1): 636, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215207

RESUMO

BACKGROUND: This study aimed to investigate the epidemiology, microbiology, and risk factors associated with mortality and multi-drug resistance bacterial bloodstream infections (BSIs) among adult cancer patients in Shiraz, Iran. We also report a four-year trend of antimicrobial resistance patterns of BSIs. METHODS: We conducted a retrospective study at a referral oncology hospital from July 2015 to August 2019, which included all adults with confirmed BSI. RESULTS: 2393 blood cultures tested during the four-year study period; 414 positive cultures were included. The mean age of our patients was 47.57 ± 17.46 years old. Central Line-Associated BSI (CLABSI) was more common in solid tumors than patients with hematological malignancies. Gram-negative (GN) bacteria were more detected (63.3%, 262) than gram-positive bacteria (36.7%, 152). Escherichia coli was the most common gram-negative organism (123/262, 47%), followed by Pseudomonas spp. (82/262, 31%) and Klebsiella pneumoniae (38/262, 14.5%). Coagulase-negative staphylococci (CoNS) was the most frequently isolated pathogen among gram-positive bacteria (83/152, 54.6%). Acinetobacter spp., Pseudomonas spp., E. coli, and K. pneumoniae were the most common Extended-Spectrum Beta-Lactamase (ESBL) producers (100, 96.2, 66.7%, and 60.7, respectively). Acinetobacter spp., Pseudomonas spp., Enterobacter spp., E. coli, and K. pneumoniae were the most common carbapenem-resistant (CR) isolates (77.8, 70.7, 33.3, 24.4, and 13.2%, respectively). Out of 257 Enterobacterales and non-fermenter gram-negative BSIs, 39.3% (101/257) were carbapenem-resistant. Although the incidence of multi-drug resistance (MDR) gram-negative BSI increased annually during 2015-2018, the mortality rate of gram-negative BSI remains unchanged at about 20% (p-value = 0.55); however, the mortality rate was significantly greater (35.4%) in those with resistant gram-positive BSI (p-value = 0.001). The overall mortality rate was 21.5%. Early (7-day mortality) and late mortality rate (30-day mortality) were 10 and 3.4%, respectively. CONCLUSIONS: The emergence of MDR gram-negative BSI is a significant healthcare problem in oncology centers. The high proportion of the most frequently isolated pathogens were CR and ESBL-producing Enterobacterales and Pseudomonas spp. We have few effective choices against MDRGN BSI, especially in high-risk cancer patients, which necessitate newer treatment options.


Assuntos
Bacteriemia/complicações , Bactérias/patogenicidade , Farmacorresistência Bacteriana , Resistência a Múltiplos Medicamentos , Neoplasias/mortalidade , Sepse/complicações , Bacteriemia/microbiologia , Bactérias/isolamento & purificação , Terapia Combinada , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/etiologia , Neoplasias/patologia , Estudos Retrospectivos , Fatores de Risco , Sepse/microbiologia
15.
Medicine (Baltimore) ; 100(27): e26596, 2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34232210

RESUMO

ABSTRACT: The objectives of this study were to understand the clinical presentations of febrile young infants with severe bacterial infection (SBI), and to investigate the pathogen variations throughout the vaccine era and after antenatal group B Streptococcus (GBS) screening.All infants < 90 days old with a body temperature of ≥38.0°C and admitted to the emergency department were retrospectively enrolled in our study. SBI was defined as a positive culture of urine, blood, or cerebrospinal fluid. All clinical variables were analyzed and compared between the SBI group and the non-SBI group, to identify the relevant risk factors for SBI in infants with pyrexia.A total of 498 infants were studied, 279 of whom (56%) had SBI. The body temperature at triage was higher in the SBI group, and the difference was highly obvious in the neonatal group. White blood cell count and C-reactive protein levels were both significantly higher in the SBI group (P < .05), whereas neutrophil percentage and band percentage demonstrated no significant differences. Escherichia coli was the most common pathogen and plasmid-mediated extended-spectrum lactamases were detected in up to 9.1%. GBS was detected in 16 cases of bacteremia (6 cases with concurrent meningitis).The body temperature at triage may provide a clue for differentiating sick babies, especially in the neonatal group. Complete serum analysis is required for infection survey, especially white blood cell and C-reactive protein. Escherichia coli is the most common pathogen, and clinician should raise awareness of drug resistance in some patients. The prevalence of GBS infection in the young infant group remains high after routine antenatal GBS screening.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Febre/etiologia , Infecções Bacterianas/complicações , Infecções Bacterianas/diagnóstico , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Feminino , Febre/sangue , Febre/epidemiologia , Seguimentos , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Taiwan/epidemiologia
16.
Chimia (Aarau) ; 75(6): 543-547, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34233822

RESUMO

Nature has evolved a remarkable array of biosynthetic enzymes that install diverse chemistries into natural products (NPs), bestowing them with a range of important biological properties that are of considerable therapeutic value. This is epitomized by the ribosomally synthesized and post-translationally modified peptides (RiPPs), a class of peptide natural products that undergo extensive post-translational modifications to produce structurally diverse bioactive peptides. In this review, we provide an overview of our research into the proteusin RiPP family, describing characterized members and the maturation enzymes responsible for their unique chemical structures and biological activities. The diverse enzymology identified in the first two proteusin pathways highlights the enormous potential of the RiPP class for new lead structures and novel pharmacophore-installing maturases as biocatalytic tools for drug discovery efforts.


Assuntos
Produtos Biológicos , Bactérias/metabolismo , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Peptídeos , Processamento de Proteína Pós-Traducional , Ribossomos/metabolismo
17.
Chimia (Aarau) ; 75(6): 550, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34233824
18.
Front Cell Infect Microbiol ; 11: 663756, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222038

RESUMO

Objective: Microorganisms play a key role in the initiation and progression of periodontal disease. Research studies have focused on seeking specific microorganisms for diagnosing and monitoring the outcome of periodontitis treatment. Large samples may help to discover novel potential biomarkers and capture the common characteristics among different periodontitis patients. This study examines how to screen and merge high-quality periodontitis-related sequence datasets from several similar projects to analyze and mine the potential information comprehensively. Methods: In all, 943 subgingival samples from nine publications were included based on predetermined screening criteria. A uniform pipeline (QIIME2) was applied to clean the raw sequence datasets and merge them together. Microbial structure, biomarkers, and correlation network were explored between periodontitis and healthy individuals. The microbiota patterns at different periodontal pocket depths were described. Additionally, potential microbial functions and metabolic pathways were predicted using PICRUSt to assess the differences between health and periodontitis. Results: The subgingival microbial communities and functions in subjects with periodontitis were significantly different from those in healthy subjects. Treponema, TG5, Desulfobulbus, Catonella, Bacteroides, Aggregatibacter, Peptostreptococcus, and Eikenella were periodontitis biomarkers, while Veillonella, Corynebacterium, Neisseria, Rothia, Paludibacter, Capnocytophaga, and Kingella were signature of healthy periodontium. With the variation of pocket depth from shallow to deep pocket, the proportion of Spirochaetes, Bacteroidetes, TM7, and Fusobacteria increased, whereas that of Proteobacteria and Actinobacteria decreased. Synergistic relationships were observed among different pathobionts and negative relationships were noted between periodontal pathobionts and healthy microbiota. Conclusion: This study shows significant differences in the oral microbial community and potential metabolic pathways between the periodontitis and healthy groups. Our integrated analysis provides potential biomarkers and directions for in-depth research. Moreover, a new method for integrating similar sequence data is shown here that can be applied to other microbial-related areas.


Assuntos
Microbiota , Periodontite , Bactérias/genética , Humanos , Bolsa Periodontal , Periodonto
19.
Molecules ; 26(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205408

RESUMO

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H2O2), in which the nanozyme will promote the generation of ROS to kill bacteria based on the decomposition of H2O2. According to this criterion, a cerium oxide nanoparticle (Nanoceria, CeO2, a classical nanozyme with high peroxidase activity)-based nanozyme-H2O2 system would be very efficient for bacterial disinfection. However, CeO2 is a nanozyme with multiple enzyme-like activities. In addition to high peroxidase activity, CeO2 nanozymes also possess high superoxide dismutase activity and antioxidant activity, which can act as a ROS scavenger. Considering the fact that CeO2 nanozymes have both the activity to promote ROS production and the opposite activity for ROS scavenging, it is worth exploring which activity will play the dominating role in the CeO2-H2O2 system, as well as whether it will protect bacteria or produce an antibacterial effect. In this work, we focused on this discussion to unveil the role of CeO2 in the CeO2-H2O2 system, so that it can provide valuable knowledge for the design of a nanozyme-H2O2-based antibacterial system.


Assuntos
Bactérias/efeitos dos fármacos , Cério/farmacologia , Peróxido de Hidrogênio/farmacologia , Nanopartículas/química , Nanoestruturas/química , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Bactérias/metabolismo , Oxirredução/efeitos dos fármacos , Peroxidase/metabolismo , Espécies Reativas de Oxigênio/metabolismo
20.
Int J Mol Sci ; 22(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204625

RESUMO

Bacteria have evolved sophisticated signaling mechanisms to coordinate interactions with organisms of other domains, such as plants, animals and human hosts. Several important signal molecules have been identified that are synthesized by members of different domains and that play important roles in inter-domain communication. In this article, we review recent data supporting that histamine is a signal molecule that may play an important role in inter-domain and inter-species communication. Histamine is a key signal molecule in humans, with multiple functions, such as being a neurotransmitter or modulator of immune responses. More recent studies have shown that bacteria have evolved different mechanisms to sense histamine or histamine metabolites. Histamine sensing in the human pathogen Pseudomonas aeruginosa was found to trigger chemoattraction to histamine and to regulate the expression of many virulence-related genes. Further studies have shown that many bacteria are able to synthesize and secrete histamine. The release of histamine by bacteria in the human gut was found to modulate the host immune responses and, at higher doses, to result in host pathologies. The elucidation of the role of histamine as an inter-domain signaling molecule is an emerging field of research and future investigation is required to assess its potential general nature.


Assuntos
Bactérias/metabolismo , Histamina/metabolismo , Transdução de Sinais , Animais , Bactérias/genética , Liberação de Histamina , Humanos , Modelos Biológicos , Modelos Moleculares
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