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1.
Anal Chem ; 96(6): 2676-2683, 2024 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-38290431

RESUMEN

Sepsis is an extremely dangerous medical condition that emanates from the body's response to a pre-existing infection. Early detection of sepsis-inducing bacterial infections can greatly enhance the treatment process and potentially prevent the onset of sepsis. However, current point-of-care (POC) sensors are often complex and costly or lack the ideal sensitivity for effective bacterial detection. Therefore, it is crucial to develop rapid and sensitive biosensors for the on-site detection of sepsis-inducing bacteria. Herein, we developed a graphene oxide CRISPR-Cas12a (GO-CRISPR) biosensor for the detection of sepsis-inducing bacteria in human serum. In this strategy, single-stranded (ssDNA) FAM probes were quenched with single-layer graphene oxide (GO). Target-activated Cas12a trans-cleavage was utilized for the degradation of the ssDNA probes, detaching the short ssDNA probes from GO and recovering the fluorescent signals. Under optimal conditions, we employed our GO-CRISPR system for the detection of Salmonella Typhimurium (S. Typhimurium) with a detection sensitivity of as low as 3 × 103 CFU/mL in human serum, as well as a good detection specificity toward other competing bacteria. In addition, the GO-CRISPR biosensor exhibited excellent sensitivity to the detection of S. Typhimurium in spiked human serum. The GO-CRISPR system offers superior rapidity for the detection of sepsis-inducing bacteria and has the potential to enhance the early detection of bacterial infections in resource-limited settings, expediting the response for patients at risk of sepsis.


Asunto(s)
Infecciones Bacterianas , Técnicas Biosensibles , Grafito , Sepsis , Humanos , Sistemas CRISPR-Cas/genética , Sepsis/diagnóstico , Bacterias , Colorantes , Óxidos
2.
Mol Phylogenet Evol ; 198: 108121, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38851309

RESUMEN

The subgenus Aeschyntelus includes six species that show variations in body color and shape, thus making it difficult to identify them based on morphological identification alone. To date, no genetic study has evaluated species within this genus. Herein, we collected 171 individuals from 90 localities of Rhopalus and employed an integrative taxonomic approach that incorporated morphological data, mitochondrial genomic data (COI, whole mitochondrial data) and nuclear genomic data (18S + 28S rRNAs, nuclear genome-wide SNPs) to delineate species boundaries. Our analyses confirmed the status of nine described species of Rhopalus and proposed the recognition of one new species known as Rhopalus qinlinganus sp. nov., which is classified within the subgenus Aeschyntelus. Discrepancies arising from nuclear and mitochondrial data suggest the presence of mito-nuclear discordance. Specifically, mitochondrial data indicated admixture within Clade A, comprising R. kerzhneri and R. latus, whereas genome-wide SNPs unambiguously identified two separate species, aligning with morphological classification. Conversely, mitochondrial data clearly distinguished Clade B- consisting of R. sapporensis into two lineages, whereas genome-wide SNPs unequivocally identified a single species. Our study also provides insights into the evolutionary history of Aeschyntelus, thus indicating that it likely originated in East Asia during the middle Miocene. The development of Aeschyntelus biodiversity in the southwestern mountains of China occurred via an uplift-driven diversification process. Our findings highlight the necessity of integrating both morphological and multiple molecular datasets for precise species identification, particularly when delineating closely related species. Additionally, it reveals the important role of mountain orogenesis on speciation within the southwestern mountains of China.

3.
Mol Phylogenet Evol ; 195: 108055, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38485106

RESUMEN

Comparative phylogeographic studies of closely related species sharing co-distribution areas can elucidate the role of shared historical factors and environmental changes in shaping their phylogeographic pattern. The bean bugs, Riptortus pedestris and Riptortus linearis, which both inhabit subtropical regions in East Asia, are recognized as highly destructive soybean pests. Many previous studies have investigated the biological characteristics, pheromones, chemicals and control mechanisms of these two pests, but few studies have explored their phylogeographic patterns and underlying factors. In this study, we generated a double-digest restriction site-associated DNA sequencing (ddRAD-seq) dataset to investigate phylogeographic patterns and construct ecological niche models (ENM) for both Riptortus species. Our findings revealed similar niche occupancies and population genetic structures between the two species, with each comprising two phylogeographic lineages (i.e., the mainland China and the Indochina Peninsula clades) that diverged approximately 0.1 and 0.3 million years ago, respectively. This divergence likely resulted from the combined effects of temperatures variation and geographical barriers in the mountainous regions of Southwest China. Further demographic history and ENM analyses suggested that both pests underwent rapid expansion prior to the Last Glacial Maximum (LGM). Furthermore, ENM predicts a northward shift of both pests into new soybean-producing regions due to global warming. Our study indicated that co-distribution soybean pests with overlapping ecological niches and similar life histories in subtropical regions of East Asia exhibit congruent phylogeographic and demographic patterns in response to shared historical biogeographic drivers.


Asunto(s)
Glycine max , Heterópteros , Animales , Glycine max/genética , Filogenia , Variación Genética , Evolución Molecular , ADN Mitocondrial/genética , Filogeografía , Asia Oriental , Heterópteros/genética
4.
Mol Phylogenet Evol ; 195: 108056, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38493987

RESUMEN

The yellow spotted stink bug (YSSB), Erthesina fullo (Thunberg, 1783) is an important Asian pest that has recently successfully invaded Europe and an excellent material for research on the initial stage of biological invasion. Here, we reported the native evolutionary history, recent invasion history, and potential invasion threats of YSSB for the first time based on population genetic methods [using double digest restriction-site associated DNA (ddRAD) data and mitochondrial COI and CYTB] and ecological niche modelling. The results showed that four lineages (east, west, southwest, and Hainan Island) were established in the native range with a strong east-west differentiation phylogeographical structure, and the violent climate fluctuation might cause population divergence during the Middle and Upper Pleistocene. In addition, land bridges and monsoon promote dispersal and directional genetic exchanging between island populations and neighboring continental populations. The east lineage (EA) was identified as the source of invasion in Albania. EA had the widest geographical distribution among all other lineages, with a star-like haplotype network with the main haplotype as the core. It also had a rapid population expansion history, indicating that the source lineage might have stronger diffusion ability and adaptability. Our findings provided a significant biological basis for fine tracking of invasive source at the lineage or population level and promote early invasion warning of potential invasive species on a much subtler lineage level.


Asunto(s)
Heterópteros , Animales , Filogeografía , Filogenia , Heterópteros/genética , Evolución Biológica , Mitocondrias/genética , ADN Mitocondrial/genética , Variación Genética
5.
Trends Analyt Chem ; 1682023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37840598

RESUMEN

Infectious diseases (such as sepsis, influenza, and malaria), caused by various pathogenic bacteria and viruses, are widespread across the world. Early and rapid detection of disease-related pathogens is necessary to reduce their spread in the world and prevent their potential global pandemics. The clustered regularly interspaced short palindromic repeats (CRISPR) technology, as the next-generation molecular diagnosis technique, holds immense promise in the detection of infectious diseases because of its remarkable advantages, including supreme flexibility, sensitivity, and specificity. While numerous CRISPR-based biosensors have been developed for application in environmental monitoring, food safety, and point-of-care diagnosis, there remains a critical need to summarize and explore their potential in human health. This review aims to address this gap by focusing on the latest advancements in CRISPR-based biosensors for infectious disease detection. We provide an overview of the current status, pre-amplification methods, the unique feature of each CRISPR system, and the design of CRISPR-based biosensing strategies to detect disease-associated nucleic acids. Last but not least, the review analyzes the current challenges and provides future perspectives, which will contribute to developing more effective CRISPR-based biosensors for human health.

6.
Appl Microbiol Biotechnol ; 107(4): 1361-1371, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36635397

RESUMEN

Mitochondrial pyruvate carriers (MPCs), located in the inner membrane of mitochondria, are essential carriers for pyruvate to enter mitochondria. MPCs regulate a wide range of intracellular metabolic processes, such as glycolysis, the tricarboxylic acid cycle (TCA cycle), fatty acid metabolism, and amino acid metabolism. However, the metabolic regulation of MPCs in macrofungi is poorly studied. We studied the role of MPCs in Ganoderma lucidum (GlMPC) on ganoderic acid (GA) biosynthesis regulation in G. lucidum. In this study, we found that the mitochondrial/cytoplasmic ratio of pyruvate was downregulated about 75% in GlMPC1- and GlMPC2-silenced transformants compared with wild type (WT). In addition, the GA content was 17.72 mg/g and increased by approximately 50% in GlMPC1- and GlMPC2-silenced transformants compared with WT. By assaying the expression levels of three key enzymes and the enzyme activities of isocitrate dehydrogenase (IDH) and α-ketoglutarate dehydrogenase (α-KGDH) of the TCA cycle in GlMPC1- and GlMPC2-silenced transformants, it was found that the decrease in GlMPCs activity did not significantly downregulate the TCA cycle rate, and the enzyme activity of IDH increased by 44% compared with WT. We then verified that fatty acid ß-oxidation (FAO) supplements the TCA cycle by detecting the expression levels of key enzymes involved in FAO. The results showed that compared with WT, the GA content was 1.14 mg/g and reduced by approximately 40% in co-silenced transformants. KEY POINTS: • GlMPCs affects the distribution of pyruvate between mitochondria and the cytoplasm. • Acetyl-CoA produced by FAO maintains the TCA cycle. • Acetyl-CoA produced by FAO promotes the accumulation of GA.


Asunto(s)
Reishi , Reishi/genética , Reishi/metabolismo , Transportadores de Ácidos Monocarboxílicos/metabolismo , Acetilcoenzima A/metabolismo , Ciclo del Ácido Cítrico , Mitocondrias/metabolismo , Ácidos Grasos/metabolismo , Piruvatos/metabolismo
7.
Crit Rev Food Sci Nutr ; 62(4): 905-916, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33030032

RESUMEN

Current food production faces a tremendous challenge due to the growing human population. The global population is estimated to reach 9 billion by 2050 with 70% more food being required. Safe food is an important dimension of food security, and food traceability across the supply chain is a key component of this. However, current food traceability systems are challenged by frequent occurrences of food safety incidents and food recalls that have damaged consumer confidence, caused huge economic loss, and put pressure on food safety agencies. This review focuses on smart food traceability that has the potential to significantly improve food safety in global food supply chains. The basic concepts and critical perspectives for various detection strategies for food safety are summarized, including portable detection devices, smart indicators and sensors integrated on food packages, and data-assisted whole-genome sequencing. In addition, new digital technologies, such as Internet-of-things (IoTs) and cloud computing, are discussed with the aim of providing readers with an overview of the exciting opportunities in smart food traceability systems.


Asunto(s)
Inocuidad de los Alimentos , Abastecimiento de Alimentos , Alimentos , Humanos
8.
Environ Sci Technol ; 56(22): 16230-16239, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-36173693

RESUMEN

Although bacteria-phage interactions have broad environmental applications and ecological implications, the influence of phage predation on bacterial aggregation and structural stability remains largely unexplored. Herein, we demonstrate that inefficient lytic phage predation can promote host filamentous bacterium Piscinibacter colonization onto non-host Thauera aggregates, improving the structural and hydraulic stability of the dual-species aggregates. Specifically, phage predation at 103-104 PFU/mL (i.e., multiplication of infection at 0.01-0.1) promoted initial Piscinibacter colonization by 10-15 folds and resulted in 29-31% higher abundance of Piscinibacter in the stabilized aggregates than that in the control aggregates without phage predation. Transcriptomic analysis revealed upregulated genes related to quorum sensing (by 15-92 folds) and polysaccharide secretion (by 10-90 folds) within the treated aggregates, which was consistent with 120-172% higher content of polysaccharides for the treated dual-species aggregates. Confocal laser scanning microscopic images further confirmed the increase of filamentous bacteria and polysaccharides (both with wider distribution) within the dual-species aggregates. Accordlingly, the aggregates' structural strength (via atomic force microscopes) and shear resistance (via hydraulic stress tests) increased by 77 and 42%, respectively, relative to the control group. In the long-term experiments, the enhanced hydraulic stability of the treated aggregates could facilitate dwelling bacteria propagation in flow-through conditions. Overall, our study demonstrates that phage predation can promote bacterial aggregation and enhance aggregate structural stability, revealing the beneficial role of lytic phage predation on bacterial symbiosis and environmental adaptivity.


Asunto(s)
Bacteriófagos , Animales , Conducta Predatoria , Percepción de Quorum , Bacterias
9.
Environ Sci Technol ; 56(12): 8920-8931, 2022 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-35438974

RESUMEN

Biofilms can be pervasive and problematic in water treatment and distribution systems but are difficult to eradicate due to hindered penetration of antimicrobial chemicals. Here, we demonstrate that indigenous prophages activated by low-intensity plasma have the potential for efficient bacterial inactivation and biofilm disruption. Specifically, low-intensity plasma treatment (i.e., 35.20 W) elevated the intracellular oxidative reactive species (ROS) levels by 184%, resulting in the activation of prophage lambda (λ) within antibiotic-resistant Escherichia coli K-12 (lambda+) [E. coli (λ+)]. The phage activation efficiency was 6.50-fold higher than the conventional mitomycin C induction. Following a cascading effect, the activated phages were released upon the lysis of E. coli (λ+), which propagated further and lysed phage-susceptible E. coli K-12 (lambda-) [E. coli (λ-)] within the biofilm. Bacterial intracellular ROS analysis and ROS scavenger tests revealed the importance of plasma-generated ROS (e.g., •OH, 1O2, and •O2-) and associated intracellular oxidative stress on prophage activation. In a mixed-species biofilm on a permeable membrane surface, our "inside-out" strategy could inactivate total bacteria by 49% and increase the membrane flux by 4.33-fold. Furthermore, the metagenomic analysis revealed that the decrease in bacterial abundance was closely associated with the increase in phage levels. As a proof-of-concept, this is the first demonstration of indigenous prophage activations by low-intensity plasma for antibiotic-resistant bacterial inactivation and biofilm eradication, which opens up a new avenue for managing associated microbial problems.


Asunto(s)
Bacteriófagos , Escherichia coli K12 , Gases em Plasma , Antibacterianos/farmacología , Bacterias , Biopelículas , Escherichia coli , Gases em Plasma/farmacología , Profagos/fisiología , Especies Reactivas de Oxígeno
10.
Arch Insect Biochem Physiol ; 111(1): e21901, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35368111

RESUMEN

We describe and illustrate two new species of Sosibia from China: Sosibia gibba sp. nov. and Sosibia ovata sp. nov. This report includes a key to Sosibia species from China and a description of the distribution area in China. The two mitochondrial genomes of these new Sosibia species were sequenced and annotated for the first time. The compositional biases, codon usage, nucleotide composition, and construct tRNA secondary structures of the two mitogenomes were analyzed. The phylogenetic relationships based on the mitogenomes using Bayesian inference and maximum likelihood methods supported the monophyly of Necrosciinae and divided it into two distinct clades: A: (Sipyloidea + [Sosibia + Calvisia]); and B: (Neohirasea + Micadina).


Asunto(s)
Genoma Mitocondrial , Animales , Teorema de Bayes , Insectos , Neoptera , Filogenia
11.
J Basic Microbiol ; 62(11): 1337-1345, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35792532

RESUMEN

Trehalose-6-phosphate synthase (TPS) is a key enzyme that participates in trehalose metabolism, which can synthesize trehalose in a two-step pathway with trehalose phosphatase, but its role in fungi is rarely studied, especially in large basidiomycetes. In this study, the tps gene of Ganoderma lucidum was cloned and named as gltps. And gltps-silenced strains were constructed by RNA interference. In this study, it is found that the extracellular polysaccharide content increased 1.6-2-fold, but there was no significant change on intracellular polysaccharide content in gltps-silenced strains compared with the wild-type (WT) strain. Furthermore, the cell wall compositions of the gltps-silenced strains were also altered, which showed that the chitin and ß-1,3-glucan contents were significantly decreased. Compared with WT, the concentration of chitin decreased by 20%-50% and that of ß-1, 3-glucan decreased by 15%-30%. The study found that the cells of gltps-silenced strains were more sensitive to cell wall stress, which might be due to changes in the compounds and structure of the cell wall. These results showed that gltps had an important effect on carbohydrate metabolism of G. lucidum cells.


Asunto(s)
Reishi , Trehalosa/metabolismo , Pared Celular/metabolismo , Glucosiltransferasas/genética , Glucosiltransferasas/metabolismo , Quitina/metabolismo , Polisacáridos/metabolismo , Metabolismo de los Hidratos de Carbono
12.
J Basic Microbiol ; 62(6): 740-749, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35199357

RESUMEN

Phosphoglucose isomerase (PGI) is a key enzyme that participates in polysaccharide synthesis, which is responsible for the interconversion of glucose-6-phosphate (G-6-P) and fructose-6-phosphate (F-6-P), but there is little research focusing on its role in fungi, especially in higher basidiomycetes. The pgi gene was cloned from Lentinula edodes and named lepgi. Then, the lepgi-silenced strains were constructed by RNA interference. In this study, we found that lepgi-silenced strains had significantly less biomass than the wild-type (WT) strain. Furthermore, the extracellular polysaccharide (EPS) and intracellular polysaccharide (IPS) levels increased 1.5- to 3-fold and 1.5-fold, respectively, in lepgi-silenced strains. Moreover, the cell wall integrity in the silenced strains was also altered, which might be due to changes in the compounds and structure of the cell wall. The results showed that compared to WT, silencing lepgi led to a significant decrease of approximately 40% in the ß-1,3-glucan content, and there was a significant increase of 2-3-fold in the chitin content. These findings provide support for studying the biological functions of lepgi in L. edodes.


Asunto(s)
Hongos Shiitake , Pared Celular , Clonación Molecular , Glucosa-6-Fosfato Isomerasa/genética , Polisacáridos , Hongos Shiitake/genética
13.
Anal Chem ; 93(6): 3217-3225, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33525867

RESUMEN

The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction has drawn increasing attention in the field of analytical science. However, the poor stability of Cu(I) usually hinders not only the simplicity of the click reaction but also its applications in precise analyses. Therefore, the development of a nanocatalyst containing stable Cu(I) is of great significance for broadening the application of CuAAC-based assays. Herein, inspired by the active center structure of natural multicopper oxidases (MCOs), we successfully prepared a novel nanocatalyst containing abundant stable Cu(I) as an artificial "clickase" (namely, CCN) by using glutathione to stabilize Cu(I). The stability and enzyme-like catalytic activity in the CuAAC reaction of the prepared CCN clickase were studied, and the catalytic mechanism of the CCN clickase-mediated CuAAC reaction between 3-azide-7-hydroxycoumarin (Azide 1) and propargyl alcohol (Alkyne 2) was also revealed. Compared with the existing solid CuO nanocatalysts used in CuAAC-based assays, CCN clickases exhibited plenty of superior properties (including high stability, excellent catalytic activity, no requirements of dissolution and reducing agents/radical initiator during the detection, well-defined porosities benefiting the substrate diffusion, and good biocompatibility), which can greatly increase the reaction efficiency and shorten the detection time. Encouraged by these remarkable performances, CCN clickases were used as labels to establish a new catalytic click fluorescence immunoassay for foodborne pathogens. Notably, the proposed CCN clickase-based immunoassay exhibited high analytical performances for the quantification of Salmonella enteritidis in the linear range of 102-106 CFU/mL with a limit of detection as low as 11 CFU/mL. The developed method has also been used in the determination of S. enteritidis in food samples, showing its great potential in the detection of foodborne pathogens.


Asunto(s)
Alquinos , Química Clic , Azidas , Catálisis , Cobre , Reacción de Cicloadición , Inmunoensayo
14.
Ecotoxicol Environ Saf ; 222: 112497, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34273850

RESUMEN

Sewage sludge (SS) and garden waste (GW) compost can be used as soil amendments to improve the soil environment. Studies done till date have been focused on the changes of harmful substances during sludge composting, but the safety and efficacy of SS and GW composting on woodland soil environment are still unclear. In the study, a field experiment was performed using to investigate the safety and efficacy of SS and GW compost as a soil amendment on woodland soil. Soil nutrients (such as nitrogen, phosphorus and potassium), organic matter and electrical conductivity were significantly increased after the addition of the SS and GW compost, while there were no significant changes in soil heavy metals content and soil enzyme activities. From these soil properties, it was found that SS and GW compost was safe and efficacious in improving the soil environment. The application of SS and GW compost had no significant effect on microbial diversity. Co-occurrence network analysis revealed that SS and GW compost efficaciously enhanced the interaction between bacterial communities, which proved that it was safe and efficacious. Furthermore, SS and GW compost enhanced ABC transporters and carbohydrate metabolism of bacterial community, while reduced the pathotroph action (such as the plant pathogen) and wood saprotrophs. Overall, these results proved the safety and efficacy of SS and GW compost as soil amendments after being added to the soil. This study contributes to the use of harmless treatments and reutilization processes of SS and GW.


Asunto(s)
Compostaje , Contaminantes del Suelo , Bosques , Jardines , Aguas del Alcantarillado , Suelo , Contaminantes del Suelo/análisis
15.
Analyst ; 145(15): 5226-5231, 2020 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-32597917

RESUMEN

The current clinical protocol to conduct a bacterial antibiotic susceptibility test (AST) requires at least 18 hours, and cannot be accomplished during a single visit for patients. Here, a new method based on the technique of CRISPR-Cas12a is utilized to accomplish a bacterial genotypic AST within one hour with good accuracy. Two amplification approaches are employed and compared: (1) enriching the bacterial concentration by culturing in growth media; and (2) amplifying target DNA from raw samples by recombinase polymerase amplification (RPA). The results show that CRISPR combined with RPA can rapidly and accurately provide a bacterial genotypic AST of urine samples with urinary tract infections for precise antibiotic treatment. As such, this technology could open a new class of rapid bacterial genotypic AST for various infectious diseases.


Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Infecciones Urinarias , Antibacterianos/farmacología , Bacterias/genética , Sistemas CRISPR-Cas/genética , Humanos , Infecciones Urinarias/diagnóstico , Infecciones Urinarias/tratamiento farmacológico
16.
Analyst ; 144(4): 1345-1352, 2019 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-30564809

RESUMEN

The monitoring of drinking water for indicators of fecal contamination is crucial for ensuring a safe supply. In this study, a novel electrochemical method was developed for the rapid and sensitive detection of Escherichia coli (E. coli) in drinking water. This strategy is based on the use of engineered bacteriophages (phages) to separate and concentrate target E. coli when conjugated with magnetic beads, and to facilitate the detection by expressing gold binding peptides fused alkaline phosphatase (GBPs-ALP). The fusion protein GBPs-ALP has both the enzymatic activity and the ability to directly bind onto a gold surface. This binding-peptide mediated immobilization method provided a novel and simple approach to immobilize proteins on a solid surface, requiring no post-translational modifications. The concentration of E. coli was determined by measuring the activity of the ALP on gold electrodes electrochemically using linear sweep voltammetry (LSV). This approach was successfully applied in the detection of E. coli in drinking water. We were able to detect 105 CFU mL-1 of E. coli within 4 hours. After 9 hours of preincubation, 1 CFU of E. coli in 100 mL of drinking water was detected with a total assay time of 12 hours. This approach compares favorably to the current EPA method and has the potential to be applied to detect different bacteria in other food matrices.


Asunto(s)
Bacteriófagos/metabolismo , Agua Potable/microbiología , Escherichia coli/aislamiento & purificación , Escherichia coli/metabolismo , Electroquímica , Electrodos , Oro/química
17.
Anal Bioanal Chem ; 411(12): 2487-2492, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30903224

RESUMEN

A peptide-graphene oxide nanosensor has been developed to detect tobacco etch virus (TEV) protease and bacteria infected with an engineered bacteriophage. In the detection strategy, a peptide (sequence: RKRFRENLYFQSCP) is tagged with fluorophores and graphene oxide (GO) is used to adsorb the peptides while quenching their fluorescence. In the presence of TEV protease, fluoropeptides are cleaved between glutamine (Q) and serine (S), resulting in the recovery of fluorescence signal. Based on the fluorescent intensity, the detection limit of TEV protease is 51 ng/µL. Additionally, we have utilized the sensing system to detect bacteria cells. Bacteriophages, which were engineered to carry TEV protease genes, were used to infect target bacteria (Escherichia coli) resulting in the translation and release of the protease. This allowed the estimation of bacteria at the concentration of 104 CFU/mL. This strategy has the potential to be developed as a multiplex detection platform of multiple bacterial species. Graphical abstract.


Asunto(s)
Técnicas Biosensibles , Colifagos/enzimología , Colifagos/aislamiento & purificación , Endopeptidasas/aislamiento & purificación , Escherichia coli/virología , Técnicas de Transferencia de Gen , Grafito/química , Nanopartículas , Péptidos/química , Secuencia de Aminoácidos , Colifagos/genética , Recuento de Colonia Microbiana , Endopeptidasas/genética , Fluorescencia , Colorantes Fluorescentes/química , Genes Virales , Límite de Detección , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Prueba de Estudio Conceptual
18.
Chem Soc Rev ; 46(5): 1272-1283, 2017 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-27942636

RESUMEN

Pathogenic bacterial contamination is a major threat to human health and safety. In this review, we summarize recent strategies for the integration of recognition elements with nanomaterials for the detection and sensing of pathogenic bacteria. Nanoprobes can provide sensitive and specific detection of bacterial cells, which can be applied across multiple applications and industries.


Asunto(s)
Bacterias/aislamiento & purificación , Técnicas Biosensibles , Nanoestructuras/química , Humanos
19.
Anal Chem ; 89(3): 1650-1657, 2017 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-28208254

RESUMEN

In this study, an enzyme-based electrochemical method was developed for the detection of Escherichia coli (E. coli) using the T7 bacteriophages engineered with lacZ operon encoding for beta-galactosidase (ß-gal). The T7lacZ phages can infect E. coli, and have the ability to trigger the overexpression of ß-gal during the infection of E. coli. The use of the engineered phages resulted in a more sensitive detection of E. coli by (1) overexpression of ß-gal in E. coli during the specific infection and (2) release of the endogenous intracellular ß-gal from E. coli following infection. The endogenous and phage-induced ß-gal was detected using the electrochemical method with 4-aminophenyl-ß-galactopyranoside (PAPG) as a substrate. The ß-gal catalyzed PAPG to an electroactive species p-aminophenol (PAP) which could be monitored on an electrode. The electrochemical signal was proportional to the concentration of E. coli in the original sample. We demonstrated the application of our strategy in aqueous samples (drinking water, apple juice, and skim milk). Using this method, we were able to detect E. coli at the concentration of approximately 105 CFU/mL in these aqueous samples in 3 h and 102 CFU/mL after 7 h. This strategy has the potential to be extended to detect different bacteria using specific bacteriophages engineered with gene encoding for appropriate enzymes.


Asunto(s)
Bacteriófagos/genética , Técnicas Electroquímicas , Escherichia coli/aislamiento & purificación , Aminofenoles/química , Aminofenoles/metabolismo , Bebidas/microbiología , Electrodos , Escherichia coli/enzimología , Galactósidos/química , Galactósidos/metabolismo , Concentración de Iones de Hidrógeno , Microbiología del Agua , beta-Galactosidasa/genética
20.
Nanotechnology ; 28(6): 06LT01, 2017 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-28044995

RESUMEN

In this study, we successfully applied vapor-phase polymerization towards the synthesis of PEDOT nanofibers which were subsequently functionalized with gold particles and used as electrodes for electrochemical sensing. Two methods were used to synthesize the PEDOT nanofibers including (1) electrospinning followed by vapor-phase polymerization (EVP), and (2) one-step vapor-phase polymerization (OSVP). The average diameter of EVP fibers was approximately 350 nm, and OSVP was approximately 200 nm. Gold particles (∼500 nm) were synthesized by an oxidation-reduction reaction between gold precursors and residue EDOT monomers on the surface of the PEDOT nanofibers. In order to investigate the electrochemical performance of these electrodes, ascorbic acid was chosen as an analyte model. Our results indicated that PEDOT nanofiber electrodes showed an enhanced response with respect to bare gold electrodes. Furthermore, the OSVP PEDOT nanofibers with gold particles demonstrated the highest sensitivity at low ascorbic acid concentrations. These hierarchically assembled, gold particle-decorated, conductive polymer nanofibers were further fabricated into flexible electrodes, demonstrating a potential in advanced applications such as wearable electronics.

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