Showing papers on "Escherichia coli published in 2022"
TL;DR: In this paper , the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria was studied by synthesizing ZnO nano-and microparticles.
Abstract: Abstract The aim of our work was the synthesis of ZnO nano- and microparticles and to study the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria. We fabricated ZnO nano- and microparticles through facile chemical and physical routes. The crystal structure, morphology, textural properties, and photoluminescent properties were characterized by powder X-ray diffraction, electron microscopies, nitrogen adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained ZnO structures were highly crystalline and monodispersed with intensive green emission. ZnO NPs and NRs showed the strongest antibacterial activity against Escherichia coli and Staphylococcus aureus compared to microparticles due to their high specific surface area. However, the ZnO HSs at higher concentrations also strongly inhibited bacterial growth. S. aureus strain was more sensitive to ZnO particles than the E. coli. ZnO NPs and NRs were more harmful to cancer cell lines than to normal ones at the same concentration.
62 citations
TL;DR: Phage treatment of Mycobacterium infections is challenging due to the limited repertoire of therapeutically useful phages, but favorable clinical outcomes in patients lacking any other treatment options support continued development of adjunctive phage therapy for some mycobacterial infections.
Abstract: Abstract Background Nontuberculous Mycobacterium infections, particularly Mycobacterium abscessus, are increasingly common among patients with cystic fibrosis and chronic bronchiectatic lung diseases. Treatment is challenging due to intrinsic antibiotic resistance. Bacteriophage therapy represents a potentially novel approach. Relatively few active lytic phages are available and there is great variation in phage susceptibilities among M. abscessus isolates, requiring personalized phage identification. Methods Mycobacterium isolates from 200 culture-positive patients with symptomatic disease were screened for phage susceptibilities. One or more lytic phages were identified for 55 isolates. Phages were administered intravenously, by aerosolization, or both to 20 patients on a compassionate use basis and patients were monitored for adverse reactions, clinical and microbiologic responses, the emergence of phage resistance, and phage neutralization in serum, sputum, or bronchoalveolar lavage fluid. Results No adverse reactions attributed to therapy were seen in any patient regardless of the pathogen, phages administered, or the route of delivery. Favorable clinical or microbiological responses were observed in 11 patients. Neutralizing antibodies were identified in serum after initiation of phage delivery intravenously in 8 patients, potentially contributing to lack of treatment response in 4 cases, but were not consistently associated with unfavorable responses in others. Eleven patients were treated with only a single phage, and no phage resistance was observed in any of these. Conclusions Phage treatment of Mycobacterium infections is challenging due to the limited repertoire of therapeutically useful phages, but favorable clinical outcomes in patients lacking any other treatment options support continued development of adjunctive phage therapy for some mycobacterial infections.
59 citations
TL;DR: The findings suggest that the antitumor effect of these CMC-Ag nanoparticles is due to the induction of apoptosis and necrosis in hepatic cancer cells via increased caspase-8 and -9 activities and diminished levels of VEGFR-2.
Abstract: Traditional cancer treatments include surgery, radiation, and chemotherapy. According to medical sources, chemotherapy is still the primary method for curing or treating cancer today and has been a major contributor to the recent decline in cancer mortality. Nanocomposites based on polymers and metal nanoparticles have recently received the attention of researchers. In the current study, a nanocomposite was fabricated based on carboxymethyl cellulose and silver nanoparticles (CMC-AgNPs) and their antibacterial, antifungal, and anticancer activities were evaluated. The antibacterial results revealed that CMC-AgNPs have promising antibacterial activity against Gram-negative (Klebsiella oxytoca and Escherichia coli) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus). Moreover, CMC-AgNPs exhibited antifungal activity against filamentous fungi such as Aspergillus fumigatus, A. niger, and A. terreus. Concerning the HepG2 hepatocellular cancer cell line, the lowest IC50 values (7.9 ± 0.41 µg/mL) were recorded for CMC-AgNPs, suggesting a strong cytotoxic effect on liver cancer cells. As a result, our findings suggest that the antitumor effect of these CMC-Ag nanoparticles is due to the induction of apoptosis and necrosis in hepatic cancer cells via increased caspase-8 and -9 activities and diminished levels of VEGFR-2. In conclusion, CMC-AgNPs exhibited antibacterial, antifungal, and anticancer activities, which can be used in the pharmaceutical and medical fields.
51 citations
TL;DR: In this article , the main mechanism of action (MOA) of ZnO NPs has not been fully elucidated by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy.
Abstract: Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanoparticulate materials due to their antimicrobial properties, but their main mechanism of action (MOA) has not been fully elucidated. This study characterized ZnO NPs by using X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy. Antimicrobial activity of ZnO NPs against the clinically relevant bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and the Gram-positive model Bacillus subtilis was evaluated by performing resazurin microtiter assay (REMA) after exposure to the ZnO NPs at concentrations ranging from 0.2 to 1.4 mM. Sensitivity was observed at 0.6 mM for the Gram-negative and 1.0 mM for the Gram-positive cells. Fluorescence microscopy was used to examine the interference of ZnO NPs on the membrane and the cell division apparatus of B. subtilis (amy::pspac-ftsZ-gfpmut1) expressing FtsZ-GFP. The results showed that ZnO NPs did not interfere with the assembly of the divisional Z-ring. However, 70% of the cells exhibited damage in the cytoplasmic membrane after 15 min of exposure to the ZnO NPs. Electrostatic forces, production of Zn2+ ions and the generation of reactive oxygen species were described as possible pathways of the bactericidal action of ZnO. Therefore, understanding the bactericidal MOA of ZnO NPs can potentially help in the construction of predictive models to fight bacterial resistance.
48 citations
TL;DR: The biosynthesized SeNPs using extract of baker’s yeast extract exhibit antimicrobial activities and could be a useful efficacious antimicrobial agent in the preservation of food and medical field.
45 citations
TL;DR: In this paper , a defined community of 104 bacterial species composed of the most common taxa from the human gut microbiota (hCom1) was constructed and characterized in vitro, and mice were colonized with hCom1 and then challenged with a human fecal sample.
45 citations
TL;DR: In this article , the catalytic effectiveness of AgNPs and AuNPs was studied in the popular nanocatalyst reaction, nitroaromatic reduction, and dye degradation.
Abstract: In this paper, the application of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) synthesized using a biomimetic lipid, N-myristoyltaurine (N14T) was evaluated in common fields. The catalytic effectiveness of AgNPs and AuNPs was studied in the popular nanocatalyst reaction, nitroaromatic reduction, and dye degradation. Both NPs display catalytic activity in the nitroaromatic compound and organic dyes reduction reaction involving sodium borohydride and the rate constant is estimated as 10-3 s-1. Strikingly, the reaction initiation time (t0) and completion time (tc) differ significantly between AgNPs and AuNPs. Analyzing the reaction kinetic profile revealed that the reaction carried out with AuNPs showed a shorter t0 and tc, suggesting a better catalyst than AgNPs. In addition, the efficiency of the NPs was examined in Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa). In difference to the catalytic study, AuNPs display poor antibacterial activity. Whereas AgNPs kill the tested bacteria at 250 μM via disturbing bacterial membrane integrity and produce excess reactive oxygen species. The toxicology study carried out with zebrafish animal model reveals that both AgNPs and AuNPs are non-toxic. The findings suggest that each nanomaterial possesses unique physicochemical properties irrespective of stabilization with the same molecules.
44 citations
20 Jun 2022
TL;DR: The DarTG toxin-antitoxin (TA) system as discussed by the authors protects bacteria against phage infection via ADP-ribosylation of the viral DNA, and this can be evaded by phages via mutation of their DNA polymerase or the gp61.2 anti-DarT factor.
Abstract: Toxin-antitoxin (TA) systems are broadly distributed, yet poorly conserved, genetic elements whose biological functions are unclear and controversial. Some TA systems may provide bacteria with immunity to infection by their ubiquitous viral predators, bacteriophages. To identify such TA systems, we searched bioinformatically for those frequently encoded near known phage defence genes in bacterial genomes. This search identified homologues of DarTG, a recently discovered family of TA systems whose biological functions and natural activating conditions were unclear. Representatives from two different subfamilies, DarTG1 and DarTG2, strongly protected E. coli MG1655 against different phages. We demonstrate that for each system, infection with either RB69 or T5 phage, respectively, triggers release of the DarT toxin, a DNA ADP-ribosyltransferase, that then modifies viral DNA and prevents replication, thereby blocking the production of mature virions. Further, we isolated phages that have evolved to overcome DarTG defence either through mutations to their DNA polymerase or to an anti-DarT factor, gp61.2, encoded by many T-even phages. Collectively, our results indicate that phage defence may be a common function for TA systems and reveal the mechanism by which DarTG systems inhibit phage infection. The DarTG toxin-antitoxin system protects bacteria against phage infection via ADP-ribosylation of the viral DNA, and this can be evaded by phages via mutation of their DNA polymerase or the gp61.2 anti-DarT factor.
44 citations
TL;DR: An emissive Ru(II) metallacycle (herein referred to as 1) that is excited by 808-nm laser and emits at a wavelength of ∼1,000 nm via coordination-driven self-assembly is presented, broads the applications of supramolecular photosensitizers through the strategy of lengthening their wavelengths.
Abstract: Significance Bacterial infection is the major risk to public health. Developing emissive metal–based photosensitizers against bacterial infections draws continued interest in biomedicine. The most important issue is extending the absorption and emission wavelengths of metal-based photosensitizers to ameliorate the efficiency of in vivo imaging and phototherapy. To address this, we rationally designed a long-wavelength–emissive ruthenium (II) metallacycle (herein referred to as 1) that has superior optical penetration (∼7 mm) and satisfactory reactive oxygen species–generation performance. Complex 1 has promising broad-spectrum antibacterial activity and low toxicity to mammalian cells. Moreover, 1 enables high-performance, in vivo, fluorescent imaging-guided phototherapy of Staphylococcus aureus–infected mice, with ignorable adverse effects, thus demonstrating that 1 could be a good platform for pathogen phototheranostics.
38 citations
TL;DR: In this article , chemical analysis and biological activities of Kei apple (Dovyalis caffra) methanolic extract were evaluated using HPLC and GC-MS, and the results indicated that D. Caffra juice extract is a potential candidate for further experiments to assess its use as potential alternative therapeutic agent.
Abstract: Secondary plant metabolites remain one of the key sources of therapeutic agents despite the development of new approaches for the discovery of medicinal drugs. In the current study, chemical analysis, and biological activities of Kei apple (Dovyalis caffra) methanolic extract were evaluated. Chemical analysis was performed using HPLC and GC-MS. Antiviral and anticancer effect were assessed using the crystal violet technique and activity against human liver cells (HepG2), respectively. Antibacterial activity was tested with the disc diffusion method. The obtained results showed that chlorogenic acid (2107.96 ± 0.07 µg/g), catechin (168 ± 0.58 µg/g), and gallic acid (15.66 ± 0.02 µg/g) were the main bioactive compounds identified by HPLC techniques. While, compounds containing furan moieties, as well as levoglucosenone, isochiapin B, dotriacontane, 7-nonynoic acid and tert-hexadecanethiol, with different biological activities were identified by GC-MS. Additionally, inhibition of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) scavenging was 79.25% at 2000 µg/mL, indicating its antioxidant activity with IC50 of 728.20 ± 1.04 µg/mL. The tested extract exhibited potential anticancer activity (58.90% toxicity) against HepG2 cells at 1000 µg/mL. Potential bacterial inhibition was observed mainly against Escherichia coli and Proteus vulgaris, followed by Staphylococcus aureus and Bacillus subtilis with a diameter of growth inhibition ranging from 13 to 24 mm. While weak activities were recorded for fungi Candida albicans (10 mm). The extract showed mild antiviral activity against human coronavirus 229E with a selective index (SI) of 10.4, but not against human H3N2 (SI of 0.67). The molecular docking study's energy ratings were in good promise with the experiment documents of antibacterial and antiviral activities. The findings suggest that D. caffra juice extract is a potential candidate for further experiments to assess its use as potential alternative therapeutic agent.
36 citations
TL;DR: In this article , a suite of soybean straw biochars were fabricated under different pyrolysis temperatures (600-1000 °C), which were utilized as peroxydisulfate (PS) activators for TC degradation and TC resistant Escherichia coli (E. coli) disinfection.
TL;DR: The study showed that the NMR-based metabolomics is promising in elucidating the metabolic changes of various E. coli strains in pea sprouts during an antimicrobial process, and provides clue for controlling “big six” contamination in fresh produce.
TL;DR: The results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.
Abstract: Phototheranostics is a potential area for precision medicine, which has received increasing attention for antibacterial applications. Integrating all phototheranostic modalities in a single molecule and achieving precise spatial colocalization is a challenging task because of the complexity of energy dissipation and molecular design. Here, a type of quaternary amine functionalized aggregation-induced emission (AIE), AIEgen, was synthesized and used to produce singlet oxygen (1O2) and heat, which were used to eradicate the bacteria. With the introduction of the positive charge in AIEgen, AIE nanoparticles (AIE NPs) could selectively target bacteria. Notably, the AIE NPs displayed obvious antibacterial performance against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The antibacterial rates of AIE NPs were as high as 99.9% and 99.8% for S. aureus and E. coli, respectively. Therefore, our results suggested the potential of AIE NPs acting as broad-spectrum antimicrobial materials, which provided a strategy for treating different microorganisms.
TL;DR: The existence of a previously unexplored universe of genotoxic small molecules from the microbiome that may affect host biology in homeostasis and disease is revealed.
Abstract: Microbiota-derived metabolites that elicit DNA damage can contribute to colorectal cancer (CRC). However, the full spectrum of genotoxic chemicals produced by indigenous gut microbes remains to be defined. We established a pipeline to systematically evaluate the genotoxicity of an extensive collection of gut commensals from inflammatory bowel disease patients. We identified isolates from divergent phylogenies whose metabolites caused DNA damage and discovered a distinctive family of genotoxins—termed the indolimines—produced by the CRC-associated species Morganella morganii. A non–indolimine-producing M. morganii mutant lacked genotoxicity and failed to exacerbate colon tumorigenesis in mice. These studies reveal the existence of a previously unexplored universe of genotoxic small molecules from the microbiome that may affect host biology in homeostasis and disease. Description A new class of bacterial genotoxins Individuals with inflammatory bowel disease are at increased risk of developing colorectal cancer compared with the general population. The gut microbiome is among the many factors that can influence tumorigenesis, in part by modulating the immune system and producing microbial metabolites. Cao et al. developed a functional screen to test whether gut bacteria from patients with inflammatory bowel disease have genotoxic effects (see the Perspective by Puschhof and Sears). The authors discovered a family of DNA damage–inducing microbial metabolites called indolimines, which were produced by the Gram-negative bacteria Morganella morganii. In a mouse model of colon cancer, M. morganii exacerbated tumor burden, but a mutant form of the bacteria unable to produce indolimine did not. This diverse series of genotoxic small molecules from the human microbiome may play a role in intestinal tumorigenesis. —PNK Functional screening of commensal gut microbiota reveals small-molecule genotoxins in patients with inflammatory bowel disease. INTRODUCTION Gut microbiota can potentially contribute to the development and progression of colorectal cancer (CRC) by producing small-molecule genotoxins. For example, select commensal Escherichia coli strains produce the canonical microbiota-derived genotoxin colibactin, which engenders the formation of DNA double-strand breaks (DSBs) in intestinal epithelial cells and exacerbates CRC in mouse models. Furthermore, human CRCs harbor colibactin-associated mutational signatures, implying a direct role for microbiota-induced DNA damage in CRC. However, the impacts of microbiota-derived genotoxins beyond colibactin remain largely unexplored. RATIONALE Given the extensive diversity of small-molecule metabolites produced by bacteria, we hypothesized that additional taxa from the human gut microbiome might produce previously undiscovered small molecules that cause DNA damage in host cells. Identifying and characterizing such genotoxins and their respective biosynthetic pathways may reveal causal roles of gut microbes in shaping host biology and disease susceptibility. Thus, we designed a large-scale electrophoresis-based DNA damage screening pipeline to evaluate the genotoxicity of a collection of more than 100 gut commensals isolated from patients with inflammatory bowel disease (IBD). RESULTS We identified diverse bacteria from the human microbiota whose small-molecule metabolites caused genotoxicity in both cell-free and cell-based DNA damage assays. For example, small-molecule metabolites from gram-positive bacteria (including Clostridium perfringens and Clostridium ramosum strains) and gram-negative bacteria (including multiple Morganella morganii strains) directly damaged DNA in cell-free assays and induced the expression of the DSB marker γ-H2AX and cell-cycle arrest in epithelial cells. However, the DNA damage patterns caused by these metabolites were distinct from colibactin-induced cross-links, and these isolates lacked the biosynthetic machinery to produce colibactin or other known genotoxins. These data thus implied the existence of previously unrecognized microbiota-derived genotoxins. M. morganii is enriched in the gut microbiota of both IBD and CRC patients. Using a combination of comparative metabolomics and bioactivity-guided natural product-discovery techniques, we discovered a family of M. morganii-derived small-molecule genotoxins—termed the indolimines—that elicited DNA damage in cell-based and cell-free assays. Furthermore, we identified a previously uncharacterized bacterial decarboxylase (annotated as an aspartate aminotransferase encoded by the aat gene) that was essential for indolimine synthesis and constructed an isogenic aat mutant M. morganii that lacked genotoxicity in both cell-free and cell-based DNA damage assays. Compared with the non–indolimine-producing mutant, wild-type M. morganii caused increased intestinal permeability and induced transcriptional signatures associated with abnormal DNA replication and intestinal epithelial cell proliferation in gnotobiotic mice. Furthermore, indolimine-producing M. morganii induced increased colonic tumor burden in the context of a mock microbial community in a mouse model of CRC. CONCLUSION By leveraging function-based assessments of the microbiome, we uncovered the existence of a broader universe of microbiota-derived small-molecule genotoxins. We found that diverse bacterial strains isolated from IBD patients exhibited DNA-damaging activities and discovered a previously undescribed family of genotoxins, termed the indolimines, produced by the IBD- and CRC-associated species M. morganii. Indolimine-producing M. morganii caused increased intestinal permeability and exacerbated colon tumorigenesis in gnotobiotic mice. Overall, these studies imply an expanded role for microbiota-derived genotoxins in shaping host biology and disease susceptibility. Human gut microbes isolated from IBD patients produce small-molecule genotoxins. Diverse gut microbes isolated from patients with IBD exhibit direct genotoxicity. M. morganii produces a family of genotoxic small molecule metabolites, termed the indolimines. Indolimine-producing M. morganii induces DNA damage in intestinal epithelial cells (IECs) and increased colon tumor burdens in gnotobiotic mouse models.
TL;DR: In this article , the authors analyzed the overall metabolic responses of Escherichia coli biofilms to the combined stresses of ultrasound and low concentration acidic electrolysed water (LcAEW, free available chlorine: 4 mg/L).
Abstract: This study aimed to better understand the overall metabolic responses of Escherichia coli biofilms to the combined stresses of ultrasound and low concentration acidic electrolysed water (LcAEW, free available chlorine: 4 mg/L). The inactivation kinetics of all E. coli strains (ATCC 25922, ATCC 35150 and ATCC 43895) were simulated well by the modified Weibull model (R2: 0.81–0.97; RMSE: 0.04–0.71). By analysing metabolite profiles, ultrasound mainly disrupted nucleotide metabolism in E. coli cells within biofilms, as most intracellular nucleotide-related compounds (e.g., uridine, ATP, ADP) showed decreased trend especially in ATCC 25922 and ATCC 35150. Increased contents of most amino acids and decreased contents of most carbohydrates were shown in all strains after LcAEW treatment. Under combined treatment, adaptive strategies like glutamate decarboxylase system and mixed acid fermentation were activated to different extents among the three strains. These findings revealed that NMR-based metabolomics technology is promising in identifying strain-specific metabolic responses of biofilms to different antimicrobial treatments, providing guidance for future mechanism studies related to food contact surface sanitisation.
TL;DR: A comprehensive review on the taxonomic position, species composition and different phylotypes of Klebsiella spp, describing the diversity and worldwide distribution of the MDR-hv clones, the genetic mutation and horizontal gene transfer events that drive the evolution of such clones, and the potential impact of MDRhv infections on human health is provided in this paper .
TL;DR: In this article , the role of basal autophagy in the maintenance of neuronal health was investigated in mouse brain tissue and used proteomics to identify the major cargos engulfed within autophagosomes, validating the findings in rodent primary and human iPSC-derived neurons.
TL;DR: In this article , the authors examined the sanitising efficacy of a 10-min low-concentration electrolysed water (LcEW) treatment against eight Escherichia coli serotypes (the “big six”) using pea sprouts as the food matrix.
TL;DR: In this paper , the authors used native E. coli as chassis for transgene delivery to impact host physiology and found that the reintroduction of these strains induces perpetual engraftment in the intestine.
TL;DR: The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam(C/T), imipenem-relebactam, meropenem-vaborbactsam, aztreonam-avIBactam and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa
Abstract: The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), imipenem-relebactam, meropenem-vaborbactam, aztreonam-avibactam (AZA), and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa and in Escherichia coli using isogenic backgrounds. Although metallo-β-lactamases conferred resistance in most cases, except for AZA, several clavulanic-acid-inhibited extended-spectrum β-lactamases (PER, BEL, SHV) had a significant impact on the susceptibility to CZA, C/T, and FDC. ABSTRACT The ability of broad-spectrum β-lactamases to reduce the susceptibility to ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), imipenem-relebactam, meropenem-vaborbactam, aztreonam-avibactam (AZA), and cefiderocol (FDC) was evaluated both in Pseudomonas aeruginosa and in Escherichia coli using isogenic backgrounds. Although metallo-β-lactamases conferred resistance in most cases, except for AZA, several clavulanic-acid-inhibited extended-spectrum β-lactamases (PER, BEL, SHV) had a significant impact on the susceptibility to CZA, C/T, and FDC.
TL;DR: In this article , a multicentre case-control study of 422 patients with CRKP infection and 948 with carbapenem-susceptible K. pneumoniae (CSKP) infection from March to July 2017 was conducted.
03 Oct 2022
TL;DR: In this paper , Sirtuins (DSRs) are used to degrade nicotinamide adenine dinucleotide (NAD+) during infection, depleting the cell of this essential molecule and aborting phage propagation.
Abstract: Defence-associated sirtuins (DSRs) comprise a family of proteins that defend bacteria from phage infection via an unknown mechanism. These proteins are common in bacteria and harbour an N-terminal sirtuin (SIR2) domain. In this study we report that DSR proteins degrade nicotinamide adenine dinucleotide (NAD+) during infection, depleting the cell of this essential molecule and aborting phage propagation. Our data show that one of these proteins, DSR2, directly identifies phage tail tube proteins and then becomes an active NADase in Bacillus subtilis. Using a phage mating methodology that promotes genetic exchange between pairs of DSR2-sensitive and DSR2–resistant phages, we further show that some phages express anti-DSR2 proteins that bind and repress DSR2. Finally, we demonstrate that the SIR2 domain serves as an effector NADase in a diverse set of phage defence systems outside the DSR family. Our results establish the general role of SIR2 domains in bacterial immunity against phages. The SIR2-domain-containing protein DSR2 from Bacillus subtilis protects against SPR phage infection via NAD+ depletion. Some phages express anti-DSR2 proteins, blocking bacterial immunity.
TL;DR: The in vivo inactivation and following recovery during storage suggested that the combination treatment presented a potential inactivation process for organic vegetables or sprouts.
TL;DR: Results indicate a synergistic effect between the self-propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli, and the design of efficient light-driven microrobots with promising applications in microbiology and biomedicine.
Abstract: Urinary-based infections affect millions of people worldwide. Such bacterial infections are mainly caused by Escherichia coli (E. coli) biofilm formation in the bladder and/or urinary catheters. Herein, the authors present a hybrid enzyme/photocatalytic microrobot, based on urease-immobilized TiO2 /CdS nanotube bundles, that can swim in urea as a biocompatible fuel and respond to visible light. Upon illumination for 2 h, these microrobots are able to remove almost 90% of bacterial biofilm, due to the generation of reactive radicals, while bare TiO2 /CdS photocatalysts (non-motile) or urease-coated microrobots in the dark do not show any toxic effect. These results indicate a synergistic effect between the self-propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli. This work provides a photo-biocatalytic approach for the design of efficient light-driven microrobots with promising applications in microbiology and biomedicine.
TL;DR: In this article , copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum, and the created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), and energy-dispersive Xray spectroscope (EDX).
Abstract: Mycosynthesis of nanoparticle (NP) production is a potential ecofriendly technology for large scale production. In the present study, copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum. The created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the biosynthesized CuONPs were performed against biofilm forming Klebsiella oxytoca ATCC 51,983, Escherichia coli ATCC 35,218, Staphylococcus aureus ATCC 25,923, and Bacillus cereus ATCC 11,778. The anti-bacterial activity result was shown with the zone of inhibition determined to be 14 ± 0.31 mm, 16 ± 0.53 mm, 11 ± 0.57 mm, and 10 ± 0.57 mm respectively. Klebsiella oxytoca and Escherichia coli were more susceptible to CuONPs with minimal inhibitory concentration (MIC) values 6.25 and 3.12 µg/mL, respectively, while for Staphylococcus aureus and Bacillus cereus, MIC value was 12.5 and 25 μg/mL, respectively. The minimum biofilm inhibition concentration (MBIC) result was more evident, that the CuONPs have excellent anti-biofilm activity at sub-MIC levels reducing biofilm formation by 49% and 59% against Klebsiella oxytoca and Escherichia coli, while the results indicated that the MBIC of CuONPs on Bacillus cereus and Staphylococcus aureus was higher than 200 μg/mL and 256 μg/mL, respectively, suggesting that these CuONPs could not inhibit mature formatted biofilm of Bacillus cereus and Staphylococcus aureus in vitro. Overall, all the results were clearly confirmed that the CuONPs have excellent anti-biofilm ability against Klebsiella oxytoca and Escherichia coli. The prepared CuONPs offer a smart approach for biomedical therapy of resistant microorganisms because of its promoted antimicrobial action, but only for specified purposes.
TL;DR: In this paper, the effects of biochar (BC) on the horizontal transfer of ARG-carrying plasmids to Escherichia coli via transformation were systematically investigated and it was shown that BC could significantly inhibit the transformation of ARGs and the inhibition degree increased with pyrolysis temperature.
TL;DR: In this article , eight kinds of chitosan fibers were selected to characterize and analyze their composition, surface morphology, and mechanical properties, and the relationship between antibacterial activity and molecular weight and degree of deacetylation was established.
TL;DR: In this article , the effects of biochar (BC) on the horizontal transfer of ARG-carrying plasmids to Escherichia coli via transformation were systematically investigated and it was shown that BC could significantly inhibit the transformation of ARGs and the inhibition degree increased with pyrolysis temperature.
TL;DR: In this article , the authors investigated the kinetics of the inactivation of Escherichia coli in organic broccoli sprouts by mild heat (MH) and lactic acid (LA).
TL;DR: In this article , a pan-genomic analysis of a global collection of 752 Escherichia coli isolates from diverse sources was performed to identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island.
Abstract: Escherichia coli ST58 has recently emerged as a globally disseminated uropathogen that often progresses to sepsis. Unlike most pandemic extra-intestinal pathogenic E. coli (ExPEC), which belong to pathogenic phylogroup B2, ST58 belongs to the environmental/commensal phylogroup B1. Here, we present a pan-genomic analysis of a global collection of 752 ST58 isolates from diverse sources. We identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage includes three-quarters of all ExPEC sequences in our study and has a broad host range, although poultry and porcine sources predominate. By contrast, strains isolated from cattle often lack ColV plasmids. Our data indicate that ColV plasmid acquisition contributed to the divergence of the major ST58 sub-lineage, and different sub-lineages inhabit poultry, swine and cattle.