Excellent Antibacterial Activity Research Articles

Discovery of quaternized pyridine-thiazole-ruthenium complexes as potent anti-Staphylococcus aureus agents

Quaternization of ruthenium complexes may be a promising strategy for the development of new antibiotics. In response to the increasing bacterial resistance, we integrated the quaternary amine structure into the design of ruthenium complexes and evaluated their antibacterial activity. All the ruthenium complexes showed good antibacterial activity against the tested Staphylococcus aureus (S. aureus). Ru-8 was the most effective antibacterial agent that displayed excellent antibacterial activity against S. aureus (MIC = 0.78–1.56 μg/mL). In vitro experiments showed that all nine ruthenium complexes had low hemolytic toxicity to rabbit erythrocytes. Notably, Ru-8 was found to disrupt bacterial cell membranes, alter their permeability, and induce ROS production in bacteria, all the above leading to the death of bacteria without inducing drug resistance. To further explore the antibacterial activity of Ru-8in vivo, we established a mouse skin wound infection model and a G. mellonella larvae infection model. Ru-8 exhibited significant antibacterial efficacy against S. aureus in vivo and low toxicity to mouse tissues. The Ru-8 showed low toxicity to Raw264.7 cells (mouse monocyte macrophage leukemia cells). This study indicates that the ruthenium complex ruthenium quaternary was a promising strategy for the development of new antibacterial agents.

Synthesis and analysis of multifunctional graphene oxide/Ag2O-PVA/chitosan hybrid polymeric composite for wound healing applications

The requirement for accurate treatments for skin diseases and wounds, generated a rising interest towards multifunctional polymer composites, that are capable of mimicking the natural compositions in human body. Also, electroactive composite films disseminate endogenous electrical stimulations that encourage cell migration and its proliferation at wound site, proposing greater opportunities in upgrading the conventional wound patches. In this work, the composite film made of graphene oxide, Ag2O, PVA and chitosan were developed for wound healing applications, by the solution casting method. The even dispersibility of nanofiller in polymeric matrix was validated from the physicochemical analyses. The increment in roughness of the composite film surface was noted from AFM images. The thermal stability and porous nature of the polymer composite were also verified. A conductivity value of 0.16 × 10−4 Scm−1 was obtained for the film. From MTT assay, it was noted that the films were non-cytotoxic and supported cell adhesion along with cell proliferation of macrophage (RAW 264.7) cells. Moreover, the composite film also demonstrated non-hemolytic activity of <2 %, as well as excellent antibacterial activity towards E. coli and S. aureus. Thus, the obtained results validated that the prepared composite film could be chosen as an innovative candidate for developing state-of-the-art wound dressings.

Maleated epoxidized natural rubber grafted cassava starch/silver composite coating for cloth glove: Preparation and physical properties

The green composite was obtained from maleated epoxidized natural rubber (MENR) latex grafted cassava starch (CS) (MNS) and silver nanoparticles (AgNPs) by using a green route process. The immersion of AgNPs in the MNS matrix was checked with UV–visible spectrometer. The SEM was applied to study the morphology of AgNPs particle. The thermal stability of the MNSAg composite increased with increasing AgNPs. The AgNPs well distributed in the MNS matrix. The silver was used to facilitate the facile and fast preparation and to improve the mechanical strength and thermal stability at 420–450 °C of the MNSAg composites. The MNSAg composite containing AgNPs exhibited excellent antibacterial activities against both Escherichia coli and Staphylococcus aureus. Moreover, it showed the high UV absorption. It was used to coat with cloth gloves. The degree of biodegradation of this sample was about 80–90 % after being buried in soil.

Highly active carbon dots based nanozyme for enhanced cholesterol detection and antibacterial activity

Recently, nanozyme have emerged as promising direction for chemical sensing, biomedicine, environmental monitoring. However, the novel nanozyme with better catalytic activity and specificity is urgently required realized great application performance. Herein, Fe doped carbon dots (Cit-Fe-CDs) with peroxidase (POD) like activity are synthesized by hydrothermal treatment of ferric ammonium citrate. Due to the strong coordination capacity between Fe(Ⅲ) and citric acid, the Cit-Fe-CDs exhibited excellent POD activity. Namely the catalytic constant (Kcat) and catalytic efficiency (Kcat /Km) are determined, which are much higher than previous work. Highly effective colorimetric detection of cholesterol in human serum have been realized by the POD activity of Cit-Fe-CDs. Under optimal conditions, the linear range is determined to be 10 and 100 μM with a detection limit (LOD) of 0.061 μM. The LOD is two orders of magnitude lower than most of the existing analysis method. Since substantial amounts of free radicals are involved in the catalytic cycle of POD activity, excellent antibacterial activity against Methicillin-Resistant Staphylococcus aureus (MRSA) should be realized by Cit-Fe-CDs. Notably, about 99.999 % inactivation rate towards MRSA can be realized by 125 μg/mL Cit-Fe-CDs, which showcases promising prospects in addressing bacterial resistance concerns. And we have confirmed that the antibacterials mechanism is related to the generation of hydroxyl radicals by the excellent POD activity of Cit-Fe-CDs.

Development and characterization of multifunctional fish gelatin composite films reinforced with ε‐polylysine and zinc oxide nanoparticles

AbstractActive compounds were usually incorporated into biopolymer films to enhance their properties. The tensile strength (TS) and elongation at break (EAB) of the gelatin composite films increased along with the addition of ε‐polylysine (ε‐PL) and zinc oxide nanoparticles (nano‐ZnO). When the concentrations of ε‐PL and nano‐ZnO were 4% and 0.5%, TS and EAB reached to the maximum which were 53.98 ± 2.61 MPa and 16.05 ± 1.76%. The water vapor permeability, water solubility, and water content of the composite films decreased from 2.01 ± 0.04 10−10 g m−1 Pa−1 s−1 to 1.56 ± 0.07 × 10−10 g m−1 Pa−1 s−1, from 45.23 ± 1.54% to 31.39 ± 1.24% and from 23.89 ± 1.41% to 17.34 ± 2.61%, respectively, compared with gelatin film. The light barrier capacity of the composite film was improved. The surface of the film was relatively smooth, and the cross‐section was overall flat. FTIR results indicated that no chemical reaction occurred among ε‐PL, nano‐ZnO and gelatin. The chemical structure of the films remained unchanged throughout the heat‐sealing process. Moreover, the gelatin films containing ε‐PL and nano‐ZnO showed excellent antibacterial activity. Our findings suggest that the gelatin composite films with antibacterial property hold promise for the application in food packaging materials.

Ultrasonic assisted green synthesis of CuO nanoparticles: a real catalytic and antimicrobial agent

ABSTRACT This study reported facile biosynthesis of CuO nanoparticles employing leaf extract of Prosopis glandulosa as a stabilising agent by modest ultrasonic assisted technique. The synthesised nanoparticles were characterised via greatly refined systems comprising UV-visible, FTIR, XRD, SEM EDX, Zeta sizer, and Zeta potential. These facilities triggered the study of optical, functionality, crystallinity, surface morphology, elemental composition, and surface potential of the synthesised nanoparticles. The SEM and FT-IR analysis confirmed the semi-spherical shapes and functionalities of the synthesised NPs respectively. The zeta size and zeta potential of CuO NPs were established to be 65 nm and −1.42 mV respectively. The resultant NPs were applied as an efficient antimicrobial and catalytic candidate for the successful degradation of Eriochrome Black T (EBT) dye. Various factors were optimised such as dose, time, and NaBH4 concentration to achieve maximum catalytic efficiency of CuO nanoparticles. The NPs show excellent catalytic performance of about 92% degradation of EBT within 30 minutes. The antimicrobial performance was also tested by varying the concentration of NPs (250, 500, 1000, and 2000 g/mL via disc diffusion protocol. The results show that CuO NPs have excellent antibacterial activity alongside E. coli at MIC values of 250 g/mL as equated to S. areas and Aspergillus niger.

The Optimization of the Synthesis of Antibacterial Coatings on Ti6Al4V Coupons Obtained by Electron Beam Melting

Prosthetic joint infection represents a problem that worsens the patient’s quality of life and produces an economic impact on health systems. We report the anodization of Ti6Al4V coupons obtained by electron beam melting to produce a nanostructured surface. Anodization at 10 V produced TiO2 nanopores with a diameter in the range of 15–20 nm. Thereafter, Ag nanoparticles (AgNPs) were deposited in three different ways to provide antibacterial functionality to the coatings: electrochemically, thermally, and chemically. The electrochemical method did not provide good coverage of AgNPs. At 0.1 V of synthesis potential, cubic, octahedral, and truncated octahedral Ag crystals were obtained. The thermal method provided a good distribution of AgNPs but it damaged the TiO2 nanostructure. The chemical method showed the best distribution of AgNPs over the anodized surface and preserved the anodized nanostructure. For this reason, the chemical method was selected to perform further studies. Ag+ release was monitored in simulated body fluid at 37 °C, reaching 1.86 mg Ag+/L after 42 days. The antibacterial coating showed excellent antibacterial activity and inhibited biofilm formation for Staphylococcus epidermidis RP62A and Staphylococcus aureus V329 strains (lethality &gt; 99.9% for both bacteria and assays).

Synthesis, Antimicrobial Evaluation, and In Silico Studies of 2-Substituted-Phenyl-3-(5-Aryl/Heteroaryl Substituted Thiazol-2-yl) Thiazolidin-4-One Derivatives.

In a one-pot reaction involving 3-(2-aminothiazol-5-yl)-2H-chromen-2-one/5-(naphthalen-1-yl)thiazol-2-amines 5-6 with various substituted aldehydes and mercaptoacetic acid, we obtained the corresponding 2-(4-substituted-phenyl)-3-[5-(2-oxo-2H-chromen-3-yl)thiazol-2-yl] thiazolidin-4-ones 8(a-h) and 2-(4-substituted-phenyl)-3-[5-(naphthalen-1-yl)thiazol-2-yl] thiazolidin-4-ones 9(a-h). The antimicrobial activity of all compounds was evaluated against Pseudomonas aeruginosa (MTCC-424), Salmonella typhi (MTCC-531), Staphylococcus aureus (MTCC-737), and Candida albican (MTCC-227). Molecular docking further supported the findings, which showed that the compounds 8d and 9d had excellent antibacterial action against all tested pathogens.

Synthesis and Biological Evaluation of Novel Coumarin Derivatives Bearing a Sulfonamide Moiety as Antiviral and Antibacterial Agent

AbstractTwenty novel 4-bromocoumarin derivatives bearing a sulfonamide moiety were designed and synthesized. Their antiviral and antibacterial activities were systematically evaluated. The test results show that all the target compounds possess moderate to excellent antiviral and antibacterial activities. Among all target compounds, one compound exhibited good antiviral activity against TMV, CMV, and PVY, which is superior to ribavirin. Moreover, two target compounds exhibited good in vitro antibacterial activity against Psa, with an EC50 value of 44.9 mg/L and 49.3 mg/L, respectively, which were better than thiodiazole copper and zinc thiazole, with an EC50 value of 56.3 mg/L and 50.2 mg/L, respectively. The results provide insights for the development of multifunctional pesticides.

Florfenicol core–shell composite nanogels as oral administration for efficient treatment of bacterial enteritis

To reduce the bitterness of florfenicol, avoid its degradation by gastric acid, and enhance its antibacterial activity against Escherichia coli by targeting and slowly releasing drugs at the site of intestinal infection, with pectin as an anion carrier and chitosan oligosaccharides (COS) as a cationic carrier, florfenicol-loaded COS@pectin core nanogels were self-assembled by electrostatic interaction and then encapsulated in sodium carboxymethylcellulose (CMCNa) shell nanogels through the complexation of CMCNa and Ca2+ to prepare florfenicol core–shell composite nanogels in this study. The florfenicol core–shell composite nanogels were investigated for their formula choice, physicochemical characterization, pH-responsive performances, antibacterial activity, therapeutic efficacy, and in vitro and in vivo biosafety studies. The results indicated that the optimized formula was 0.6 g florfenicol, 0.79 g CMCNa, 0.30 g CaCl2, 0.05 g COS, and 0.10 g pectin, respectively. In addition, the mean particle diameter, polydispersity index, zeta potential, loading capacity, and encapsulation efficiency were 124.0 ± 7.2 nm, –22.9 ± 2.5 mV, 0.42 ± 0.03, 43.4 % ± 3.1 %, and 80.5 % ± 3.4 %, respectively. The appearance, lyophilized mass, resolvability, scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and fourier transform infrared (FTIR) showed that the florfenicol core–shell composite nanogels were successfully prepared. Florfenicol core–shell composite nanogels had satisfactory stability, rheology, and pH-responsiveness, which were conducive to avoid degradation by gastric acid and achieve targeted and slow release at intestinal infection sites. More importantly, florfenicol core–shell composite nanogels had excellent antibacterial activity against Escherichia coli, a satisfactory therapeutic effect, and good palatability. In vitro and in vivo biosafety studies suggested the great promise of florfenicol core–shell composite nanogels. Therefore, the prepared florfenicol core–shell composite nanogels may be helpful for the treatment of bacterial enteritis as a biocompatible oral administration.

Development of narrow-spectrum topoisomerase-targeting antibacterials against mycobacteria

New 2-pyrrolamidobenzothiazole-based inhibitors of mycobacterial DNA gyrase were discovered. Among these, compounds 49 and 51, show excellent antibacterial activity against Mycobacterium tuberculosis and Mycobacterium abscessus with a notable preference for mycobacteria. Both compounds can penetrate infected macrophages and reduce intracellular M. tuberculosis load. Compound 51 is a potent inhibitor of DNA gyrase (M. tuberculosis DNA gyrase IC50 = 4.1 nM, Escherichia coli DNA gyrase IC50 of <10 nM), selective for bacterial topoisomerases. It displays low MIC90 values (M. tuberculosis: 0.63 μM; M. abscessus: 2.5 μM), showing specificity for mycobacteria, and no apparent toxicity. Compound 49 not only displays potent antimycobacterial activity (MIC90 values of 2.5 μM for M. tuberculosis and 0.63 μM for M. abscessus) and selectivity for mycobacteria but also exhibits favorable solubility (kinetic solubility = 55 μM) and plasma protein binding (with a fraction unbound of 2.9 % for human and 4.7 % for mouse). These findings underscore the potential of fine-tuning molecular properties to develop DNA gyrase B inhibitors that specifically target the mycobacterial chemical space, mitigating the risk of resistance development in non-target pathogens and minimizing harm to the microbiome.

Tailoring zirconia surface topography via femtosecond laser-induced nanoscale features: effects on osteoblast cells and antibacterial properties

The performance and long-term durability of dental implants hinge on the quality of bone integration and their resistance to bacteria. This research aims to introduce a surface modification strategy for zirconia implants utilizing femtosecond laser ablation techniques, exploring their impact on osteoblast cell behavior and bacterial performance, as well as the integral factors influencing the soft tissue quality surrounding dental implants. Ultrafast lasers were employed to craft nanoscale groove geometries on zirconia surfaces, with thorough analyses conducted using x-ray diffraction, scanning electron microscopy, atomic force microscopy, and water contact angle measurements. The study evaluated the response of human fetal osteoblastic cell lines to textured zirconia ceramics by assessing alkaline phosphatase activity, collagen I, and interleukin 1βsecretion over a 7 day period. Additionally, the antibacterial behavior of the textured surfaces was investigated usingFusobacterium nucleatum, a common culprit in infections associated with dental implants. Ciprofloxacin (CIP), a widely used antibacterial antibiotic, was loaded onto zirconia ceramic surfaces. The results of this study unveiled a substantial reduction in bacterial adhesion on textured zirconia surfaces. The fine biocompatibility of these surfaces was confirmed through the MTT assay and observations of cell morphology. Moreover, the human fetal osteoblastic cell line exhibited extensive spreading and secreted elevated levels of collagen I and interleukin 1βin the modified samples. Drug release evaluations demonstrated sustained CIP release through a diffusion mechanism, showcasing excellent antibacterial activity against pathogenic bacteria, includingStreptococcus mutans, Pseudomonas aeruginosa, andEscherichia coli.

Advanced Functional Photochromic Wearables with Superior Durability and Stability for Sustainable Applications

AbstractThe rewritable wearables based on photochromism have emerged as attractive candidates in inkless printing applications. Among various photochromic materials, polyoxometalates have great potential for rewritable wearables, with major advantages in fast response upon UV irradiation, long‐term photochemical stability, and excellent fatigue resistance. However, the development of rewritable wearables based on polyoxometalates is limited by low combining fastness, weak stability, and poor scalability. Here, a scalable strategy is reported to fabricate an ideal rewritable wearable based on fundamental charge balance mechanism. The pristine cotton substrate is grafted by cationic polymer brushes to incorporate photochromic phosphomolybdic acid (PMoA) anions through electrostatic attraction, and then the cationic surfactants with alkyl chains are introduced to encapsulate the PMoA anions to achieve charge balance subsequently. The resultant rewritable wearables display the long‐awaited properties, such as high color contrast, favorable reversibility (&gt;10 cycles), long color retention (&gt;15 days) and high stability against detergent and sweat (pH 6.5–8.0) during repeated washing (50 cycles) and wearing. As a demonstration, a rewritable T‐shirt is scalably fabricated, and excellent antibacterial activity and biocompatibility are demonstrated as well, which is expected to be a sustainable solution for regular fabric printing in household products and public display.

Isolation and chemical immobilization of E. coli‐specific bacteriophage with NH2‐MIL‐101(Fe) MOF, a high photoluminescence rod‐shaped microcrystals for low‐level bacteria detection

As concern raised by the World Health Organization (WHO) of antibiotic‐resistant and bio‐defensive bacteria, a metal–organic framework (MOF) based optical biosensor came into consideration for precise, quick, and sensitive detection of Escherichia coli (E. coli) (ATCC 10799) using bacteriophage as a bio‐recognition element. In the present study, amine‐functionalized Fe‐based MOF, i.e., NH2‐MIL‐101(Fe), was synthesized by the solvothermal method (approx. 531–1106 nm in size and 20 mV zeta potentials by DLS) and further characterized by SEM, XRD, ATR‐FTIR, UV–VIS, and photoluminescent (PL) spectroscopy. The lytic bacteriophage was isolated from a sewage sample, purified, and concentrated using the ultra‐centrifugation method and achieved a high titer of 7.3 × 1012 PFU/ml. The concentration, stability, and accessible receptor binding domains (RBDs) of the biorecognition element for binding with their analytes play an important role in developing sensitive and specific biosensor systems. To fulfill the mentioned criteria, optimized glutaraldehyde concentration was estimated at 0.25%, at 30 °C for conjugating maximum bacteriophage titer of 8.6 × 105 PFU/ml for each 1 mg amine functionalized iron‐based MOF. The synthesized detection probe has shown excellent photoluminescence and antibacterial activity and achieved a detection limit of 652 CFU/ml over a bacterial detection concentration range from 5.78 × 101 to 5.78 × 106 CFU/ml for E. coli with 10–12 min of response time, high specificity, and long‐term stability even at room temperature. Therefore, it can be inferred that this MOF‐based strategy can be helpful in the specific and sensitive detection of various bacterial pathogens using bacteriophage as a bio‐recognition element.

Enzyme‐Responsive Polyion Complex Nanoparticles of Cationic Antimicrobials for Activatable Antibacterial Therapy

AbstractA self‐assembled “caging” strategy is presented for the safe delivery of potent cationic antimicrobials that suffer from non‐specific toxicity for the effective treatment of in vivo systemic bacterial infection. The key development here is a new block copolymer consisting of a poly(ethylene glycol) (PEG) stealth block and an anionic and lipase‐degradable block of poly(ɛ‐caprolactone) (PCL) and phosphonic acid‐bearing methacrylate copolymer, synthesized by hybrid copolymerization of methacrylate and cyclic esters. The anionic blocks electrostatically interact with cationic antimicrobials to form neutrally charged polyion complexes with the PEG blocks on the surface. The PCL component imparts the nanocomplex with biodegradability by bacterial secretory lipase. In the proof‐of‐concept study, cationic polyimidazolium that shows excellent antibacterial activity but severe toxicity is packaged by the block copolymer into nanocomplexes, which are stable in complex environments of high salt and protein concentrations and released the antimicrobials upon degradation of the copolymer by bacteria‐secreted lipase. The “caging” formulation of polyimidazolium eliminated its toxicity and led to highly effective bactericidal performance comparable to free polyimidazolium. This caging strategy does not require sophisticated chemical modification of cationic antimicrobials, offering a broadly applicable formulation strategy to overcome their common toxicity issue that has become a primary translational barrier.

Synthesis of Copper Oxide Nanoparticles Using Leaf Extracts of Dillenia Indica and Mikania Micrantha: Investigation of their Potential as Photocatalysts and Antibacterial Agents

AbstractThe fields of biomedicine and catalysis have both shown a great deal of interest in copper oxide nanoparticles (CuONPs). Green synthesis methods are being frequently employed to develop highly active CuONPs. This research investigates the potential photocatalytic and antibacterial applications of two CuONPs that were synthesized utilizing extracts from Dillenia indica (D‐CuONPs) and Mikania micrantha (M‐CuONPs) leaves. Analysis using electron microscopy revealed that CuONPs are uniformly spherical and average size around 15 nm. The development of single‐phase CuONPs with a monoclinic structure is shown by X‐ray diffraction studies. The FTIR peaks at 695 cm−1 and 860 cm−1 represent a stretching of Cu−O, signifying the formation of CuO nanostructure. The EDX profiles stated that the CuONPs are correlated with compliantly intensified Cu and O signals. Under solar irradiation, around 90 % of congo red (CR) dye was degraded by both CuONPs in 120 min, with the rate constants of 0.0187 and 0.0174 min−1, respectively. Furthermore, CuONPs have excellent antibacterial activity against bacteria belonging to both Gram classes. Overall, CuONPs hold great potential for inhibiting the growth of pathogenic bacteria and for degrading organic dyes in the presence of sunlight. As such, they can be manufactured on a large scale using plant sources.

Fabrication of metal-organic frameworks containing Cu2+ coated medical PVC catheters with durable antiplatelet and antibacterial activities

Polyvinyl chloride (PVC) catheters are widely used in medical environments especially in blood-contacting devices. In this study, a copper containing MOF material was coated on a PVC catheter to endow it with antiplatelet adhesion and antibacterial activity for potential clinical applications. The immobilization of the coordination polymer containing Cu2+ (Cu-MOF) on the inner surface of PVC catheters was carried out using a bioinspired coating combined with a layer-by-layer self-assembly strategy. Characterization of the Cu-MOF modified surfaces was confirmed using micro-infrared spectroscopy (MIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and water contact angle measurements (WCA). The resultant modified surfaces significantly reduced non-specific adsorption to model proteins with excellent anti-biofouling activity, as well as significantly inhibited the platelet adhesion and activation with superior antiplatelet activity. In vitro whole blood circulation test using a peristaltic pump also showed good antithrombotic properties. Besides, the Cu-MOF modified surfaces exhibited good hemocompatibility (hemolysis ratio < 5 %) and excellent antibacterial activity (approximately 97 % against S. auerus and E. coli). This study develops a simple and effective method for the surface modification of medical PVC catheter as potential blood-contacting biomaterials.

Stepwise co-assembled biomimetic hydrogel with antibacterial, angiogenesis, and tissue regeneration acceleration for diabetic wound healing

Bacterial infections and inadequate tissue regeneration capacity are prevalent issues in diabetic wounds, impeding the healing process. To solve these problems, a biomimetic hydrogel combined with bacterial cellulose (BC), recombinant human collagen type III (RHC), and ε-poly-L-Lysine (EPL) is fabricated by stepwise co-assembly technology. Owing to the RHC and EPL modifications of BC, the biomimetic hydrogel exhibited antibacterial effects and promoted fibroblast proliferation and angiogenesis, which accelerated the healing of diabetic wounds. Biomimetic hydrogels exhibit good mechanical properties and excellent water absorption, that can protect wounds and provide a moist environment. In addition, in vitro studies have shown that the hydrogels exhibit excellent antibacterial activity and biocompatibility. In vivo studies on diabetic wound healing have shown that biomimetic hydrogels can promote angiogenesis, accelerate collagen deposition, and re-epithelialize wound sites to promote wound healing. This study provides a new and promising strategy for the treatment of diabetic wounds.

Probiotic characteristics and whole genome sequence analysis of Lactiplantibacillus plantarum ZFM518 isolated from infant feces

AbstractEmerging research has shown that lactic acid bacteria in the intestines of newborns play a beneficial role in the growth, immune function, and metabolism of infants after birth. In this study, four strains of Lactobacillus were isolated from fecal samples of newborns, and a safe Lactiplantibacillus plantarum ZFM518 (ZFM518) strain was obtained after the screening, which showed excellent antibacterial activity and adhesion potential. The strain exhibited excellent ability to survive in acidic environments, simulated gastric juice, and simulated intestinal environments, respectively. ZFM518 had a bacteriostatic zone of 31.12 ± 0.33 mm against Staphylococcus aureus, a hydrophobic rate of 76.97% ± 3.35%, and a survival activity of 96.54% ± 0.14% under a simulated intestinal fluid environment. Moreover, ZFM518 can produce up to 161.11 ± 9.67 ng/mL of folate. A genome‐wide investigation of ZFM518 revealed that the majority of its genes were involved in the metabolism of amino acids, carbohydrates, adhesion, immunological defense, and antibacterial activity. In addition, only one antibiotic resistance gene of the antimicrobial peptide was annotated. These results indicate that ZFM518 is a new strain with a strong comprehensive ability and probiotic potential. This study can provide practical support for screening potential probiotics from infant feces and provide a theoretical basis for developing probiotic resources.

Novel trans-Resveratrol Derivatives: Design, Synthesis, Antibacterial Activity, and Mechanisms.

Rice bacterial leaf blight and rice bacterial leaf streak have induced tremendous damage to production of rice worldwide. To discover an effective novel antibacterial agent, a series of novel trans-resveratrol (RSV) derivatives containing 1,3,4-oxadiazole and amide moieties were designed and synthesized for the first time. Most of them showed excellent antibacterial activities against Xanthomonas oryzae pv oryzicola and Xanthomonas oryzae pv oryzae. Especially, compound J12 had the best inhibitory with the half-maximal effective concentration values of 4.2 and 5.0 mg/L, respectively, which were better than that of RSV (63.7 and 75.4 mg/L), bismerthiazol (79.5 and 89.6 mg/L), and thiodiazole copper (105.4 and 112.8 mg/L). Furthermore, compound J12 had an excellent control effect against rice bacterial leaf streak and rice bacterial leaf blight, with protective activities of 46.2 and 42.1% and curative activities of 44.5 and 41.7%, respectively. Preliminary mechanisms indicated that compound J12 could not only remarkably decrease biofilm formation, extracellular polysaccharide production, and the synthesis of extracellular enzymes but also destroy bacterial cell surface morphology, thereby reducing the pathogenicity of bacteria. In addition, compound J12 could increase the activity of defense-related enzymes and affect the expression of multiple pathogenic-related genes including plant-pathogen interaction, the MAPK signaling pathway, and phenylpropanoid biosynthesis, and this could improve the defense of rice against rice bacterial leaf streak infection. The present work indicates that the RSV derivatives can be used as promising candidates for the development of antibacterial agents.