High Adhesion Ability Research Articles

Comparative genomic analysis of pathogenic factors of Listeria spp. using whole-genome sequencing

Listeria monocytogenes is an important foodborne pathogen known for causing listeriosis. To gain insights into the pathogenicity, genetic characterization, and evolution of various Listeria species, in vitro cell adhesion and invasion ability assays and whole-genome sequencing were performed using four Listeria strains isolated from livestock and poultry slaughterhouses. The four Listeria strains exhibited adhesion and invasion abilities in Caco-2 and RAW264.7 cells. Pathogenic Liv1-1 and Lm2-20 had higher adhesion ability, but non-pathogenic Lin4-99 was more invasive than Lm2-20 (p < 0.05). Genetic characterization revealed the presence of a single chromosome without plasmid across four strains with similar whole-genome sizes and G + C% content. Analysis of key pathogenic genes underscored the presence of multiple virulence genes among the four Listeria strains. In contrast, non-pathogenic Listeria lacked LIPI-1, LIPI-2, and LIPI-3 genes, which could possibly be the cause of their non-pathogenicity despite their in vitro cell adhesion and invasion abilities. Thus, genetic determinants of Listeria do not necessarily predict cell adhesion and/or invasive ability in vitro. This study presents a comprehensive comparative genome-wide analysis of four Listeria strains, offering invaluable insights into the pathogenesis of the Listeria genus.

Effect of surface textures fabricated by two-dimensional ultrasonic vibration-assisted milling on the key surface properties of dental ceramics

The exceptionally high hardness and active plaque adhesion ability of 3Y-TZP ceramics often cause lots of oral diseases. This work intends to enhance the service performance of such ceramic dentures in human oral cavity by surface texturing technique. Efforts have been made to tackle the surface texture formation mechanism under 2D-UVAM process and establish the connection between the key surface properties and texture morphologies. The impacts of cutting parameters, vibration parameters, and tool geometry parameters on texture morphologies were rigorously studied. The coupling effect of wettability, antibacterial activity, and frictional performance of textured ceramic surfaces was also investigated. The acquired results indicate that the fish-scale texture with high density helps to enhance the hydrophobicity of the zirconia ceramics, while the wavy texture with low density promotes the ceramic material towards a hydrophilic direction. The antibacterial activity is highly related to wettability. The larger contact angle generally means the more pronounced inhibition effect on plaque adhesion. The wear of natural teeth decreases significantly after introducing textures on the ceramic surfaces, but the wear amount is not sensitive to wettability. Therefore, the hydrophobic surface can simultaneously improve the antibacterial characteristics of 3Y-TZP ceramics and its tribological compatibility with the natural teeth.

Multi-functional properties of lactic acid bacteria strains derived from canine feces.

Probiotics, especially Lactic Acid Bacteria (LAB), can promote the health of host animals in a variety of ways, such as regulating intestinal flora and stimulating the host's immune system. In this study, 206 LAB strains were isolated from 48 canine fecal samples. Eleven LAB strains were selected based on growth performance, acid and bile salt resistance. The 11 candidates underwent comprehensive evaluation for probiotic properties, including antipathogenic activity, adhesion, safety, antioxidant capacity, and metabolites. The results of the antipathogenic activity tests showed that 11 LAB strains exhibited strong inhibitory effect and co-aggregation ability against four target pathogens (E. coli, Staphylococcus aureus, Salmonella braenderup, and Pseudomonas aeruginosa). The results of the adhesion test showed that the 11 LAB strains had high cell surface hydrophobicity, self-aggregation ability, biofilm-forming ability and adhesion ability to the Caco-2 cells. Among them, Lactobacillus acidophilus (L177) showed strong activity in various adhesion experiments. Safety tests showed that 11 LAB strains are sensitive to most antibiotics, with L102, L171, and L177 having the highest sensitivity rate at 85.71%, and no hemolysis occurred in all strains. Antioxidant test results showed that all strains showed good H2O2 tolerance, high scavenging capacity for 1, 1-diphenyl-2-trinitrophenylhydrazine (DPPH) and hydroxyl (OH-). In addition, 11 LAB strains can produce high levels of metabolites including exopolysaccharide (EPS), γ-aminobutyric acid (GABA), and bile salt hydrolase (BSH). This study provides a thorough characterization of canine-derived LAB strains, highlighting their multifunctional potential as probiotics. The diverse capabilities of the strains make them promising candidates for canine dietary supplements, offering a holistic approach to canine health. Further research should validate their efficacy in vivo to ensure their practical application.

Research on improving the efficiency of electricity transmission

A study of ways to modernize the current-carrying part of overhead lines to improve the efficiency of electricity transmission through the use of innovative types of wires was conducted. The technical and economic characteristics of AC, ACCR, and AERO-Z wires were analyzed. The results of the analysis revealed that further improvement of the design of AC wires should be based on new progressive developments that would meet such technical requirements as reliability, survivability and durability; corrosion resistance; high adhesion ability; resistance to vibration during operation under the influence of adverse climatic factors; resistance to environmental temperature effects. As an innovative solution to this issue, high-temperature (ACCR) and specially designed (AERO-Z) wires have been developed in foreign countries. A comparative analysis of the types of wires used in Ukrainian power grids with innovative types of wires used in power grids of foreign countries was performed. The results of the comparison of AC, ACCR, and AERO-Z wires show that the factor that limits the scope of application of ACCR wire, even for spans with extremely high requirements for power transmission characteristics, is its extremely high cost. This is because the technical characteristics of this wire are better than those of AC wire and it has a relatively low cost compared to ACCR wire, and its special design is adapted to adverse climatic conditions that affect the characteristics of electricity transmission.

A facile dip-coating approach to prepare robust superhydrophobic fabric modified by γ-Fe2O3/epoxy resin/lauric acid for oil/water separation, lossless water transportation, and flame retardancy

A facile approach to prepare superhydrophobic fabric with high adhesive ability towards water droplets was developed via a simple dip-coating method. Immersing the cotton fabric (CF) into the γ-Fe2O3/epoxy resin/lauric acid (FEL) suspension for several minutes, followed by heat curing at 80 °C for 2 h, the superhydrophobic fabric (CF-FEL) was obtained. The quality ratio of γ-Fe2O3 to epoxy resin effect on superhydrophobicity of°F-FEL was discussed. The water contact angle was 156° when 0.15 g γ-Fe2O3 particles were applied. Based on the sticky water adhesion, the CF-FEL could be utilized to realize the transportation of water droplet without mass loss. Meanwhile, due to the capillary force and stagger fibers, the CF-FEL exhibited excellent separation flux and efficiency to separate heavy oil/water mixtures. The mechanical durability of the CF-FEL was also evaluated through tape peeling and rubbing test, which further indicated the feasibility of practical application. Moreover, the CF-FEL showed superior flame retardancy because it inherited the thermal stability property of epoxy resin and γ-Fe2O3 particles. Thus, the prepared CF-FEL is multifunctional and the preparation method is facile and environmentally friendly.

Bacterial contamination in neonatal intensive care units in Misurata, Libya: analysis of causative organisms, biofilm formation, and antimicrobial susceptibility

Abstract Background: Intensive care units (ICUs) play a critical role in treating life-threatening conditions. The presence of bacteria on objects and instruments in ICUs is a significant cause of hospital-acquired infections. Aim: This study aimed to assess the level of bacterial contamination on objects and instruments frequently touched by healthcare workers (HCWs) and in contact with neonates. Resistance profile and biofilm producibility were also measured. Methods: A total of 150 swabs were collected from various surfaces in the neonatal intensive care units (NICU) of three hospitals in the city of Misurata, Libya. These samples formed the basis of the study. Standard techniques were used to isolate, identify, and determine biofilm formation ability and antibiotic susceptibility of the bacterial isolates. Results: Out of the 150 samples, bacterial growth was observed in 100. The most commonly isolated potential pathogens were Pseudomonas aeruginosa at a rate of 31.33%, followed by Klebsiella pneumonia (18%), Staphylococcus aureus (9.33%), E. coli (4.66%), and finally Acinetobacter baumanni (3.33%) of the total swabs taken. Bed, ICU floor, doorknob, ICU window, and CPAP were the main sources of bacterial contamination in the ICU unit. Among the S. aureus isolates, 50% (7 out of 14) were found to be methicillin resistant. Most of the bacterial isolates showed resistance to Cefotaxime and Augmentin. The gram-negative bacteria showed high adhesion ability (70.9 %) significantly (P= 0.035) more than S. aureus isolates (35.7%). Conclusion: The study revealed a high level of bacterial contamination on objects and instruments in the NICU. The isolated pathogens like Pseudomonas aeruginosa, Klebsiella pneumonia, S. aureus and Acinetobacter baumanni pose a significant risk of hospital-acquired infections. The extremely high prevalence of beta-lactam antibiotics resistance among isolated bacteria accounts for a great public health danger.

Self-Healable Adhesive Hydrogel with a Preserved Underwater Adhesive Ability Based on Histidine-Zinc Coordination and a Bioengineered Hybrid Mussel Protein.

Mussels are marine organisms that are capable of constructing an underwater adhesion between their bodies and rigid structures. It is well known that mussels achieve underwater adhesion through the presence of mussel adhesive proteins (MAPs) that contain high levels of 3,4-dihydroxyphenylalanine (DOPA). Although the extraordinary underwater adhesive properties of mussels are attributed to DOPA, its capacity to play a dual role in surface adhesion and internal cohesion is inherently limited. However, mussels employ a combination of chemical moieties, not just DOPA, along with anatomical components, such as plaque and byssus, in underwater adhesion. This also involves junction proteins that connect the plaque and byssus. In this study, a novel hybrid MAP was bioengineered via the fusion of the plaque protein (foot protein type 1) and the histidine-rich domain of the junction protein (foot protein type 4). To achieve direct adhesion underwater, the adhesive should maintain surface adhesion without disintegrating. Notably, the histidine-Zn-coordinated hybrid MAP hydrogel maintained a high surface adhesion ability even after cross-linking because of the preservation of its unoxidized and non-cross-linked DOPA moieties. The formulated adhesive hydrogel system based on the bioengineered hybrid MAP exhibited self-healing properties, owing to the reversible metal coordination bonds. The developed adhesive hydrogel exhibits outstanding levels of bulk adhesion in underwater environments, highlighting its potential as an effective adhesive biomaterial. Therefore, the introduction of histidine-rich domains into MAPs may be applied in various studies to formulate mussel-inspired adhesives with self-healing properties and to fully utilize the adhesive ability of DOPA.

Highly Adhesive and Self-Healing Zwitterionic Hydrogels as Antibacterial Coatings for Medical Devices.

Bacterial infection of medical devices has caused incalculable losses to maintenance costs and health care. A single coating with antibacterial function cannot guarantee the long-term use of the device, because the coating will be damaged and fall off during reuse. To solve this problem, the development of coatings with high adhesion and self-healing ability is a wise direction. In this paper, a multifunctional polyzwitterionic antibacterial hydrogel coating (PZG) composed of amphozwitterion monomer, anionic monomer, and quaternary ammonium cationic monomer was synthesized by dipping UV photoinitiated polymerization. The structure of PZGs was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Ascribing to the hydrogel internal electrostatic interaction, hydrogen bond, and cation-π interaction, the obtained PZGs exhibited high ductility (>1200% strain) and appropriate strength (>189 kPa). Remarkably, PZGs could also adhere firmly on different substrates through noncovalent interaction, and their adhesion could be controlled by adjusting the amount of zwitterionic. Reversible physical interactions in polymer networks endowed hydrogels with excellent self-healing properties. In addition, PZGs exhibit good antibacterial activity and biocompatibility due to the synergistic effect of quaternary ammonium cation and amphozwitterion monomer. This work provides a multifunctional antibacterial coating for medical equipment and has broad application prospects in the biomedical field.

Roles of luxS in regulation of probiotic characteristics and inhibition of pathogens in Lacticaseibacillus paracasei S-NB

Lactic acid bacteria (LAB) have excellent tolerance to the gastrointestinal environment and high adhesion ability to intestinal epithelial cells, which could be closely related to the LuxS/AI-2 Quorum sensing (QS) system. Here, the crucial enzymes involved in the synthesis of AI-2 was analyzed in Lacticaseibacillus paracasei S-NB, and the luxS deletion mutant was constructed by homologous recombination based on the Cre-lox system. Afterwards, the effect of luxS gene on the probiotic activities in L. paracasei S-NB was investigated. Notably, the tolerance of simulated gastrointestinal digestion, AI-2 production, ability of auto-aggregation and biofilm formation significantly decreased (p < 0.05 for all) in the S-NB△luxS mutant. Compared to the wild-type S-NB, the degree of reduction in the relative transcriptional level of the biofilm -related genes in Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923 was diminished when co-cultured with S-NB△luxS. Furthermore, the inhibitory effect of S-NB△luxS on the adhesion (competition, exclusion and displacement) of E. coli ATCC 25922 and S. aureus ATCC 25923 to Caco-2 cells markedly decreased. Therefore, comprehensive analysis of the role by luxS provides an insight into the LuxS/AI-2 QS system of L. paracasei S-NB in the regulation of strain characteristics and inhibition of pathogens.

Isolation, Characterization and Therapeutic Evaluation of Lactic Acid Bacteria from Traditional and Non-Traditional Sources

ABSTRACT Probiotics from non-traditional sources (nondairy and non-intestinal) have better potential of surviving in the nondairy based foods that are required to overcome the limitations of dairy-based (traditional) probiotic products. This study aimed to evaluate the probiotic potential of lactic acid bacteria isolated from traditional and non-traditional sources in vitro. Thirteen isolates were evaluated for their probiotic properties, including survival under harsh conditions, antimicrobial activity, cell surface hydrophobicity, auto-aggregation and safety. Nondairy isolates (Limosilactobacillus fermentum AIFe1, Pediococcus pentosaceus BRDb27, Lactiplantibacillus plantarum ACFe58 and Lactiplantibacillus plantarum KCFe63) and dairy isolate (Limosilactobacillus fermentum NCCu21) exhibited excellent beneficial properties. Isolate KCFe63 showed good antioxidant potential (66.91% ± 0.02) and cholesterol assimilation (81.48% ± 0.07), while isolate BRDb27 displayed high adhesion ability (77.98% ± 0.71) toward HT-29 cells whereas isolate ACFe58 revealed antiproliferative effects against MCF-7 cells (40.55% ± 0.15 cell survival). These findings suggest that the non-traditional isolates are promising probiotic candidates and can be further explored for commercialization.

Transcriptomics reveals the mechanism of high-adhesive Bacillus subtilis inhibiting fresh fish spoilage

Aquatic products are highly susceptible to spoilage caused by adherence of spoilage bacteria during storage, so it is crucial to develop new microecological preservatives. The probiotic B. subtilis can achieve potential preservation effects by adhering to the fish gut to regulate the amount of probiotic colonization in the flora. Here, we demonstrated the surface adhesion characteristics of B. subtilis and the mechanism of adhesion-associated gene-mediated adhesion; the regulation of B. subtilis adhesion ability by nitrogen and carbon sources, and the application of tilapia preservation. Our results revealed 10 B. subtilis adhesion-related genes, among which nitrogen sources up-regulate the adhesion genes hag and motA, carbon sources up-regulate sinR and fliG. Based on flagellum-associated high adhesion strain C6 and high adhesion regulation of B. subtilis C6_H allowed the abundance of probiotic bacteria Bacillus, Rhodobacteraceae to increase, attenuate the content of spoilage flavor substances such as 1-Octen-3-ol, 15-Crown-5 and maintain the freshness of tilapia. The results helped to reveal the adhesion mechanism of B. subtilis and to develop and apply microecological preservatives with high quality adhesion ability.

Evaluation of probiotic, safety, and technological properties of bacteriocinogenic Enterococcus faecium and Enterococcus faecalis strains isolated from lighvan and koozeh cheeses

The technological, safety, and probiotic properties were determined of fifteen enterocin producing strains of Enterococcus faecium and Enterococcus faecalis isolated from traditional Iranian lighvan and koozeh cheeses. The highest inhibitory activity of the strains was against Escherichia coli (ATCC 25922) and Listeria innocua (ATCC 33090) indicators. Most of the isolates were able to hydrolyse casein, but none showed lipolytic or β-haemolytic properties and only 4 Ent. faecium strains were able to decarboxylate l-histidine or l-ornithine. No strains had ace, cylA, cylB, VanA, and VanB genes. Only the Ent. faecium strains C20, KR34, and LR75 harboured cpd, gelE, and efaAfs genes, respectively. Ent. faecium M9, LR74, KR30, and KR37, which had no virulence genes or antibiotic resistance genes, had desirable technological properties and favourable probiotic properties, showing high survival in digestive conditions, and high adhesion ability to Caco2 epithelial cells correlating to high auto-aggregation.

An Injectable Composite Hydrogel of Verteporfin-Bonded Carboxymethyl Chitosan and Oxidized Sodium Alginate Facilitates Scarless Full-Thickness Skin Regeneration.

Full-thickness skin defect has always been a major challenge in clinics due to fibrous hyperplasia in the repair process. Hydrogel composite dressings loaded with anti-fibrotic drugs have been considered as a promising strategy for scarless skin regeneration. In this work, a hydrogel composite (VP-CMCS-OSA) of carboxymethyl chitosan (CMCS) and oxidized sodium alginate (OSA), with loading anti-fibrotic drug verteporfin (VP), is developed based on two-step chemical reactions. Verteporfin is bonded with carboxymethyl chitosan through EDC/NHS treatment to form VP-CMCS, and then VP-CMCS is crosslinked with oxidized sodium alginate by Schiff base reaction to form VP-CMCS-OSA hydrogel. The characterization by SEM, FTIR, and UV-Vis shows the microstructure and chemical bonding of VP-CMCS-OSA. VP-CMCS-OSA hydrogel demonstrates the properties of high tissue adhesion, strong self-healing, and tensile ability. In the full-thickness skin defect model, the VP-CMCS-OSA composite hydrogels hasten wound healing due to the synergistic effects of hydrogels and verteporfin administration. The histological examination reveals the regular collagen arrangement and more skin appendages after VP-CMCS-OSA composite hydrogel treatment, indicating the full-thickness skin regeneration without potential scar formation. The outcomes suggest that the verteporfin-loaded composite hydrogel could be a potential method for scarless skin regeneration.

MiR-15a nanometric compound restrains the activity and adhesion of Hela cells through survivin signal pathway

We herein studied the mechanism of miR-15a nanometer compound (NMC) by assessing its activity and adhesion in Hela cells through survivin signal pathway. The miR-15a nanometer compound was prepared and Hela-S3 cells were divided into miR-15a group, miR-NC group and NC group for in vitro studies. Proliferative activity was detected with MTT method while invasive ability was detected with Transwell closet method. Adhesive capacity was compared and Survivin and Caspase-3 protein expressions were detected with Western blot assay. Results showed that, grain size of miR-15a NMC was reduced along with increased N/P value, and Zeta potential was negative, and was converted into positive charge along with increased N/P value. The particle size distribution was uniform and potential was moderated when the N/P value was twenty. The proliferation ability and invasive capacity in miR-15a group was reduced significantly along with lower A540 value and higher adhesive ability as well as reduced survivin and increased Caspase-3 level. The proliferative, invasive and adhesive capacity of Hela cells were all restrained by the miR-15a NMC, and apoptosis was prompted through restraining of the survivin signaling pathway, so as to affect the occurrence and development of cervical carcinoma.

Genomic and metabolic properties of Staphylococcus gallinarum FCW1 MCC4687 isolated from naturally fermented coconut water towards GRAS assessment

Staphylococcus gallinarum FCW1 was isolated from naturally fermented coconut-water and identified by biochemical and molecular methods. Probiotic characterization and safety assessment were conducted through a series of in vitro tests. A high survival rate was observed when the strain was tested for resistance to bile, lysozyme, simulated gastric and intestinal fluid, phenol, and different temperature and salt concentrations. The strain showed antagonism against some pathogens, was susceptible to all antibiotics tested except penicillin, and showed no hemolytic and DNase activity. Hydrophobicity, autoaggregation, biofilm formation, and antioxidation tests indicated that the strain possessed a high adhesive and antioxidant ability. Enzymatic activity was used to evaluate the metabolic capacities of the strain. In-vivo experiment on zebrafish was performed to check its safety status. The whole-genome sequencing indicated that the genome contained 2,880,305 bp with a GC content of 33.23%. The genome annotation confirmed the presence of probiotic-associated genes and genes for oxalate degradation, sulfate reduction, acetate metabolism, and ammonium transport in the FCW1 strain, adding to the theory that this strain may be helpful in treating kidney stones. This study revealed that the strain FCW1 might be an excellent potential probiotic in developing fermented coconut beverages and treating and preventing kidney stone disease.

Characterization of adhesion, anti-adhesion, co-aggregation, and hydrophobicity of Helicobacter pylori and probiotic strains

ObjectivesTo characterize the adhesion ability of nine Helicobacter pylori strains and eight probiotics in human oral keratinocyte cells (H357 cells) in comparison to intestinal cells (Caco-2 and HIEC-6 cells). Subsequently, the anti-adhesion and co-aggregation abilities of the selected probiotic strains on H. pylori strains were investigated. MethodsNine H. pylori strains, including H. pylori ATCC43504 (type strain), and 8 clinical strains, were isolated from oral samples of three patients (one non-disease, one gastritis patient, and one gastric cancer patient). Eight selected probiotic strains were used, as follows: Lacticaseibacillus paracasei SD1, Lacticaseibacillus rhamnosus SD4, L. rhamnosus SD11, Limosilactobacillus fermentum SD7, L. rhamnosus GG, Limosilactobacillus reuteri ATCC-PTA6475, Lacticaseibacillus casei Shirota, and L. paracasei CNCM I-1572. The adhesion and anti-adhesion abilities of H. pylori and the probiotic strains were investigated in H357, Caco-2, and HIEC-6 cells. Co-aggregation at various pHs, hydrophobicity, and surface receptors of the cell lines for H. pylori strains were examined. ResultsAll probiotic and H. pylori strains adhered to H357 significantly better than Caco-2, and HIEC-6 cells. Three probiotic strains (SD7, SD4, SD11) showed significantly higher adhesion than others. Of the clinical H. pylori strains, isolates from a gastric cancer patient had the highest adhesion ability to all of the cell lines tested. Probiotic strains that exhibited high adhesion ability provided high anti-adhesion and co-aggregation against H. pylori strains. Acidic conditions encouraged the co-aggregation of probiotics to H. pylori strains. ConclusionThis study provides information relating to the adhesion abilities of clinical H. pylori and probiotic strains to the oral mucosa when compared to the intestinal mucosa. Certain probiotic strains may be useful for the successful eradication of H. pylori infection via anti-adhesion and co-aggregation.

Core/Shell Nitrogen-Doped TiO2@SiO2 Nano-Catalyst as an Additive in Photocatalytic Paint for Gaseous Acetaldehyde Decomposition

A nitrogen-doped TiO2@SiO2 core/shell nano-photocatalyst (N-TiO2@SiO2) was used as an additive in photocatalytic paint and applied for the photocatalytic degradation of gaseous acetaldehyde under light-emitting diode (LED) visible light irradiation. N-TiO2 was synthesised via the solvothermal method and then encapsulated by SiO2 via the sol-gel method. The incorporation of the N atom into the TiO2 structure was observed by X-ray photoelectron spectroscopy. The N-TiO2@SiO2 core/shell structure was determined by TEM images. The photodegradation of gaseous acetaldehyde using the prepared N-TiO2@SiO2 photocatalytic paint was examined in a closed chamber under LED light irradiation. The photodegradation of acetaldehyde by N-TiO2@SiO2 photocatalytic paint (31%) was significantly higher than that of TiO2 paint (5%) and N-TiO2 paint (20%) within 16 h. The chemical resistance and adhesion ability of N-TiO2@SiO2 photocatalytic paint were investigated following Thai Industrial Standards (TIS) no. 2321 and standard test methods for rating adhesion by tape test (ASTM D 3359-22). The N-TiO2@SiO2 paint showed good acid and alkali resistance, as well as high adhesion ability comparable with commercial paint (without a photocatalyst).

Lactobacillus pentosus MJM60383 Inhibits Lipid Accumulation in Caenorhabditis elegans Induced by Enterobacter cloacae and Glucose.

Gut microbiota are known to play an important role in obesity. Enterobacter cloacae, a Gram-negative bacterium, has been considered a pathogenic bacterium related to obesity in the gut. In this study, we established an obesity model of C. elegans by feeding E. cloacae combined with a high glucose diet (HGD), which significantly induced lipid accumulation. An anti-lipid mechanism study revealed that the fatty acid composition and the expression level of fat metabolism-related genes were altered by feeding E. cloacae to C. elegans under HGD conditions. Lactic acid bacteria that showed antagonistic activity against E. cloacae were used to screen anti-obesity candidates in this model. Among them, L. pentosus MJM60383 (MJM60383) showed good antagonistic activity. C. eleans fed with MJM60383 significantly reduced lipid accumulation and triglyceride content. The ratio of C18:1Δ9/C18:0 was also changed in C. elegans by feeding MJM60383. In addition, the expression level of genes related to fatty acid synthesis was significantly decreased and the genes related to fatty acid β-oxidation were up-regulated by feeding MJM60383. Moreover, MJM60383 also exhibited a high adhesive ability to Caco-2 cells and colonized the gut of C. elegans. Thus, L. pentosus MJM60383 can be a promising candidate for anti-obesity probiotics. To the best of our knowledge, this is the first report that uses E. cloacae combined with a high-glucose diet to study the interactions between individual pathogens and probiotics in C. elegans.

Potential Probiotic Properties of Exopolysaccharide-Producing Lacticaseibacillus paracasei EPS DA-BACS and Prebiotic Activity of Its Exopolysaccharide.

Exopolysaccharide (EPS)-producing Lacticaseibacillus paracasei EPS DA-BACS was isolated from healthy human feces and its probiotic properties, as well as the structure and prebiotic activity of the EPS from this strain were examined. EPS from L. paracasei EPS DA-BACS had a ropy phenotype, which is known to have potential health benefits and is identified as loosely cell-bounded glucomannan-type EPS with a molecular size of 3.7 × 106 Da. EPS promoted the acid tolerance of L. paracasei EPS DA-BACS and provided cells with tolerance to gastrointestinal stress. The purified EPS showed growth inhibitory activity against Clostridium difficile. L. paracasei EPS DA-BACS cells completely inhibited the growth of Bacillus subtilis, Pseudomonas aeruginosa, and Aspergillus brasiliensis, as well as showed high growth inhibitory activity against Staphylococcus aureus and Escherichia coli. Treatment of lipopolysaccharide-stimulated RAW 264.7 cells with heat-killed L. paracasei EPS DA-BACS cells led to a decrease in the production of nitric oxide, indicating the anti-inflammatory activity of L. paracasei EPS DA-BACS. Purified EPS promoted the growth of Lactobacillus gasseri, Bifidobacterium bifidum, B. animalis, and B. faecale which showed high prebiotic activity. L. paracasei EPS DA-BACS harbors no antibiotic resistance genes or virulence factors. Therefore, L. paracasei EPS DA-BACS exhibits anti-inflammatory and antimicrobial activities with high gut adhesion ability and gastrointestinal tolerance and can be used as a potential probiotic.

Partial purification and application of a bacteriocin produced by probiotic Lactococcus lactis C15 isolated from raw milk

Food-borne pathogens pose health challenges to consumers and are serious concerns in the food industry. Accordingly, we investigated the probiotic properties of Lactococcus lactis C15 and the biological properties of the bacteriocin it produces. The results show C15 exhibited strong gastrointestinal tolerance, excellent cell surface properties, high adhesion ability to Caco-2 cells (>90%), and good safety in vitro. The active peptide produced by C15 has inhibitory activity against pathogens, even after exposure to elevated temperatures (60–121 °C) and low pH values (pH 2–5). L. lactis C15 contains the Lactococcin B gene, which produces a nisin-like bacteriocin. Partially purified bacteriocin effectively antagonized the growth of Escherichia coli added to ultra-high temperature instantaneous sterilization (UHT) milk. The inhibition of E. coli was similar to that of the reference bacteriocin (nisin). This research aimed to provide a new strategy for food preservation that avoids traditional chemical preservatives.