scholarly journals A Novel Nano-Antimicrobial Polymer Engineered with Chitosan Nanoparticles and Bioactive Peptides as Promising Food Biopreservative Effective against Foodborne Pathogen E. coli O157-Caused Epithelial Barrier Dysfunction and Inflammatory Responses

2021 ◽  
Vol 22 (24) ◽  
pp. 13580
Author(s):  
Ming Kuang ◽  
Haitao Yu ◽  
Shiyan Qiao ◽  
Tao Huang ◽  
Jiaqi Zhang ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Inflammatory Responses ◽  
Cell Model ◽  
Chitosan Nanoparticles ◽  
Foodborne Pathogen ◽  
Mitogen Activated Protein Kinase ◽  
Barrier Dysfunction ◽  
E Coli

For food quality and safety issues, the emergence of foodborne pathogenic bacteria has further accelerated the spread of antibiotic residues and drug resistance genes. To alleviate the harm caused by bacterial infections, it is necessary to seek novel antimicrobial agents as biopreservatives to prevent microbial spoilage. Nanoantimicrobials have been widely used in the direct treatment of bacterial infections. CNMs, formed by chitosan nanoparticles and peptides, are promising antibiotic alternatives for use as excellent new antibacterial drugs against pathogenic bacteria. Herein, the current study evaluated the function of CNMs in the protection of foodborne pathogen Escherichia coli (E. coli) O157 infection using an intestinal epithelial cell model. Antibacterial activity assays indicated that CNMs exerted excellent bactericidal activity against E. coli O157. Assessment of the cytotoxicity risks toward cells demonstrated that 0.0125–0.02% of CNMs did not cause toxicity, but 0.4% of CNMs caused cytotoxicity. Additionally, CNMs did not induced genotoxicity either. CNMs protected against E. coli O157-induced barrier dysfunction by increasing transepithelial electrical resistance, decreasing lactate dehydrogenase and promoting the protein expression of occludin. CNMs were further found to ameliorate inflammation via modulation of tumor factor α, toll-like receptor 4 and nuclear factor κB (NF-κB) expression via inhibition of mitogen-activated protein kinase and NF-κB activation and improved antioxidant activity. Taken together, CNMs could protect the host against E. coli O157-induced intestinal barrier damage and inflammation, showing that CNMs have great advantages and potential application as novel antimicrobial polymers in the food industry as food biopreservatives, bringing new hope for the treatment of bacterial infections.

scholarly journals Escherichia coli as Commensal and Pathogenic Bacteria among Food-Producing Animals: Health Implications of Extended Spectrum β-Lactamase (ESBL) Production

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2239
Author(s):  
Sónia Ramos ◽  
Vanessa Silva ◽  
Maria de Lurdes Enes Dapkevicius ◽  
Manuela Caniça ◽  
María Teresa Tejedor-Junco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Severe Infection ◽  
Farm Animals ◽  
Neonatal Meningitis ◽  
Salmonella Spp ◽  
E Coli

Escherichia coli are facultative, anaerobic Gram-negative rods with many facets. Within resistant bacterial populations, they play an important ecological role and can be used as a bioindicator of antimicrobial resistance. All animal species used for food production, as well as humans, carry E. coli in their intestinal tracts; plus, the genetic flexibility and adaptability of this bacteria to constantly changing environments allows it to acquire a great number of antimicrobial resistance mechanisms. Thus, the prevalence of antimicrobial resistance in these commensal bacteria (or others, such as enterococci) can be a good indicator for the selective pressure caused by the use of antimicrobial agents, providing an early warning of the emergence of antimicrobial resistance in pathogens. As many as 90% of E. coli strains are commensals inhabiting the intestinal tracts of humans and warm-blooded animals. As a commensal, it lives in a mutually beneficial association with its hosts and rarely causes diseases. However, E. coli also remains as one of the most frequent causes of several common bacterial infections in humans and animals. In humans, it is the prominent cause of enteritis, community- and hospital-acquired urinary tract infection (UTI), septicemia, postsurgical peritonitis, and other clinical infections, such as neonatal meningitis, while, in farm animals, it is more prominently associated with diarrhea. On a global scale, E. coli can be considered the most important human pathogen, causing severe infection along with other major bacterial foodborne agents, such as Salmonella spp. and Campylobacter. Thus, the importance of resistance in E. coli, typically considered a benign commensal, should not be underestimated.

Probiotics Slow the Growth of Pathogenic Bacteria

2019 ◽  
Vol 14 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Rowles H. L.
Keyword(s):  
Growth Rate ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diarrheal Disease ◽  
Growth Curves ◽  
Mortality Rates ◽  
Controlled Delivery ◽  
E Coli ◽  
Multiple Strains ◽  
Commercial Probiotics

Probiotics are live microorganisms, which when ingested in sufficient amounts, confer health benefits to the host by improving the gut microflora balance. The purpose of this research was to determine whether commercial probiotic products containing multitude of commensal bacteria would reduce the growth rate of pathogenic bacteria, specifically Escherichia coli and Salmonella typhimurium. Growth curves were established, and the growth rates were compared for samples of E. coli, S. typhimurium, Nature’s Bounty Controlled Delivery probiotic, Sundown Naturals Probiotic Balance probiotic, and cocultures of the pathogenic bacteria mixed with the probiotics. The findings of this research were that the commercial probiotics significantly reduced the growth rate of E. coli and S. typhimurium when combined in cocultures. Probiotics containing multiple strains may be taken prophylactically to reduce the risk of bacterial infections caused by E. coli and S. typhimurium. Probiotics could be used to reduce the high global morbidity and mortality rates of diarrheal disease.

scholarly journals AMPK activates Parkin independent autophagy and improves post sepsis immune defense against secondary bacterial lung infections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathaniel B. Bone ◽  
Eugene J. Becker ◽  
Maroof Husain ◽  
Shaoning Jiang ◽  
Anna A. Zmijewska ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Inflammatory Responses ◽  
Abdominal Sepsis ◽  
Immune Defense ◽  
Bacterial Killing ◽  
Lung Infections ◽  
Sepsis Survivors ◽  
The Impact

AbstractMetabolic and bioenergetic plasticity of immune cells is essential for optimal responses to bacterial infections. AMPK and Parkin ubiquitin ligase are known to regulate mitochondrial quality control mitophagy that prevents unwanted inflammatory responses. However, it is not known if this evolutionarily conserved mechanism has been coopted by the host immune defense to eradicate bacterial pathogens and influence post-sepsis immunosuppression. Parkin, AMPK levels, and the effects of AMPK activators were investigated in human leukocytes from sepsis survivors as well as wild type and Park2−/− murine macrophages. In vivo, the impact of AMPK and Parkin was determined in mice subjected to polymicrobial intra-abdominal sepsis and secondary lung bacterial infections. Mice were treated with metformin during established immunosuppression. We showed that bacteria and mitochondria share mechanisms of autophagic killing/clearance triggered by sentinel events that involve depolarization of mitochondria and recruitment of Parkin in macrophages. Parkin-deficient mice/macrophages fail to form phagolysosomes and kill bacteria. This impairment of host defense is seen in the context of sepsis-induced immunosuppression with decreased levels of Parkin. AMPK activators, including metformin, stimulate Parkin-independent autophagy and bacterial killing in leukocytes from post-shock patients and in lungs of sepsis-immunosuppressed mice. Our results support a dual role of Parkin and AMPK in the clearance of dysfunctional mitochondria and killing of pathogenic bacteria, and explain the immunosuppressive phenotype associated Parkin and AMPK deficiency. AMPK activation appeared to be a crucial therapeutic target for the macrophage immunosuppressive phenotype and to reduce severity of secondary bacterial lung infections and respiratory failure.

scholarly journals Synthesis and Antimicrobial Properties of Highly Cross-Linked pH-Sensitive Hydrogels through Gamma Radiation

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2223
Author(s):  
Moises Bustamante-Torres ◽  
Victor H. Pino-Ramos ◽  
David Romero-Fierro ◽  
Sandra P. Hidalgo-Bonilla ◽  
Héctor Magaña ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Film Formation ◽  
Antimicrobial Properties ◽  
Ph Sensitive ◽  
Scanning Calorimetry ◽  
Polymeric Systems ◽  
E Coli ◽  
High Prevalence

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.

scholarly journals A Sulfated Polysaccharide from Saccharina japonica Suppresses LPS-Induced Inflammation Both in a Macrophage Cell Model via Blocking MAPK/NF-κB Signal Pathways In Vitro and a Zebrafish Model of Embryos and Larvae In Vivo

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 593
Author(s):  
Shengnan Wang ◽  
Liying Ni ◽  
Xiaoting Fu ◽  
Delin Duan ◽  
Jiachao Xu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Responses ◽  
Cell Model ◽  
Mitogen Activated Protein Kinase ◽  
Raw 264.7 Cells ◽  
Signal Pathways ◽  
Raw 264.7 ◽  
Scale Production ◽  
Pharmaceutical Industries

Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated Saccharinajaponica polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells and zebrafish. Its chemical and structural properties were investigated via HPLC, GC, FTIR, and NMR spectroscopy. In vitro experiments demonstrated that LJPS significantly inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and suppressed pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production via the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways in LPS-induced RAW 264.7 cells. Moreover, LJPS showed strong protective effects against LPS-induced inflammatory responses in zebrafish, increasing the survival rate, reducing the heart rate and yolk sac edema size, and inhibiting cell death and the production of intracellular reactive oxygen species (ROS) and NO. Its convenience for large-scale production and significant anti-inflammatory activity indicated the potential application of LJPS in functional foods, cosmetics, and pharmaceutical industries.

scholarly journals Potentiation of Tobramycin by Silver Nanoparticles against Pseudomonas aeruginosa Biofilms

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marc B. Habash ◽  
Mara C. Goodyear ◽  
Amber J. Park ◽  
Matthew D. Surette ◽  
Emily C. Vis ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Acute Infection ◽  
Public Health Problem ◽  
Chronic Infections ◽  
Content Type

ABSTRACT Increasing antibiotic resistance among pathogenic bacterial species is a serious public health problem and has prompted research examining the antibacterial effects of alternative compounds and novel treatment strategies. Compounding this problem is the ability of many pathogenic bacteria to form biofilms during chronic infections. Importantly, these communities are often recalcitrant to antibiotic treatments that show effectiveness against acute infection. The antimicrobial properties of silver have been known for decades, but recently silver and silver-containing compounds have seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the ability of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the aminoglycoside antibiotic tobramycin, to inhibit established Pseudomonas aeruginosa biofilms. Our results demonstrate that smaller 10-nm and 20-nm AgNPs were more effective at synergistically potentiating the activity of tobramycin. Visualization of biofilms treated with combinations of 10-nm AgNPs and tobramycin reveals that the synergistic bactericidal effect may be caused by disrupting cellular membranes. Minimum biofilm eradication concentration (MBEC) assays using clinical P. aeruginosa isolates shows that small AgNPs are more effective than larger AgNPs at inhibiting biofilms, but that the synergy effect is likely a strain-dependent phenomenon. These data suggest that small AgNPs synergistically potentiate the activity of tobramycin against P. aeruginosa in vitro and may reveal a potential role for AgNP/antibiotic combinations in treating patients with chronic infections in a strain-specific manner.

scholarly journals Nutritional influences on some major enteric bacterial diseases of pig

2002 ◽  
Vol 15 (2) ◽  
pp. 333-371 ◽  
Author(s):  
John R Pluske ◽  
David W Pethick ◽  
Deborah E Hopwood ◽  
David J Hampson
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Dietary Guidelines ◽  
Ecological Niches ◽  
Dietary Interventions ◽  
Brachyspira Pilosicoli ◽  
Bacterial Diseases ◽  
Positive Effects ◽  
Underlying Basis

AbstractThere are several enteric bacterial diseases and conditions of pigs that require control to prevent overt disease, to reduce morbidity and mortality, and to improve the efficiency of production. Traditionally, veterinarians, feed manufacturers and producers have relied upon antibiotics and minerals (for example, ZnO, CuSO4) in diets for a large part of this control. However, recent trends, particularly in Europe, are to reduce antimicrobial use and seek alternative or replacement strategies for controlling enteric bacterial diseases. The majority of these strategies rely on ‘nutrition’, taken in its broadest sense, to reduce the susceptibility of pigs to these diseases. Evidence to date suggests that specific dietary interventions, for example feeding very highly-digestible diets based on cooked white rice, can reduce the proliferation of a number of specific enteric bacterial infections, such as post-weaning colibacillosis. No simple and universal way to reduce susceptibility to pathogens in the gastrointestinal tract has been identified, and the underlying basis for many of the reported positive effects of ‘nutrition’ on controlling enteric infections lacks robust, scientific understanding. This makes it difficult to recommend dietary guidelines to prevent or reduce enteric bacterial diseases. Furthermore, some diseases, such as porcine intestinal spirochaetosis caused byBrachyspira pilosicoli, are sometimes associated with other pathogens (co-infections). In such cases, each pathogen might have different nutrient requirements, ecological niches and patterns of metabolism for which a variety of dietary interventions are needed to ameliorate the disease. Greater understanding of how ‘nutrition’ influences gut epithelial biology and immunobiology, and their interactions with both commensal and pathogenic bacteria, holds promise as a means of tackling enteric disease without antimicrobial agents. In addition, it is important to consider the overall system (i.e. management, housing, welfare) of pig production in the context of controlling enteric bacterial diseases.

scholarly journals Enteroaggregative Escherichia coli Disrupts Epithelial Cell Tight Junctions

2010 ◽  
Vol 78 (11) ◽  
pp. 4958-4964 ◽  
Author(s):  
Maura C. Strauman ◽  
Jill M. Harper ◽  
Susan M. Harrington ◽  
Erik Juncker Boll ◽  
James P. Nataro
Keyword(s):  
Escherichia Coli ◽  
Tight Junction ◽  
Tight Junctions ◽  
Cell Model ◽  
Barrier Dysfunction ◽  
T84 Cells ◽  
E Coli ◽  
Eaec Strain ◽  
Epithelial Barrier Dysfunction

ABSTRACT Enteroaggregative Escherichia coli (EAEC) is responsible for inflammatory diarrhea in diverse populations, but its mechanisms of pathogenesis have not been fully elucidated. We have used a previously characterized polarized intestinal T84 cell model to investigate the effects of infection with EAEC strain 042 on tight junction integrity. We find that infection with strain 042 induces a decrease in transepithelial electrical resistance (TER) compared to uninfected controls and to cells infected with commensal E. coli strain HS. When the infection was limited after 3 h by washing and application of gentamicin, we observed that the TER of EAEC-infected monolayers continued to decline, and they remained low even as long as 48 h after the infection. Cells infected with the afimbrial mutant strain 042aafA exhibited TER measurements similar to those seen in uninfected monolayers, implicating the aggregative adherence fimbriae II (AAF/II) as necessary for barrier dysfunction. Infection with wild-type strain 042 induced aberrant localization of the tight junction proteins claudin-1 and, to a lesser degree, occludin. EAEC-infected T84 cells exhibited irregular shapes, and some cells became elongated and/or enlarged; these effects were not observed after infection with commensal E. coli strain HS or 042aafA. The effects on tight junctions were also observed with AAF/I-producing strain JM221, and an afimbrial mutant was similarly deficient in inducing barrier dysfunction. Our results show that EAEC induces epithelial barrier dysfunction in vitro and implicates the AAF adhesins in this phenotype.

scholarly journals Preparation and Characterization of Chitosan Nanoparticles-Doped Cellulose Films with Antimicrobial Property

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ain Nadirah Binti Romainor ◽  
Suk Fun Chin ◽  
Suh Cem Pang ◽  
Lesley Maurice Bilung
Keyword(s):  
Antimicrobial Activity ◽  
Citric Acid ◽  
Antimicrobial Agents ◽  
Antimicrobial Property ◽  
Chitosan Nanoparticles ◽  
Assay Method ◽  
E Coli ◽  
Cellulose Films ◽  
Diffusion Assay

Cellulose films with antimicrobial property were prepared by incorporation of chitosan nanoparticles as antimicrobial agents into the cellulose films. The antimicrobial property of these chitosan nanoparticles-doped cellulose films againstEscherichia coli(E. coli) was evaluated via diffusion assay method, minimum inhibitory concentration (MIC) method, and minimum bactericidal concentration (MBC) method. The effects of antimicrobial agent amount, size-related property (nanoparticles and bulk chitosan), and crosslinking by citric acid on antimicrobial activity of cellulose films were studied. It was observed that the antimicrobial activity was enhanced when chitosan nanoparticles were used as compared to when bulk chitosan was used. A maximumE. coliinhibition of 85% was achieved with only 5% (v/v) doping of chitosan nanoparticles into the cellulose films. Crosslinking of the cellulose films with citric acid was observed to have resulted in 50% reduction of water absorbency and a slight increase ofE. coliinhibition by 3% for chitosan nanoparticles-doped cellulose films.

scholarly journals Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli. (Antibacterial Test of Chitosan Nanoparticles against Staphylococcus Aureus and Escherichia coli)

2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Alce Magani ◽  
Trina Tallei ◽  
Beivy Kolondam
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Chitosan Nanoparticles ◽  
Inhibition Zone ◽  
Antibacterial Test ◽  
E Coli ◽  
Inhibition Of Growth ◽  
Significant Difference ◽  
One Way Anova

Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli.(Antibacterial Test of Chitosan Nanoparticles against Staphylococcus Aureus and Escherichia coli) Alce K. Magani*, Trina E. Tallei, Beivy J. KolondamProgram Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] (Article History: Received 30-12-2019; Revised 15-01-2020; Accepted 23-01-2020) Abstrak Antibakteri merupakan zat yang dapat menghambat pertumbuhan bakteri dan dapat membunuh bakteri penyebab infeksi. Staphylococcus aureus dan Escherichia coli merupakan bakteri Gram positif dan Gram negatif yang dapat menimbulkan infeksi atau penyakit dalam tubuh. Penelitian ini bertujuan untuk menguji aktivitas bakteri patogen dengan memakai nanopartikel kitosan sebagai antibakteri yang dibuat dalam empat konsentrasi (0,5%, 1%, 1,5% dan 2%) serta penggunaan kontrol asam asetat 1%, ciprofloxacin dan air steril sebagai pembanding. Metode penelitian yang digunakan yaitu metode gelasi ionik untuk pembuatan nanopartikel kitosan dan difusi agar untuk pengujian antibakteri. Data dianalisis dengan One Way Anova yang dilanjutkan dengan metode BNT (Beda Nyata Terkecil). Hasil penelitian diperoleh penghambatan pertumbuhan bakteri S. aureus dan E. coli tertinggi pada konsentrasi 0,5%, dengan diameter zona hambat hari pertama sampai hari ketiga 12,31 mm, 9,98 mm, dan 20,46 mm pada S. aureus dan 15,88 mm, 18,71 mm, dan 20,43 mm pada E. coli, kategori kuat, dan bersifat bakteriostatik dan penghambatan terendah pada konsentrasi 2% dengan diameter zona hambat pada S. aureus yaitu 5,56 mm, 5,50 mm, dan 5,40 mm, dan pada E. coli yaitu 5,93 mm, 9,64 mm, dan 12,58 mm, kategori sedang, dan bersifat bakteriostatik. Kata kunci: Kitosan, nanopartikel kitosan, aktivitas antibakteri.  Abstract Antibacteria is a substance that can inhibit the growth of bacteria and able to kill bacteria that cause infections. Staphylococcus aureus and Escherichia coli are Gram positive and Gram negative bacteria that able to cause infections or diseases. This study aimed to examine the activity of pathogenic bacteria by using chitosan nanoparticles as antibacterial. The treatments were made in four concentrations (0.5%, 1%, 1.5% and 2%) and, for comparison, there were also acetic acid control, ciprofloxacin and sterile water. The research method used is the ionic gelation method for the manufacture of chitosan nanoparticles and agar diffusion for antibacterial testing. Data were analyzed with One Way Anova followed by LSD (Least Significant Difference) method. The results showed the highest inhibition of growth of S. aureus and E. coli bacteria at a concentration of 0.5%, with a diameter of inhibition zones of the first day to the third day of 12.31 mm, 9.98 mm, and 20.46 mm in S. aureus and 15,88 mm, 18,71 mm, and 20,43 mm in E. coli, the strong category, and are bacteriostatic and the lowest inhibition was at 2% concentration with inhibition zone diameters in S. aureus namely 5.568 mm, 5.50 mm, and 5, 40 mm, and in E. coli, 5.93 mm, 9.63 mm and 12.58 mm, the medium category and bacteriostatic.Key words: Chitosan, nanoparticles chitosan, antibacterial activity.

Sign in / Sign up

Export Citation Format

Share Document