scholarly journals Protective and Anti-Inflammatory Effects of Protegrin-1 on Citrobacter rodentium Intestinal Infection in Mice

2021 ◽  
Vol 22 (17) ◽  
pp. 9494
Author(s):  
Celina Osakowicz ◽  
Lauren Fletcher ◽  
Jeff L. Caswell ◽  
Julang Li
Keyword(s):  
Antimicrobial Activity ◽  
Broad Spectrum ◽  
Intestinal Inflammation ◽  
Clinical Signs ◽  
Significant Rise ◽  
Resistant Bacteria ◽  
Protective Effects ◽  
Citrobacter Rodentium ◽  
Intestinal Infection ◽  
Infectious Colitis

Infectious intestinal colitis, manifesting as intestinal inflammation, diarrhea, and epithelial barrier disruption, affects millions of humans worldwide and, without effective treatment, can result in death. In addition to this, the significant rise in antibiotic-resistant bacteria poses an urgent need for alternative anti-infection therapies for the treatment of intestinal disorders. Antimicrobial peptides (AMPs) are potential therapies that have broad-spectrum antimicrobial activity due to their (1) unique mode of action, (2) broad-spectrum antimicrobial activity, and (3) protective role in GI tract maintenance. Protegrin-1 (PG-1) is an AMP of pig origin that was previously shown to reduce the pathological effects of chemically induced digestive tract inflammation (colitis) and to modulate immune responses and tissue repair. This study aimed to extend these findings by investigating the protective effects of PG-1 on pathogen-induced colitis in an infection study over a 10-day experimental period. The oral administration of PG-1 reduced Citrobacter rodentium intestinal infection in mice as evidenced by reduced histopathologic change in the colon, prevention of body weight loss, milder clinical signs of disease, and more effective clearance of bacterial infection relative to challenged phosphate-buffered saline (PBS)-treated mice. Additionally, PG-1 treatment altered the expression of various inflammatory mediators during infection, which may act to resolve inflammation and re-establish intestinal homeostasis. PG-1 administered in its mature form was more effective relative to the pro-form (ProPG-1). To our knowledge, this is the first study demonstrating the protective effects of PG-1 on infectious colitis.

122 Bioactive Peptides for Enhancing Intestine Health

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 65-65
Author(s):  
Julang Li ◽  
Nadeem Akhtar ◽  
Celina Osakowicz ◽  
Lauren Fletcher ◽  
Karmin O ◽  
...  
Keyword(s):  
Animal Health ◽  
Clinical Signs ◽  
Body Weight Loss ◽  
Cost Effective ◽  
Significant Rise ◽  
Feed Ratio ◽  
Resistant Bacteria ◽  
Intestinal Development ◽  
Antibiotic Resistant ◽  
Animal Trials

Abstract Intestinal disorders and colitis affect both animals and humans. The pathogenesis behind the inflammation is complex and not entirely understood. Furthermore, the significant rise in antibiotic-resistant bacteria has emphasized an urgent need for alternative anti-infective therapies. Antimicrobial peptides (AMPs) is one of the appealing alternative to antibiotics due to their antimicrobial activity, mode of actions, and potential role in tissue repair. Epidermal growth factor (EGF) plays an important role in intestinal proliferation and differentiation and thus promotes intestinal development. Using food grade microorganisms such as Lactococcus lactis and yeast as hosts, our laboratory has produced recombinant porcine protegrin-1 (PG-1), a pig originated antimicrobial peptide and EGF via fermentation. Oral administration of PG-1 reduced Citrobacter rodentium induced intestinal infection in mice. This was evidenced by reduced histopathological changes in the colon, prevention of body weight loss, milder clinical signs of disease, and ultimately more effective clearance of bacterial infection. On the other hand, animal trials using the recombinant EGF demonstrated that it enhances intestinal development and growth of early weaned pig fed with antibiotic-free diet. Moreover, piglets challenged with enterotoxigenic Escherchia coli (E. coli) K88 showed similar beneficial responses to EGF as those fed diets with antibiotic in terms of improving gain to feed ratio and lowering oxidative stress. Taken together, our findings suggest the potential for cost-effective production and application of recombinant bioactive proteins as alternatives to antibiotics in animal health and production.

scholarly journals A52 BUTYRATE SUPPLEMENTATION AMELIORATES DAMAGE CAUSED BY ENTERIC CITROBACTER RODENTIUM INFECTION

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 61-62
Author(s):  
L S Celiberto ◽  
G Healey ◽  
J Xu ◽  
L Xia ◽  
B Vallance
Keyword(s):  
Butyric Acid ◽  
Tissue Damage ◽  
Intestinal Inflammation ◽  
Bacterial Colonization ◽  
Clinical Signs ◽  
Host Susceptibility ◽  
Mucus Layer ◽  
Citrobacter Rodentium ◽  
Oral Gavage ◽  
Intestinal Mucus

Abstract Background Patients with inflammatory bowel disease (IBD) often display a dysbiotic microbiome as well as a defective intestinal mucus layer, which appears thinner and more penetrable than the mucus layer of healthy subjects. Tributyrin (TB), a prodrug of butyric acid, has shown beneficial effects in models of IBD due to its anti-inflammatory effects. We previously showed that mice lacking the major intestinal mucin Muc2 (Muc2-/-) or lacking the “Core1” enzyme responsible for glycosylating Muc2 (C1galt1-/-) were highly susceptible to infection by Citrobacter rodentium, a murine model of intestinal inflammation. Aims The study explored the role of gut mucus in providing host defense against C. rodentium, as well as the effects of TB supplementation in the prevention of mucosal damage in this model. Methods Six to ten week old wildtype (WT), Muc2-/-, flox control (C1galt1f/f) and C1galt1-/- mice were infected with C. rodentium (∼2.5 × 108 CFU) by oral gavage. For TB supplementation experiments, mice received 100µL of TB or glycerol as a control by oral gavage every other day starting on day 1 post infection. Mice were monitored daily throughout the experiment and were euthanized at day 6 of infection. Several tissues of interest were collected to verify bacterial colonization in the gut and at systemic sites as well as histological tissue damage. Cecal contents were collected for the analysis of short chain fatty acids, while blood was collected by cardiac puncture after oral gavage with FITC-dextran to measure intestinal permeability. Results While WT and C1galt1f/f mice were only modestly susceptible to C. rodentium infection, Muc2-/- and C1galt1-/- mice displayed dramatically (100 fold) increased pathogen burdens, significantly greater intestinal macroscopic and histopathology scores, and heightened barrier disruption as compared to controls. Moreover, Muc2-/- and C1galt1-/- mice showed significantly lower levels of butyric acid as compared to control mice under baseline conditions. Interestingly, when supplemented with TB, Muc2-/- and C1galt1-/- proved less susceptible to C. rodentium infection, as indicated by reduced weight loss and clinical signs of colitis, while pathogen burdens were greatly reduced as was histological tissue damage, and epithelial barrier dysfunction. The same protection was conferred when TB was administered as a dietary supplementation, thus confirming its beneficial effect in protecting mice against C. rodentium infection. Conclusions These findings demonstrate that intestinal mucus controls host susceptibility to C. rodentium infection via control over butyrate levels, and highlight the need to explore the mechanisms by which gut mucus modulates the resident microbiota and its metabolites. Funding Agencies CCC, CIHR

scholarly journals Characterizing the Mechanism of Action of an Ancient Antimicrobial, Manuka Honey, against Pseudomonas aeruginosa Using Modern Transcriptomics

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Daniel Bouzo ◽  
Nural N. Cokcetin ◽  
Liping Li ◽  
Giulia Ballerin ◽  
Amy L. Bottomley ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Mechanism Of Action ◽  
Broad Spectrum ◽  
Bacterial Resistance ◽  
Resistant Bacteria ◽  
Antibiotics Resistance ◽  
Manuka Honey ◽  
Content Type ◽  
Bacterial Membranes

ABSTRACT Manuka honey has broad-spectrum antimicrobial activity, and unlike traditional antibiotics, resistance to its killing effects has not been reported. However, its mechanism of action remains unclear. Here, we investigated the mechanism of action of manuka honey and its key antibacterial components using a transcriptomic approach in a model organism, Pseudomonas aeruginosa. We show that no single component of honey can account for its total antimicrobial action, and that honey affects the expression of genes in the SOS response, oxidative damage, and quorum sensing. Manuka honey uniquely affects genes involved in the explosive cell lysis process and in maintaining the electron transport chain, causing protons to leak across membranes and collapsing the proton motive force, and it induces membrane depolarization and permeabilization in P. aeruginosa. These data indicate that the activity of manuka honey comes from multiple mechanisms of action that do not engender bacterial resistance. IMPORTANCE The threat of antimicrobial resistance to human health has prompted interest in complex, natural products with antimicrobial activity. Honey has been an effective topical wound treatment throughout history, predominantly due to its broad-spectrum antimicrobial activity. Unlike traditional antibiotics, honey-resistant bacteria have not been reported; however, honey remains underutilized in the clinic in part due to a lack of understanding of its mechanism of action. Here, we demonstrate that honey affects multiple processes in bacteria, and this is not explained by its major antibacterial components. Honey also uniquely affects bacterial membranes, and this can be exploited for combination therapy with antibiotics that are otherwise ineffective on their own. We argue that honey should be included as part of the current array of wound treatments due to its effective antibacterial activity that does not promote resistance in bacteria.

scholarly journals HJH-1, a Broad-Spectrum Antimicrobial Activity and Low Cytotoxicity Antimicrobial Peptide

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2026 ◽  
Author(s):  
Qing Wang ◽  
Yanzhao Xu ◽  
Mengmeng Dong ◽  
Bolin Hang ◽  
Yawei Sun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Broad Spectrum ◽  
Ph Value ◽  
Bacterial Species ◽  
Membrane Integrity ◽  
Resistant Bacteria ◽  
Bacterial Membrane ◽  
Α Subunit ◽  
Promising Alternative

With the overuse of antibiotics, multidrug-resistant bacteria pose a significant threat to human health. Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics. This study examines the antimicrobial and membrane activity of HJH-1, a cationic peptide derived from the hemoglobin α-subunit of bovine erythrocytes P3. HJH-1 shows potent antimicrobial activity against different bacterial species associated with infection and causes weaker hemolysis of erythrocytes, at least five times the minimum inhibitory concentration (MIC). HJH-1 has good stability to tolerance temperature, pH value, and ionic strength. The anionic membrane potential probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)] and propidium iodide are used as indicators of membrane integrity. In the presence of HJH-1 (1× MIC), Escherichia coli membranes rapidly depolarise, whereas red blood cells show gradual hyperpolarisation. Scanning electron microscopy and transmission electron micrographs show that HJH-1 (1× MIC) damaged the membranes of Escherichia coli, Staphylococcus aureus, and Candida albicans. In conclusion, HJH-1 damages the integrity of the bacterial membrane, preventing the growth of bacteria. HJH-1 has broad-spectrum antibacterial activity, and these activities are performed by changing the normal cell transmembrane potential and disrupting the integrity of the bacterial membrane.

scholarly journals Characterising the mechanism of action of an ancient antimicrobial, honey, using modern transcriptomics

2020 ◽  
Author(s):  
Daniel Bouzo ◽  
Nural N. Cokcetin ◽  
Liping Li ◽  
Giulia Ballerin ◽  
Amy L. Bottomley ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Mechanism Of Action ◽  
Broad Spectrum ◽  
Bacterial Resistance ◽  
Model Organism ◽  
Resistant Bacteria ◽  
Antibiotics Resistance ◽  
Manuka Honey ◽  
Bacterial Membranes ◽  
Expression Of Genes

AbstractManuka honey has broad-spectrum antimicrobial activity and unlike traditional antibiotics, resistance to its killing effects has not been reported. However, its mechanism of action remains unclear. Here we investigated the mechanism of action of manuka honey and its key antibacterial components using a transcriptomic approach in a model organism, Pseudomonas aeruginosa. We show that no single component of honey can account for its total antimicrobial action, and that honey affects the expression of genes in the SOS response, oxidative damage and quorum sensing. Manuka honey uniquely affects genes involved in the explosive cell lysis process and in maintaining the electron transport chain, causing protons to leak across membranes and collapsing the proton motive force; and induces membrane depolarisation and permeabilisation in P. aeruginosa. These data indicate that the activity of manuka honey comes from multiple mechanisms of action that do not engender bacterial resistance.ImportanceThe threat of antimicrobial resistance to human health has prompted interest in complex, natural products with antimicrobial activity. Honey has been an effective topical wound treatment throughout history, predominantly due to its broad-spectrum antimicrobial activity. Unlike traditional antibiotics, honey-resistant bacteria have not been reported, however, honey remains underutilised in the clinic in part due to a lack of understanding of its mechanism of action. Here we demonstrate that honey affects multiple processes in bacteria, and this is not explained by its major antibacterial components. Honey also uniquely affects bacterial membranes and this can be exploited for combination therapy with antibiotics that are otherwise ineffective on their own. We argue that honey should be included as part of the current array of wound treatments due to its effective antibacterial activity that does not promote resistance in bacteria.

Ultrastable radical-doped coordination compounds with antimicrobial activity against antibiotic-resistant bacteria

2020 ◽  
Vol 56 (92) ◽  
pp. 14353-14356
Author(s):  
Hua Ke ◽  
Fen Hu ◽  
Lingyi Meng ◽  
Qi-Hua Chen ◽  
Qian-Sheng Lai ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Broad Spectrum ◽  
Coordination Compounds ◽  
Lone Pair ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Π Interactions ◽  
Drug Resistant Bacteria

Radical-doped coordination compounds—generated as a result of lone pair–π interactions and having a long-lived charge-separated state—display photochromism and broad-spectrum antimicrobial activity, even against multi-drug-resistant bacteria.

Immunological mechanisms involved in probiotic-mediated protection against Citrobacter rodentium-induced colitis

2016 ◽  
Vol 7 (3) ◽  
pp. 397-407 ◽  
Author(s):  
Y. Jiang ◽  
G. Yang ◽  
F. Meng ◽  
W. Yang ◽  
J. Hu ◽  
...  
Keyword(s):  
Intestinal Inflammation ◽  
Lactobacillus Rhamnosus ◽  
Interferon Γ ◽  
Interleukin 17 ◽  
Protective Effects ◽  
Citrobacter Rodentium ◽  
Mesenteric Lymph Nodes ◽  
Immunological Mechanisms ◽  
Inflammatory Bowel ◽  
Factor Α

Inflammatory bowel disease is a group of chronic, incurable inflammatory disorders of the gastrointestinal tract that cause severe diarrhoea, intestinal inflammation, pain, fatigue and weight loss. In this study, we first developed a model of Citrobacter rodentium-induced colitis and then evaluated the protective effects of selected probiotics on inflammation. The results showed that administration of a combination of probiotics including Lactobacillus rhamnosus ATCC 53103, Lactobacillus acidophilus ATCC 4356 and Lactobacillus plantarum A significantly increased the production of CD11c+ dendritic cells in the spleen (3.62% vs phosphate buffered saline (PBS)-treated control, P<0.01) and mesenteric lymph nodes (MLNs). In addition, the presence of probiotics significantly up-regulated the development of CD4+/CD25+/Foxp3+ regulatory T cells in MLNs by approximately 2.07% compared to the effect observed in the PBS-treated control (P<0.01) and down-regulated the expression of inflammatory cytokines, including interleukin-17, tumour necrosis factor-α and interferon-γ, by 0.11, 0.11 and 0.15%, respectively, compared to the effect observed in the PBS-treated control (P<0.01).These effects conferred protection against colitis, as shown by histopathological analyses.

Pea-protein alginate encapsulation adversely affects development of clinical signs of Citrobacter rodentium-induced colitis in mice treated with probiotics

2018 ◽  
Vol 64 (10) ◽  
pp. 744-760 ◽  
Author(s):  
Natallia Varankovich ◽  
Alexander Grigoryan ◽  
Kirsty Brown ◽  
G. Douglas Inglis ◽  
Richard R.E. Uwiera ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Lactobacillus Rhamnosus ◽  
Cytokine Expression ◽  
Lactobacillus Helveticus ◽  
Abnormal Behavior ◽  
Citrobacter Rodentium ◽  
Infectious Colitis ◽  
Food Ingredients ◽  
Pea Protein ◽  
Freeze Dried

The efficacy of two strains of Lactobacillus probiotics (Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0052) immobilized in microcapsules composed of pea protein isolate (PPI) and alginate microcapsules was assessed using a mouse model of Citrobacter rodentium-induced colitis. Accordingly, 4-week-old mice were fed diets supplemented with freeze-dried probiotics (group P), probiotic-containing microcapsules (group PE) (lyophilized PPI–alginate microcapsules containing probiotics), or PPI–alginate microcapsules containing no probiotics (group E). Half of the mice (controls, groups P, PE, and E) received C. rodentium by gavage 2 weeks after initiation of feeding. Daily monitoring of disease symptoms (abnormal behavior, diarrhea, etc.) and body weights was undertaken. Histopathological changes in colonic and cecal tissues, cytokine expression levels, and pathogen and probiotic densities in feces were examined, and the microbial communities of the distal colon mucosa were characterized by 16S rRNA sequencing. Infection with C. rodentium led to marked progression of infectious colitis, as revealed by symptomatic and histopathological data, changes in cytokine expression, and alteration of composition of mucosal communities. Probiotics led to changes in most of the disease markers but did not have a significant impact on cytokine profiles in infected animals. On the basis of cytokine expression analyses and histopathological data, it was evident that encapsulation materials (pea protein and calcium alginate) contributed to inflammation and worsened a set of symptoms in the cecum. These results suggest that even though food ingredients may be generally recognized as safe, they may in fact contribute to the development of an inflammatory response in certain animal disease models.

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