scholarly journals Guarea kunthiana Bark Extract Enhances the Antimicrobial Activities of Human and Bovine Neutrophils

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Natalja Jerjomiceva ◽  
Hisham Seri ◽  
Ragheda Yaseen ◽  
Nicole de Buhr ◽  
William N. Setzer ◽  
...  
Keyword(s):  
Cell Types ◽  
Antimicrobial Activities ◽  
Bark Extract ◽  
Bacterial Survival ◽  
First Line ◽  
E Coli ◽  
Microbial Infections ◽  
Survival Assay ◽  
Folk Remedies ◽  
Bovine Neutrophils

Guarea kunthiana is used in folk remedies for the treatment of several diseases including microbial infections. The mechanism behind this phenomenon still needs to be elucidated. Here, we investigated the effect of G. kunthiana bark extract on antimicrobial functions of human and bovine neutrophils as the first line of defense against infections. For this aim, neutrophils were isolated from either human or bovine blood and treated with G. kunthiana bark extract. The antimicrobial activity of the neutrophils against Staphylococcus (S.) aureus and Escherichia (E.) coli was tested in a bacterial survival assay and a fluorescence-based phagocytosis assay. Furthermore, the formation of neutrophil extracellular traps (NETs) was visualized by immunofluorescence microscopy. We show that neutrophils treated with G. kunthiana extract distinctly increased phagocytosis of S. aureus or E. coli. Interestingly, we demonstrate that G. kunthiana bark extract induces the formation of NETs in both cell types. This effect was abolished when treating the cells with diphenyleniodonium chloride (DPI) pointing to a direct implication of the NADPH oxidase-dependent formation of reactive oxygen species in this process. In summary, our data strongly suggest that G. kunthiana bark extract boosts the antimicrobial activities of neutrophils as the first line of defense against invading pathogens.

scholarly journals Antimicrobial Activities of a Plethora of Medicinal Plant Extracts and Hydrolates against Human Pathogens and Their Potential to Reverse Antibiotic Resistance

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Dieudonné Lemuh Njimoh ◽  
Jules Clement N. Assob ◽  
Seraphine Ebenye Mokake ◽  
Dinga Jerome Nyhalah ◽  
Claude Kwe Yinda ◽  
...  
Keyword(s):  
Antimicrobial Activities ◽  
Drug Resistant ◽  
Human Pathogens ◽  
Therapeutic Approaches ◽  
E Coli ◽  
Medicinal Plant Extracts ◽  
Microbial Infections ◽  
Inhibitory Potential ◽  
Conventional Antibiotics ◽  
Nauclea Pobeguinii

Microbial infections till date remain a scourge of humanity due to lack of vaccine against some infections, emergence of drug resistant phenotypes, and the resurgence of infections amongst others. Continuous quest for novel therapeutic approaches remains imperative. Here we (i) assessed the effects of extracts/hydrolates of some medicinal plants on pathogenic microorganisms and (ii) evaluated the inhibitory potential of the most active ones in combination with antibiotics. Extract E03 had the highest DZI (25 mm). Extracts E05 and E06 were active against all microorganisms tested. The MICs and MBCs of the methanol extracts ranged from 16.667 × 103 μg/mL to 2 μg/mL and hydrolates from 0.028 to 333333 ppm. Extract E30 had the highest activity especially againstS. saprophyticus(MIC of 6 ppm) andE. coli(MIC of 17 ppm). Combination with conventional antibiotics was shown to overcome resistance especially with E30. Analyses of the extracts revealed the presence of alkaloids, flavonoids, triterpenes, steroids, phenols, and saponins. These results justify the use of these plants in traditional medicine and the practice of supplementing decoctions/concoctions with conventional antibiotics.Nauclea pobeguinii (E30), the most active and synergistic of all these extracts, and some hydrolates with antimicrobial activity need further exploration for the development of novel antimicrobials.

scholarly journals Trogocytosis-associated cell to cell spread of intracellular bacterial pathogens

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Shaun Steele ◽  
Lauren Radlinski ◽  
Sharon Taft-Benz ◽  
Jason Brunton ◽  
Thomas H Kawula
Keyword(s):  
Immune Cell ◽  
Bacterial Pathogens ◽  
Immune Surveillance ◽  
Cell Types ◽  
Antimicrobial Activities ◽  
Host Cells ◽  
Phagocytic Cells ◽  
Microbial Infections ◽  
Infected Cells

Macrophages are myeloid-derived phagocytic cells and one of the first immune cell types to respond to microbial infections. However, a number of bacterial pathogens are resistant to the antimicrobial activities of macrophages and can grow within these cells. Macrophages have other immune surveillance roles including the acquisition of cytosolic components from multiple types of cells. We hypothesized that intracellular pathogens that can replicate within macrophages could also exploit cytosolic transfer to facilitate bacterial spread. We found that viable Francisella tularensis, as well as Salmonella enterica bacteria transferred from infected cells to uninfected macrophages along with other cytosolic material through a transient, contact dependent mechanism. Bacterial transfer occurred when the host cells exchanged plasma membrane proteins and cytosol via a trogocytosis related process leaving both donor and recipient cells intact and viable. Trogocytosis was strongly associated with infection in mice, suggesting that direct bacterial transfer occurs by this process in vivo.

scholarly journals Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves and Cloves

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1406
Author(s):  
Rita Cava-Roda ◽  
Amaury Taboada-Rodríguez ◽  
Antonio López-Gómez ◽  
Ginés Benito Martínez-Hernández ◽  
Fulgencio Marín-Iniesta
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Food Packaging ◽  
Antimicrobial Effect ◽  
Antimicrobial Activities ◽  
Inhibitory Effects ◽  
Cinnamon Bark ◽  
E Coli ◽  
Pure Compounds ◽  
Main Component

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

scholarly journals Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Food Industry ◽  
Balkan Peninsula ◽  
Antimicrobial Activities ◽  
Natural Sources ◽  
E Coli ◽  
Food Borne ◽  
Metabolite Profiles ◽  
Aspergillus Sp ◽  
First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

scholarly journals Three-Year Trend in Escherichia coli Antimicrobial Resistance among Children’s Urine Cultures in an Italian Metropolitan Area

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 597
Author(s):  
Luca Pierantoni ◽  
Laura Andreozzi ◽  
Simone Ambretti ◽  
Arianna Dondi ◽  
Carlotta Biagi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Metropolitan Area ◽  
Bacterial Infections ◽  
Asymptomatic Bacteriuria ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
First Line ◽  
E Coli ◽  
First Line Therapy ◽  
Tract Infections

Urinary tract infections (UTIs) are among the most common bacterial infections in children, and Escherichia coli is the main pathogen responsible. Several guidelines, including the recently updated Italian guidelines, recommend amoxicillin-clavulanic acid (AMC) as a first-line antibiotic therapy in children with febrile UTIs. Given the current increasing rates of antibiotic resistance worldwide, this study aimed to investigate the three-year trend in the resistance rate of E. coli isolated from pediatric urine cultures (UCs) in a metropolitan area of northern Italy. We conducted a retrospective review of E. coli-positive, non-repetitive UCs collected in children aged from 1 month to 14 years, regardless of a diagnosis of UTI, catheter colonization, urine contamination, or asymptomatic bacteriuria. During the study period, the rate of resistance to AMC significantly increased from 17.6% to 40.2% (p < 0.001). Ciprofloxacin doubled its resistance rate from 9.1% to 16.3% (p = 0.007). The prevalence of multidrug-resistant E. coli rose from 3.9% to 9.2% (p = 0.015). The rate of resistance to other considered antibiotics remained stable, as did the prevalence of extended spectrum beta-lactamases and extensively resistant E. coli among isolates. These findings call into question the use of AMC as a first-line therapy for pediatric UTIs in our population, despite the indications of recent Italian guidelines.

scholarly journals Synthesis and In Vitro Antimicrobial Evaluation of Photoactive Multi—Block Chalcone Conjugate Phthalimide and 1,8-Naphthalimide Novolacs

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Periyan Durairaju ◽  
Chinnasamy Umarani ◽  
Govindasami Periyasami ◽  
Perumberkandigai Adikesavan Vivekanand ◽  
Mostafizur Rahaman
Keyword(s):  
Spectroscopic Analysis ◽  
Photophysical Properties ◽  
Gel Permeation Chromatography ◽  
13C Nmr Spectroscopy ◽  
Antimicrobial Activities ◽  
Microbial Activities ◽  
E Coli ◽  
Molecular Weights ◽  
Antimicrobial Evaluation

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.

A Novel Method for Preparation of Antimicrobial Cellulose Textile by Surface Carbamatization and N-Chlorination

2011 ◽  
Vol 399-401 ◽  
pp. 1088-1092
Author(s):  
Liu Yang Wang ◽  
Fang Ying Wang ◽  
Biao Bing Wang
Keyword(s):  
Nitrogen Content ◽  
Shake Flask ◽  
Antimicrobial Activities ◽  
Sodium Hypochlorite Solution ◽  
E Coli ◽  
Cellulose Fabric ◽  
Carbamate Group ◽  
Novel Method ◽  
Cellulose Fabrics ◽  
Temperature Time

Surface carbamatization of cellulose fabric was accomplished through co-heating with urea. The carbamate group on textile surface was transformed to N-chlorocarbamate after exposure to sodium hypochlorite solution. Effect of carbamatization temperature, time on Nitrogen content of fabrics was investigated, and the effect of bleach technology on chlorine content on fabrics was also studied. Using shake flask method antimicrobial activities against E. coli and S. aureus were studied. The results showed that when carbamatization temperature was 138°C and the time was 3 hours, nitrogen content of cellulose fabric was the highest: 1.47%. Antibacterial ability of cellulose fabrics with 0.81mg/g chlorine against E. coli and S. aureus was 99.9999% and 100%, respectively.

Antibacterial Effects of Long-Chain Polyphosphates on Selected Spoilage and Pathogenic Bacteria

2008 ◽  
Vol 71 (7) ◽  
pp. 1401-1405 ◽  
Author(s):  
JEREMY A. OBRITSCH ◽  
DOJIN RYU ◽  
LUCINA E. LAMPILA ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Food Industry ◽  
Pathogenic Bacteria ◽  
Antimicrobial Activities ◽  
Lag Phase ◽  
E Coli ◽  
Inhibition Of Growth ◽  
K 12 ◽  
Chain Lengths ◽  
And Staphylococcus Aureus ◽  
Long Chain

The antimicrobial activities of four long-chain food-grade polyphosphates were studied at concentrations allowed in the food industry (&lt;5,000 ppm) in defined basal media by determining the inhibition of growth of three gram-negative and four gram-positive spoilage and pathogenic bacteria. Both generation time and lag phase of Escherichia coli K-12, E. coli O157: H7, and Salmonella Typhimurium were increased with all of the polyphosphates tested. Bacillus subtilis and Staphylococcus aureus were more sensitive to polyphosphates, but not in all cases, with multiphased growth. The growth of Lactobacillus plantarum was inhibited by polyphosphates at concentrations above 750 ppm, but the lag time of Listeria monocytogenes was shortened by the presence of polyphosphates. No single polyphosphate was maximally inhibitory against all bacteria. Polyphosphates with chain lengths of 12 to 15 were significantly different from those with chain lengths of 18 to 21 depending on the organism and concentrations of polyphosphate used. Overall, higher polyphosphate concentrations resulted in greater inhibition of bacterial growth.

scholarly journals DPPH-Scavenging and Antimicrobial Activities of Asteraceae Medicinal Plants on Uropathogenic Bacteria

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Phan-Canh Trinh ◽  
Le-Thi-Thanh Thao ◽  
Hoang-Tran-Viet Ha ◽  
TuAnh Nguyen
Keyword(s):  
Antimicrobial Agents ◽  
Natural Antioxidants ◽  
Ethyl Acetate Fraction ◽  
Antimicrobial Activities ◽  
Chrysanthemum Morifolium ◽  
Bacterial Strains ◽  
Ageratum Conyzoides ◽  
Potent Effect ◽  
E Coli ◽  
Dpph Scavenging

Asteraceae species were widely applied in traditional medicines in Asian countries as sources of natural antioxidants and antimicrobial agents. This study aimed to evaluate DPPH-scavenging capacities and antimicrobial activities of nine Asteraceae species collected from Southern Vietnam. Antioxidant and antimicrobial activities were determined by standard protocols. Essential oils from Ageratum conyzoides, Helianthus annuus, and Artemisia vulgaris indicated significant inhibitory effects on Staphylococcus aureus and Candida spp. Crude extracts and fractions from Taraxacum officinale, Chrysanthemum morifolium, A. conyzoides, and Tagetes erecta showed inhibitory ability on at least one testing bacterial strains including S. aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. In a study on clinical isolates, ethyl acetate fraction from A. conyzoides flower displayed the most potent effect on uropathogenic E. coli and K. pneumoniae with MIC at 1.25–10 mg/ml and 5–12.5 mg/ml, respectively. DPPH-scavenging assay indicated that T. erecta extract had the lowest IC50 (17.280 μg/ml) and is 2.4 times higher than vitamin C (7.321 μg/ml). This study revealed that A. conyzoides has good potential against uropathogenic E. coli and K. pneumoniae, and therefore could be applied for prophylactic treatment of urinary infection.

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