Ultrastructural localization and antibacterial activity of phenoloxidase in amphioxus Branchiostoma belcheri tsingtauense

2001 ◽  
Vol 81 (4) ◽  
pp. 705-706 ◽  
Author(s):  
Guorong Li ◽  
Shicui Zhang ◽  
Hongyan Li
Keyword(s):  
Antibacterial Activity ◽  
Epithelial Cells ◽  
Active Material ◽  
Specific Inhibitor ◽  
Ultrastructural Localization ◽  
The Body ◽  
Reaction Products ◽  
E Coli ◽  
Branchiostoma Belcheri ◽  
Secondary Lysosomes

Phenoloxidase (PO) has been shown to be present in both invertebrates and vertebrates, yet little is known about the PO in Branchiostoma belcheri tsingtauense. The present study demonstrated that the PO activity existed histochemically the epithelial cells of the gill bar and intestine of adult animal, producing brown to black melanin deposits. Ultrastructural examination revealed that PO reaction products were localized in the cytoplasmic granules of the epidermal cells, the epithelial cells of gill bar and intestine and most of them were electron-dense and homogenous. Frequently, the PO reaction products were also observed in the secondary lysosomes.  The mucus from the body surface had little antibacterial activity against Escherichia coli, but it enhanced the antibacterial activity of L-dopa and the enhancement was suppressed by PTU, a PO specific inhibitor. This indicates that the active material inhibiting the E. coli growth in the mucus is PO.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

scholarly journals Antibacterial Activity of Soap Formulated from Garlic (Allium sativum L.) Extract

2021 ◽  
pp. 63-67
Author(s):  
John Lloyd Bernaldez ◽  
Manuela Cecille G. Vicencio
Keyword(s):  
Antibacterial Activity ◽  
Physical Properties ◽  
Allium Sativum ◽  
The Body ◽  
Phytochemical Screening ◽  
E Coli ◽  
Commercial Soap ◽  
Unpleasant Odor ◽  
Ph Range ◽  
Paper Disc

Allium sativum, commonly known as ‘garlic’ has long been used as an antibacterial agent that can actually inhibits growth of infectious agents and at the same time protect the body from the pathogens. This study was conducted to determine the antibacterial activity of soap from garlic extract using the paper-disc method and Kirby-Bauer antibacterial sensitivity test against Staphylococcus aureus and Escherichia coli, and to determine the physical properties of garlic soap and the presence of saponin through phytochemical screening. Garlic soap showed antibacterial activity against E. coli and S. aureus. Mean zone of inhibition was numerically higher in plate extract obtained using garlic soap (14.70mm-18mm), compared to commercial soap. Result of phytochemical screening showed the extract from garlic contains saponin, which is an important ingredient for making soap. Physical properties showed unpleasant odor, dirty white color, smooth texture and pH range of 6.5-7.5. Further studies to determine the potential of garlic soap in the other strains of bacteria.

scholarly journals Antibacterial Activity of Chlorhexidine Bigluconate in Relation to Biofilm Monocultures

2021 ◽  
Vol 6 (1) ◽  
pp. 184-193
Author(s):  
G. G. Chistyakova ◽  
◽  
G. A. Skorokhod ◽  
I. O. Pohodenko-Chudakova
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Statistical Processing ◽  
Single Species ◽  
Modern Medicine ◽  
Reduction Factor ◽  
The Body ◽  
Contact Method ◽  
E Coli ◽  
High Level

On the background of a high percentage of caries incidence, the prevalence of its complications is increasing – pulpitis, apical periodontitis. Teeth with complicated caries can cause odontogenic inflammatory processes in the maxillofacial region. Being foci of chronic infection and intoxication, they have an adverse effect on the body as a whole. In connection with the above, it is obvious that determining the optimal concentration of chlorhexidine bigluconate and exposure to the dentin of the crown part of the tooth in case of carious lesion of the latter is currently very important. The purpose of the study was to evaluate the antimicrobial activity of chlorhexidine (by suspension and contact method) in various concentrations in relation to monocultures of biofilm formed on tooth sections and in U-shaped 96-well plastic plates. Material and methods. In this work, one of the most relevant pathogens for modern medicine was Staphylococcus aureus, which was one of the most powerful pathogens that form biofilms, was used as a model. The antimicrobial activity of chlorhexidine bigluconate was evaluated on S. aureus and E. coli biofilm cultures formed on dental samples and in polystyrene plastic tablets. Antimicrobial activity was evaluated by the reduction factor was determined by the difference in the number of decimal logarithms of CFU/ml in the experiment compared to the control. The obtained data was subjected to statistical processing. Results and discussion. The study revealed that 2.0 % solution of chlorhexidine bigluconate had a high level of antibacterial activity against tablet biofilm cultures of S. aureus and E. coli. When it was exposed to S. aureus and E. coli tablet biofilm cultures with exposures of 30 and 60 seconds, statistically significant differences were found (p=0.02). Secondly, statistically significant differences in the effect of sensitivity of single-species biofilm cultures of dental samples to the effect of antiseptic at the specified concentration were determined (p=0.007). At the same time, the level of antibacterial activity of 2.0 % chlorhexidine bigluconate solution in respect of tablet biofilm cultures of S. aureus and E. coli was significantly higher than in biofilm cultures of S. aureus and E. coli of dental samples (p<0.05). Conclusion. The obtained results give grounds for using them in clinical practice in order to improve the effectiveness of caries treatment which will help reduce the number of complications and on the one hand, corresponds to the main direction of medicine ‒ prevention and on the other hand, increases the level of specialized medical care provided to the population as a whole

scholarly journals CorA Affects Tolerance of Escherichia coli and Salmonella enterica Serovar Typhimurium to the Lactoperoxidase Enzyme System but Not to Other Forms of Oxidative Stress

2005 ◽  
Vol 71 (11) ◽  
pp. 6515-6523 ◽  
Author(s):  
Jan Sermon ◽  
Eva M.-R. P. Wevers ◽  
Leentje Jansen ◽  
Philipp De Spiegeleer ◽  
Kristof Vanoirbeek ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Stress Responses ◽  
Salmonella Enterica ◽  
Specific Inhibitor ◽  
Open Reading Frames ◽  
Reaction Products ◽  
E Coli ◽  
Lactoperoxidase System ◽  
Serovar Typhimurium

ABSTRACT The enzyme lactoperoxidase is part of the innate immune system in vertebrates and owes its antimicrobial activity to the formation of oxidative reaction products from various substrates. In a previous study, we have reported that, with thiocyanate as a substrate, the lactoperoxidase system elicits a distinct stress response in Escherichia coli MG1655. This response is different from but partly overlapping with the stress responses to hydrogen peroxide and to superoxide. In the current work, we constructed knockouts in 10 lactoperoxidase system-inducible genes to investigate their role in the tolerance of E. coli MG1655 to this antimicrobial system. Five mutations resulted in a slightly increased sensitivity, but one mutation (corA) caused hypersensitivity to the lactoperoxidase system. This hypersensitive phenotype was specific to the lactoperoxidase system, since neither the sensitivity to hydrogen peroxide nor to the superoxide generator plumbagin was affected in the corA mutant. Salmonella enterica serovar Typhimurium corA had a similar phenotype. Although corA encodes an Mg2+ transporter and at least three other inducible open reading frames belonged to the Mg2+ regulon, repression of the Mg stimulon by Mg2+ did not change the lactoperoxidase sensitivity of either the wild-type or corA mutant. Prior exposure to 0.3 mM Ni2+, which is also transported by CorA, strongly sensitized MG1655 but not the corA mutant to the lactoperoxidase system. Furthermore, this Ni2+-dependent sensitization was suppressed by the CorA-specific inhibitor Co(III) hexaammine. These results indicate that CorA affects the lactoperoxidase sensitivity of E. coli by modulating the cytoplasmic concentrations of transition metals that enhance the toxicity of the lactoperoxidase system.

scholarly journals Aktivitas Antibakteri Ekstrak Etanol Daun Gatal (Laportea aestuans (L.) Chew)

2018 ◽  
Vol 9 (1) ◽  
pp. 1-7
Author(s):  
Eva S. Simaremare ◽  
Agustina Ruban ◽  
Dirk Y.P. Runtuboi
Keyword(s):  
Antibacterial Activity ◽  
Local Community ◽  
Ethanol Extract ◽  
Salmonella Typhi ◽  
The Body ◽  
Diffusion Method ◽  
Disc Diffusion Method ◽  
E Coli ◽  
Indigenous Plant ◽  
Made In

Daun gatal (Laportea aestuans) is an indigenous plant of Papua hich has been widely used for pain relief as traditional medication in the local community. The leaves were just picked then treated to cure for painful body. This treatment are giving itchy sense as an indication that medication is working on the body as local people assumed. The aim of the study was to determine the activity of antibacteria of daun gatal against Escherichia coli, Staphylococcus aureus and Salmonella typhi. Samples of daun gatal were collected from Biak Numfor Papua. The methods are started with filtering of daun gatal using 100 mash and extracted with ethanol. Extract was made in 250, 500, 750, 1000 ppm, with chloramphenicol as a control positive, while the test of antibacterial activity was done by disc diffusion method. The results showed that daun gatal has antibacterial activity against E. coli, S. aureus and S. typhi. Daun gatal extract (L. aestuans) is effective in inhibiting the growth of bacterias with zone inhibition of 1000 ppm extracts which were 8.55 mm (E. coli), 9.02 mm (S. typhi), dan 9.37 mm (S. aureus). Key words: Antibacteria, E. coli, L. aestuans, S. aureus and S. typhi.

scholarly journals Novel Antibacterial Peptides Isolated from the Maillard Reaction Products of Half-Fin Anchovy (Setipinna taty) Hydrolysates/Glucose and Their Mode of Action in Escherichia coli

Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 47 ◽  
Author(s):  
Jiaxing Wang ◽  
Rongbian Wei ◽  
Ru Song
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Liquid Chromatography ◽  
Maillard Reaction ◽  
Size Exclusion ◽  
H2o2 Production ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
E Coli ◽  
Production Of Hydrogen

The Maillard reaction products (MRPs) of half-fin anchovy hydrolysates and glucose, named as HAHp(9.0)-G MRPs, were fractionated by size exclusion chromatography into three major fractions (F1–F3). F2, which demonstrated the strongest antibacterial activity against Escherichia coli (E. coli) and showed self-production of hydrogen peroxide (H2O2), was extracted by solid phase extraction. The hydrophobic extract of F2 was further isolated by reverse phase-high performance liquid chromatography into sub-fractions HE-F2-1 and HE-F2-2. Nine peptides were identified from HE-F2-1, and two peptides from HE-F2-2 using liquid chromatography-electrospray ionization/multi-stage mass spectrometry. Three peptides, FEDQLR (HGM-Hp1), ALERTF (HGM-Hp2), and RHPEYAVSVLLR (HGM-Hp3), with net charges of −1, 0, and +1, respectively, were synthesized. The minimal inhibitory concentration of these synthetic peptides was 2 mg/mL against E. coli. Once incubated with logarithmic growth phase of E. coli, HGM-Hp1 and HGM-Hp2 induced significant increases of both extracellular and intracellular H2O2 formation. However, HGM-Hp3 only dramatically enhanced intracellular H2O2 production in E. coli. The increased potassium ions in E. coli suspension after addition of HGM-Hp1 or HGM-Hp2 indicated the destruction of cell integrity via irreversible membrane damage. It is the first report of hydrolysates MRPs-derived peptides that might perform the antibacterial activity via inducing intracellular H2O2 production.

The role of 17β-estrogen in Escherichia coli adhesion on human vaginal epithelial cells via FAK phosphorylation

2021 ◽  
Author(s):  
Xia Liu ◽  
Ting Luan ◽  
Wanqing Zhou ◽  
Lina Yan ◽  
Hua Qian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Specific Inhibitor ◽  
Estrogen Receptor Α ◽  
Epithelial Cell Line ◽  
Vaginal Epithelial Cell ◽  
E Coli ◽  
Vaginal Epithelial Cells

Estrogen, the predominant sex hormone, has been found to be related to the occurrence of vaginal infectious diseases. However, its role in the occurrence and development of bacterial vaginitis caused by Escherichia coli is still unclear. The objective of this study was to investigate the role of 17β-estrogen in E. coli adhesion on human vaginal epithelial cells. The vaginal epithelial cell line, VK2/E6E7, was used to study the molecular events induced by estrogen between E. coli and cells. An adhesion study was performed to evaluate the involvement of the estrogen-dependent focal adhesion kinase (FAK) activation with cell adhesion. The phosphorylation status of FAK and estrogen receptor α (ERα) upon estrogen challenge was assessed by Western blotting. Specific inhibitors for ERα were used to validate the involvement of ERα-FAK signaling cascade. The results showed that, following the stimulation with 1000 nM estrogen for 48 h, a transient activation of ERα and FAK was observed, as well as the increased average number of E. coli adhering to vaginal epithelial cell. In addition, estrogen-induced activation of ERa and FAK was inhibited by the specific inhibitor of ERα, especially when the inhibitor reached a 10 μM concentration and acted for 1 h, and a decrease in the number of adherent E. coli was observed simultaneously. However, this inhibitory effect diminished as the concentration of estrogen increased. In conclusion, FAK and ERα signaling cascades were assosiated with the increasing E. coli adherence to vaginal epithelial cells, which was promoted by a certain concentration of estrogen.

Antibacterial Activity of Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Kyoung- Sun Seo ◽  
Seong Woo Jin ◽  
Seongkyu Choi ◽  
Kyeong Won Yun
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Agent ◽  
Methanol Extract ◽  
The Other ◽  
Diffusion Method ◽  
E Coli ◽  
Agar Diffusion ◽  
Agar Diffusion Method ◽  
Crude Methanol Extract

The antibacterial activity of three Cupressaceae plants (Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa) was tested against three bacteria using the agar diffusion method. The ether and ethylacetate fraction of crude methanol extract from the three plants showed potent antibacterial activity against the tested microorganisms. The result showed that Staphylococcus aureus revealed the most sensitivity among the tested bacteria. Thujaoccidentalisether fraction and Thujaorientalis hexane fraction exhibited the highest antibacterial activity against Staphylococcus aureus. E. coli was shown the highest MIC values compared to the other two tested bacteria, which indicates the lowest antibacterial activity against the bacterium. This study promises an interesting future for designing a potentially active antibacterial agent from the three Cupressaceae plants.

Bioenhancing Effect of Cow Urine Distillate and Pepper Extract on Antibacterial Activity of Azadirachta Indica Leaves

1970 ◽  
Vol 9 (2) ◽  
pp. 3212-3214
Author(s):  
Pramod Dhakal ◽  
Ankit a Achary ◽  
Vedamurthy Joshi
Keyword(s):  
Antibacterial Activity ◽  
Azadirachta Indica ◽  
Pathogenic Bacteria ◽  
Ethanol Extract ◽  
Watery Diarrhea ◽  
Diffusion Method ◽  
E Coli ◽  
Drug Molecules ◽  
Cow Urine

Bioenhancers are drug facilitator which do not show the typical drug activity but in combination to enhance the activity of other molecule in several way including increase the bioavailability of drug across the membrane, potentiating the drug molecules by conformational interaction, acting as receptor for drug molecules and making target cell more receptive to drugs and promote and increase the bioactivity or bioavailability or the uptake of drugs in combination therapy. The objective of the present study was to evaluate the antibacterial and activity of combination in Azadirachta indica extract with cow urine distillate and pepper extract against common pathogenic bacteria, a causative agent of watery diarrhea. It has been found that Indian indigenous cow urine and its distillate also possess bioenhancing ability. Bioenhancing role of cow urine distillate (CUD) and pepper extract was investigated on antibacterial activity of ethanol extract of Azadirachta indica. Antibacterial activity of ethanol extract neem alone and in combination with CUD and pepper extract were determined the ATCC strains against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and E-coli by cup plate diffusion method. Ethanol extract of neem has showed more effect on P. aeruginosa, E-coli than S. aureus and K. pneumonia with combination of CUD and pepper extract. CUD and pepper did not show any inhibition of test bacteria in low concentration. The antibacterial effect of combination of extract and CUD was higher than the inhibition caused by extract alone and is suggestive of the bioenhancing role of cow urine distillate and pepper. Moreover, inhibition of test bacteria was observed with less concentration of extract on combining with CUD

Identification of N-Substituted Triazolo-azetidines as Novel Antibacterials using pDualrep2 HTS Platform

2019 ◽  
Vol 22 (5) ◽  
pp. 346-354
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Large Scale ◽  
Underlying Mechanism ◽  
Luciferase Assay ◽  
Reporter System ◽  
E Coli ◽  
Starting Point ◽  
High Concentrations ◽  
Mic Value

Aim and Objective: Antibiotic resistance is a serious constraint to the development of new effective antibacterials. Therefore, the discovery of the new antibacterials remains one of the main challenges in modern medicinal chemistry. This study was undertaken to identify novel molecules with antibacterial activity. Materials and Methods: Using our unique double-reporter system, in-house large-scale HTS campaign was conducted for the identification of antibacterial potency of small-molecule compounds. The construction allows us to visually assess the underlying mechanism of action. After the initial HTS and rescreen procedure, luciferase assay, C14-test, determination of MIC value and PrestoBlue test were carried out. Results: HTS rounds and rescreen campaign have revealed the antibacterial activity of a series of Nsubstituted triazolo-azetidines and their isosteric derivatives that has not been reported previously. Primary hit-molecule demonstrated a MIC value of 12.5 µg/mL against E. coli Δ tolC with signs of translation blockage and no SOS-response. Translation inhibition (26%, luciferase assay) was achieved at high concentrations up to 160 µg/mL, while no activity was found using C14-test. The compound did not demonstrate cytotoxicity in the PrestoBlue assay against a panel of eukaryotic cells. Within a series of direct structural analogues bearing the same or bioisosteric scaffold, compound 2 was found to have an improved antibacterial potency (MIC=6.25 µg/mL) close to Erythromycin (MIC=2.5-5 µg/mL) against the same strain. In contrast to the parent hit, this compound was more active and selective, and provided a robust IP position. Conclusion: N-substituted triazolo-azetidine scaffold may be used as a versatile starting point for the development of novel active and selective antibacterial compounds.

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