scholarly journals Antibacterial Mechanism of Silkworm Seroins

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2985
Author(s):  
Hongtao Zhu ◽  
Xiaolu Zhang ◽  
Mengyao Lu ◽  
Haiqin Chen ◽  
Shiyi Chen ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Elisa Test ◽  
Antibacterial Mechanism ◽  
Gram Positive Bacteria ◽  
Terminal Domain ◽  
Silkworm Cocoon ◽  
Bacterial Peptidoglycan

Seroin 1 and seroin 2 are abundant in silkworm cocoon silk and show strong antibacterial activities, and thus are thought to protect cocoon silk from damage by bacteria. In this study, we characterized the expression pattern of silkworm seroin 3, and found that seroin 3 is synthesized in the female ovary and secreted into egg to play its roles. After being infected, seroin 1, 2, and 3 were significantly up-regulated in the silkworm. We synthesized the full-length protein of seroin 1, 2, and 3 and their N/C-terminal domain (seroin-N/C), and compared the antimicrobial activities in vitro. All three seroins showed higher antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria. Seroin 2 showed better antibacterial effect than seroin 1 and 3, whereas seroin 1/2/3-N was better than seroin 1/2/3-C. We found that seroin 2-C has stronger peptidoglycan binding ability than seroin 2-N per the ELISA test. The binding sites of seroin 2 with bacteria were blocked by peptidoglycan, which resulted in the loss of the antibacterial activity of seroin 2. Collectively, these findings suggest that seroin 1 and 2 play antibacterial roles in cocoon silk, whereas seroin 3 functions in the eggs. The three silkworm seroins have the same antibacterial mechanism, that is, binding to bacterial peptidoglycan by the C-terminal domain and inhibiting bacterial growth by the N-terminal domain.

scholarly journals A Preliminary Investigation on the In-Vitro Antibacterial Activities of Cave Actinomycetes

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Asifa Mushtaq ◽  
Musharaf Gul ◽  
Seema Rawat ◽  
Jay Krishan Tiwari
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Scientific Community ◽  
Preliminary Investigation ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Industrial Applications ◽  
Gram Positive Bacteria ◽  
Streptomyces Genus

Actinomycetes are prolific producers of secondary metabolites majority of which have phenomenal industrial applications. Actinomycetes recovered from cave habitats have generated a considerable interest among the scientific community with respect to their adaptability under such unique environmental conditions. Garhwal Himalaya, Uttarakhand abodes several pristine caves which have not been previously explored for the presence of actinomycetes. The present study has been undertaken to assess the in vitro antibacterial properties of actinomycetes recovered from some of the caves located in Garhwal Himalayan region. In the present study, a total of 127 actinomycetes were isolated from three distinct caves. Majority of the isolates exhibited antibacterial activity against gram-positive bacteria. Actinomycetes isolates RCM1 and SCMM1 were observed to evince promising antibacterial activities. Members of Streptomyces genus were found to be predominant in all the samples.

scholarly journals Biogenetic Conversion of Wyerone and Dihydrowyerone into Wyerone Epoxide in Vicia faba Cotyledons and Screening of Antibacterial Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Nedhal A. Al-Douri ◽  
Randa N. Haddadin ◽  
Ashok K. Shakya ◽  
Ghaleb A. Oriquat
Keyword(s):  
Antibacterial Activity ◽  
Vicia Faba ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Stress Factors ◽  
Gram Positive Bacteria ◽  
The Family ◽  
Zones Of Inhibition ◽  
Plant Produce ◽  
First Time

Background. Vicia faba is a plant that belongs to the family Fabaceae. Cotyledons of this plant produce compounds called phytoalexins as a result of fungal and bacterial infection or stress factors. The phytoalexins are furanoacetylenic compounds. They include wyerone, wyerol, wyerone acid, their dihydro derivatives, and wyerone epoxide. These compounds have antimicrobial activities mainly against fungi. Objective. The purpose of this study was to elucidate the biogenetic conversion of wyerone and dihydrowyerone to wyerone epoxide in V. faba and to investigate the antibacterial activities of some of these phytoalexins. Materials and Methods. Seeds of Vicia faba were used. Labelled wyerone and dihydrowyerone were obtained by treating CuCl2-induced cotyledons with sodium (2-14C) acetate and separated by TLC and HPLC. Labelled wyerone and dihydrowyerone were then applied to induced bean cotyledons to establish any possible interconversion to wyerone epoxide. Antibacterial activity of wyerone, wyerone acid, and wyerone epoxide was investigated by disc diffusion test against a panel of microorganisms. Zones of inhibition were reported. Results. The radiolabeling studies showed that 12.4% of 14C-wyerone, and 6.01% of 14C-dihydrowyerone were incorporated into wyerone epoxide. This indicates that wyerone epoxide was most probably derived from wyerone and dihydrowyerone. In addition, a new compound, 11-hydroxywyerone was isolated for the first time. Additionally, this study showed that wyerone, wyerone epoxide, and wyerone acid had no antibacterial activity against Gram-negative bacteria but were active against Gram-positive bacteria.

In Vitro Antibacterial Activities and Mechanisms of Action of Fatty Acid Monoglycerides Against Four Foodborne Bacteria

2020 ◽  
Vol 83 (2) ◽  
pp. 331-337
Author(s):  
WENYUE WANG ◽  
RUI WANG ◽  
GUIJU ZHANG ◽  
FANGLI CHEN ◽  
BAOCAI XU
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Carbon Chain ◽  
Antimicrobial Activities ◽  
Inhibitory Effect ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Alkaline Conditions

ABSTRACT Naturally occurring monoglyceride esters of fatty acids have been associated with a broad spectrum of antimicrobial activities. We used an automated turbidimetric method to measure the MIC and assess the antimicrobial activity of five monoglycerides (monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin) against pathogenic strains of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial activity of monocaprin was highest because its carbon chain is shorter than those of other monoglycerides. The MICs of monocaprin against S. aureus, B. subtilis, P. aeruginosa, and E. coli were 0.32, 0.32, 2.5, and 2.5 mg/mL, respectively. Monocaprin had antibacterial activity under neutral and alkaline conditions (pH 7.0 to 9.0) but had no inhibitory effect on S. aureus, B. subtilis, and E. coli under weakly acidic conditions (pH 6.0). The antibacterial mechanism of monocaprin against gram-positive strains (S. aureus and B. subtilis) resulted from destruction of the cell membrane. In contrast, the antibacterial activity of monocaprin against gram-negative strains (P. aeruginosa and E. coli) was attributed to damage to lipopolysaccharides in the cell walls. Because of its inhibitory effect on both gram-positive and gram-negative bacteria, monocaprin could be used as an antibacterial additive in the food industry. HIGHLIGHTS

scholarly journals In vitro Antibacterial Activity of Mentha spicata Essential Oil against Some Pathogenic Bacteria

2021 ◽  
Vol 11 (1) ◽  
pp. 13-15
Author(s):  
Sara I. Othman ◽  
Fouad H. Kamel
Keyword(s):  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Mentha Spicata ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aerial Parts ◽  
In Vitro Antibacterial Activity ◽  
Pharmaceutical Industries

Mentha spicata (M. spicata) is within family Lamiaceae that spreads mainly in the temperate and subtemperate zones of the world. It is considered as a good source of essential oils (EOs), which is widely used in food production and pharmaceutical industries. The aim of the current study is to evaluate antibacterial activities associated with the EO of M. spicata cultivated in Iraq-Erbil city. The aerial parts of M. spicata were subjected to hydro distillation to extract the oil. Antimicrobial potential was tested against many microorganisms, signifying Gram-negative and Gram-positive bacteria. EO of M. spicata demonstrated antimicrobial activities with best susceptibility observed for Gram-negative bacteria toward the oil. The results suggest that EO of M. spicata may have potential value as antibacterial activities.

scholarly journals IN VITRO ANTIBACTERIAL ACTIVITIES OF DIFFERENT SOLVENT EXTRACTS OF CAJANUS CAJAN L. SEED COAT AND COTYLEDON

2018 ◽  
Vol 11 (5) ◽  
pp. 325
Author(s):  
Pratima H ◽  
Pratima Marthad
Keyword(s):  
Antibacterial Activity ◽  
Seed Coat ◽  
Cajanus Cajan ◽  
Ethanolic Extract ◽  
Antibacterial Activities ◽  
Salmonella Typhi ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Successive Extraction

 Objectives: The present study was conducted to assess the antibacterial activity of seed coat and cotyledon of Cajanus cajan with various solvents such as petroleum ether, chloroform, ethanol, and aqueous.Methods: The crude extracts were obtained using Soxhlet successive extraction method. The antibacterial activity of seed coat and cotyledon extracts at different concentration (50 and 100 mg/mL) was evaluated against certain pathogenic Gram-positive bacteria of Bacillus subtilis, Staphylococcus aureus, and Streptococcus pneumoniae and Gram-negative bacteria of Salmonella typhi, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa by agar well diffusion assay.Results: The results show that the ethanolic extract of seed coat had highest activity against B. subtilis (22.0±0.13 mm). Whereas, the aqueous extract of cotyledon had highest activity against S. aureus (20.0±0.02 mm) and S. typhi (20.0±0.04 mm) at 100 mg/mL. The S. pneumoniae and P. aeruginosa were completely resistant to all extracts of seed coat. Similarly, S. pneumoniae, K. pneumoniae, E. coli, and P. aeruginosa were totally resistant to all tested cotyledon extracts. The phytochemical results show the presence of alkaloids, steroids, phenols, flavonoids, tannins, lignins, glycosides, and absence of saponins in seed coat and cotyledon.Conclusion: This study shows that C. cajan seed coat and cotyledon had potential antibacterial activity against B. subtilis, S. aureus, and S. typhi. These extracts may be exploited for the development of antimicrobial and alternative remedies for infections and diseases caused by respective pathogens.

scholarly journals Biologically relevant surrogates of coumarins: 2-phenyl H-isophosphinoline 2-oxides with antibacterial activity

2021 ◽  
Vol 16 (2) ◽  
pp. 283-296
Author(s):  
Mina Hariri ◽  
Fatemeh Darvish ◽  
Karen-Pacelye Mengue Me Ndong ◽  
Rachida Babouri ◽  
Rachida Babouri ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Biologically Relevant ◽  
Gram Positive Bacteria ◽  
Disk Diffusion Assay ◽  
Selective Antimicrobial Activity ◽  
Diffusion Assay

The present study aims to investigate the in vitro antibacterial activities of several isophosphinoline-2-oxides that can be perceived as combined bio isosteres of coumarins and flavonoids. More specifically, antibacterial activity was evaluated against four bacterial strains, including the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa and the Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis by using disk diffusion assay. Notably, isophosphinoline-2-oxide compounds showed promising and highly selective antimicrobial activity against S. aureus.

scholarly journals In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Load ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Biofilm Model ◽  
Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

scholarly journals Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Positive ◽  
Weak Activity ◽  
Agar Dilution

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

scholarly journals Phytochemical Screening, Polyphenols Content, Antioxidant Power, and Antibacterial Activity of Herniaria hirsuta from Morocco

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kenza Ammor ◽  
Dalila Bousta ◽  
Sanae Jennan ◽  
Bahia Bennani ◽  
Abdellah Chaqroune ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Antioxidant Power ◽  
Negative Effect ◽  
Hydroethanolic Extract

The aim of this study is to investigate in vitro antioxidant and antibacterial activities of the aqueous and hydroethanolic extracts for aerial parts of Herniaria hirsuta. Extracts were screened for their possible antioxidant activities by three tests: DPPH free radical-scavenging, reducing power, and molybdenum systems. The screening of antibacterial activity of extracts was individually evaluated against sixteen bacteria species using a disc diffusion method. Flavonoids, total phenols, and tannins content were performed for both extracts. It shows higher content in the hydroethanolic extract. The hydroethanolic extract showed a significant antioxidant activity for the three methods studies to the aqueous extract, but nonsignificant results compared to the reference (BHT). However, both extracts have negative effect on the strains studies for the antibacterial activity.

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