scholarly journals Characterization and Antimicrobial Efficacy of Bovine Dermcidin, a Novel Antimicrobial Peptide Gene

2019 ◽  
Author(s):  
Nevien Sabry ◽  
Tarek Moussa
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Disulfide Bonds ◽  
Ph Value ◽  
Rna Isolation ◽  
Antimicrobial Effect ◽  
Blood Analysis ◽  
Bacterial Strains ◽  
Nacl Concentration ◽  
Peptide Gene

Description of a novel bovine antimicrobial peptide and its antimicrobial spectrum. RNA isolation and RT-PCR were done from various tissues. DCD peptide was synthesized, and antimicrobial activity was analyzed. Bovine dermcidin gene contains five exons intermittent by 4 introns. Bovine DCD-mRNA was 398 bp with ORF 336 bp. Bovine DCD was expressed in skin and blood. Analysis of the amino acid compositions revealed that cysteine was repeated 6 times indicating the presence of 3 disulfide bonds that play role in the peptide stability. Staphylococcus epidermidis, Streptococcus bovis, and Enterococcus faecalis were affected by Bovine DCD peptide. Highest antimicrobial effect was at 50 and 100 µg/ml. The effect on Escherichia coli and Candida albicans was slightly low. In all bacteria, Bovine DCD peptide activity did not affect by varying pH values, but in Staphylococcus aureus, the activity was affected greatly at pH 4.5 and 5.5. The optimum salt concentrations were 100 and 50 mM NaCl with all bacterial strains and E. coli, respectively. In case of C. albicans, the antimicrobial activity of Bovine DCD peptide decreased with increasing the pH value regardless the NaCl concentration. The pH 6.5 of the sweat buffer was the optimum for the Bovine DCD peptide activity.

In vitro antimicrobial and preliminary phytochemical screening of some Samburu Anti‐diarrhoeal medicinal plants ‐ Kenya

2012 ◽  
Vol 2 (5) ◽  
pp. 217-226
Author(s):  
E. O. Omwenga ◽  
P. O. Okemo ◽  
P. K. Mbugua
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plants ◽  
Fungal Pathogens ◽  
Antimicrobial Effect ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Fungal Strains ◽  
Local Isolate ◽  
Agar Disc

The antimicrobial effect of some selected Samburu medicinal plants was evaluated on bacterial strains like Staphylococcus aureus ‐ ATCC 20591, Bacillus subtillis ‐ Local isolate, Salmonella typhi‐ATCC 2202, Escherichia coli‐STD. 25922 and Pseudomonas aeroginosa ‐ ATCC 25852 and fungal strains like Candida albicans ATCC EK138, Aspergillus niger ATCC 16404, Aspergillusflavus‐Local isolate, Fusarium lateritium‐Local isolate, and Penicillium spp.‐ local isolate. Methanol was used as solvent for the extraction from the selected medicinal plants used by the Samburu community. The in vitro antimicrobial activity was performed by agar disc diffusion and micro‐dilution technique. The most susceptible Gram‐positive bacterium was S. aureus, while the most susceptible Gram‐negative bacterium was P. aeroginosa. The extracts of Gomphocarpus fruticosus (L) W.T. Aiton showed less activity against the bacterial strains investigated. The most active antibacterial plants were Euphorbia scarlatica S. Carter, and Euclea divinoram Hiern. Incidentally most of the extracts were inactive against the fungal strains with only a few proving to be slightly active against the C. albicans i.e. Loranthus acaciae Zucc., Kedrostis pseudogijef (Gilg) C. Jeffrey, Euclea divinoram Hiern. and Croton macrostachyus (A. Rich). Benths. The significant antimicrobial activity of active extracts was compared with the standard antimicrobials, cefrodoxima, amoxicillin and fluconazole. The MICs of the most active plants ranged from 18.75mg/ml to 37.50mg/ml. The MBCs ranged between 18.75mg/ml to75mg/ml. These results were significant at P< 0.01. The findings show that most of the medicinal plants used by the Samburu community have some significant activity on the bacterial but not fungal pathogens known to cause diarrhoea.

scholarly journals In Vitro Assessment for Antimicrobial Activity of Lactobacillus Helveticus and its Natural Glycopeptides Against Mastitis Causing Pathogens in Dairy Cat

2015 ◽  
Vol 9 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Gundega Gulbe ◽  
Anda Valdovska ◽  
Vaira Saulite ◽  
Jevgenijs Jermolajevs
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Lactobacillus Helveticus ◽  
Haemolytic Activity ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Coagulase Negative Staphylococci

Probiotic lactic acid bacteria have a great potential to control bovine mastitis as well as they are favourable choice to treat many infectious diseases of human. These bacteria are well known as having many properties which make them beneficial to control pathogenic microorganisms. These include, the ability to adhere to cell, the reduction of pathogenic bacteria adherents, the co–aggregation, the production of organic acids, hydrogen peroxide, bacteriocin and etc., to be safe and non–pathogenic, which antagonize pathogenic microorganisms. However, each strain must be well identified and characterized in vitro before using for disease treatment. The aim of the present study was to screen three kind of test suspensions: TS1, TS2 and TS3, which contains probiotic lactic acid bacterium Lactobacillus helveticus or its natural glycopeptides, and other natural immunomodulators, in order to investigate which content were the most effective in inhibiting several mastitis causing bacteria in dairy cattle: coagulase–positive Staphylococcus aureus, coagulase–negative staphylococci S. haemolyticus, S. saprophyticus, S. simulans, S. vitulinus, and Gram–negative bacteria Citrobacter freundii and Serratia liquefaciens. Test suspensions TS1, TS2 and TS3 were adjusted by pH 6.3, then tested in vitro by well diffusion assay to determine their antimicrobial effect against bacteria. Furthermore haemolytic activity of applied test suspensions were determined. In results TS1 (9-13 mm) and TS2 (10-15 mm) showed the inhibition effect on four of eight tested bacterial strains, whereas TS3 did not displayed any antimicrobial effect. TS2 have a greatest antimicrobial activity as they resulted in the largest inhibition zones.

scholarly journals Antibacterial Activity of Melissa officinalis L., Mentha piperita L., Origanum vulgare L. and Malva mauritiana against Bacterial Microflora Isolated from Fish

2017 ◽  
Vol 1 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Alīna Klūga ◽  
Margarita Terentjeva ◽  
Attila Kántor ◽  
Maciej Kluz ◽  
Czeslaw Puchalski ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Effect ◽  
Enterobacter Cloacae ◽  
Mentha Piperita ◽  
Bacterial Strains ◽  
Melissa Officinalis ◽  
Origanum Vulgare ◽  
Flight Mass Spectrometry ◽  
Serratia Liquefaciens

Abstract The aim of the present study was to detect the antibacterial activity of medicinal plants against fish microflora. A total of 4 ethanolic extracts of 6 plant species were collected from local environments of Slovakia and screened for antibacterial activity against bacterial microflora. Extracts of Melissa officinalis L., Mentha piperita L., Origanum vulgare L. and Malva mauritiana were used. Bacterial strains were isolated from common bleak (Alburnus alburnus) and common rudd (Scardinius erythrophthalmus) of Latvian origin. All bacterial strains were identified with the Matrix- Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). Among fish microflora, Acinetobacter pittii, A. baumannii, Buttiauxella agrestis, Delftia acidovorans, Enterobacter cloacae, Serratia liquefaciens, Pseudomonas alcaligenes, Ps. oryzihabitans, Staphylococcus epidermidis, St. caprae, Pantoea agglomerans, Lelliottia amnigena, Providencia rettgeri, Escherichia coli and Rahnella aquatilis were identified. It has been shown that all plant extracts exhibit different degrees of antimicrobial activity against the tested bacteria. All bacterial strains in the present study were moderate sensitive to all extracts applied. The strongest antimicrobial effect of Malva mauritiana and Melissa officinalis L. against Pseudomonas oryzihabitans (6.67±1.53 resp. 9.67±0.58 mm) were found. The best antimicrobial activity of Mentha piperita L. was against Staphylococcus epidermis (7.33±0.58 mm) and strongest antimicrobial effect of Origanum vulgare L. was same against two bacterial strains Enterobacter cloacae and Serratia liquefaciens (9.67±0.58 mm).

scholarly journals Antibacterial Activity of Nanoemulsions Based on Essential Oils Compounds Against Species of Xanthomonas that Cause Citrus Canker

2021 ◽  
Vol 12 (2) ◽  
pp. 1835-1846
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Antimicrobial Effect ◽  
Citrus Canker ◽  
Agitation Speed ◽  
Bacterial Disease ◽  
Particle Sizes ◽  
Bacterial Strains ◽  
Citrus Production ◽  
Great Damage

Citrus canker is a bacterial disease that affects citrus crops, caused by microorganisms of the genus Xanthomonas responsible for great damage to citrus production. In this work, the antimicrobial effect of nanoemulsions based on the major compounds of essential oils (EOs) eugenol, thymol, geraniol and menthone were investigated against two strains of Xanthomonas that cause citrus canker (Xac and XauB). Nanoemulsions were produced for each compound using two different stirring speeds (7,000 and 12,000 rpm). All nanoemulsions underwent analysis to characterize particle sizes and stability. Thymol nanoemulsions had the smallest particle sizes (59.8 to 73.9 nm) and the highest stability and also showed the ability to inhibit the development of both strains of bacteria, with minimum inhibitory concentrations (MIC) of 0.03% (v/v), along with eugenol (0.03% (v/v) for Xac and 0.02% (v/v) for XauB) and geraniol nanoemulsions (0.06% (v/v) for both bacteria). Thymol was the compound with the highest minimum bactericidal concentrations (MBC), with values of 0.03% (v/v) for both bacterial strains. Eugenol showed MBC only against XauB, at a concentration of 0.03% (v/v). Geraniol did not show bactericidal activity, suggesting a bacteriostatic action of this compound with the tested microorganisms. In general, the antimicrobial activity of the nanoemulsions was increased with increased agitation speed, particle reduction and greater stability. Therefore, nanoemulsification can be an alternative to applying the antimicrobial activity of natural compounds in the control of citrus canker.

scholarly journals Transcriptome Analysis of Psacothea hilaris: De Novo Assembly and Antimicrobial Peptide Prediction

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 676 ◽  
Author(s):  
Joon Ha Lee ◽  
Hoyong Chung ◽  
Yong Pyo Shin ◽  
In-Woo Kim ◽  
Sathishkumar Natarajan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Peptide ◽  
De Novo ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Illumina Platform ◽  
E Coli ◽  
Innate Defense

Antimicrobial peptides (AMPs) are the frontline innate defense system evolutionarily preserved in insects to combat invading pathogens. These AMPs could serve as an alternative to classical antibiotics to overcome the burden of treating multidrug resistant bacteria. Psacotheasin, a knottin type AMP was isolated from Psacothea hilaris and shown to exhibit antimicrobial activity, especially against fungi through apoptosis mediated cell death. In this study, we aimed to identify novel probable AMPs from Psacothea hilaris, the yellow spotted longicorn beetle. The beetle was immunized with the two bacterial strains (E. coli and S. aureus), and the yeast strain C. albicans. After immunization, total RNA was isolated and sequenced in Illumina platform. Then, beetle transcriptome was de novo assembled and searched for putative AMPs with the known physiochemical features of the AMPs. A selection of AMP candidates were synthesized and tested for antimicrobial activity. Four peptides showed stronger activity against E. coli than the control AMP, melittin while one peptide showed similar activity against S. aureus. Moreover, four peptides and two peptides showed antifungal activity stronger than and similar to melittin, respectively. Collectively one peptide showed both antibacterial and antifungal activity superior to melittin; thus, it provides a potent antimicrobial peptide. All the peptides showed no hemolysis in all the tested concentrations. These results suggest that in silico mining of insects’ transcriptome could be a promising tool to obtain and optimize novel AMPs for human needs.

scholarly journals Effect of pH on the antimicrobial activity of the macrophage metabolite itaconate

Microbiology ◽  
2021 ◽  
Vol 167 (5) ◽  
Author(s):  
Dustin Duncan ◽  
Andréanne Lupien ◽  
Marcel A. Behr ◽  
Karine Auclair
Keyword(s):  
Antimicrobial Activity ◽  
Type Species ◽  
Antimicrobial Effect ◽  
Bacterial Strains ◽  
Content Type ◽  
Biologically Relevant ◽  
Link Type ◽  
Activity Measurements ◽  
Serovar Typhimurium ◽  
The Media

The production of itaconate by macrophages was only discovered in 2011. An increasing number of studies have since revealed essential biological functions for this small molecule, ranging from antimicrobial to immunomodulator. The antibacterial role of itaconate has however been questioned because the estimated concentration of itaconate in macrophages (low-millimolar) is lower than the minimum inhibitory concentration (MIC) of itaconate reported for several bacterial strains (low-to-mid-millimolar). We note that some of these investigations have tended to ignore the high acidity of this small diacid (pKas 3.85 and 5.45), thereby potentially biassing activity measurements. We measured the MIC of itaconate in Escherichia coli (not known to metabolize itaconate) and in Salmonella enterica serovar Typhimurium (known to metabolize itaconate) at varying pH values to probe the effect that pH has on itaconate toxicity. Herein, we demonstrate that the antimicrobial effect of itaconate is dependent upon the pH of the media and that itaconate does have antimicrobial activity at biologically relevant pH and concentrations. Under nutrient-poor conditions, the antimicrobial activity of itaconate in both E. coli and S. Typhimurium increased approximately 200-fold when the pH was dropped by one unit, whereas itaconate was not found to be toxic under nutrient rich conditions. Our results also reveal that the activity of itaconate is synergistic with acidity, yet is not a function of increased permeability with protonation. Similar experiments performed with succinate (a pKa-matched diacid) yielded drastically different results, consistent with a target-based mechanism of action for itaconate. Overall, our work shows the importance of controlling the pH when performing experiments with itaconic acid.

scholarly journals In vitro antimicrobial activity of total extracts of the leaves of Petiveria alliacea L. (Anamu)

2013 ◽  
Vol 49 (2) ◽  
pp. 241-250 ◽  
Author(s):  
Ania Ochoa Pacheco ◽  
Jorge Marín Morán ◽  
Zenia González Giro ◽  
Adrian Hidalgo Rodríguez ◽  
Rachel Juliet Mujawimana ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Isopropyl Alcohol ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Antimicrobial Effect ◽  
Bacterial Strains ◽  
Chemical Parameters ◽  
Petiveria Alliacea ◽  
Quality Control Parameters

The antimicrobial activity of 13 total extracts was evaluated, 10 soft extracts (B) and 3 blended extracts (E) prepared from dry and fresh leaves of Petiveria alliacea L. Various solvents were used for their preparation: hydroalcoholic solution at 30%, 80% and isopropyl alcohol. The antimicrobial effect of the extracts was tested by means of the method of Kirby-Bauer, using four bacterial strains from the ATCC collection (Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa) and a leveduriform fungus (Candida albicans). The following quality control parameters were determined for most active extracts: physical, physical-chemical and chemical parameters. The results were: nine extracts showed antibacterial activity, being the most concentrated (B8 and E3), the ones with the highest activity in the presence of the bacteria tested; the effect of blended extracts (E1, E2 and E3) was greater in the presence of P. aeruginosa. Blended extracts are considered more potent and active than soft extracts. No antifungal activity was obtained for both types of extracts. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined for both extracts, with the following results: MIC-soft extracts (>100 mg/mL), blended extracts (>50 mg/mL); MBC-soft extracts (≥400 mg/mL), blended extracts (≥200 mg/mL) based on fresh leaves.

scholarly journals High-Quality Nucleic Acid Isolation from Hard-to-Lyse Bacterial Strains Using PMAP-36, a Broad-Spectrum Antimicrobial Peptide

2021 ◽  
Vol 22 (8) ◽  
pp. 4149
Author(s):  
Hye-sun Cho ◽  
Munjeong Choi ◽  
Yunjung Lee ◽  
Hyoim Jeon ◽  
Byeongyong Ahn ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Broad Spectrum ◽  
Bacterial Species ◽  
Rna Isolation ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
High Quality ◽  
Nucleic Acid Isolation

The efficiency of existing cell lysis methods to isolate nucleic acids from diverse bacteria varies depending on cell wall structures. This study tested a novel idea of using broad-spectrum antimicrobial peptides to improve the lytic efficiency of hard-to-lyse bacteria and characterized their differences. The lysis conditions of Staphylococcus aureus using recombinant porcine myeloid antimicrobial peptide 36 (PMAP-36), a broad-spectrum pig cathelicidin, was optimized, and RNA isolation was performed with cultured pellets of ten bacterial species using various membranolytic proteins. Additionally, three other antimicrobial peptides, protegrin-1 (PG-1), melittin, and nisin, were evaluated for their suitability as the membranolytic agents of bacteria. However, PMAP-36 use resulted in the most successful outcomes in RNA isolation from diverse bacterial species. The amount of total RNA obtained using PMAP-36 increased by ~2-fold compared to lysozyme in Salmonella typhimurium. Streptococci species were refractory to all lytic proteins tested, although the RNA yield from PMAP-36 treatment was slightly higher than that from other methods. PMAP-36 use produced high-quality RNA, and reverse transcription PCR showed the efficient amplification of the 16S rRNA gene from all tested strains. Additionally, the results of genomic DNA isolation were similar to those of RNA isolation. Thus, our findings present an additional option for high quality and unbiased nucleic acid isolation from microbiomes or challenging bacterial strains.

scholarly journals Antimicrobial Activity of Aqueous Extracts of Potentilla Reptans L. Rhizome and Aerial Part

2018 ◽  
Vol 19 (4) ◽  
pp. 321-324 ◽  
Author(s):  
Marina Tomovic ◽  
Marija Popovic-Milenkovic ◽  
Slobodan Jankovic
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Aerial Part ◽  
Antimicrobial Effect ◽  
Diffusion Method ◽  
Aqueous Extracts ◽  
Bacterial Strains ◽  
The Family ◽  
Potentilla Reptans

Abstract Potentilla reptans is a little studied plant of the genus Potentilla, the family Rosaceae. The aim of this study is to determine antimicrobial effects of aqueous extracts of P. reptans aerial part and rhizome against standardized bacterial strains. The antimicrobial activity of aqueous extracts of P. reptans aerial part and rhizome was tested against one fungus, Candida albicans, and two standard bacterial strains, Staphylococcus aureus and Escherichia coli, using an agar diffusion method. Both examined extracts showed a significant antimicrobial activity against Escherichia coli and Staphylococcus aureus at the concentrations of 10 to 150 mg/ml. The rhizome extract showed stronger antimicrobial effect against the tested strains of bacteria than the aerial part extract. The obtained results represent preliminary results of antimicrobial activity of this plant and suggest that in future, the studies should examine antimicrobial activity against other bacterial strains and minimum inhibitory concentration.

scholarly journals Fatty Acid Conjugation Leads to Length-Dependent Antimicrobial Activity of a Synthetic Antibacterial Peptide (Pep19-4LF)

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 844
Author(s):  
Philip Storck ◽  
Florian Umstätter ◽  
Sabrina Wohlfart ◽  
Cornelius Domhan ◽  
Christian Kleist ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Antimicrobial Activity ◽  
Fatty Acid ◽  
Antimicrobial Peptide ◽  
Saturated Fatty Acids ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
High Antimicrobial Activity ◽  
Hydrophobic Motif

The increasing number of infections caused by multidrug-resistant bacteria requires an intensified search for new antibiotics. Pep19-4LF is a synthetic antimicrobial peptide (GKKYRRFRWKFKGKLFLFG) that was previously designed with the main focus on high antimicrobial activity. The hydrophobic motif, LFLFG, was found to be essential for antimicrobial activity. However, this motif shows several limitations such as aggregation in biological media, low solubility, and small yields in peptide synthesis. In order to obtain more appropriate peptide characteristics, the hydrophobic motif was replaced with fatty acids. For this purpose, a shortened variant of Pep19-4LF (Pep19-short; GKKYRRFRWKFKGK) was synthesized and covalently linked to saturated fatty acids of different chain lengths. The peptide conjugates were tested with respect to their antibacterial activity by microdilution experiments on different bacterial strains. The length of the fatty acid was found to be directly correlated to the antimicrobial activity up to an ideal chain length (undecanoic acid, C11:0). This conjugate showed high antimicrobial activity in absence of toxicity. Time–kill studies revealed a fast and bactericidal mode of action. Furthermore, the first in vivo experiments of the conjugate in rodents demonstrated pharmacokinetics appropriate for application as a drug. These results clearly indicate that the hydrophobic motif of the peptide can be replaced by a single fatty acid of medium length, simplifying the design of this antimicrobial peptide while retaining high antimicrobial activity in the absence of toxicity.

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