The antimicrobial peptide DGL13K is active against resistant gram-negative bacteria and subinhibitory concentrations stimulate bacterial growth without causing resistance

2020 ◽  
Author(s):  
Zhang-He Goh
Keyword(s):  
Antimicrobial Peptide ◽  
Bacterial Growth ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Subinhibitory Concentrations

scholarly journals Interaction of Antimicrobial Peptide Temporin L with Lipopolysaccharide In Vitro and in Experimental Rat Models of Septic Shock Caused by Gram-Negative Bacteria

2006 ◽  
Vol 50 (7) ◽  
pp. 2478-2486 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Roberto Ghiselli ◽  
Federico Mocchegiani ◽  
Fiorenza Orlando ◽  
...  
Keyword(s):  
Septic Shock ◽  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Amphibian Skin ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Rat Models ◽  
E Coli ◽  
Tnf Α

ABSTRACT Sepsis remains a major cause of morbidity and mortality in hospitalized patients, despite intense efforts to improve survival. The primary lead for septic shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the quest for compounds with antiendotoxin properties is actively pursued. We investigated the efficacy of the amphibian skin antimicrobial peptide temporin L in binding Escherichia coli LPS in vitro and counteracting its effects in vivo. Temporin L strongly bound to purified E. coli LPS and lipid A in vitro, as proven by fluorescent displacement assay, and readily penetrated into E. coli LPS monolayers. Furthermore, the killing activity of temporin L against E. coli was progressively inhibited by increasing concentrations of LPS added to the medium, further confirming the peptide's affinity for endotoxin. Antimicrobial assays showed that temporin L interacted synergistically with the clinically used β-lactam antibiotics piperacillin and imipenem. Therefore, we characterized the activity of temporin L when combined with imipenem and piperacillin in the prevention of lethality in two rat models of septic shock, measuring bacterial growth in blood and intra-abdominal fluid, endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, and lethality. With respect to controls and single-drug treatments, the simultaneous administration of temporin L and β-lactams produced the highest antimicrobial activities and the strongest reduction in plasma endotoxin and TNF-α levels, resulting in the highest survival rates.

scholarly journals Improved Derivatives of Bactenecin, a Cyclic Dodecameric Antimicrobial Cationic Peptide

1999 ◽  
Vol 43 (5) ◽  
pp. 1274-1276 ◽  
Author(s):  
Manhong Wu ◽  
Robert E. W. Hancock
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Tryptophan Residue ◽  
Gram Negative Bacteria ◽  
Cationic Peptide ◽  
Gram Positive ◽  
Antimicrobial Spectrum ◽  
Gram Negative ◽  
Derivatives Of

ABSTRACT Both linear and cyclic derivatives of the cyclic 12-amino-acid antimicrobial peptide bactenecin were designed based on optimization of amphipathicity and charge location. In general, increasing the number of positive charges at the N and C termini and adding an extra tryptophan residue in the loop not only increased the activities against both gram-positive and gram-negative bacteria but also broadened the antimicrobial spectrum.

scholarly journals Interactions of an antimicrobial peptide, magainin 2, with outer and inner membranes of Gram-negative bacteria

1997 ◽  
Vol 1327 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Katsumi Matsuzaki ◽  
Ken-ichi Sugishita ◽  
Mitsunori Harada ◽  
Nobutaka Fujii ◽  
Koichiro Miyajima
Keyword(s):  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals “Clicking” an Ionic Liquid to a Potent Antimicrobial Peptide: On the Route towards Improved Stability

2020 ◽  
Vol 21 (17) ◽  
pp. 6174
Author(s):  
Ana Gomes ◽  
Lucinda J. Bessa ◽  
Patrícia Correia ◽  
Iva Fernandes ◽  
Ricardo Ferraz ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Peptide ◽  
Clinical Isolate ◽  
Bioactive Peptides ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Improved Stability

A covalent conjugate between an antibacterial ionic liquid and an antimicrobial peptide was produced via “click” chemistry, and found to retain the parent peptide’s activity against multidrug-resistant clinical isolates of Gram-negative bacteria, and antibiofilm action on a resistant clinical isolate of Klebsiella pneumoniae, while exhibiting much improved stability towards tyrosinase-mediated modifications. This unprecedented communication is a prelude for the promise held by ionic liquids -based approaches as tools to improve the action of bioactive peptides.

scholarly journals Optimization of Agitation Rate in Bioreactor Increases Chitinase Activity of Serratia marcescens PT6

2020 ◽  
Vol 147 ◽  
pp. 03019
Author(s):  
Amara Faiz Wriahusna ◽  
Niswah Umhudloh Dzakiyya ◽  
Indun Dewi Puspita ◽  
Sri Pudjiraharti
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Growth ◽  
Agar Medium ◽  
Chitinase Activity ◽  
Colloidal Chitin ◽  
Gram Negative Bacteria ◽  
Agitation Rate ◽  
Anova Analysis ◽  
Gram Negative ◽  
Shrimp Pond

Serratia marcescens PT6 is a Gram-negative bacteria isolated from shrimp pond sediment that capable of producing chitinase. This study aimed to observe the effect of agitation rate on growth and chitinase activity of S. marcescens PT-6 in a bioreactor. The production of chitinase was done in 1.5 l bioreactor using colloidal chitin broth at the condition of pH 7, the temperature of 30°C, aeration of 0.04 vvm, and variation of agitation rate (200, 350, 500 rpm). Bacterial growth was measured by colonies counting in agar medium, while chitinase activity was measured by means of colorimetric every day for four days incubation. The results of ANOVA analysis show that the agitation rate had no effect on bacterial growth, but a significant effect (P<0.05) was observed on chitinase activity. The highest growth and chitinase activity were obtained at 200 rpm, with the highest chitinase activity of 0.006 ± 0.001 U/ml was at day-2. This study implies that the optimized agitation rate in the bioreactor increased the chitinase activity produced by S. marcescens PT-6.

scholarly journals Pattern of antibiotic resistance of various strains of bacteria causing acute tonsillitis

2021 ◽  
Vol 7 (6) ◽  
pp. 994
Author(s):  
N. Jyothsna ◽  
A. Ramya ◽  
K. Abhilash ◽  
Bathsa Liza Johnson
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Growth ◽  
Bacterial Strain ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Acute Tonsillitis ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antibiotic Drugs ◽  
Significant Difference

<p class="abstract"><strong>Background:</strong> Our study was done to determine the pattern of antibiotic resistance of various strains of bacteria causing acute tonsillitis.</p><p class="abstract"><strong>Methods:</strong> the study was a randomized cross sectional study. Patients matching the inclusion criteria were included. Duration of study was 6 months.</p><p class="abstract"><strong>Results:</strong> Out of 120 cases, 46 cases showed no bacterial growth (NBG) and 74 cases showed bacterial growth. 42 cases were gram-negative bacterial strain and 32 cases were positive bacterial strain out of 72 bacterial grown cases. A list of 25 antibiotic drugs in gram-negative and 31 drugs in gram-positive strain, their sensitivity and resistance were taken and noted. Among gram-negative bacteria imipenem (71.4%) showed highest sensitivity. Highest antibiotic resistance was seen in ampicillin (85.71%). Least sensitivity is observed in clindamycin, amoxicillin+clavulanic acid with 2.38%. Among gram-positive bacteria, highest sensitivity was noted in cefotaxime (75%). Highest antibiotic resistance was seen in cotrimoxazole (46.8%). Least sensitivity is observed in netilmicin, sulbactam with 3.12%.</p><p class="abstract"><strong>Conclusions:</strong> The number of drugs resistant to the gram-positive bacteria are lesser than number of drugs sensitive, which showed significant difference (p&lt;0.05). Significant difference of antibiotic drugs was not found in gram-negative bacteria. Our study findings helped in appropriate and guarded use of the antibiotic drugs in acute tonsillitis, minimizing the exposure of individuals to antibiotic resistance by choosing an appropriate sensitive drug, therefore improving the quality of therapy.</p>

scholarly journals NMR Study of the Secondary Structure and Biopharmaceutical Formulation of an Active Branched Antimicrobial Peptide

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4290 ◽  
Author(s):  
Francesca Castiglia ◽  
Fabrizia Zevolini ◽  
Giulia Riolo ◽  
Jlenia Brunetti ◽  
Alessandra De Lazzari ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Antimicrobial Peptide ◽  
Process Development ◽  
Pharmacokinetic Profile ◽  
Point Of View ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Acinetobacter Baumanii ◽  
Gram Negative ◽  
Nmr Study

The synthetic antimicrobial peptide SET-M33 is being developed as a possible new antibacterial candidate for the treatment of multi-drug resistant bacteria. SET-M33 is a branched peptide featuring higher resistance and bioavailability than its linear analogues. SET-M33 shows antimicrobial activity against different species of multi-resistant Gram-negative bacteria, including clinically isolated strains of Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanii and Escherichia coli. The secondary structure of this 40 amino acid peptide was investigated by NMR to fully characterize the product in the framework of preclinical studies. The possible presence of helixes or β-sheets in the structure had to be explored to predict the behavior of the branched peptide in solution, with a view to designing a formulation for parenteral administration. Since the final formulation of SET-M33 will be strictly defined in terms of counter-ions and additives, we also report the studies on a new salt form, SET-M33 chloride, that retains its activity against Gram-negative bacteria and gains in solubility, with a possible improvement in the pharmacokinetic profile. The opportunity of using a chloride counter-ion is very convenient from a process development point of view and did not increase the toxicity of the antimicrobial drug.

Inhibition of Food-Borne Pathogens by T1, a Novel Antimicrobial Peptide as a Potential Food Preservative

2008 ◽  
Vol 4 (4) ◽  
Author(s):  
Yali Tang ◽  
Yonghui Shi ◽  
Wei Zhao ◽  
Gang Hao ◽  
Guowei Le
Keyword(s):  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Food Preservative ◽  
Recombinant Peptide ◽  
Gram Negative ◽  
Food Borne Pathogens ◽  
Theoretical Design ◽  
Food Borne ◽  
Antimicrobial Mechanism ◽  
Potential Food

An efficient and convenient purifying procedure for recombinant peptide was established. Thereby, the aimed antimicrobial peptide T1 containing the conservative sequences derived from cecropin was successfully expressed and purified. The composition of amino acid of the purified peptide T1 was consistent with that of theoretical design. The significant antimicrobial activity of T1 against gram-positive and gram-negative bacteria was demonstrated, suggesting that the conservative sequences in cecropin play an important role in the antimicrobial mechanism and that antimicrobial peptide T1 has the potential to be used as the food preservative.

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