scholarly journals Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Multidrug Resistant ◽  
Moderate Activity ◽  
Dependent Manner ◽  
Bacterial Strains ◽  
Acinetobacter Baumanii ◽  
Concentration Dependent Manner ◽  
Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

scholarly journals In Vitro Bactericidal Activity of Human β-Defensin 3 against Multidrug-Resistant Nosocomial Strains

2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bactericidal Activity ◽  
Stenotrophomonas Maltophilia ◽  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Gram Negative

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.

scholarly journals Invitro antibacterial activity of Cassia fistula Linn methanolic leaf extracts

2019 ◽  
Vol 8 (2) ◽  
pp. 270
Author(s):  
Bindhu R. Kamath ◽  
Sabeena Kizhedath
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Cassia Fistula ◽  
Leaf Extracts ◽  
E Coli

Background: Cassia fistula Linn is a plant which is widely grown in India and is used for medicinal purposes. The study was carried out with an objective to demonstrate the antimicrobial activity of leaves of Cassia fistula Linn. The aim of the study is to assess antibacterial and antifungal activity of methanolic leaf extract of Cassia fistula Linn against selected clinical isolates.Methods: The antimicrobial activity of methanolic extract of Cassia fistula was evaluated using agar well diffusion method and to zone of inhibition of extract was determined. Clinical isolates of Staphyloccocus aureus, MRSA, Pseudomonas aeruginosa, E. coli and Proteus were screened.Results: The methanolic extracts exhibited antibacterial activity against Staphylococcus aureus. The extract was not active against E. coli, Proteus, MRSA, Pseudomonas aeruginosa. The extract also failed to demonstrate antifungal activity against Candida albicans and Aspergillus niger.Conclusions: The global emergence of multidrug resistant bacterial strains is increasing, limiting the effectiveness of current drugs and treatment failure of infections. A novel approach to the prevention of antibiotic resistance of pathogenic species is the use of new compounds that are not based on existing synthetic antimicrobial agents.

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 Involvement of pmrAB and phoPQ in Polymyxin B Adaptation and Inducible Resistance in Non-Cystic Fibrosis Clinical Isolates of Pseudomonas aeruginosa

2009 ◽  
Vol 53 (10) ◽  
pp. 4345-4351 ◽  
Author(s):  
Kristen N. Schurek ◽  
Jorge L. M. Sampaio ◽  
Carlos R. V. Kiffer ◽  
Sumiko Sinto ◽  
Caio M. F. Mendes ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Permeability ◽  
Outer Membrane ◽  
Resistance Genes ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Resistant Isolate ◽  
Dependent Manner ◽  
Concentration Dependent Manner

ABSTRACT During investigation of susceptibility testing methods for polymyxins, 24 multidrug-resistant clinical isolates of Pseudomonas aeruginosa were observed to have a distinct, reproducible phenotype in which skipped wells were observed during broth microdilution testing for polymyxin B. Possible mechanisms underlying this phenotype were investigated. The effects of various concentrations of polymyxin B on growth, the expression of resistance genes, and outer-membrane permeability were observed. Real-time PCR was performed to compare the expression, in response to selected concentrations of polymyxin B, of genes related to the PhoP-PhoQ and PmrA-PmrB two-component regulatory systems in polymyxin B-susceptible isolate PAO1, polymyxin B-resistant isolate 9BR, and two isolates (19BR and 213BR) exhibiting the skipped-well phenotype. 19BR and 213BR appeared to have similar basal levels of expression compared to that of PAO1 for phoQ, arnB, and PA4773 (from the pmrAB operon), and in contrast, 9BR had 52- and 280-fold higher expression of arnB and PA4773, respectively. The expression of arnB and PA4773 increased in response to polymyxin B in a concentration-dependent manner for 9BR but not for 19BR and 213BR. For these isolates, expression was significantly increased for arnB and PA4773, as well as phoQ, only upon exposure to 2 μg/ml polymyxin B but not at a lower concentration of 0.125 μg/ml. The sequencing of the pmrAB and phoPQ operons for all three isolates revealed a number of unique mutations compared to that for PAO1. 1-N-phenylnaphthylamine (NPN) was used to study the effect of preincubation with polymyxin B on the self-promoted uptake of polymyxin B across the outer membrane. The preincubation of cells with 2 μg/ml polymyxin B affected baseline membrane permeability in 19BR and 213BR and also resulted in a reduced rate of NPN uptake in these isolates and in PAO1 but not in 9BR. The results presented here suggest that the skipped-well isolates have the ability to adapt to specific concentrations of polymyxin B, inducing known polymyxin B resistance genes involved in generating alterations in the outer membrane.

scholarly journals Biological studies concerning the antioxidant and antimicrobial activities of Pelargonium species cultivated in Egypt (Family-Geraniaceae)

2015 ◽  
Vol 4 (2) ◽  
pp. 340-342
Author(s):  
Abdel Nasser Badawy Singab ◽  
Hala Mohamed El-Hefnawy ◽  
Dalia Galal El-Kolobby
Keyword(s):  
Free Radical ◽  
Radical Scavenging ◽  
Moderate Activity ◽  
Dependent Manner ◽  
Market Place ◽  
Bacterial Strains ◽  
Concentration Dependent Manner ◽  
Biological Studies ◽  
Successive Extraction ◽  
Soxhlet Apparatus

Plant-derived pharmaceuticals have become prominent in the market place, making it a favored healthcare choice. In this study, air dried samples of aerial parts of Pelargonium X fragrans Willd. and Pelargonium peltatum L’Hérit. were separately extracted using successive extraction with a soxhlet apparatus. Each extract was tested for its antimicrobial activity using two Gram-negative bacterial strains (Pseudomonas aeruginosa and Escherichia coli), two Gram-positive bacterial strains (Bacillus subtillus and Staphyllococcus aureus), and clinical fungal isolates (Aspergillus niger and Candida albicans). Also, their antioxidant activity was tested using a DPPH free radical assay. The ethyl acetate, n-Butanol and the total extracts showed moderate activity against the tested microorganisms with significant high activity against E. coli. The free radical scavenging property was found to be in a concentration dependent manner in all the tested fractions. The most effective antioxidant fractions in both spp. was the n-Butanol fraction (85% and 85.2%) at the concentration of 0.375µg/ml followed by the total ethanolic extracts (78.1% and 84.62%), respectively, with the same concentration compared to the standard reference ascorbic acid which showed a significant radicals scavenging potential (79.1%) in the concentration of 1µg/ml.DOI: http://dx.doi.org/10.3329/icpj.v4i2.21481 International Current Pharmaceutical Journal, January 2015, 4(2): 340-342

Complexes of Cu (II) with a-Ketoglutaric Acid and 1- (o-tolyl) Biguanide Synthesis, characterization and biological Activity

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Copper Complexes ◽  
Substrate Adhesion ◽  
Inert Substrate

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

scholarly journals Rhamnolipids Nano-Micelles as a Potential Hand Sanitizer

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Marwa Reda Bakkar ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Elham R. S. Soliman ◽  
Manar S. Fouda ◽  
Amir Mahfouz Mokhtar Sarguos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Active Sites ◽  
Specific Interaction ◽  
Virus Transmission ◽  
Multidrug Resistant ◽  
Future Perspective ◽  
Resistant Bacteria ◽  
In Silico Studies

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.

scholarly journals Transcriptional Response of Multidrug-Resistant Klebsiella pneumoniae Clinical Isolates to Ciprofloxacin Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Roman Farooq Alvi ◽  
Bilal Aslam ◽  
Muhammad Hidayat Rasool ◽  
Saima Muzammil ◽  
Abu Baker Siddique ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Stress Responses ◽  
Genetic Resistance ◽  
Transcriptional Response ◽  
Multidrug Resistant ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Isolation And Identification ◽  
Concentration Dependent Manner ◽  
High Level

Background. The term “persisters” refers to a small bacterial population that persists during treatment with high antibiotic concentration or dose in the absence of genetic resistance. The present study was designed to investigate the transcriptional response in indigenous Klebsiella pneumoniae under the ciprofloxacin stress. Methods. Isolation and identification of K. pneumoniae were carried out through standard microbiological protocols. The characterization of quinolone resistance was performed by estimating the quinolone susceptibility testing, MIC estimation, and detecting the QRDR and PMQR. Transcriptional response of the isolates to ciprofloxacin was determined using qPCR. Results. Among 34 isolates, 23 (67%) were resistant to ciprofloxacin. Both QRDR (gyrA and gyrB) and PMQR (qnrA, qnrB, and qnrS) were detected in the isolates, and all were found resistant to ciprofloxacin. The mRNA levels of both mutS and euTu under the influence of ciprofloxacin were significantly increased. On ciprofloxacin exposure, the mRNA levels of the DNA damage response element (mutS) were raised in a time-dependent fashion. K. pneumoniae showed high-level resistance to ciprofloxacin in the presence of mutations in QRDR and PMQR genes. Conclusion. The transcriptional response revealed the upregulation of DNA repair and protein folding elements (mutS and euTu) in ciprofloxacin stress and delayed cell division. The ciprofloxacin was found to trigger various stress responses in a time- and concentration-dependent manner.

scholarly journals Chemical Composition, Antioxidant and Antibacterial Activity of Bunium persicum, Eucalyptus globulus, and Rose Water on Multidrug-Resistant Listeria Species

2018 ◽  
Vol 23 ◽  
pp. 2515690X1775131 ◽  
Author(s):  
Farhad Sharafati Chaleshtori ◽  
Mohamad Saholi ◽  
Reza Sharafati Chaleshtori
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Eucalyptus Globulus ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Antioxidant Power ◽  
Listeria Species ◽  
Bunium Persicum

This research was aimed at investigating the antioxidant and antibacterial activity of Bunium persicum, Eucalyptus globulus, and rose water on multidrug-resistant Listeria species. The antibiotic resistance of Listeria spp obtained from seafood samples were determined by the Kirby-Bauer method. The antioxidant and antibacterial activity of the essential oils and extracts were evaluated using ferric reducing antioxidant power and microdilution methods, respectively. A total 2 samples (1.88%) were positive for Listeria spp. L monocytogenes was found to be resistant to ampicillin, amoxicillin/clavulanic acid, penicillin, vancomycin, and kanamycin. B persicum essential oil showed the greatest antioxidant activity (248.56 ± 1.09 µM Fe2+/g). The E globulus essential oil showed consistently strong antimicrobial activity against L monocytogenes and L grayi, while rose water showed no antimicrobial activity against any of the tested bacterial strains. The results showed that after adding the B persicum and E globulus essential oils to bacteria, the cell components’ release increased significantly.

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