Preparation and evaluation of antibacterial properties of Pexiganan, a Magainin analogue with Broadly-Spectrum Antimicrobial Activity

2021 ◽  
Vol 15 (6) ◽  
pp. 1778-1784
Author(s):  
Kiarash Ghazvini ◽  
Alireza Neshani ◽  
Hadi Farsiani

Introduction: Pexiganan is one of the most popular Maganin-2 analogues, which has broadly- spectrum bactericidal effects against both gram-positive and gram-negative bacteria. In this study, the effects of temperature, pH, and in vitro resistant analysis were evaluated on the antibacterial activity of this peptide. Materials and Methods: Pexiganan recombinant was expressed in P. pastoris GS115, and after its characterization, the cell cytotoxicity characteristics, effects of temperature on antibacterial activity, as well as the emergence of resistance to pexiganan in continuous sub-cultures and MIC of this peptide were investigated against 12 bacterial pathogens. Results: Pexiganan was not cytotoxic to HeLa cell lines. Increasing the temperature had no effect on the zone of inhibition, but increasing the pH caused a significant increase in MIC against S. aureus ATCC 29213 strain. In addition, Pexiganan had inhibitory properties against all the 12 human pathogens (MIC range: 1-32 /g / ml), and no resistance was observed even after 28 sub- cultures. Conclusion: Pexiganan is an AMP with antimicrobial properties against a wide range of susceptible and drug-resistant human pathogens with a very low rate of resistance compared to available antibiotics and is a reliable candidate for further investigation on therapeutic applications. Keywords: Pexiganan; Antimicrobial Peptides; Resistance; Minimum Inhibitory Concentration

2019 ◽  
Vol 65 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Yu.V. Butina ◽  
T.V. Kudayarova ◽  
E.A. Danilova ◽  
M.K. Islyaikin

The work is devoted to predicting and studying biological properties of N-substituted analogs of 3,5-diamino-1,2,4-thiadiazole, which, in their turn, include in the composition of many drugs that exhibit a wide range of pharmacological actions. For searching of new alternative drugs with an antibacterial activity, but lacking resistance of microorganism strains to them, a computer screening of 2N-alkyl-substituted 5-amino-3-imino-1,2,4-thiadiazolines previously synthesized by us was carried out. The prediction of the spectrum of biological activity, as well as the determination of the probable toxicity of these compounds, was performed using the freely available computer programs PASS, Anti-Bac-Pred, and GUSAR. The study of the antibacterial activity in vitro against gram-positive (Staphylococcus aureus, Staphylococcus saprophyticus, Staphylococcus epidermidis) and gram-negative (Escherichia coli, Pseudomonas aeruginosae) bacterial strains was performed by the disco-diffusion method. Experimental data roughly correspond to the predictions.


Author(s):  
Festus O. Taiwo ◽  
Craig A. Obafemi ◽  
David A. Akinpelu A. Akinpelu

Aims: This studies aims at the synthesis of new heterocyclic systems and study its biological and pharmacological properties. Objective: This study was designed to synthesized some quinoxaline-2,3-dione with sulfonamide moiety, characterize the synthesized compounds, and study the antimicrobial properties of the synthesized compounds on some bacterial strains. Materials and Methods: Six quinoxaline-6-sulfonohydrazone derivatives were synthesized by reacting quinoxaline-6-sulfonohydrazine with some substituted benzaldehydes and ketones. The compounds were tested for their potential antibacterial properties. Results: All the test compounds possessed promising antibacterial property against a panel of bacterial strains used for this study. The MIC values exhibited by these compounds ranged between 0.0313 and 0.250 mg/mL. Among the compounds tested, compound 2 showed appreciable antibacterial activity. Discussion and Conclusion: The study concluded that all the compounds exhibited appreciable bactericidal effects towards all the bacterial strains, particularly, compound 2 This is an indication that such compounds possessing broad spectrum activities will be useful in formulating antimicrobial compounds which could be used to treat infections caused by pathogens that are now developing resistance against the available antibiotics.


2019 ◽  
pp. 96-104
Author(s):  
N. Hrynchuk ◽  
N. Vrynchanu

The emergence and spread of antibiotic-resistant strains of microorganisms reduces the effectiveness of antibiotic therapy and requires finding solutions to problems, one of which is the study of antimicrobial properties in drugs of various pharmacological groups. The purpose of the work was to summarize the data on the antibacterial activity of thioridazine and its derivatives to determine the feasibility and prospects of creating new antibacterial drugs on their basis. The paper presents literature data on the effects of thioridazine on the causative agent of tuberculosis, antistaphylococcal activity, susceptibility of plasmodium and trypanosoma. The antibacterial activity of the drug was established within in vitro studies with the determination of MIC towards gram-positive and gram-negative microorganisms, ex vivo using macrophage lines, as well as within in vivo experiments on mice. It is established that the neuroleptic thioridazine is characterized by pronounced anti-tuberculosis activity, the mechanism of action is associated with the impact on the cell membrane of M. tuberculosis, inactivation by calmodulin and inhibition of specific NADH-dehydrogenase type II. The literature data indicate that thioridazine is able to increase the activity of isoniazid against the strains of mycobacteria that are susceptible and resistant to its action. It has been established that resistance to thioridazine in antibiotic-resistant M. tuberculosis strains is not formed. The drug is characterized by its ability to inhibit the growth and reproduction of both methicylin-sensitive (MSSA) and methicilin-resistant (MRSA) strains of Staphylococcus aureus, which has been proven within in vitro experiments. The effectiveness of thioridazine has been proven within in vivo experiments in case of skin infection and sepsis caused by S. aureus. Antimicrobial effect of the drug is also observed towards to plasmodium (P. falciparum) and trypanosomes (Trypanosoma spp.). Currently, the synthesis of thioridazine derivatives is carried out to identify compounds with a pronounced antibacterial effect. Some of the first synthesized compounds are not inferior or superior to thioridazine by the inhibitory effect. Thus, these data suggest that drugs of different pharmacological groups, including drugs that affect the nervous system - thioridazine and its derivatives, can be a source of replenishment of the arsenal of antimicrobial drugs to control such threatening infections as tuberculosis and diseases caused by polyresistant strains of microorganisms.


2019 ◽  
Vol 34 (2) ◽  
pp. 125-127
Author(s):  
Md Sahadat Hossain ◽  
Kamal Kanta Das ◽  
Mrityunjoy Acharjee

Current investigation depicted in-vitro antibacterial activity of available betel leaf (sweet, hot and fresh betel leaves) collected from different place of Bangladesh. The in-vitro antimicrobial activities of the ethanol and methanol extracts of the betel leaf were noticeable against tested bacteria. Among 3 categories of samples, the antibacterial action of ethanol extracts of hot betal leaf was found the highest against most of the bacteria except Klebsiella sp. and Staphylococcus sp., while the methanol extract showed antibacterial activity against all the pathogenic strains tested. The highest MIC (1mg/ml) and the lowest MIC values (25mg/ml) of hot betel leaf and sweet betel leaf were found against E. coli and all test organisms, respectively. This evidence revealed that betel leaf extracts can be used to combat against human pathogens. Bangladesh J Microbiol, Volume 34 Number 2 December 2017, pp 125-127


2021 ◽  
Vol 285 ◽  
pp. 05012
Author(s):  
A. K. Milyuhinа ◽  
L. A. Zabodalova ◽  
U. Kyzdarbek ◽  
I. R. Romazyaeva ◽  
N. Yu. Klyuchko

Rosmarinus officinalis L. is known for its antioxidant and antibacterial properties against a variety of microorganisms. In this work, research has been carried out on pharmacy rosemary. Its antioxidant and antimicrobial properties have been determined. This study showed that the ethanol extract of R. officinalis L. has a pronounced antimicrobial activity against strains of both gram-positive and gram-negative bacteria. The extract also showed good antioxidant activity. Rosemary showed significantly more potent antibacterial activity against E. coli. The diameter of the zone of oppression was 17 mm. Thus, Rosemary Pharmaceutical has demonstrated potential as a dietary supplement due to its stronger antibacterial activity.


2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  

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.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3854
Author(s):  
Joanna Czechowska ◽  
Ewelina Cichoń ◽  
Anna Belcarz ◽  
Anna Ślósarczyk ◽  
Aneta Zima

Bioactive, chemically bonded bone substitutes with antibacterial properties are highly recommended for medical applications. In this study, biomicroconcretes, composed of silicon modified (Si-αTCP) or non-modified α-tricalcium phosphate (αTCP), as well as hybrid hydroxyapatite/chitosan granules non-modified and modified with gold nanoparticles (AuNPs), were designed. The developed biomicroconcretes were supposed to combine the dual functions of antibacterial activity and bone defect repair. The chemical and phase composition, microstructure, setting times, mechanical strength, and in vitro bioactive potential of the composites were examined. Furthermore, on the basis of the American Association of Textile Chemists and Colorists test (AATCC 100), adapted for chemically bonded materials, the antibacterial activity of the biomicroconcretes against S. epidermidis, E. coli, and S. aureus was evaluated. All biomicroconcretes were surgically handy and revealed good adhesion between the hybrid granules and calcium phosphate-based matrix. Furthermore, they possessed acceptable setting times and mechanical properties. It has been stated that materials containing AuNPs set faster and possess a slightly higher compressive strength (3.4 ± 0.7 MPa). The modification of αTCP with silicon led to a favorable decrease of the final setting time to 10 min. Furthermore, it has been shown that materials modified with AuNPs and silicon possessed an enhanced bioactivity. The antibacterial properties of all of the developed biomicroconcretes against the tested bacterial strains due to the presence of both chitosan and Au were confirmed. The material modified simultaneously with AuNPs and silicon seems to be the most promising candidate for further biological studies.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3628
Author(s):  
Anna Woziwodzka ◽  
Marta Krychowiak-Maśnicka ◽  
Grzegorz Gołuński ◽  
Anna Felberg ◽  
Agnieszka Borowik ◽  
...  

Antimicrobial resistance is a major healthcare threat globally. Xanthines, including caffeine and pentoxifylline, are attractive candidates for drug repurposing, given their well-established safety and pharmacological profiles. This study aimed to analyze potential interactions between xanthines and aromatic antibiotics (i.e., tetracycline and ciprofloxacin), and their impact on antibiotic antibacterial activity. UV-vis spectroscopy, statistical-thermodynamical modeling, and isothermal titration calorimetry were used to quantitatively evaluate xanthine-antibiotic interactions. The antibacterial profiles of xanthines, and xanthine-antibiotic mixtures, towards important human pathogens Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, and Enterobacter cloacae were examined. Caffeine and pentoxifylline directly interact with ciprofloxacin and tetracycline, with neighborhood association constant values of 15.8–45.6 M−1 and enthalpy change values up to −4 kJ·M−1. Caffeine, used in mixtures with tested antibiotics, enhanced their antibacterial activity in most pathogens tested. However, antagonistic effects of caffeine were also observed, but only with ciprofloxacin toward Gram-positive pathogens. Xanthines interact with aromatic antibiotics at the molecular and in vitro antibacterial activity level. Given considerable exposure to caffeine and pentoxifylline, these interactions might be relevant for the effectiveness of antibacterial pharmacotherapy, and may help to identify optimal treatment regimens in the era of multidrug resistance.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Lian-Hua Fu ◽  
Qing-Long Gao ◽  
Chao Qi ◽  
Ming-Guo Ma ◽  
Jun-Feng Li

Silver-based antimicrobial nanomaterials are considered as the most promising antibacterial agents owing to their outstanding antimicrobial efficacy and their relatively low toxicity to human beings. In this work, we report on a facile and environment-friendly microwave-hydrothermal method to prepare cellulose/Ag nanocomposites using hemicellulose as the reductant. The influences of the microwave-hydrothermal heating time and temperature, as well as the hemicellulose concentration on the formation of cellulose nanocomposites, were investigated in detail. Experimental results indicated that the hemicellulose was an effective reductant for silver ions, with higher temperature and longer heating time favoring the formation of silver with higher crystallinity and mass content in the nanocomposites. Moreover, the antimicrobial properties of the as-prepared cellulose/Ag nanocomposites were explored using Gram-positive S. aureus ATCC 6538 and Gram-negative E. coli HB 101 by both disc diffusion method and agar dilution method, and the nanocomposites showed excellent antibacterial activity. These results demonstrate that the as-prepared cellulose/Ag nanocomposites, as a kind of antibacterial material, are promising for applications in a wide range of biomedical fields.


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