scholarly journals An Evaluation of the Antibacterial Properties of Tormentic Acid Congener and Extracts From Callistemon viminalis on Selected ESKAPE Pathogens and Effects on Biofilm Formation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Tafadzwa Chipenzi ◽  
Genuine Baloyi ◽  
Tatenda Mudondo ◽  
Simbarashe Sithole ◽  
Godloves Fru Chi ◽  
...  

ESKAPE pathogens, namely, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, are responsible for a majority of all healthcare-acquired infections (HAI). The bacteria cause nosocomial infections in immunocompromised patients. Extracts from Callistemon viminalis have been shown to have antibacterial, antifungal, and anti-inflammatory activities. Tormentic acid congener, a pentacyclic triterpene saponin, was isolated from C. viminalis leaves. This study aimed to investigate the antibacterial effects of tormentic acid congener and leaf extracts on biofilm formation by A. baumannii, S. aureus, S. pyogenes, and P. aeruginosa. The antibacterial effects were determined by the microbroth dilution method, and ciprofloxacin was used as the standard antibacterial drug. Biofilm formation and detachment assays were performed using crystal violet staining. Production of extracellular polymeric DNA and polysaccharides from biofilms was also determined. Tormentic acid congener showed time-dependent antibacterial activity against P. aeruginosa with a MIC of 100 µg/ml and caused significant protein leakage. Antibacterial activity was found when tormentic acid congener was tested against both S. aureus and P. aeruginosa. The MICs were found to be 25 µg/ml and 12.5 µg/ml for P. aeruginosa and S. aureus cells, respectively. S. pyogenes was found to be susceptible to tormentic acid congener and the hydroethanolic extract with an MIC of 100 µg/ml and 25 µg/ml, respectively. A. baumannii was found not to be susceptible to the compound or the extracts. The compound and the extracts caused a significant decrease in the biofilm extracellular polysaccharide content of S. pyogenes. The extracts and tormentic acid congener caused detachment of biofilms and decreased the release of extracellular DNA and capsular polysaccharides from biofilms of P. aeruginosa and S. aureus. Tormentic acid congener and extracts, thus, have significant antibacterial and antibiofilm activities on these selected ESKAPE bacteria and can act as source lead compounds for the development of antibacterial triterpenoids.

2014 ◽  
Vol 67 (10) ◽  
pp. 1471 ◽  
Author(s):  
Naveen K. Dolla ◽  
Chao Chen ◽  
Jonah Larkins-Ford ◽  
Rajmohan Rajamuthiah ◽  
Sakthimala Jagadeesan ◽  
...  

Berberine–INF55 hybrids are a promising class of antibacterials that combine berberine and the NorA multidrug resistance pump inhibitor INF55 (5-nitro-2-phenylindole) together in one molecule via a chemically stable linkage. Previous studies demonstrated the potential of these compounds for countering efflux-mediated antibacterial drug resistance but they didn’t establish whether the compounds function as originally intended, i.e. with the berberine moiety providing antibacterial activity and the attached INF55 component independently blocking multidrug resistance pumps, thereby enhancing the activity of berberine by reducing its efflux. We hypothesised that if the proposed mechanism is correct, then hybrids carrying more potent INF55 pump inhibitor structures should show enhanced antibacterial effects relative to those bearing weaker inhibitors. Two INF55 analogues showing graded reductions in NorA inhibitory activity compared with INF55 were identified and their corresponding berberine–INF55 hybrids carrying equivalent INF55 inhibitor structures synthesised. Multiple assays comparing the antibacterial effects of the hybrids and their corresponding berberine–INF55 analogue combinations showed that the three hybrids all show very similar activities, leading us to conclude that the antibacterial mechanism(s) of berberine–INF55 hybrids is different from berberine–INF55 combinations.


2018 ◽  
pp. 52-56
Author(s):  
D. V. Tapalsky ◽  
K. M. Kosenkova

Objective : to study antibacterial properties of Hypogymnia physodes extract and its combinations with antibiotics against vancomycin-sensitive and vancomycin-resistant strains of enterococci. Material and methods. Minimum inhibitory concentrations (MICs) of the acetone extract of H. physodes for reference and clinical isolates of Enterococcus faecalis were determined by the serial broth dilution method. Evaluation of efficiency of the combined effect of the H. physodes extract in combination with antibiotics was carried out using the modified disc-diffusion method and «chessboard» method. Results. We have revealed marked antibacterial activity (MIC 32-64 mcg/ml) of the acetone extract of H. physodes against vancomycin-sensitive and vancomycin-resistant strains of enterococci and found a synergistic effect (ΣFIC from 0.125 to 0.375) of the combination of the H. physodes extract and aminoglycosides against E. faecalis , including vancomycin-resistant strains. Conclusion. H. physodes is a promising source of compounds with antibacterial activity, further research is required to identify and isolate a secondary metabolite having synergistic activity in combination with aminoglycosides from the lichen extract.


2017 ◽  
Vol 49 (2) ◽  
pp. 93
Author(s):  
Agni Febrina Pargaputri ◽  
Elly Munadziroh ◽  
Retno Indrawati

Background: Enterococcus. faecalis (E. faecalis) and Fusobacterium nucleatum (F. nucleatum) are the most common bacteria found in infected tooth root canal. Most of these bacteria often cause failure in endodontic treatments. Pluchea indica Less leaf is a species of plants that has several chemical properties. It consists of flavonoids, tannins, polyphenols, and essensial oils which have been reported as antibacterial agents. Because of its benefits, the extract of Pluchea indica Less leaves may be potentially developed as one of root canal sterilization dressing. Purpose: This study aimed to determine antibacterial activity of Pluchea indica Less leaves extract against E. faecalis and F. nucleatum bacteria. Method: Dilution method was conducted first to show Minimum Inhibitory Concentration (MIC) of the extract against E. faecalis and F. nucleatum. The antibacterial activity test on Pluchea indica Less leaves extract was performed on E. faecalis and F. nucleatum bacteria using agar diffusion method. The Pluchea indica Less leaves extract used for antibacterial activity test was at a concentrations of 100%, 50%, 25%, 12.5%, and 6.25%. Thirty-five petridiscs were used and divided into five groups based on the extract concentration. Result: The results showed strong and moderate antibacterial effects of the Pluchea indica Less leaves extract on E. faecalis at the concentrations of 100% and 50%, while on F. nucleatum only at the concentration of 100% with moderate effect. Conclusion: Pluchea indica Less leaves extract has antibacterial activity against E. faecalis and F. nucleatum bacteria with strong-moderate effect.


Author(s):  
Pradeep K Naik ◽  
Debasmita Dubey ◽  
Priya Cheruvanachari ◽  
Animesh Pattnaik ◽  
Swaraj K Babu

Aim: To evaluate the antibacterial efficacy, the presence of different phytoconstituents of the leaf extracts of Indian plant Celastrus paniculatus against 6 antibiotic-resistant bacteria along with the evaluation of their antioxidant potentiality. Methods: The leaf extracts were prepared using 4 solvents, water, methanol, n-butanol, and acetone. The antibacterial property was evaluated using agar well diffusion and micro-broth dilution method. Qualitative phytochemical analysis was performed using standard protocols for each solvent extract to check for the presence of the secondary metabolites and phytochemicals which attributes to the antibacterial effectivity of C. paniculatus. Further, the antioxidant potentiality of all the 4 leaf-solvent-extracts was estimated using the DPPH method. Results: The n-butanol leaf extract exhibited the highest antibacterial and antioxidant activity, followed by acetone, methanol extracts. The aqueous extracts exhibited negligible antibacterial activity. Conclusion: This study validated the antibacterial properties of C. paniculatus leaf extracts against both gram-positive and negative bacteria and the phytochemical analysis revealed the presence of many secondary importance which can be attributed to its therapeutic properties. Hence, this plant can be further used as a complementary or alternative choice of drug for combatting multidrug-resistant bacterial pathogens. Keywords: Antibiotic resistance; Medicinal plants; Celastrus Paniculatus; Antibacterial activity, Phytochemical Analysis; Antioxidant activity


2015 ◽  
Vol 61 (4) ◽  
pp. 31-39 ◽  
Author(s):  
Paweł Kwiatkowski ◽  
Stefania Giedrys-Kalemba ◽  
Małgorzata Mizielińska ◽  
Artur Bartkowiak

SummaryIntroduction:Recently, interest in essential oils used in natural medicine, has been increasing. Essential oils are still being tested for their potential uses as an alternative remedies for the treatment of many infectious diseases.Objective:The aim of the study was to evaluate antibacterial properties of commercial essential oils (rosemary, caraway and fennel) to reduce the number ofStaphylococcus aureusandEscherichia coli.Methods:The antibacterial activity of essential oils was investigated by agar dilution method.Results:The result of experiments showed that essential oils contained in microbiological media significantly reduced the number ofS. aureusandE. colicells. The best antibacterial properties possessed caraway oil: 1 mg/g forS. aureusand 10 mg/g forE. coli,weaker rosemary (5 mg/g) and fennel (20 mg/g) oils.Conclusion:Results confirmed the inhibiting effect of commercial essential oils onS. aureusandE. coliand provide a scientific ground for future research.


2019 ◽  
Vol 20 (9) ◽  
pp. 2121 ◽  
Author(s):  
Jastrzebska ◽  
Mellea ◽  
Salerno ◽  
Grzes ◽  
Siergiejczyk ◽  
...  

We report here the reaction of in situ prepared PhSeZnCl with steroid derivatives having an epoxide as an electrophilic functionalization. The corresponding ring-opening reaction resulted to be regio- and stereoselective affording to novel phenylselenium-substituted steroids. Assessment of their antibacterial properties against multidrug-resistant bacteria, such as Pseudomonas aeruginosa Xen 5 strain, indicates an interesting bactericidal activity and their ability to prevent bacterial biofilm formation.


2020 ◽  
Vol 14 (6) ◽  
pp. 2362-2372
Author(s):  
Moussa Bamba ◽  
Christel Neut ◽  
Simon Bordage ◽  
Soro Dramane ◽  
Jules Kouadio N’guessan ◽  
...  

Anogeissus leiocarpus (DC.) Guill. & Perr. (Combretaceae) et Combretum collinum Fresen. (Combretaceae) sont deux plantes de la flore ivoirienne couramment utilisées pour traiter plusieurs pathologies telles que les affections cutanées, le paludisme et la fatigue générale. Ce travail s’inscrit dans le cadre de la valorisation de cette flore. Il vise donc à évaluer l’activité antibactérienne des extraits méthanoliques bruts des feuilles de Combretum collinum et des écorces de racines de Anogeissus leiocarpus sur la croissance "in vitro" des souches de Staphylococcus aureus résistantes à la méticilline. La méthode de diffusion en milieu gélosé (solide) a été utilisée pour évaluer la sensibilité des souches bactériennes aux extraits et à déterminer les concentrations minimales inhibitrices (CMI), Quant au screening phytochimique, il a été réalisé par une chromatographie sur couche mince (CCM). La concentration minimale inhibitrice est comprise entre 0,62 mg/ml et 1,25 mg/ml pour Anogeissus leiocarpus et est de 0,325 mg/ml pour Combretum collinum. Le screening phytochimique a révélé la présence de flavonoïdes et de tanins dans l’extrait méthanolique de Anogeissus leiocarpus alors que dans l’extrait méthanolique de Combretum collinum, ce sont des acides phénoliques qui ont été mis en évidence. Il ressort donc que ces deux plantes sont dotées d’un important pouvoir antibactérien et contiennent plusieurs composés chimiques. Elles pourraient donc constituer des voies de prospection pour la recherche de nouvelles molécules antibactériennes en réalisant une étude bio-guidée des extraits bruts et en évaluant leur cytotoxicité sur des cellules hépatiques saines.Mots clés: Antibactérienne, plantes médicinales, flore ivoirienne, extraits methanoliques English Title: Phytochemical screening of methanolic extracts from leaves of Combretum collinum and roots of Anogeisus leiocarpus and in vitro antibacterial effect on multiresistant strains of Staphylococcus aureus Both Anogeissus leiocarpus (DC.) Guill. & Perr. (Combretaceae) and Combretum collinum Fresen. (Combretaceae) are Ivorian national flora plants commonly used in treating skin disorders, malaria, and general fatigue. The current study consists of the valorization of this flora, and aims therefore at revealing antibacterial activity of the methanol crude extracts obtained from stem bark and leaves of the respective plants, against Methicillin-resistant Staphylococcus aureus strains. Agar gel diffusion method was used to assess bacteria susceptibility, and broth dilution method allowed determination of minimum inhibition concentrations (MICs). These parameters varied from 0.62 mg/ml to 1.25 mg/ml for Anogeissus leiocarpus, while they reached 0.325 mg/ml for Combretum collinum. In addition, phytochemical screening brought about flavonoids and tanins for the plant, and phenolic acids for the other one. In conclusion, these named plants contain several chemical compounds with antibacterial properties, and could be of great interest in the search of new molecular compounds provided with antibacterial activity through bio-guided experiments. Furthermore, they could best hold value by testing those methanol extracts over hepatic sane cells for cytotoxicity assessment. Keywords: antibacterial, medicinal plants, Ivorian national flora, methanolic extracts.    


2020 ◽  
Vol 9 (40) ◽  
pp. 2947-2950
Author(s):  
Shabbarish Chockalingam ◽  
Preetha S ◽  
Jeevitha M ◽  
Lavanya Pratap

BACKGROUND Capparis decidua and Selenium have several antibacterial properties along with other highly desirable properties, but for long they have not been explored. Nanoparticles are efficient in transporting drugs as they are easily absorbed by the body due to their small size. We wanted to evaluate the antibacterial activity of Capparis decidua mediated selenium nanoparticles against Streptococcus mutans, Lactobacillus, and Enterococcus faecalis. METHODS 4 wells were dug in three Petri dishes of Agar which were coated with a layer of bacteria, Streptococcus mutans, Lactobacillus and Enterococcus faecalis. The wells were filled with different amounts of the extract in the order of 50 µL, 100 µL and 150 µL with the fourth well having 50 µL of the antibiotic. Zone of inhibition was measured. RESULTS After the measurements were made, the results obtained showed good zone of inhibition against Streptococcus mutans, Lactobacillus and Enterococcus faecalis. CONCLUSIONS This study suggests that Capparis decidua fruit mediated with Selenium Nanoparticles have a high antibacterial activity. KEY WORDS Antibacterial Effects, Capparis decidua, Selenium, Nanoparticles


2016 ◽  
Vol 70 (2) ◽  
pp. 140-144 ◽  
Author(s):  
Somadina Emineke ◽  
Alan J Cooper ◽  
Sarah Fouch ◽  
Brian R Birch ◽  
Bashir A Lwaleed

AimsBiofilms are ubiquitous and when mature have a complex structure of microcolonies in an extracellular polysaccharide and extracellular DNA matrix. Indwelling medical devices harbour biofilms which have been shown to cause infections and act as reservoirs for pathogens. Urinary catheters are often in place for considerable periods of time and are susceptible to both encrustation and biofilm formation. Strategies for minimising biofilm occurrence underpin an active research area in biomedicine. Manuka honey has, inter alia, well-established antibacterial properties. This study aims to assess the influence of honey on early biofilm formation in an established in vitro model.MethodsAn established model of early biofilm formation using static bacterial cultures in vinyl 96-well plates was used to grow Escherichia coli, strain ATC 25922 and Proteus mirabilis, strain 7002. Planktonic cells were removed and the residual biofilm was stained with crystal violet, which were subsequently eluted and quantified spectrophotometrically. Manuka honey (Unique Manuka Factor 15+) was added either with the bacteria or up to 72 hours after.ResultsBiofilms in this model was developed over 3 days, after which growth stalled. Mixed (1:1) cultures of E. coli and P. mirabilis grew slower than monocultures. In mixed cultures, honey gave a dose-dependent reduction in biofilm formation (between 3.3 and 16.7%w/v). At 72 hours, all concentrations inhibited maximally (p<0.001). Application of honey to cultures after 24 and 48 hours also reduced the adherent bacterial biomass (p<0.05–p<0.01).ConclusionManuka honey at dilutions as low as 3.3% w/v in some protocols and at 10% or above in all protocols tested significantly inhibits bacterial attachment to a vinyl substrate and reduces further early biofilm development. No augmentation of growth over untreated controls was observed in any experiment.


2019 ◽  
Vol 7 (3) ◽  
pp. 99-103
Author(s):  
Mehdi Goudarzi ◽  
Masoumeh Mehdipour ◽  
Bahareh Hajikhani ◽  
Sadegh Sadeghinejad ◽  
Batool Sadeghi-Nejad

Background: Micro-organisms resistant to most of the commercial antibiotics are rapidly expanding and there is an urgent need for detection of novel antimicrobial compounds. Tooth decay is a dental infection with bacterial sources such as Streptococcus mutans and Streptococcus sanguis. Objectives: The present study aimed to evaluate the in vitro antibacterial effects of different concentrations of Citrus limon peel, pineapple fruit, and pineapple peel extracts on oral pathogens such as S. mutants and S. sanguis. Materials and Methods: In this experimental study, the hydroethanolic extracts of the selected plants were prepared by maceration method and their antibacterial effects were evaluated by agar well diffusion method. Results: Two-fold dilutions of plant extract solutions were tested to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against each selected microorganism. The results of the current study revealed that pineapple peel extracts had the highest antibacterial effect on S. sanguis (MIC: 1.56 mg/mL and MBC: 3.12 mg/mL). Pineapple fruit had the lowest antibacterial activity against S. mutans (MIC: 25 mg/mL and MBC: 100 mg/mL). C. limon peel had significant antibacterial activity against S. mutans and S. sanguis. Conclusion: The peel of C. limon and pineapple had significant antibacterial activity against cariogenic microorganisms such as S. mutans and S. sanguinis.


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