scholarly journals In Vitro Antibacterial Activity of Manuka (Leptospermum scoparium J.R. et G. Forst) and winter Savory (Satureja montana L.) Essential Oils and Their Blends against Pathogenic E. coli Isolates from Pigs

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2202
Author(s):  
Filippo Fratini ◽  
Mario Forzan ◽  
Barbara Turchi ◽  
Simone Mancini ◽  
Giuseppe Alcamo ◽  
...  

Neonatal diarrhoea (ND), post-weaning diarrhoea (PWD) and oedema disease (OD) are among the most important diseases affecting pig farming due to economic losses. Among the main aetiological agents, strains of Escherichia coli are identified as the major responsible pathogens involved. Several strategies have been put in place to prevent these infections and, today, research is increasingly studying alternative methods to antibiotics to reduce the antibiotic resistance phenomenon. Essential oils (EOs) are among the alternative tools that are being investigated. In this study, the in vitro effectiveness of winter savory and manuka essential oils and their mixtures in different proportions against strains of E. coli isolated from episodes of disease in pigs was evaluated. The EOs alone demonstrated slight antibacterial effectiveness, whereas the blends, by virtue of their synergistic action, showed remarkable activity, especially the 70%–30% winter savory–manuka blend, showing itself as a potential tool for prevention and therapy.

2017 ◽  
Vol 1 ◽  
pp. 13
Author(s):  
G. Bachir Raho

The purpose of this research was to evaluate the in vitro antibacterial activity of the essential oils from the resin of Pistacia lentiscus against Staphylococcus aureus (Gram–positive bacteria) and Escherichia coli (Gram–negative bacteria). The agar disc diffusion method was used for microbial growth inhibition at various dilutions of the oils. Results showed that the tested essential oils possess antibacterial activity against S. aureus but inactive on E. coli. These results may have significant implications for the future development of resin oils of P. lentiscus as an antimicrobial agent for the treatment of the infections caused by S. aureus. 


2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.


2021 ◽  
Author(s):  
Filippo Fratini ◽  
Margherita Giusti ◽  
Simone Mancini ◽  
Francesca Pisseri ◽  
Basma Najar ◽  
...  

AbstractStaphylococcus aureus and coagulase-negative staphylococci are among the major causes of mastitis in sheep. The main goal of this research was to determine the in vitro antibacterial activity of several essential oils (EOs, n 30), then five of them were chosen and tested alone and in blends against staphylococci isolates. Five bacteria were isolated from episodes of ovine mastitis (two S. aureus and three S. xylosus). Biochemical and molecular methods were employed to identify the isolates and disk diffusion method was performed to determine their antimicrobial-resistance profile. The relative percentage of the main constituents in the tested essential oils and their blends was detected by GC-EIMS analysis. Antibacterial and bactericidal effectiveness of essential oils and blends were evaluated through minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). All of them showed sensitivity to the used antimicrobials. The EOs with the highest antibacterial activity were those belonging to the Lamiaceae family characterized by high concentrations of thymol, carvacrol and its precursor p-cymene, together with cinnamon EO, rich in cinnamaldehyde. In terms of both MIC and MBC values, the blend composed by Thymus capitatus EO 40%, Cinnamomum zeylanicum EO 20%, Thymus serpyllum EO 20% and Satureja montana EO 20% was found to be the most effective against all the isolates. Some essential oils appear to represent, at least in vitro, a valid tool against ovine mastitis pathogens. Some blends showed a remarkable effectiveness than the single oils, highlighting a synergistic effect in relation to the phytocomplex.


2020 ◽  
Vol 32 (4) ◽  
pp. 896-900
Author(s):  
M. Idrees ◽  
Y.G. Bodkhe ◽  
N.J. Siddiqui ◽  
S.S. Kola

A series of 5-(benzofuran-2-yl)-N-(3-chloro-4-(2-(p-tolyloxy) substituted quinolin-3-yl)-2-oxoazetidin-1-yl)-1-phenyl-1H-pyrazole-3-carboxamide derivatives (4a-f) were synthesized with excellent yields by cyclocondensation reaction of 5-(benzofuran-2-yl)-N′-(2-(p-tolyloxy) substituted quinolin-3-yl)methylene)-1-phenyl-1H-pyrazole-3-carbohydrazide (3a-f) with chloroacetyl chloride in presence of triethylamine in DMF. One pot condensation of 5-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide (1) with 2-(p-tolyloxy) substituted quinoline-3-carbaldehyde (2a-f) in ethanol solvent in presence of catalytic amount of acetic acid gave intermediate compounds (3a-f). The structures of newly synthesized compounds have been substantiated through elemental analysis and spectral studies viz. 1H NMR, 13C NMR, IR and mass spectra. All the synthesized compounds were screened for their in vitro antibacterial activity against pathogenic bacteria such as S. aureus and E. coli at different concentrations.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New series of organotin(IV) complexes and Schiff bases derived from amino acids have been designed and synthesized from condensation of1H-indole-2,3-dione, 5-chloro-1H-indole-2,3-dione, andα-amino acids (phenylalanine, isoleucine, and glycine). All compounds are characterized by elemental analyses, molar conductance measurements, and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance (1H,13C, and119Sn NMR) spectral studies. The results suggest that Schiff bases behave as monobasic bidentate ligands and coordinate with dibutyltin(IV) in octahedral geometry according to the general formula [Bu2Sn(L)2]. Elemental analyses and NMR spectral data of the ligands with their dibutyltin(IV) complexes agree with their proposed distorted octahedral structures. Few representative compounds are tested for their in vitro antibacterial activity against Gram-positive (B. cereus,Staphylococcusspp.) and Gram-negative (E. coli,Klebsiellaspp.) bacteria. The results show that the dibutyltin complexes are more reactive with respect to their corresponding Schiff base ligands.


Author(s):  
Yi-Hsuan Lee ◽  
Chao-Min Wang ◽  
Po-Yu Liu ◽  
Ching-Chang Cheng ◽  
Zong-Yen Wu ◽  
...  

Essential oils from the dried spikes ofNepeta tenuifolia(Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes ofN. tenuifoliathrough analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularlySalmonella enterica,Citrobacter freundii, andEscherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (againstS. enterica), 0.39 and 0.78% (againstC. freundii), and 0.097 and 0.39% (againstE. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against bothPseudomonas aeruginosareference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils ofN. tenuifoliaalso displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.


Molbank ◽  
10.3390/m1058 ◽  
2019 ◽  
Vol 2019 (2) ◽  
pp. M1058
Author(s):  
Vinuta Kamat ◽  
Rangappa Santosh ◽  
Suresh Nayak

5-methyl-2-(pyridin-3-yl)-1,3-thiazole-4-carbohydrazide (1) on treatment with 4-fluorobenzaldehyde in presence of catalytic amount of acetic acid, accessed the target compound (2) with the yield of 79%. The target compound was confirmed by 1H-NMR, 13C-NMR, FT-IR and LCMS. In vitro antibacterial activity against Staphylococcus aureus (S. Aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) were carried out and compound 2 showed promising activity against B. subtilis. In addition, compound 2 was analyzed for DNA binding study. It revealed that compound 2 has a promising affinity towards DNA double helix.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2126 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Danila O. Zakharov ◽  
Liubov G. Burova ◽  
Tatyana S. Frolova ◽  
Dmitry S. Baev ◽  
...  

Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillius subtilis, Actinomyces viscosus and Escherichia coli bacterial strains. Coumarin-benzoic acid hybrids 4с, 42с and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin (29) showed promising activity against S. aureus strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid 37c was endowed with high selectivity against B. subtilis and E. coli species. The in vitro antibacterial activity of 4с, 29, 37c and 42с can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.


Author(s):  
Samira Hsaine ◽  
Reda Charof ◽  
Khadija Ounine

Objective: Streptococcus oralis plays an important role in the biofilm formation of dental plaque and the occurrence of periodontal disease. Thepresent study was conducted to evaluate in vitro antibacterial activity of three essential oils, namely, Cinnamomum zeylanicum, Eugenia caryophyllata,and Rosmarinus officinalis against S. oralis.Methods: The antibacterial activity of essential oils was investigated by diffusion method using sterile discs (or aromatograms). The minimuminhibitory concentration (MIC) of essential oils showing important antibacterial activity was measured using the broth dilution method.Results: Evaluation of the antibacterial activity of three essential oils as determined by the aromatogram technique showed that the essential oilof R. officinalis had no effect on S. oralis, while the latter was extremely sensitive to the other two essential oils, but with a higher efficiency of theessential oil of C. zeylanicum (42 mm diameter) than E. caryophyllata (20 mm diameter). Similarly, the MIC and minimum bactericidal concentration(MBC) were higher for the essential oil of C. zeylanicum than the essential oil of E. caryophyllata. The MBC/MIC ratio is of the order of 2. The essentialoils studied therefore appear to exert bactericidal activity against S. oralis.Conclusion: The findings suggest that essential oils of C. zeylanicum and E. caryophyllata may be used as an alternative to synthetic antibiotics.Keywords: Essential oil, Cinnamomum zeylanicum, Eugenia caryophyllata, Rosmarinus officinalis, Antimicrobial activity, Streptococcus oralis.


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