Screening, Characterization, and Identification of Antibacterial Compounds from Actinobacteria

Author(s):  
T. Savitha ◽  
Ashraf Khalifa ◽  
A. Sankaranarayanan
Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
T Sripisut ◽  
S Deachathai ◽  
LC Chang ◽  
S Laphookhieo

Salmonellosis is known to be one of important issues that affect poultry industry as well as it can affect human health. Recently, multiple challenges are facing the use of natural antibacterial compounds, such as herbal extracts to overcome the massive increase in bacterial antibiotic resistance. Different Salmonella serotypes were recovered throughout examination of diarrheic poultry. These strains showed multidrug resistance by disc diffusion methods also, the resistance genes qnrS and aac (6′)-Ib-cr were detected in S. Enteritidis and S.Typhimurium which isolated from broiler's organs and muscles. The methanolic extracts of five plants (Alhagi maurorum, Conyza dioscoridis, Coriander sativum, Caracuma longa and Cuminum cyminum) were tested for their antibacterial activity against different isolated Salmonella serotypes using minimum inhibitory concentrations (MIC). Conyza dioscoridis was the most effective extract retarding microbial growth of Salmonella Enteritidis, while other plant extracts showed variable antimicrobial activity. These results are promising in the way of replacing the antibiotic therapy with natural substances to overcome the multidrug resistance.


2019 ◽  
Vol 16 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Dikdik Kurnia ◽  
Eti Apriyanti ◽  
Cut Soraya ◽  
Mieke H. Satari

Background: A significant number of antibiotics are known to inhibit peptidoglycan synthesis in the cross-linking stage, while the drug fosfomycin is the only one known to inhibit MurA. Escalated antibiotic resistance has had an impact on the efficacy of fosfomycin, thus demanding the discovery of suitable substitutes with improved potential for MurA inhibition. The aim of this work is to isolate antibacterial compounds from Sarang Semut (Myrmecodia pendans) and to evaluate their antibacterial activity against pathogenic oral bacteria of Enterococcus faecalis ATCC 29212 and inhibitory activity against MurA enzyme. Methods: The antibacterial compounds from Sarang Semut were isolated by a bioactivity-guided separation method with various solvents and combination of column chromatography on normal and reverse phases. The compounds with concentrations of 1000 and 5000 ppm were assessed against E. faecalis ATCC 29212 by agar well diffusion method, with chlorhexidine and fosfomycin being used as positive controls. Results: Two antibacterial compounds isolated from Sarang Semut were identified as two new flavonoids derivates of 1 (10 mg) and 2 (4 mg). Both compounds were tested for antibacterial activities against E. faecalis. MIC values of compounds 1 and 2 were 8.15 and 8.05 mm at 1000 ppm and 8.62 and 8.55 mm at 5000 ppm, respectively. MBC values were 156 and 625 ppm for 1 and 625 and 2500 ppm for 2, respectively. In an inhibitory murA enzyme activity assay, compounds 1 and 2 were shown to inhibit the enzyme activity by IC50 values of 21.7 and 151.3 ppm. Conclusion: The study demonstrated that ethyl acetate fraction of Sarang Semut contained antibacterial flavonoids as active constituents that showed activity against E. faecalis. These results showed the plant’s potential in herbal medicine and the development of new antibacterial agent for pathogenic dental caries.


2016 ◽  
Vol 5 (12) ◽  
pp. 5138
Author(s):  
Shyamji Shukla* ◽  
Priyanka Soni ◽  
Harish K. Kewat

There is an alarming increase in the problem of resistance towards antibiotics amongst most of the pathogenic bacterial strains in recent years. This has drawn the attention of researchers around the world to search for novel and eco-friendly antibacterial compounds. Several biological sources have been explored in this respect but medicinal plants have taken a centre stage out of all. Plants have been known as a reservoir of number of bioactive compounds specially the antibacterial ones since time immemorial. Therefore, the present investigation was undertaken to analyze the antibacterial potential of the medicinal plant Achyranthes aspera. This study revealed that highest antibacterial activity was observed in the methanolic extract of stem against almost all test Bacteria. It showed maximum activity against E.coli (30 mm), followed by S. aureus (28 mm), Enterococcus sp.(25mm), Salmonella typhi ( 20 mm) and least activity was recorded in same extract against K.pneumoniae (6 mm). Four phytochemicals were screened in various solvent extracts. They are alkaloid, flavonoids, saponins and tannins.


Planta Medica ◽  
2020 ◽  
Author(s):  
Violette Hamers ◽  
Clément Huguet ◽  
Mélanie Bourjot ◽  
Aurélie Urbain

AbstractInfectious diseases are among the greatest threats to global health in the 21st century, and one critical concern is due to antibiotic resistance developed by an increasing number of bacterial strains. New resistance mechanisms are emerging with many infections becoming more and more difficult if not impossible to treat. This growing phenomenon not only is associated with increased mortality but also with longer hospital stays and higher medical costs. For these reasons, there is an urgent need to find new antibiotics targeting pathogenic microorganisms such as ESKAPEE bacteria. Most of currently approved antibiotics are derived from microorganisms, but higher fungi could constitute an alternative and remarkable reservoir of anti-infectious compounds. For instance, pleuromutilins constitute the first class of antibiotics derived from mushrooms. However, macromycetes still represent a largely unexplored source. Publications reporting the antibacterial potential of mushroom extracts are emerging, but few purified compounds have been evaluated for their bioactivity on pathogenic bacterial strains. Therefore, the aim of this review is to compile up-to-date data about natural products isolated from fruiting body fungi, which significantly inhibit the growth of ESKAPEE pathogenic bacteria. When available, data regarding modes of action and cytotoxicity, mandatory when considering a possible drug development, have been discussed in order to highlight the most promising compounds.


Microbiology ◽  
2012 ◽  
Vol 158 (3) ◽  
pp. 835-842 ◽  
Author(s):  
Min Yu ◽  
Junfeng Wang ◽  
Kaihao Tang ◽  
Xiaochong Shi ◽  
Shushan Wang ◽  
...  

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