scholarly journals The Biotechnological Potential of Secondary Metabolites from Marine Bacteria

Author(s):  
Boris Andryukov ◽  
Valery Mikhailov ◽  
Nataly Besednova

The highly dangerous trend of escalating bacterial resistance to modern antibiotics has evolved in recent decades, with increasingly more drug-resistant strains of pathogens emerging and spreading each year. This poses a threat to not only public health, but also to entire mankind. Marine bioresources, considered as a promising alternative to traditional antibiotics and a valuable source of biologically active compounds with high pharmacological potential, now attract increasing attention of researchers. Modern biotechnology combines the genetic engineering methods and the unusual biosynthetic pathways utilized by marine microorganisms to produce natural antibiotics. The goal of this review is to summarize the latest trends in searching for new natural antimicrobial agents based on secondary metabolites of marine bacteria. The targeted control of biosynthesis mechanisms using the metabolic engineering methods in order to create hybrid peptide synthetases or to obtain hybrid peptides by disrupting the target gene of nonribosomal synthesis becomes a noteworthy trend in modern biotechnology. This pathway is not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the exocrine activity of pathogenic bacteria and, consequently, their viability.

2019 ◽  
Vol 7 (6) ◽  
pp. 176 ◽  
Author(s):  
Boris Andryukov ◽  
Valery Mikhailov ◽  
Nataly Besednova

Marine habitats are a rich source of molecules of biological interest. In particular, marine bacteria attract attention with their ability to synthesize structurally diverse classes of bioactive secondary metabolites with high biotechnological potential. The last decades were marked by numerous discoveries of biomolecules of bacterial symbionts, which have long been considered metabolites of marine animals. Many compounds isolated from marine bacteria are unique in their structure and biological activity. Their study has made a significant contribution to the discovery and production of new natural antimicrobial agents. Identifying the mechanisms and potential of this type of metabolite production in marine bacteria has become one of the noteworthy trends in modern biotechnology. This path has become not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the viability of pathogenic bacteria.


Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.


2011 ◽  
Vol 36 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Y Ramakrishna ◽  
H Goda ◽  
MS Baliga ◽  
AK Munshi

The association between the oral microbiota and oral diseases is well established. Various antimicrobial agents including antibiotics are commercially available against oral pathogenic bacteria. For the reasons of antibiotic resistance, their adverse effects and financial considerations in the developing countries, there is a need for alternate preventive and curative treatment options that are also safe, effective and economical. Traditional medicines have been used since ancient times for the treatment of oral diseases including dental caries, periodontal diseases that affect the majority of the population and can affect a person's overall health. Natural phytochemicals are certain organic components isolated from plants and some of these extracts are considered to be beneficial to health. They serve as antioxidants, enhance immune response,provide protection against oral cancer and other diseases and also repair DNA damage caused by smoking and other toxic exposure, and detoxify carcinogens. The natural products derived from medicinal plants have proven to be an abundant source of biologically active compounds, many of which have been the basis for the development of new lead chemicals for pharmaceuticals.They are considered to be good alternatives to synthetic chemicals. This article presents a review of natural alternatives derived from plants and plant products that can serve as a prevention and treatment option against cariogenic bacteria.


Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 270
Author(s):  
Ilhem Saadouli ◽  
Imène Zendah El Euch ◽  
Emna Trabelsi ◽  
Amor Mosbah ◽  
Alaeddine Redissi ◽  
...  

Streptomyces is the most frequently described genus of Actinomycetes, a producer of biologically active secondary metabolites. Indeed, the Streptomyces species produces about 70% of antibiotics and 60% of antifungal molecules used in agriculture. Our study was carried out with the goal of isolating and identifying antimicrobial secondary metabolites from Streptomyces misionensis V16R3Y1 isolated from the date palm rhizosphere (southern Tunisia). This strain presented a broad range of antifungal activity against Fusarium oxysporum, Aspergillus flavus, Penicillium expansum, Aspergillus niger, Candida albicans, Candida metapsilosis, and Candida parapsilosis and antibacterial activity against human pathogenic bacteria, including Escherichia fergusonii, Staphylococcus aureus, Salmonella enterica, Enterococcus faecalis, Bacillus cereus and Pseudomonas aeruginosa. The purification procedure entailed ethyl acetate extract, silica gel column, and thin layer chromatography. Based on 1H NMR metabolomic procedure application, also supported by the GC-MS analysis, cyclic dipeptide (l-Leucyl-l-Proline) was identified as the major compound in the bioactive fraction. In order to confirm the identity of the active compound and to have a large quantity thereof, a chemical synthesis of the cyclic dipeptide was performed. The synthetic compound was obtained with a very good yield (50%) and presented almost the same effect compared to the extracted fraction. This study indicates for the first time that Streptomyces misionensis V16R3Y1 exhibits a broad spectrum of antimicrobial activities, produced cyclic dipeptide (l-Leucyl-l-Proline) and might have potential use as a natural agent for pharmaceutical and agri-food applications.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.


2019 ◽  
Vol 7 (9) ◽  
pp. 278 ◽  
Author(s):  
Lorenzo

The advent of multidrug resistance among pathogenic bacteria is devastating the worth of antibiotics and changing the way of their administration, as well as the approach to use new or old drugs. The crisis of antimicrobial resistance is also due to the unavailability of newer drugs, attributable to exigent regulatory requirements and reduced financial inducements. The emerging resistance to antibiotics worldwide has led to renewed interest in old drugs that have fallen into disuse because of toxic side effects. Thus, comprehensive efforts are needed to minimize the pace of resistance by studying emergent microorganisms and optimize the use of old antimicrobial agents able to maintain their profile of susceptibility. Chloramphenicol is experiencing its renaissance because it is widely used in the treatment and prevention of superficial eye infections due to its broad spectrum of activity and other useful antimicrobial peculiarities, such as the antibiofilm properties. Concerns have been raised in the past for the risk of aplastic anemia when chloramphenicol is given intravenously. Chloramphenicol seems suitable to be used as topical eye formulation for the limited rate of resistance compared to fluoroquinolones, for its scarce induction of bacterial resistance and antibiofilm activity, and for the hypothetical low impact on ocular microbiota disturbance. Further in-vitro and in vivo studies on pharmacodynamics properties of ocular formulation of chloramphenicol, as well as its real impact against biofilm and the ocular microbiota, need to be better addressed in the near future.


2020 ◽  
Author(s):  
Léonel Feugap ◽  
Irene Kengne ◽  
Jean-De-Dieu Tamokou ◽  
Claudia Ngnokam ◽  
Mahamat Djamalladine ◽  
...  

Abstract The treatment of infectious diseases with antimicrobial agents continues to present problems in modern-day medicine with many studies showing significant increase in the incidence of bacterial resistance to several antibiotics. The screening of plant extracts and natural compounds for antimicrobial activity has demonstrated that higher plants represent a potential source of new anti-infective agents. The aim of this study was to evaluate the antimicrobial and antioxidant activities of extracts and compounds from the whole plant Trifolium baccarinii Chiov. with their mechanisms of antibacterial action. Biochanin A (1), formononetin (2), luteolin (3), luteolin-4'-O-β-D-glucopyranoside (4), 4,7,2'-trihydroxy-4'-methoxyisoflavanol (5), sissotrin (6), 1-méthyl-β-D-glucopyranoside (7), ononin (8), D-mannitol (9) and 3-O-β-D-glucuronopyranosylsoyasapogenol B (10) were isolated from T. baccarinii. The MeOH, EtOAc and n-BuOH extracts as well as compounds 1–6 from T. baccarinii displayed the most antimicrobial and antioxidant activities. The MeOH extract and compound 5 exhibited antibacterial activity through bacteriolytic effect and reduction of the antioxidant defenses in the bacterial cells. Interestingly, none of the tested samples showed cytotoxic activity against normal cells; highlighting their good selectivity toward pathogenic bacteria and yeasts. Hence, they are promising lead candidates with antibacterial potential against methicillin resistant S. aureus (MRSA).


2000 ◽  
Vol 44 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Herin Oh ◽  
Maria Hedberg ◽  
David Wade ◽  
Charlotta Edlund

ABSTRACT The increasing problem of antibiotic resistance among pathogenic bacteria requires development of new antimicrobial agents. One line of investigation is the synthesis of antimicrobial hybrid peptides. The aim of the present investigation was to determine the in vitro activities of 16 cecropin-melittin hybrid peptides (CAMEL analogues) against 60 anaerobic bacterial strains, to compare their activities with those of seven clinically used antimicrobial agents, and to compare different methods for anaerobic susceptibility testing of these peptides. The stability of one of the peptides, temporin B, with different stereoisomeric configurations was investigated in a fecal milieu. The CAMEL analogues showed antimicrobial activity against the anaerobic bacteria, with MICs ranging from 0.125 to 32 μg/ml. The overall activities (the MICs at which 90% of isolates are inhibited) of the CAMEL analogues against anaerobic bacteria were mainly inferior to those of imipenem, clindamycin, and piperacillin but were equal to or superior to those of metronidazole, cefoxitin, ciprofloxacin, and chloramphenicol. The agarose dilution method was found to be an accurate method for the testing of large numbers of bacterial strains. The d isomer of temporin B was inactivated more slowly in feces than the l isomer. This study shows that the CAMEL analogues are potential agents for the treatment of anaerobic infections.


2006 ◽  
Vol 72 (5) ◽  
pp. 3302-3308 ◽  
Author(s):  
Rafael Ferre ◽  
Esther Badosa ◽  
Lidia Feliu ◽  
Marta Planas ◽  
Emili Montesinos ◽  
...  

ABSTRACT Short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria Erwinia amylovora, Pseudomonas syringae, and Xanthomonas vesicatoria and compared to the previously described peptide Pep3 (WKLFKKILKVL-NH2). The antimicrobial activity of Pep3 and 22 analogues was evaluated in terms of the MIC and the 50% effective dose (ED50) for growth. Peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation were also determined. Pep3 and several analogues inhibited growth of the three pathogens and had a bactericidal effect at low micromolar concentrations (ED50 of 1.3 to 7.3 μM). One of the analogues consisting of a replacement of both Trp and Val with Lys and Phe, respectively, resulted in a peptide with improved bactericidal activity and minimized cytotoxicity and susceptibility to protease degradation compared to Pep3. The best analogues can be considered as potential lead compounds for the development of new antimicrobial agents for use in plant protection either as components of pesticides or expressed in transgenic plants.


2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Marta Gomarasca ◽  
Thaynan F. C. Martins ◽  
Lilo Greune ◽  
Philip R. Hardwidge ◽  
M. Alexander Schmidt ◽  
...  

ABSTRACT Commonly used antimicrobials show poor cellular uptake and often have limited access to intracellular targets, resulting in low antimicrobial activity against intracellular pathogens. An efficient delivery system to transport these drugs to the intracellular site of action is needed. Cell-penetrating peptides (CPPs) mediate the internalization of biologically active molecules into the cytoplasm. Here, we characterized two CPPs, α1H and α2H, derived from the Yersinia enterocolitica YopM effector protein. These CPPs, as well as Tat (trans-activator of transcription) from HIV-1, were used to deliver the antibiotic gentamicin to target intracellular bacteria. The YopM-derived CPPs penetrated different endothelial and epithelial cells to the same extent as Tat. CPPs were covalently conjugated to gentamicin, and CPP-gentamicin conjugates were used to target infected cells to kill multiple intracellular Gram-negative pathogenic bacteria, including Escherichia coli K1, Salmonella enterica serovar Typhimurium, and Shigella flexneri. Taken together, CPPs show great potential as delivery vehicles for antimicrobial agents and may contribute to the generation of new therapeutic tools to treat infectious diseases caused by intracellular pathogens.


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