Alkaliphilic Bacteria and Thermophilic Actinomycetes as New Sources of Antimicrobial Compounds

2016 ◽  
pp. 29-58
Keyword(s):  
Antimicrobial Compounds ◽  
Thermophilic Actinomycetes ◽  
Alkaliphilic Bacteria

Alkaliphilic Bacteria and Thermophilic Actinomycetes as New Sources of Antimicrobial Compounds

2017 ◽  
pp. 29-57
Author(s):  
Suchitra B. Borgave ◽  
Meghana S. Kulkarni ◽  
Pradnya P. Kanekar ◽  
Dattatraya G. Naik
Keyword(s):  
Antimicrobial Compounds ◽  
Thermophilic Actinomycetes ◽  
Alkaliphilic Bacteria

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

Drug Delivery Systems Based on Titania Nanotubes and Active Agents for Enhanced Osseointegration of Bone Implants

2020 ◽  
Vol 27 (6) ◽  
pp. 854-902 ◽  
Author(s):  
Raluca Ion ◽  
Madalina Georgiana Necula ◽  
Anca Mazare ◽  
Valentina Mitran ◽  
Patricia Neacsu ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tio2 Nanotubes ◽  
Therapeutic Agent ◽  
Bone Defects ◽  
Delivery Systems ◽  
Antimicrobial Compounds ◽  
Bone Implant ◽  
Bioactive Agents ◽  
Localized Drug Delivery ◽  
Regeneration Of Bone

TiO2 nanotubes (TNTs) are attractive nanostructures for localized drug delivery. Owing to their excellent biocompatibility and physicochemical properties, numerous functionalizations of TNTs have been attempted for their use as therapeutic agent delivery platforms. In this review, we discuss the current advances in the applications of TNT-based delivery systems with an emphasis on the various functionalizations of TNTs for enhancing osteogenesis at the bone-implant interface and for preventing implant-related infection. Innovation of therapies for enhancing osteogenesis still represents a critical challenge in regeneration of bone defects. The overall concept focuses on the use of osteoconductive materials in combination with the use of osteoinductive or osteopromotive factors. In this context, we highlight the strategies for improving the functionality of TNTs, using five classes of bioactive agents: growth factors (GFs), statins, plant derived molecules, inorganic therapeutic ions/nanoparticles (NPs) and antimicrobial compounds.

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

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.

scholarly journals Comparison of a Short Linear Antimicrobial Peptide with Its Disulfide-Cyclized and Cyclotide-Grafted Variants against Clinically Relevant Pathogens

2021 ◽  
Vol 9 (6) ◽  
pp. 1249
Author(s):  
Johannes Koehbach ◽  
Jurnorain Gani ◽  
Kai Hilpert ◽  
David J Craik
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Human Serum ◽  
World Health ◽  
Resistant Bacteria ◽  
Moderate Activity ◽  
Antimicrobial Compounds ◽  
Strong Activity ◽  
Linear Peptide ◽  
Linear Version

According to the World Health Organization (WHO) the development of resistance against antibiotics by microbes is one of the most pressing health concerns. The situation will intensify since only a few pharmacological companies are currently developing novel antimicrobial compounds. Discovery and development of novel antimicrobial compounds with new modes of action are urgently needed. Antimicrobial peptides (AMPs) are known to be able to kill multidrug-resistant bacteria and, therefore, of interest to be developed into antimicrobial drugs. Proteolytic stability and toxicities of these peptides are challenges to overcome, and one strategy frequently used to address stability is cyclization. Here we introduced a disulfide-bond to cyclize a potent and nontoxic 9mer peptide and, in addition, as a proof-of-concept study, grafted this peptide into loop 6 of the cyclotide MCoTI-II. This is the first time an antimicrobial peptide has been successfully grafted onto the cyclotide scaffold. The disulfide-cyclized and grafted cyclotide showed moderate activity in broth and strong activity in 1/5 broth against clinically relevant resistant pathogens. The linear peptide showed superior activity in both conditions. The half-life time in 100% human serum was determined, for the linear peptide, to be 13 min, for the simple disulfide-cyclized peptide, 9 min, and, for the grafted cyclotide 7 h 15 min. The addition of 10% human serum led to a loss of antimicrobial activity for the different organisms, ranging from 1 to >8-fold for the cyclotide. For the disulfide-cyclized version and the linear version, activity also dropped to different degrees, 2 to 18-fold, and 1 to 30-fold respectively. Despite the massive difference in stability, the linear peptide still showed superior antimicrobial activity. The cyclotide and the disulfide-cyclized version demonstrated a slower bactericidal effect than the linear version. All three peptides were stable at high and low pH, and had very low hemolytic and cytotoxic activity.

scholarly journals Biodegradable Antimicrobial Films for Food Packaging: Effect of Antimicrobials on Degradation

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1256
Author(s):  
Eva Hernández-García ◽  
María Vargas ◽  
Chelo González-Martínez ◽  
Amparo Chiralt
Keyword(s):  
Food Packaging ◽  
Negative Impact ◽  
Relevant Information ◽  
Antimicrobial Compounds ◽  
Microorganism Population ◽  
Relevant Effect ◽  
Antimicrobial Materials ◽  
Spoilage Bacteria ◽  
Compost Soil ◽  
Specific Influence

The environmental problem generated by the massive consumption of plastics makes necessary the developing of biodegradable antimicrobial materials that can extend food shelf-life without having a negative impact on the environment. The current situation regarding the availability of biodegradable food packaging materials has been analysed, as well as different studies where antimicrobial compounds have been incorporated into the polymer matrix to control the growth of pathogenic or spoilage bacteria. Thus, the antimicrobial activity of active films based on different biodegradable polymers and antimicrobial compounds has been discussed. Likewise, relevant information on biodegradation studies carried out with different biopolymers in different environments (compost, soil, aquatic), and the effect of some antimicrobials on this behavior, are reviewed. In most of the studies, no relevant effect of the incorporated antimicrobials on the degradation of the polymer were observed, but some antimicrobials can delay the process. The changes in biodegradation pattern due to the presence of the antimicrobial are attributed to its influence on the microorganism population responsible for the process. More studies are required to know the specific influence of the antimicrobial compounds on the biodegradation behavior of polymers in different environments. No studies have been carried out or marine media to this end.

The effectiveness of commercial antimicrobial compounds against saccharolytic microorganisms isolated from a beet sugar production line

2004 ◽  
Vol 20 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Nikolaos Arvanitis ◽  
Charalambos Z. Kotzamanidis ◽  
George N. Skaracis ◽  
Amalia D. Karagouni
Keyword(s):  
Production Line ◽  
Antimicrobial Compounds ◽  
Sugar Production ◽  
Beet Sugar

scholarly journals Melanization in Cryptococcus neoformans Requires Complex Regulation

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Radames J. B. Cordero ◽  
Emma Camacho ◽  
Arturo Casadevall
Keyword(s):  
Cryptococcus Neoformans ◽  
Defense Mechanisms ◽  
Environmental Stressors ◽  
Antimicrobial Compounds ◽  
Human Pathogen ◽  
Content Type ◽  
Signaling Mechanisms ◽  
Complex Regulation ◽  
Multiple Levels ◽  
Melanin Binding

ABSTRACT The fungal human pathogen Cryptococcus neoformans undergoes melanization in response to nutrient starvation and exposure to exogenous melanin precursors. Melanization protects the fungus against host defense mechanisms such as oxidative damage and other environmental stressors (e.g., heat/cold stress, antimicrobial compounds, ionizing radiation). Conversely, the melanization process generates cytotoxic intermediates, and melanized cells are potentially susceptible to overheating and to certain melanin-binding drugs. Despite the importance of melanin in C. neoformans biology, the signaling mechanisms regulating its synthesis are poorly understood. The recent report by D. Lee, E.-H. Jang, M. Lee, S.-W. Kim, et al. [mBio 10(5):e02267-19, 2019, https://doi.org/10.1128/mBio.02267-19] provides new insights into how C. neoformans regulates melanization. The authors identified a core melanin regulatory network consisting of transcription factors and kinases required for melanization under low-nutrient conditions. The redundant and epistatic connections of this melanin-regulating network demonstrate that C. neoformans melanization is complex and carefully regulated at multiple levels. Such complex regulation reflects the multiple functions of melanin in C. neoformans biology.

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