scholarly journals Application of iChip to Grow “Uncultivable” Microorganisms and its Impact on Antibiotic Discovery

2015 ◽  
Vol 18 (3) ◽  
pp. 303 ◽  
Author(s):  
Rinzhin T. Sherpa ◽  
Caretta J. Reese ◽  
Hamidreza Montazeri Aliabadi
Keyword(s):  
Antimicrobial Activity ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Modern Medicine ◽  
Natural Phenomenon ◽  
Significant Progress ◽  
Cultivation Method ◽  
New Antibiotics ◽  
Antibiotic Discovery

Antibiotics have revolutionized modern medicine, allowing significant progress in healthcare and improvement in life expectancy. Development of antibiotic resistance by pathogenic bacteria is a natural phenomenon; however, the rate of antibiotic resistance emergence is increasing at an alarming rate, due to indiscriminate use of antibiotics in healthcare, agriculture and even everyday products. Traditionally, antibiotic discovery has been conducted by screening extracts of microorganisms for antimicrobial activity. However, this conventional source has been over-used to such an extent that it poses the risk of “running out” of new antibiotics. Aiming to increase access to a greater diversity of microorganisms, a new cultivation method with an in situ approach called iChip has been designed. The iChip has already isolated many novel organisms, as well as Teixobactin, a novel antibiotic with significant potency against gram-positive bacteria.This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Antibacterial Compounds from Mushrooms: A Lead to Fight ESKAPEE Pathogenic Bacteria?

Planta Medica ◽  
2020 ◽  
Author(s):  
Violette Hamers ◽  
Clément Huguet ◽  
Mélanie Bourjot ◽  
Aurélie Urbain
Keyword(s):  
Antibiotic Resistance ◽  
Global Health ◽  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Antibacterial Compounds ◽  
New Antibiotics ◽  
Hospital Stays ◽  
Antibacterial Potential

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.

scholarly journals Antimicrobial Activity of Biosynthesized Silver Nanoparticles Compared to Standard Antibiotics Used in ORL Infections

2019 ◽  
Vol 70 (7) ◽  
pp. 2571-2573
Author(s):  
Alina Andreea Tischer (Tucuina) ◽  
Delia Berceanu Vaduva ◽  
Nicolae Balica ◽  
Alina Heghes ◽  
Adelina Cheveresan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibiotic Resistance ◽  
Adverse Effects ◽  
Infectious Diseases ◽  
Broad Spectrum ◽  
Bacterial Infections ◽  
New Antibiotics ◽  
Recorded Data

In recent years, bacterial infections in hospitals have grown particularly due to the development of antibiotic resistance. Recent research targets the discovery of new antibiotics that exhibit broad spectrum of action without adverse effects or minimizing adverse effects. In this study, the activity of biosynthesized silver nanoparticles against three bacteria commonly found in infectious diseases in the ORL sphere was evaluated. The recorded data revealed an activity comparable to that of the standard antibiotics used in these types of infections, with the observation that the activity of the nanoparticles could also be observed in the particular cases of antibiotic resistance.

scholarly journals Thinking Outside the Bug: Molecular Targets and Strategies to Overcome Antibiotic Resistance

2019 ◽  
Vol 20 (6) ◽  
pp. 1255 ◽  
Author(s):  
Ana Monserrat-Martinez ◽  
Yann Gambin ◽  
Emma Sierecki
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Rational Design ◽  
Disease Onset ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
New Antibiotics ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Antibiotic Discovery

Since their discovery in the early 20th century, antibiotics have been used as the primary weapon against bacterial infections. Due to their prophylactic effect, they are also used as part of the cocktail of drugs given to treat complex diseases such as cancer or during surgery, in order to prevent infection. This has resulted in a decrease of mortality from infectious diseases and an increase in life expectancy in the last 100 years. However, as a consequence of administering antibiotics broadly to the population and sometimes misusing them, antibiotic-resistant bacteria have appeared. The emergence of resistant strains is a global health threat to humanity. Highly-resistant bacteria like Staphylococcus aureus (methicillin-resistant) or Enterococcus faecium (vancomycin-resistant) have led to complications in intensive care units, increasing medical costs and putting patient lives at risk. The appearance of these resistant strains together with the difficulty in finding new antimicrobials has alarmed the scientific community. Most of the strategies currently employed to develop new antibiotics point towards novel approaches for drug design based on prodrugs or rational design of new molecules. However, targeting crucial bacterial processes by these means will keep creating evolutionary pressure towards drug resistance. In this review, we discuss antibiotic resistance and new options for antibiotic discovery, focusing in particular on new alternatives aiming to disarm the bacteria or empower the host to avoid disease onset.

scholarly journals Lipidated Analogs of the LL-37-Derived Peptide Fragment KR12—Structural Analysis, Surface-Active Properties and Antimicrobial Activity

2020 ◽  
Vol 21 (3) ◽  
pp. 887 ◽  
Author(s):  
Elżbieta Kamysz ◽  
Emilia Sikorska ◽  
Maciej Jaśkiewicz ◽  
Marta Bauer ◽  
Damian Neubauer ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Self Assembly ◽  
Multidrug Resistant ◽  
Cd Spectroscopy ◽  
Modern Medicine ◽  
Aromatic Acids ◽  
Human Red Blood Cells ◽  
N Terminus ◽  
New Antibiotics ◽  
Assembly Behavior

An increasing number of multidrug-resistant pathogens is a serious problem of modern medicine and new antibiotics are highly demanded. In this study, different n-alkyl acids (C2-C14) and aromatic acids (benzoic and trans-cinnamic) were conjugated to the N-terminus of KR12 amide. The effect of this modification on antimicrobial activity (ESKAPE bacteria and biofilm of Staphylococcus aureus) and cytotoxicity (human red blood cells and HaCaT cell line) was examined. The effect of lipophilic modifications on helicity was studied by CD spectroscopy, whereas peptide self-assembly was studied by surface tension measurements and NMR spectroscopy. As shown, conjugation of the KR12-NH2 peptide with C4-C14 fatty acid chains enhanced the antimicrobial activity with an optimum demonstrated by C8-KR12-NH2 (MIC 1–4 μg/mL against ESKAPE strains; MBEC of S. aureus 4–16 μg/mL). Correlation between antimicrobial activity and self-assembly behavior of C14-KR12-NH2 and C8-KR12-NH2 has shown that the former self-assembled into larger aggregated structures, which reduced its antimicrobial activity. In conclusion, N-terminal modification can enhance antimicrobial activity of KR12-NH2; however, at the same time, the cytotoxicity increases. It seems that the selectivity against pathogens over human cells can be achieved through conjugation of peptide N-terminus with appropriate n-alkyl fatty and aromatic acids.

scholarly journals Antimicrobial effects of fruit sauces on some pathogenic bacteria in vitro and on chicken breast meat

2021 ◽  
Vol 72 (1) ◽  
pp. 2703
Author(s):  
I VAR ◽  
S UZUNLU ◽  
I DEĞIRMENCI
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Diffusion Method ◽  
Chicken Breast ◽  
Type I ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Agar Diffusion

The use of natural food additives is currently a rising trend. In the present study, the aim was to determine the antimicrobial effects of plum, pomegranate, Seville orange and sumac sauces on E. coli O157:H7,E. coli type I,Listeriamonocytogenes, Listeria ivanovii, Salmonella Typhimurium and Staphylococcus aureus. Different concentrations (1%, 10%, 100%, v/v) of the sauces were tested on the studied bacteria in vitro using the agar diffusion and minimal inhibition concentration (MIC) methods. The results showed that the sumac sauce had the highest antimicrobial activity. The Seville orange, plum and pomegranate sauces also exerted antimicrobial activity in descending order. The antimicrobial activity of the fruit sauces was more effective at a concentration of 100% than at 10% and 1%, v/v. The most inhibitory effect was recorded for sumac sauce at a concentration of 100% (v/v) on L.monocytogenesand E. coli O157:H7. The findings of the MIC method aligned with the agar diffusion method. In addition, the in situ(food method) antimicrobial effect of the sauces on the indigenous microflora of chicken breast samples sold in stores was determined. Chicken samples hosting aerobic mesophilic bacteria, coliforms and E. coli were treated for two hours at 4 °C with plum, pomegranate, Seville orange and sumac sauces and were then monitored. The findings revealed that the Seville orange and sumac sauces were the most effective in reducing the indigenous microbial growth on the chicken samples. The plum sauce showed higher antimicrobial activity than pomegranate sauce. The phenolic content and acidity of the samples significantly (P< 0.05) affected the antimicrobial activity both in vitro (agar diffusion and MIC) and in situ (chilled chicken breast). In conclusion, the sumac and Seville orange sauces were found to be the most promising natural antibacterial agents, and their use could be recommended, for example, in catering services to reduce the risk of foodborne illness.

scholarly journals Agelasines B, D and antimicrobial extract of a marine sponge Agelas sp. from Tahuna Bay, Sangihe Islands, Indonesia

2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Walter Balansa ◽  
Stevy Imelda Murniati Wodi ◽  
Frets Jonas Rieuwpassa ◽  
Frans Gruber Ijong
Keyword(s):  
Antimicrobial Activity ◽  
Marine Sponge ◽  
Pathogenic Bacteria ◽  
Antimicrobial Drug ◽  
Flash Chromatography ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
New Antibiotics ◽  
Life Threatening ◽  
Strong Antimicrobial Activity

Abstract. Balansa W, Wodi SIM, Rieuwpassa FJ, Ijong FG. 2020. Agelasines B, D and antimicrobial extract of Agelas sp. from Tahuna Bay, Sangihe Islands, Indonesia. Biodiversitas 21: 699-706. The alarming growth of antibiotic-resistant bacteria necessitates the discovery of new antibiotics including those for combating life-threatening ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp) and fish pathogenic bacteria. This study aimed to identify antimicrobial compounds from an extract of a marine sponge collected from Enepahembang coral reef, Sangihe Islands, North Sulawesi, Indonesia. The sponge was identified by DNA barcoding as Agelas sp. and its extract was evaluated against three ESKAPE bacteria (S. aureus, K. pneumoniae, and A. baumannii) and three fish pathogenic bacteria (A. hydrophila, Edwardsiella tarda and Vibrio parahaemolyticus), using the standard disk diffusion method. It showed moderate to strong antimicrobial activity against S. aureus (25.3 mm), K. pneumoniae (15.5 mm), A. baumannii (20.2 mm), A. hydrophila (20.5 mm), E. tarda (22.4 mm) and A. salmonicida (21.2 mm). The extract was isolated by chromatographic techniques (column chromatography, flash chromatography, and high-performance liquid chromatography). The structures and relative stereochemistry of the two compounds were elucidated by HRESIMS, 1D and 2D NMR data analysis as well as by comparison with reported values. Unfortunately, limited amount of the pure compounds prevented us from further evaluating their antimicrobial activity against the test bacteria. Nevertheless, the crude extract's strong antimicrobial activity, especially against the test Gram-negative bacteria, suggests the importance of this finding in light of the recent antimicrobial drug scarcity but rapid antimicrobial resistance and the emerging paradigm of antimicrobial drug modification, redirection and/or repurposing for discovering new antibiotics particularly against the life-threatening Gram-negative bacteria.

scholarly journals Edible Seaweeds and Spirulina Extracts for Food Application: In Vitro and In Situ Evaluation of Antimicrobial Activity towards Foodborne Pathogenic Bacteria

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1442 ◽  
Author(s):  
Francesco Martelli ◽  
Martina Cirlini ◽  
Camilla Lazzi ◽  
Erasmo Neviani ◽  
Valentina Bernini
Keyword(s):  
Antimicrobial Activity ◽  
Phenolic Compounds ◽  
Pathogenic Bacteria ◽  
Challenge Test ◽  
Algal Species ◽  
Total Phenolic ◽  
Salmonella Spp ◽  
Foodborne Pathogenic Bacteria

Research is more and more focused on studying and selecting food preservatives of natural origin. In this scenario, algae are an excellent source of bioactive compounds, among which are antimicrobials, whose presence is variable depending on the algal species and environmental conditions. The aim of the present study was to obtain, by a food grade approach, antimicrobial extracts from five species already approved as foods and to test their efficacy in vitro (agar well diffusion assay) and in situ (microbial challenge test) towards foodborne pathogenic bacteria. Moreover, the total phenolic compounds of the extracts were determined in order to evaluate possible correlations with the antimicrobial activity. Strains belonging to Salmonella spp., Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were considered. Overall, the extracts showed a good antimicrobial activity in vitro towards all the tested microorganisms, especially L. monocytogenes (15 mm of inhibition diameter). The effect of inhibition was monitored during 24, 48 and 120 h showing a good persistence in time. Arthrospira platensis exerted the highest efficacy, further revealed towards L. monocytogenes on salmon tartare as bacteriostatic using 0.45% of the extract and bactericidal using 0.90%. The presence of phenolic compounds could be related to the antimicrobial activity but was not revealed as the main component of this activity. The extract with the highest phenolic content (18.79 ± 1.90 mg GAE/g) was obtained from Himanthalia elongata. The efficacy, confirmed also in a food matrix, might open perspectives for their application as food preservative.

scholarly journals Methicillin-Resistant Staphylococcus aureus in Hospitals: Latest Trends and Treatments Based on Bacteriophages

2019 ◽  
Vol 57 (12) ◽  
Author(s):  
Andrea Álvarez ◽  
Lucía Fernández ◽  
Diana Gutiérrez ◽  
Beatriz Iglesias ◽  
Ana Rodríguez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
World Health ◽  
Natural Phenomenon ◽  
Methicillin Resistant ◽  
Content Type ◽  
Wide Range ◽  
Mrsa Strains ◽  
Health Organization

ABSTRACT Even though antibiotic resistance in bacteria is a natural phenomenon, the alarming increase in pathogenic bacteria refractory to a wide range of antimicrobials is attracting attention worldwide. Indeed, the World Health Organization (WHO) has recently published a list of priority pathogens for which new antimicrobial alternatives are urgently needed. Among these pathogens, methicillin-resistant Staphylococcus aureus (MRSA) strains are perhaps the best known by the general public. In addition to its potential to acquire antibiotic resistance, S. aureus can produce a large number of virulence factors, such as hemolysins, enterotoxins, and proteases, and exhibits the ability to form biofilms as well as to evolve into different clones that can spread and colonize new environments. This review provides a brief overview of the latest options in antibacterial therapies, mainly focusing on phage therapy. In this regard, the current stage of research about antimicrobial compounds based on bacteriophages and endolysins against MRSA infections is shown and discussed.

scholarly journals Antimicrobial Activity of Fungal Extract of The Aspergillus flavus from Hiri Island, North Maluku to Pathogenic Bacteria

2020 ◽  
Vol 23 (1) ◽  
pp. 127
Author(s):  
Sri Sedjati ◽  
Ambariyanto Ambariyanto ◽  
Agus Trianto ◽  
Endang Supriyantini ◽  
Ali Ridlo ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Secondary Metabolites ◽  
Aspergillus Flavus ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Resistant Bacteria ◽  
Malt Extract ◽  
Antibacterial Compounds ◽  
New Antibiotics ◽  
Inhibition Zones

Antibacterial compounds from sponge association fungi are one of the alternatives to search for new antibiotics against resistant bacteria. This study aims to explore the secondary metabolites potential from sponge association fungi as MDR pathogens antibacterial and to cultivate these fungi using a variety of cultivation media. TE-BO-09.1. Isolate can inhibit 3 bacteria, K. pneumoniae, B subtilis, and S. aureus, but is not able to inhibit E. coli and P. aeruginosa. Cultivation using standard media of Malt Extract Agar (MEA) and media modified from fish broth (M1, M2) and cassava infusion (M3, M4) produce secondary metabolites with varying quantities and antimicrobial activity. The inhibition zone of the produced extract with 500 μg/disc concentration ranged from 7.14 to 10.32 mm. The strongest potential was shown by ethyl acetate extract from isolates cultured with M2 (9 days cultivation), of which is able to produce 10.32 mm inhibition zones against S. aureus and methanol extracts from isolates cultured with M4 (6 days cultivation), and able to produce 10.05 mm inhibition zones against K. pneumoniae. In conclusion, the fungus  Aspergillus flavus can be culture using fish broth added glucose and cassava infusion water added peptone media to potentially produce antibacterial compounds against MDR pathogens.

scholarly journals Looking Back to Amycolatopsis: History of the Antibiotic Discovery and Future Prospects

Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1254
Author(s):  
Olga V. Kisil ◽  
Tatiana A. Efimenko ◽  
Olga V. Efremenkova
Keyword(s):  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Gene Clusters ◽  
Future Prospects ◽  
Genome Sequences ◽  
Biosynthetic Gene Clusters ◽  
Antibiotic Resistant ◽  
New Antibiotics ◽  
History Of ◽  
Antibiotic Discovery

The emergence of antibiotic-resistant pathogenic bacteria in recent decades leads us to an urgent need for the development of new antibacterial agents. The species of the genus Amycolatopsis are known as producers of secondary metabolites that are used in medicine and agriculture. The complete genome sequences of the Amycolatopsis demonstrate a wide variety of biosynthetic gene clusters, which highlights the potential ability of actinomycetes of this genus to produce new antibiotics. In this review, we summarize information about antibiotics produced by Amycolatopsis species. This knowledge demonstrates the prospects for further study of this genus as an enormous source of antibiotics.

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