scholarly journals Metabolic profiling and antibacterial activity of Eryngium pristis Cham. & Schltdl. - prospecting for its use in the treatment of bacterial infections

2021 ◽  
Vol 5 (1) ◽  
pp. 020-028
Author(s):  
Fernandes Laura Silva ◽  
da Costa Ygor Ferreira Garcia ◽  
de Bessa Martha Eunice ◽  
Ferreira Adriana Lucia Pires ◽  
do Amaral Corrêa José Otávio ◽  
...  

Morbidity and mortality of the infected patients by multidrug-resistant bacteria have increased, emphasizing the urgency of fight for the discovery of new innovative antibiotics. In this sense, natural products emerge as valuable sources of bioactive compounds. Among the biodiversity, Eryngium pristis Cham. & Schltdl. (Apiaceae Lindl.) is traditionally used to treat thrush and ulcers of throat and mouth, as diuretic and emmenagogue, but scarcely known as an antimicrobial agent. With this context in mind, the goals of this study were to investigate the metabolic profile and the antibacterial activity of ethanolic extract (EE-Ep) and hexane (HF-Ep), dichloromethane (DF-Ep), ethyl acetate (EAF-Ep) and butanol (BF-Ep) fractions from E. pristis leaves. Gas Chromatography-Mass Spectrometry (GC-MS) was performed to stablish the metabolic profile and revealed the presence of 12 and 14 compounds in EAF-Ep and HF-Ep, respectively. β-selinene, spathulenol, globulol, 2-methoxy-4-vinylphenol, α-amyrin, β-amyrin, and lupeol derivative were some of phytochemicals identified. The antibacterial activity was determined by Minimal Inhibitory Concentration (MIC) using the broth micro-dilution against eight ATCC® and five methicillin-resistant Staphylococcus aureus (MRSA) clinical strains. HF-Ep was the most effective (MIC ≤ 5,000 µg/µL), being active against the largest part of tested Gram-positive and Gram-negative bacterial strains, including MRSA, with exception of Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) and (ATCC 27853). These results suggest that E. pristis is a natural source of bioactive compounds for the search of new antibiotics which can be an interesting therapeutic approach to recover patients mainly infected by MRSA strains.

2018 ◽  
Vol 14 ◽  
pp. 2881-2896 ◽  
Author(s):  
Laura Carro

Antibiotics are potent pharmacological weapons against bacterial infections; however, the growing antibiotic resistance of microorganisms is compromising the efficacy of the currently available pharmacotherapies. Even though antimicrobial resistance is not a new problem, antibiotic development has failed to match the growth of resistant pathogens and hence, it is highly critical to discover new anti-infective drugs with novel mechanisms of action which will help reducing the burden of multidrug-resistant microorganisms. Protein–protein interactions (PPIs) are involved in a myriad of vital cellular processes and have become an attractive target to treat diseases. Therefore, targeting PPI networks in bacteria may offer a new and unconventional point of intervention to develop novel anti-infective drugs which can combat the ever-increasing rate of multidrug-resistant bacteria. This review describes the progress achieved towards the discovery of molecules that disrupt PPI systems in bacteria for which inhibitors have been identified and whose targets could represent an alternative lead discovery strategy to obtain new anti-infective molecules.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Olufunmiso Olusola Olajuyigbe ◽  
Otunola Adedayo ◽  
Roger Murugas Coopoosamy

The antibacterial activity of the extracts of Aframomum melegueta including n-hexane extract (NHE), nondefatted methanol extract (NDME), and defatted methanol extract (DME) was investigated in this study. The NHE exhibited no antibacterial activity. The DME showed higher antibacterial activity than the NDME against the different isolates. At the highest concentration of 10 mg/mL in agar diffusion, NDME produced inhibition zones ranging from 11 to 29 mm against the microorganisms while DME produced inhibition zones ranging from 20 to 40 mm with the concentration of 10 mg/mL against the microorganisms. 0.1 mg/mL of the DME produced inhibition zones ranging between 12 and 14 mm in Aeromonas hydrophila ATCC 35654 and Pseudomonas aeruginosa ATCC 15442, respectively, while none of the isolates were inhibited by the NDME at a concentration of 1 mg/mL or less. In the agar dilution assay, the MICs of the NDME and DME ranged between 0.31 and 10 mg/mL, but more isolates were inhibited at 0.31 mg/mL of DME than those in NDME. In macrobroth assay, the MICs of the NDME ranged between 0.15 and 5.0 mg/mL and the MBCs ranged between 0.63 and 5.0 mg/mL, and the MICs of the DME ranged between 0.08 and 5.0 mg/mL and the MBCs were between 0.31 and 5.0 mg/mL. This study indicated that DME was more active with higher antibacterial activity than the NDME of this plant, and extracting the fatty portion of plant materials prior susceptibility testing would allow plant extracts to be more effective as well as justifying the use of Aframomum melegueta in traditional medicine for the treatment of bacterial infections.


Author(s):  
G.M. Rossolini

Antibiotics are one of the most significant advancements of modern medicine. They have changed the prognosis of several bacterial infections, and made possible advanced medical practices associated with a high risk of infectious complications. Unfortunately, antibiotics are affected by the phenomenon of antibiotic resistance, which jeopardizes their efficacy. In recent years, antibiotic discovery and development has been lagging, due to a lower appeal of this sector for the pharmaceutical industry, while antibiotic resistance has continued to evolve with the eventual emergence and dissemination of bacterial strains which are resistant to most available antibiotics and pose a major challenge to antimicrobial chemotherapy. This worrisome scenario, indicated as the “antibiotic resistance crisis”, has been acknowledged by Scientific Societies and Public Health Agencies, and is now gathering an increasing attention from the Media and Governments. This article reviews the antibiotic-resistant pathogens which currently pose major problems in terms of clinical and epidemiological impact, and briefly discuss future perspective in this field.


2016 ◽  
Vol 29 (2) ◽  
pp. 321-347 ◽  
Author(s):  
Matthew E. Falagas ◽  
Evridiki K. Vouloumanou ◽  
George Samonis ◽  
Konstantinos Z. Vardakas

SUMMARYThe treatment of bacterial infections suffers from two major problems: spread of multidrug-resistant (MDR) or extensively drug-resistant (XDR) pathogens and lack of development of new antibiotics active against such MDR and XDR bacteria. As a result, physicians have turned to older antibiotics, such as polymyxins, tetracyclines, and aminoglycosides. Lately, due to development of resistance to these agents, fosfomycin has gained attention, as it has remained active against both Gram-positive and Gram-negative MDR and XDR bacteria. New data of higher quality have become available, and several issues were clarified further. In this review, we summarize the available fosfomycin data regarding pharmacokinetic and pharmacodynamic properties, thein vitroactivity against susceptible and antibiotic-resistant bacteria, mechanisms of resistance and development of resistance during treatment, synergy and antagonism with other antibiotics, clinical effectiveness, and adverse events. Issues that need to be studied further are also discussed.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Aseer Manilal ◽  
Kuzhunellil Raghavanpillai Sabu ◽  
Melat Woldemariam ◽  
Addis Aklilu ◽  
Gelila Biresaw ◽  
...  

Background. In developing countries, the prevalence of bacterial infections is quite rampant due to several factors such as the HIV/AIDS pandemic, lack of hygiene, overcrowding, and resistance to conventional antimicrobials. Hence the use of plant-based antimicrobial agents could provide a low-cost alternative therapy. Rosmarinus officinalis is reputed as a medicinal plant in Ethiopia; however, its antibacterial activity against many of the clinical isolates remains overlooked. Methods. Tender foliage of R. officinalis was collected and extracted in ethanol (EtOH) and evaluated for their antimicrobial activity against ten multidrug-resistant (MDR) clinical isolates, human type culture pathogens, and meat-borne bacterial isolates by employing agar well diffusion assay. Results. EtOH extract of R. officinalis efficiently subdued the growth of all tested MDR clinical isolates in varying degrees. Salmonella sp. and Staphylococcus aureus were found to be the most sensitive clinical isolates. Likewise, it efficiently repressed the growth of meat-borne pathogens, particularly, S. aureus and Salmonella sp. showing its potentiality to be used as a natural antibacterial agent in the meat processing industry. The mechanism of antibiosis of plant extract against meat-borne pathogens is inferred to be bactericidal. Chemical constituents of the crude plant extract were analysed by Gas Chromatography-Mass Spectroscopy (GC-MS), Fourier Transform Infrared (FT-IR), and UV-visible spectroscopy showing genkwanin (26%), camphor (13%), endo-borneol (13%), alpha-terpineol (12%), and hydroxyhydrocaffeic acid (13%) as the major compounds. Conclusion. Overall results of the present study conclude that R. officinalis could be an excellent source of antimicrobial agents for the management of drug-resistant bacteria as well as meat-borne pathogens.


2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


2021 ◽  
Author(s):  
Matthew Mitcheltree ◽  
Amarnath Pisipati ◽  
Egor A. Syroegin ◽  
Katherine J. Silvestre ◽  
Dorota Klepacki ◽  
...  

The dearth of new medicines effective against antibiotic-resistant bacteria presents a growing global public health concern. For more than five decades, the search for new antibiotics has relied heavily upon the chemical modification of natural products (semi-synthesis), a method ill-equipped to combat rapidly evolving resistance threats. Semi-synthetic modifications are typically of limited scope within polyfunctional antibiotics, usually increase molecular weight, and seldom permit modifications of the underlying scaffold. When properly designed, fully synthetic routes can easily address these shortcomings. Here we report the structure-guided design and component-based synthesis of a rigid oxepanoproline scaffold which, when linked to the aminooctose residue of clindamycin, produces an antibiotic of exceptional potency and spectrum of activity, here named iboxamycin. Iboxamycin is effective in strains expressing Erm and Cfr rRNA methyltransferase enzymes, products of genes that confer resistance to all clinically relevant antibiotics targeting the large ribosomal subunit, namely macrolides, lincosamides, phenicols, oxazolidinones, pleuromutilins, and streptogramins. X-ray crystallographic studies of iboxamycin in complex with the native 70S bacterial ribosome, as well as the Erm-methylated 70S ribosome, uncover the structural basis for this enhanced activity, including an unforeseen and unprecedented displacement of upon antibiotic binding. In mice, iboxamycin is orally bioavailable, safe, and effective in treating bacterial infections, testifying to the capacity for chemical synthesis to provide new antibiotics in an era of rising resistance.


Author(s):  
Luis Rodrigo Ramiro-Bautista ◽  
Alejandro Hernández-Morales ◽  
Candy Carranza-Álvarez ◽  
Juan José Maldonado-Miranda

Antimicrobial resistance is a great concern in public health. Therefore, it is necessary to obtain new compounds to treat diseases caused by bacteria. Medicinal plants are an alternative to search natural compounds to improve human health, including antioxidants, anti-inflammatory, and antimicrobials compounds. Costus pulverulentus (Costaceae) C. Presl is a plant used traditionally in Huasteca Potosina to treat bacterial infections. However, the compounds involved in this activity remain poorly understood. To determine the antibacterial activity of C. pulverulentus, an ethanolic extract was obtained. Plant stem was macerated in ethanol and then was fractionated with hexane, chloroform, ethyl acetate, acetone, ethanol, and methanol. Ethanolic extract and derived fractions were tested against bacteria by the disk-diffusion agar method. The results showed that the ethanolic extract of C. pulverulentus exerted activity against Chromobacterium violaceum CV026 and Bacillus sp. at 10 and 30 μg/disk, whereas only the methanolic fraction showed similar activity to complete extract. Fraction 8 obtained from methanolic fraction showed inhibitory activity against Bacillus sp., S. aureus, and S. aureus Oxacillin resistant. Gas Chromatography-Mass Spectrometry characterization of active fraction 8 showed that it contains vanillic acid and pcoumaric acid suggesting that they are involved in the antibacterial activity of C. pulverulentus.


Author(s):  
Sangrim Kang ◽  
Kyoung Sunwoo ◽  
Yuna Jung ◽  
Junho Hur ◽  
Ki-Ho Park ◽  
...  

Multidrug resistant (MDR) bacteria have become a severe problem for public health. Developing new antibiotics for MDR bacteria is difficult, from inception to the clinically approved stage. Here, we have used a new approach; we have modified the antibiotic, ciprofloxacin (CFX), with triphenylphosphonium (TPP, PPh3) moiety via ester- (CFX-ester-PPh3) and amide-coupling (CFX-ester-PPh3), to target bacterial membranes. In this study, we have evaluated the antibacterial activities of CFX and its derivatives against 16 species of bacteria, including MDR bacteria, using minimum inhibitory concentration (MIC) assay, morphological monitoring, and expression of resistance-related genes. TPP-conjugated CFX, CFX-ester-PPh3 and CFX-amide-PPh3 showed significantly improved antibacterial activity against Gram-positive bacteria, Staphylococcus aureus, including MDR S. aureus (MRSA) strains. The MRSA ST5 5016 strain showed high antibacterial activity, with an MIC values of 11.12 µg/mL for CFX-ester-PPh3 and 2.78 µg/mL for CFX-amide-PPh3. The CFX derivatives inhibited biofilm formation in MRSA by more than 74.9% of CFX-amide-PPh3. In the sub-MIC, CFX derivates induced significant morphological changes in MRSA, including irregular deformation and membrane disruption, accompanied by a decrease in the level of resistance-related gene expression. With these promising results, this method is very likely to combat MDR bacteria, through a simple TPP moiety modification of known antibiotics, which can be readily prepared at clinical sites.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Nurit Beyth ◽  
Yael Houri-Haddad ◽  
Avi Domb ◽  
Wahid Khan ◽  
Ronen Hazan

Despite numerous existing potent antibiotics and other antimicrobial means, bacterial infections are still a major cause of morbidity and mortality. Moreover, the need to develop additional bactericidal means has significantly increased due to the growing concern regarding multidrug-resistant bacterial strains and biofilm associated infections. Consequently, attention has been especially devoted to new and emerging nanoparticle-based materials in the field of antimicrobial chemotherapy. The present review discusses the activities of nanoparticles as an antimicrobial means, their mode of action, nanoparticle effect on drug-resistant bacteria, and the risks attendant on their use as antibacterial agents. Factors contributing to nanoparticle performance in the clinical setting, their unique properties, and mechanism of action as antibacterial agents are discussed in detail.


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