scholarly journals Membrane-Activating Triphenylphosphonium Functionalized Ciprofloxacin for Multidrug Resistant Bacteria

2020 ◽  
Author(s):  
Sangrim Kang ◽  
Kyoung Sunwoo ◽  
Yuna Jung ◽  
Junho Hur ◽  
Ki-Ho Park ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Morphological Changes ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Severe Problem ◽  
Bacterial Membranes ◽  
High Antibacterial Activity ◽  
New Antibiotics ◽  
Mrsa Strains

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.

scholarly journals Membrane-Targeting Triphenylphosphonium Functionalized Ciprofloxacin for Methicillin-Resistant Staphylococcus aureus (MRSA)

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 758
Author(s):  
Sangrim Kang ◽  
Kyoung Sunwoo ◽  
Yuna Jung ◽  
Junho K. Hur ◽  
Ki-Ho Park ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Morphological Changes ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Severe Problem ◽  
Methicillin Resistant ◽  
Bacterial Membranes ◽  
High Antibacterial Activity ◽  
New Antibiotics

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, modification of an antibiotic, ciprofloxacin (CFX), with triphenylphosphonium (TPP, PPh3) moiety via ester- (CFX-ester-PPh3) and amide-coupling (CFX-amide-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 (methicillin-resistant S. aureus (MRSA)) strains. The MRSA ST5 5016 strain showed high antibacterial activity, with 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 derivatives 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.

scholarly journals Antimicrobial Mechanism of pBD2 against Staphylococcus aureus

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3513 ◽  
Author(s):  
Kun Zhang ◽  
Heng Zhang ◽  
Chunyu Gao ◽  
Ruibo Chen ◽  
Chunli Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Morphological Changes ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Quantitative Real Time Pcr ◽  
Bacterial Membranes ◽  
Qrt Pcr ◽  
High Antibacterial Activity ◽  
Therapeutic Substance

Antimicrobial peptides (AMPs) show high antibacterial activity against pathogens, which makes them potential new therapeutics to prevent and cure diseases. Porcine beta defensin 2 (pBD2) is a newly discovered AMP and has shown antibacterial activity against different bacterial species including multi-resistant bacteria. In this study, the functional mechanism of pBD2 antibacterial activity against Staphylococcus aureus was investigated. After S. aureus cells were incubated with different concentrations of pBD2, the morphological changes in S. aureus and locations of pBD2 were detected by electron microscopy. The differentially expressed genes (DEGs) were also analyzed. The results showed that the bacterial membranes were broken, bulging, and perforated after treatment with pBD2; pBD2 was mainly located on the membranes, and some entered the cytoplasm. Furthermore, 31 DEGs were detected and confirmed by quantitative real-time PCR (qRT-PCR). The known functional DEGs were associated with transmembrane transport, transport of inheritable information, and other metabolic processes. Our data suggest that pBD2 might have multiple modes of action, and the main mechanism by which pBD2 kills S. aureus is the destruction of the membrane and interaction with DNA. The results imply that pBD2 is an effective bactericide for S. aureus, and deserves further study as a new therapeutic substance against S. aureus.

scholarly journals Susceptibility of Multidrug-Resistant Bacteria, Isolated from Water and Plants in Nigeria, to Ceragenins

2018 ◽  
Vol 15 (12) ◽  
pp. 2758 ◽  
Author(s):  
Marjan Hashemi ◽  
Augusta Mmuoegbulam ◽  
Brett Holden ◽  
Jordan Coburn ◽  
John Wilson ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Environmental Isolates ◽  
Bacterial Membranes ◽  
Resistance Patterns ◽  
Confocal Images

The continuous emergence of multidrug resistant pathogens is a major global health concern. Although antimicrobial peptides (AMPs) have shown promise as a possible means of combatting multidrug resistant strains without readily engendering resistance, costs of production and targeting by proteases limit their utility. Ceragenins are non-peptide AMP mimics that overcome these shortcomings while retaining broad-spectrum antimicrobial activity. To further characterize the antibacterial activities of ceragenins, their activities against a collection of environmental isolates of bacteria were determined. These isolates were isolated in Nigeria from plants and water. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of selected ceragenins and currently available antimicrobials against these isolates were measured to determine resistance patterns. Using scanning electron microscopy (SEM), we examined the morphological changes in bacterial membranes following treatment with ceragenins. Finally, we investigated the effectiveness of ceragenins in inhibiting biofilm formation and destroying established biofilms. We found that, despite high resistance to many currently available antimicrobials, including colistin, environmental isolates in planktonic and biofilm forms remain susceptible to ceragenins. Additionally, SEM and confocal images of ceragenin-treated cells confirmed the effective antibacterial and antibiofilm activity of ceragenins.

scholarly journals Synthesis, Structure Elucidation, Antibacterial Activities, and Synergistic Effects of Novel Juglone and Naphthazarin Derivatives Against Clinical Methicillin-Resistant Staphylococcus aureus Strains

2021 ◽  
Vol 9 ◽  
Author(s):  
Valentin Duvauchelle ◽  
Chaimae Majdi ◽  
David Bénimélis ◽  
Catherine Dunyach-Remy ◽  
Patrick Meffre ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Antibacterial Properties ◽  
Clinical Importance ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Global Public Health ◽  
Gram Positive ◽  
Drug Resistant Bacteria ◽  
Mrsa Strains

Infections caused by drug-resistant bacteria are a serious threat to human and global public health. Moreover, in recent years, very few antibiotics have been discovered and developed by pharmaceutical companies. Therefore, there is an urgent need to discover and develop new antibacterial agents to combat multidrug-resistant bacteria. In this study, two novel series of juglone/naphthazarin derivatives (43 compounds) were synthesized and evaluated for their antibacterial properties against various clinical and reference Gram-positive MSSA, clinical Gram-positive MRSA, and clinical and reference Gram-negative bacteria E. coli and P. aeruginosa. These strains are of clinical importance because they belong to ESKAPE pathogens. Compounds 3al, 5ag, and 3bg showed promising activity against clinical and reference MSSA (MIC: 1–8 µg/ml) and good efficacy against clinical MRSA (MIC: 2–8 µg/ml) strains. 5am and 3bm demonstrated better activity on both MSSA (MIC: 0.5 µg/ml) and MRSA (MIC: 2 µg/ml) strains. Their MICs were similar to those of cloxacillin against clinical MRSA strains. The synergistic effects of active compounds 3al, 5ag, 5am, 3bg, and 3bm were evaluated with reference antibiotics, and it was found that the antibiotic combination with 3bm efficiently enhanced the antimicrobial activity. Compound 3bm was found to restore the sensitivity of clinical MRSA to cloxacillin and enhanced the antibacterial activity of vancomycin when they were added together. In the presence of 3bm, the MIC values of vancomycin and cloxacillin were lowered up to 1/16th of the original MIC with an FIC index of 0.313. Moreover, compounds 3al, 5ag, 5am, 3bg, and 3bm did not present hemolytic activity on sheep red blood cells. In silico prediction of ADME profile parameter results for 3bm is promising and encouraging for further development.

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 ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bioactive Compounds ◽  
Metabolic Profile ◽  
Bacterial Infections ◽  
Ethanolic Extract ◽  
Multidrug Resistant ◽  
Gas Chromatography Mass Spectrometry ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
New Antibiotics

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.

scholarly journals Complex effects of macrolide venturicidins on bacterial F-ATPases likely contribute to their action as antibiotic adjuvants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yakov M. Milgrom ◽  
Thomas M. Duncan
Keyword(s):  
Atpase Activity ◽  
Atp Synthase ◽  
Critical Factor ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Adjuvant Activity ◽  
Bacterial Membranes ◽  
Resistant Tuberculosis ◽  
Key Factor ◽  
New Antibiotics

AbstractBacterial energy metabolism is now recognized as a critical factor for the efficacy of antibiotics. The F-type ATPase/ATP synthase (FOF1) is a central player in cellular bioenergetics of bacteria and eukaryotes, and its potential as a selective antibiotic target has been confirmed by the success of bedaquiline in combatting multidrug-resistant tuberculosis. Venturicidin macrolides were initially identified for their antifungal properties and were found to specifically inhibit FOF1 of eukaryotes and bacteria. Venturicidins alone are not effective antibacterials but recently were found to have adjuvant activity, potentiating the efficacy of aminoglycoside antibiotics against several species of resistant bacteria. Here we discovered more complex effects of venturicidins on the ATPase activity of FOF1 in bacterial membranes from Escherichia coli and Pseudomonas aeruginosa. Our major finding is that higher concentrations of venturicidin induce time– and ATP–dependent decoupling of F1-ATPase activity from the venturicidin-inhibited, proton-transporting FO complex. This dysregulated ATPase activity is likely to be a key factor in the depletion of cellular ATP induced by venturicidins in prior studies with P. aeruginosa and Staphylococcus aureus. Further studies of how this functional decoupling occurs could guide development of new antibiotics and/or adjuvants that target the F-type ATPase/ATP synthase.

scholarly journals Unveiling the Mechanism of Action of 7α-acetoxy-6β-hydroxyroyleanone on an MRSA/VISA Strain: Membrane and Cell Wall Interactions

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 983
Author(s):  
Filipe Pereira ◽  
Teresa Figueiredo ◽  
Rodrigo F. M. de Almeida ◽  
Catarina A. C. Antunes ◽  
Catarina Garcia ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antibacterial Activity ◽  
Lipid Bilayers ◽  
Mechanism Of Action ◽  
Resistant Bacteria ◽  
High Antibacterial Activity ◽  
Cell Wall Disruption ◽  
Low Cytotoxicity ◽  
Mrsa Strains ◽  
Interesting Alternative

The number of cases of failure in the treatment of infections associated with resistant bacteria is on the rise, due to the decreasing efficacy of current antibiotics. Notably, 7α-Acetoxy-6β-hydroxyroyleanone (AHR), a diterpene isolated from different Plectranthus species, showed antibacterial activity, namely against Methicillin-resistant Staphylococcus aureus (MRSA) strains. The high antibacterial activity and low cytotoxicity render this natural compound an interesting alternative against resistant bacteria. The aim of this study is to understand the mechanism of action of AHR on MRSA, using the MRSA/Vancomycin-intermediate S. aureus (VISA) strain CIP 106760, and to study the AHR effect on lipid bilayers and on the cell wall. Although AHR interacted with lipid bilayers, it did not have a significant effect on membrane passive permeability. Alternatively, bacteria treated with this royleanone displayed cell wall disruption, without revealing cell lysis. In conclusion, the results gathered so far point to a yet undescribed mode of action that needs further investigation.

scholarly journals Multidrug and Pan-Antibiotic Resistance—The Role of Antimicrobial and Synergistic Essential Oils: A Review

2020 ◽  
Vol 15 (10) ◽  
pp. 1934578X2096259
Author(s):  
Karen Boren ◽  
AliceAnn Crown ◽  
Richard Carlson
Keyword(s):  
Essential Oils ◽  
Bacterial Resistance ◽  
Fungal Infections ◽  
Multidrug Resistant ◽  
World Health ◽  
Resistant Bacteria ◽  
Bacterial Membranes ◽  
New Antibiotics ◽  
Clinical Benefits

Bacterial resistance to antibiotics continues to be a grave threat to human health. Because antibiotics are no longer a lucrative market for pharmaceutical companies, the development of new antibiotics has slowed to a crawl. The World Health Organization reported that the 8 new bacterial agents approved since July 2017 had limited clinical benefits. While a cohort of biopharmaceutical companies recently announced plans to develop 2-4 new antibiotics by 2030, we needn’t wait a decade to find innovative antibiotic candidates. Essential oils (EOs) have long been known as antibacterial agents with wide-ranging arsenals. Many are able to penetrate the bacterial membrane and may also be effective against bacterial defenses such as biofilms, efflux pumps, and quorum sensing. EOs have been documented to fight drug-resistant bacteria alone and/or combined with antibiotics. This review will summarize research showing the significant role of EOs as nonconventional regimens against the worldwide spread of antibiotic-resistant pathogens. The authors conducted a 4-year search of the US National Library of Medicine (PubMed) for relevant EO studies against methicillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Escherichia coli, EO combinations/synergy with antibiotics, against MDR fungal infections, showing the ability to permeate bacterial membranes, and against the bacterial defenses listed above. EOs are readily available and are a needed addition to the arsenal against resistant pathogens.

Complex Effects of Macrolide Venturicidins on Bacterial F-ATPases Likely Contribute to Their Action as Antibiotic Adjuvants

2021 ◽  
Author(s):  
Yakov M. Milgrom ◽  
Thomas M. Duncan
Keyword(s):  
Atpase Activity ◽  
Atp Synthase ◽  
Critical Factor ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Adjuvant Activity ◽  
Bacterial Membranes ◽  
Resistant Tuberculosis ◽  
Key Factor ◽  
New Antibiotics

Abstract Bacterial energy metabolism is now recognized as a critical factor for the efficacy of antibiotics. The F-type ATPase/ATP synthase (FOF1) is a central player in cellular bioenergetics of bacteria and eukaryotes, and its potential as a selective antibiotic target has been confirmed by the success of bedaquiline in combatting multidrug-resistant tuberculosis. Venturicidin macrolides were initially identified for their antifungal properties and were found to specifically inhibit FOF1 of eukaryotes and bacteria. Venturicidins alone are not effective antibacterials but recently were found to have adjuvant activity, potentiating the efficacy of aminoglycoside antibiotics against several species of resistant bacteria. Here we discovered more complex effects of venturicidins on the ATPase activity of FOF1 in bacterial membranes from Escherichia coli and Pseudomonas aeruginosa. Our major finding is that higher concentrations of venturicidin induce time– and ATP–dependent decoupling of F1-ATPase activity from the venturicidin-inhibited, proton-transporting FO complex. This dysregulated ATPase activity is likely to be a key factor in the depletion of cellular ATP induced by venturicidins in prior studies with P. aeruginosa and Staphylococcus aureus. Further studies of how this functional decoupling occurs could guide development of new antibiotics and/or adjuvants that target the F-type ATPase/ATP synthase.

scholarly journals Antibacterial Activity of Moroccan Zantaz Honey and the Influence of Its Physicochemical Parameters Using Chemometric Tools

2021 ◽  
Vol 11 (10) ◽  
pp. 4675
Author(s):  
Youssef Elamine ◽  
Hamada Imtara ◽  
Maria Graça Miguel ◽  
Ofélia Anjos ◽  
Letícia M. Estevinho ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Principal Component ◽  
Physicochemical Characteristics ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Coumaric Acid ◽  
Atlas Mountains ◽  
Methyl Syringate ◽  
Chemometric Tools

The emergence of multidrug-resistant bacteria has prompted the development of alternative therapies, including the use of natural products with antibacterial properties. The antibacterial properties of Zantaz honey produced in the Moroccan Atlas Mountains against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated and analyzed using chemometric tools. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) against S. aureus were the lowest (112.5 ± 54.5 mg/mL), revealing that this species was most sensitive to Zantaz honey. P. aeruginosa showed an intermediate sensitivity (MIC= 118.75 ± 51.9 mg/mL), while E. coli was the most resistant to treatment (MIC = 175 ± 61.2 mg/mL). Content of monosaccharides, certain minerals, and phenolic compounds correlated with antibacterial activity (p < 0.05). Principal component analysis of physicochemical characteristics and antibacterial activity indicated that the parameters most associated with antibacterial activity were color, acidity, and content of melanoidins, fructose, epicatechin, methyl syringate, 4-coumaric acid, and 3-coumaric acid.

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