Antibacterial activity of total flavonoids from Ilex rotunda Thunb. and different antibacterials on different multidrug-resistant bacteria alone or in combination

AbstractThe problem of bacterial resistance is becoming more and more serious, which has become an urgent problem to be solved in human and veterinary. One approach to control and delay bacterial resistance is combination therapy in which antibiotics are given together with other antimicrobial or non-antimicrobial agents. Studies have shown that flavonoids from Traditional Chinese medicine (TCM) possess a high level of antibacterial activity against antibiotic resistant strains. The aim of this study was to evaluate the antibacterial effects of a combined therapy of total flavonoids from Ilex rotunda Thunb. and antibiotics against seven kinds of veterinary bacteria which were multidrug resistance bacteria. A microdilution checkerboard method was used to determine the minimal inhibitory concentrations of both types of antimicrobials, alone and in combination. The fractional inhibitory concentration index was calculated and used to classify observed collective antibacterial activity as synergistic, additive, indifferent or antagonistic.From the performed tests, the total flavonoids and antimicrobial agents were combined to inhibit different multidrug-resistant bacteria, such as Escherichia coli, Streptococcus, Pseudomonas aeruginosa, Enterococcus faecalis, Proteus vulgaris, Staphylococcus aureus, Acinetobacter baumannii. For these bacteria, total flavonoids from Ilex Rotunda Thunb. presented synergistic or additive with different antibiotics and had a certain antibacterial effect on the separated multidrug-resistant bacteria. The study shows total flavonoids from Ilex rotunda Thunb. have potential as adjuvants for the treatment of animal bacterial diseases.

Download Full-text

The Antibacterial Activity of Human Amniotic Membrane against Multidrug-Resistant Bacteria Associated with Urinary Tract Infections: New Insights from Normal and Cancerous Urothelial Models

Biomedicines ◽

10.3390/biomedicines9020218 ◽

2021 ◽

Vol 9 (2) ◽

pp. 218

Author(s):

Taja Železnik Ramuta ◽

Larisa Tratnjek ◽

Aleksandar Janev ◽

Katja Seme ◽

Marjanca Starčič Erjavec ◽

...

Keyword(s):

Antibacterial Activity ◽

Urinary Tract ◽

Urinary Tract Infections ◽

Amniotic Membrane ◽

Multidrug Resistant ◽

Basic Knowledge ◽

Resistant Bacteria ◽

Human Amniotic Membrane ◽

Multidrug Resistant Bacteria ◽

Tract Infections

Urinary tract infections (UTIs) represent a serious global health issue, especially due to emerging multidrug-resistant UTI-causing bacteria. Recently, we showed that the human amniotic membrane (hAM) could be a candidate for treatments and prevention of UPEC and Staphylococcus aureus infections. However, its role against multidrug-resistant bacteria, namely methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamases (ESBL) producing Escherichia coli and Klebsiella pneumoniae, vancomycin-resistant Enterococci (VRE), carbapenem-resistant Acinetobacter baumannii, and Pseudomonas aeruginosa has not yet been thoroughly explored. Here, we demonstrate for the first time that the hAM homogenate had antibacterial activity against 7 out of 11 tested multidrug-resistant strains, the greatest effect was on MRSA. Using novel approaches, its activity against MRSA was further evaluated in a complex microenvironment of normal and cancerous urinary bladder urothelia. Even short-term incubation in hAM homogenate significantly decreased the number of bacteria in MRSA-infected urothelial models, while it did not affect the viability, number, and ultrastructure of urothelial cells. The hAM patches had no antibacterial activity against any of the tested strains, which further exposes the importance of the hAM preparation. Our study substantially contributes to basic knowledge on the antibacterial activity of hAM and reveals its potential to be used as an antibacterial agent against multidrug-resistant bacteria.

Download Full-text

Botanicals and phytochemicals from the bark of Hypericum roeperianum (Hypericaceae) had strong antibacterial activity and showed synergistic effects with antibiotics against multidrug-resistant bacteria expressing active efflux pumps.

Journal of Ethnopharmacology ◽

10.1016/j.jep.2021.114257 ◽

2021 ◽

pp. 114257

Author(s):

Olive Monique F. Demgne ◽

Francois Damen ◽

Aimé G. Fankam ◽

Michel-Gael F. Guefack ◽

Brice E.N. Wamba ◽

...

Keyword(s):

Antibacterial Activity ◽

Synergistic Effects ◽

Efflux Pumps ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Multidrug Resistant Bacteria ◽

Active Efflux

Download Full-text

Progress in the Fight Against Multidrug-Resistant Bacteria 2005–2016: Modern Noninferiority Trial Designs Enable Antibiotic Development in Advance of Epidemic Bacterial Resistance

Clinical Infectious Diseases ◽

10.1093/cid/cix246 ◽

2017 ◽

Vol 65 (1) ◽

pp. 141-146 ◽

Cited By ~ 34

Author(s):

John H Rex ◽

George H Talbot ◽

Mark J Goldberger ◽

Barry I Eisenstein ◽

Roger M Echols ◽

...

Keyword(s):

Bacterial Resistance ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Multidrug Resistant Bacteria ◽

Antibiotic Development ◽

Noninferiority Trial

Download Full-text

Antimicrobial and Antibiofilm Peptides

Biomolecules ◽

10.3390/biom10040652 ◽

2020 ◽

Vol 10 (4) ◽

pp. 652 ◽

Cited By ~ 12

Author(s):

Angela Di Somma ◽

Antonio Moretta ◽

Carolina Canè ◽

Arianna Cirillo ◽

Angela Duilio

Keyword(s):

Antimicrobial Peptides ◽

Biofilm Formation ◽

Bacterial Resistance ◽

Antimicrobial Agents ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Antibiofilm Activity ◽

Chronic Infections ◽

Planktonic Bacteria ◽

Hostile Environments

The increasing onset of multidrug-resistant bacteria has propelled microbiology research towards antimicrobial peptides as new possible antibiotics from natural sources. Antimicrobial peptides are short peptides endowed with a broad range of activity against both Gram-positive and Gram-negative bacteria and are less prone to trigger resistance. Besides their activity against planktonic bacteria, many antimicrobial peptides also show antibiofilm activity. Biofilms are ubiquitous in nature, having the ability to adhere to virtually any surface, either biotic or abiotic, including medical devices, causing chronic infections that are difficult to eradicate. The biofilm matrix protects bacteria from hostile environments, thus contributing to the bacterial resistance to antimicrobial agents. Biofilms are very difficult to treat, with options restricted to the use of large doses of antibiotics or the removal of the infected device. Antimicrobial peptides could represent good candidates to develop new antibiofilm drugs as they can act at different stages of biofilm formation, on disparate molecular targets and with various mechanisms of action. These include inhibition of biofilm formation and adhesion, downregulation of quorum sensing factors, and disruption of the pre-formed biofilm. This review focuses on the proprieties of antimicrobial and antibiofilm peptides, with a particular emphasis on their mechanism of action, reporting several examples of peptides that over time have been shown to have activity against biofilm.

Download Full-text