scholarly journals Prosthetic Meshes for Hernia Repair: State of Art, Classification, Antimicrobial Approaches, and Fabrication Methods

2021 ◽  
Author(s):  
Ángel Serrano-Aroca ◽  
Salvador Pous-Serrano
Keyword(s):  
Hernia Repair ◽  
Mechanical Performance ◽  
Multidrug Resistant ◽  
Biological Properties ◽  
Global Market ◽  
Future Research ◽  
Foreign Body Reactions ◽  
Microbial Infections ◽  
Resistant Strains ◽  
Made In

Worldwide, hernia repair represents one of the most frequent surgical procedures encompassing a global market valued at several billion dollars. This type of surgery usually requires the implantation of a mesh that needs the appropriate chemical, physical and biological properties for the type of repair. This review thus presents a description of the types of hernias, current hernia repair methods, and the state of the art of prosthetic meshes for hernia repair providing the most important meshes used in clinical practice by surgeons working in this area classified according to their biological or chemical nature, morphology and whether bioabsorbable or not. We emphasise the importance of surgical site infection in herniatology, how to deal with this microbial problem, and we go further into the future research lines on the production of advanced antimicrobial meshes to improve hernia repair and prevent microbial infections, including multidrug-resistant strains. A great deal of progress has been made in this biomedical field in the last decade. However, we are still far from an ideal antimicrobial mesh that can also provide excellent integration to the abdominal wall, mechanical performance, low visceral adhesion and minimal inflammatory or foreign body reactions, among many other problems.

scholarly journals Mesosphaerum suaveolens (Lamiacae): Source of antimicrobial and antioxidant compounds

2020 ◽  
Vol 9 (8) ◽  
Author(s):  
José Weverton Almeida Bezerra ◽  
Felicidade Caroline Rodrigues ◽  
Adrielle Rodrigues Costa ◽  
Kyhara Soares Pereira ◽  
Natália Rodrigues Vieira ◽  
...  
Keyword(s):  
Folk Medicine ◽  
Antioxidant Properties ◽  
Volatile Oil ◽  
Multidrug Resistant ◽  
Biological Properties ◽  
Biological Action ◽  
Major Constituent ◽  
Antioxidant Compounds ◽  
Resistant Strains

The use in folk medicine of leaves of Mesosphaerum suaveolens for the treatment of diseases of the digestive system and respiratory system, raised the hypothesis that its volatile oil has biological properties against pathogenic microorganisms. To evaluate this hypothesis, the antibacterial, antifungal activity against Candida yeast strains, which modifies the action of antibiotics and antioxidants (DPPH) was evaluated in vitro. In addition, it was determined by means of Gas Chromatography (GC-FID), the constituents present in the essential oil. The results show that M. suaveolens oil has antibacterial activity against standard and multidrug-resistant strains of Staphylococcus aureus, with a MIC of 64 and 256 μg/mL respectively, however it does not have the capacity to enhance the action of commercial antibacterials. Regarding the anti-Candida activity, it was possible to observe that there was biological action, since they presented IC50 de 18.15 µg/mL for Candida albicans URM and 40.4 for Candida tropicalis INCQS 40042. In addition, the oil was able to modulate fluconazole for all strains analyzed. As for the antioxidant action, the oil demonstrated that even in low percentages, there is an action in the reduction of free radicals (IC50> 200 µg/mL). Such activities may be related to the major constituent of the oil, the sesquiterpene β-caryophyllene (C17H28O2). Thus, M. suaveolens oil is a natural source with antimicrobial and antioxidant properties.

scholarly journals Ruminococcin C, a promising antibiotic produced by a human gut symbiont

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw9969 ◽  
Author(s):  
Steve Chiumento ◽  
Clarisse Roblin ◽  
Sylvie Kieffer-Jaquinod ◽  
Sybille Tachon ◽  
Chloé Leprètre ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Eukaryotic Cells ◽  
Original Structure ◽  
Gut Health ◽  
Producer Strain ◽  
Human Gut ◽  
Microbial Infections ◽  
Modified Peptides ◽  
Public Health Challenge ◽  
Resistant Strains

A major public health challenge today is the resurgence of microbial infections caused by multidrug-resistant strains. Consequently, novel antimicrobial molecules are actively sought for development. In this context, the human gut microbiome is an under-explored potential trove of valuable natural molecules, such as the ribosomally-synthesized and post-translationally modified peptides (RiPPs). The biological activity of the sactipeptide subclass of RiPPs remains under-characterized. Here, we characterize an antimicrobial sactipeptide, Ruminococcin C1, purified from the caecal contents of rats mono-associated with Ruminococcus gnavus E1, a human symbiont. Its heterologous expression and post-translational maturation involving a specific sactisynthase establish a thioether network, which creates a double-hairpin folding. This original structure confers activity against pathogenic Clostridia and multidrug-resistant strains but no toxicity towards eukaryotic cells. Therefore, the Ruminococcin C1 should be considered as a valuable candidate for drug development and its producer strain R. gnavus E1 as a relevant probiotic for gut health enhancement.

scholarly journals The unusual structure of Ruminococcin C1 antimicrobial peptide confers clinical properties

2020 ◽  
Vol 117 (32) ◽  
pp. 19168-19177 ◽  
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Olivier Bornet ◽  
Matthieu Nouailler ◽  
Christina S. Müller ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Human Gut ◽  
Healthy Human ◽  
Unusual Structure ◽  
Compact Structure ◽  
Radical Sam ◽  
Human Intestinal Microbiota ◽  
Microbial Infections ◽  
Resistant Strains ◽  
Therapeutic Doses

The emergence of superbugs developing resistance to antibiotics and the resurgence of microbial infections have led scientists to start an antimicrobial arms race. In this context, we have previously identified an active RiPP, the Ruminococcin C1, naturally produced byRuminococcus gnavusE1, a symbiont of the healthy human intestinal microbiota. This RiPP, subclassified as a sactipeptide, requires the host digestive system to become active against pathogenic Clostridia and multidrug-resistant strains. Here we report its unique compact structure on the basis of four intramolecular thioether bridges with reversed stereochemistry introduced posttranslationally by a specific radical-SAM sactisynthase. This structure confers to the Ruminococcin C1 important clinical properties including stability to digestive conditions and physicochemical treatments, a higher affinity for bacteria than simulated intestinal epithelium, a valuable activity at therapeutic doses on a range of clinical pathogens, mediated by energy resources disruption, and finally safety for human gut tissues.

Antimicrobial Peptides and their Multiple Effects at Sub-Inhibitory Concentrations

2020 ◽  
Vol 20 (14) ◽  
pp. 1264-1273 ◽  
Author(s):  
Bruno Casciaro ◽  
Floriana Cappiello ◽  
Walter Verrusio ◽  
Mauro Cacciafesta ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Mechanisms Of Action ◽  
New Drugs ◽  
Lead Compounds ◽  
Bacterial Pathogenicity ◽  
Growth Inhibitory ◽  
Resistant Strains ◽  
Conventional Antibiotics

The frequent occurrence of multidrug-resistant strains to conventional antimicrobials has led to a clear decline in antibiotic therapies. Therefore, new molecules with different mechanisms of action are extremely necessary. Due to their unique properties, antimicrobial peptides (AMPs) represent a valid alternative to conventional antibiotics and many of them have been characterized for their activity and cytotoxicity. However, the effects that these peptides cause at concentrations below the minimum growth inhibitory concentration (MIC) have yet to be fully analyzed along with the underlying molecular mechanism. In this mini-review, the ability of AMPs to synergize with different antibiotic classes or different natural compounds is examined. Furthermore, data on microbial resistance induction are reported to highlight the importance of antibiotic resistance in the fight against infections. Finally, the effects that sub-MIC levels of AMPs can have on the bacterial pathogenicity are summarized while showing how signaling pathways can be valid therapeutic targets for the treatment of infectious diseases. All these aspects support the high potential of AMPs as lead compounds for the development of new drugs with antibacterial and immunomodulatory activities.

scholarly journals Rational design of photocatalysts for ammonia production from water and nitrogen gas

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Seokwoo Choe ◽  
Sung Min Kim ◽  
Yeji Lee ◽  
Jin Seok ◽  
Jiyong Jung ◽  
...  
Keyword(s):  
Energy Source ◽  
Rational Design ◽  
Future Research ◽  
Ammonia Production ◽  
Significant Progress ◽  
Nitrogen Gas ◽  
Research Directions ◽  
Effective Strategies ◽  
Future Research Directions ◽  
Made In

AbstractPhotocatalytic N2 reduction has emerged as one of the most attractive routes to produce NH3 as a useful commodity for chemicals used in industries and as a carbon-free energy source. Recently, significant progress has been made in understanding, exploring, and designing efficient photocatalyst. In this review, we outline the important mechanistic and experimental procedures for photocatalytic NH3 production. In addition, we review effective strategies on development of photocatalysts. Finally, our analyses on the characteristics and modifications of photocatalysts have been summarized, based on which we discuss the possible future research directions, particularly on preparing more efficient catalysts. Overall, this review provides insights on improving photocatalytic NH3 production and designing solar-driven chemical conversions.

Antibacterial and modulatory activities of β-cyclodextrin complexed with (+)-β-citronellol against multidrug-resistant strains

2021 ◽  
pp. 104928
Author(s):  
Raimundo Luiz Silva Pereira ◽  
Fábia Ferreira Campina ◽  
Maria do Socorro Costa ◽  
Rafael Pereira da Cruz ◽  
Thiago Sampaio de Freitas ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Resistant Strains

scholarly journals 1280. In-Vitro Activity of Cefiderocol, Imipenem/Relebactam, & Ceftazidime/Avibactam in Ceftolozane/Tazobactam Resistant Strains of Multidrug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander
Keyword(s):  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Resistance Testing ◽  
Clinical Samples ◽  
In Vitro Activity ◽  
Carbapenemase Gene ◽  
Resistant Strains

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

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