scholarly journals Thermal characterization of the multimeric bacteriophage endolysin PlyC

2022 ◽  
Author(s):  
James Todd Hoopes ◽  
Ryan D. Heselpoth ◽  
Frederick P. Schwarz ◽  
Daniel C Nelson
Keyword(s):  
Intermediate State ◽  
Therapeutic Potential ◽  
Antibacterial Properties ◽  
Thermal Characterization ◽  
Scanning Calorimetry ◽  
Long Term Stability ◽  
Cell Wall Binding ◽  
Partial Unfolding ◽  
Bacterial Peptidoglycan

Bacteriophage endolysins degrade the bacterial peptidoglycan and are considered enzymatic alternatives to small molecule antibiotics. In particular, the multimeric streptococcal endolysin PlyC has appealing antibacterial properties. However, a comprehensive thermal analysis of PlyC is lacking, which is necessary for evaluating long-term stability and downstream therapeutic potential. Biochemical and kinetic-based methods were used in combination with differential scanning calorimetry to investigate the structural, kinetic and thermodynamic stability of PlyC and its various subunits and domains. The PlyC holoenzyme structure is irreversibly compromised due to partial unfolding and aggregation at 46°C. Unfolding of the catalytic subunit, PlyCA, instigates this event, resulting in the kinetic inactivation of the endolysin. In contrast to PlyCA, the PlyCB octamer (the cell wall binding domain) is thermostable, denaturing at ~75°C. Isolation of PlyCA or PlyCB alone altered their thermal properties. Contrary to the holoenzyme, PlyCA alone unfolds uncooperatively and is thermodynamically destabilized whereas the PlyCB octamer reversibly dissociates into monomers and forms an intermediate state at 74°C in phosphate buffered saline, with each subunit subsequently denaturing at 927°C. Adding folded PlyCA to an intermediate state PlyCB, followed by cooling, allowed for in vitro reconstitution of the active holoenzyme.

scholarly journals THE EFFECT OF ESSENTIAL OILS ON MICROORGANISMS CAUSING CARIES AND PERIODONTITIS

2020 ◽  
Vol 20 (2) ◽  
pp. 253-259
Author(s):  
N.M. Devyatkina ◽  
N.O. Bobrova ◽  
E.M. Vazhnichaya
Keyword(s):  
Essential Oils ◽  
Dental Treatment ◽  
Therapeutic Potential ◽  
Oral Care ◽  
Antibacterial Properties ◽  
Herbal Medicines ◽  
Oral Streptococci ◽  
Tea Tree

The oral cavity contains a large number of bacteria, some of which are involved in the development of caries and periodontitis (S. mutans, S. sobrinus, Lactobacilli spp, P. intermedia, P. gingivalis, and T. forythus). The disadvantages of existing antiseptics used in dentistry necessitate the study of antibacterial properties of herbal medicines, and, in particular, of essential oils. The aim of this review is to provide the analysis of literature sources from PubMed and Google Scholar databases related to the effects of essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components on cariogenic and periodontopathic microflora. It was found out that the most in vitro studies evaluated the effects of essential oils or isolated compounds (eugenol, menthol, thymol, carvacrol, eucalyptol, and terpinene-4-ol) on S. mutans, which is considered to be the most cariogenic of oral streptococci, and the researchers limited to defining the susceptibility of the microorganism and effects on biofilm formation. Only in a few studies, the effects of essential oils on the virulence factors of oral pathogens, in particular glycosyl transferase, are represented. Clinical trials of essential oils, their components and combinations confirm the therapeutic potential of these agents in vivo, but raise the question of their effectiveness, taking into account the short-term action, which does not exceed the potency of chlorhexidine. Essential oils of cloves, mint, thyme, eucalyptus, tea tree and their components should be used for treating caries and periodontitis. They are also promising when used as agents of the oral care products, preservatives of the dental medicinal forms, and as remedies for halitosis. With a rational prescription, essential oils can be useful in improving the quality of dental treatment and preventive procedures.

scholarly journals Insight into the Lytic Functions of the Lactococcal Prophage TP712

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 881 ◽  
Author(s):  
Escobedo ◽  
Campelo ◽  
Wegmann ◽  
García ◽  
Rodríguez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Signal Peptide ◽  
Catalytic Domain ◽  
Experimental Conditions ◽  
Binding Domains ◽  
Cell Wall Binding ◽  
Additional Cell ◽  
Translational Start ◽  
Bacterial Peptidoglycan

The lytic cassette of Lactococcus lactis prophage TP712 contains a putative membrane protein of unknown function (Orf54), a holin (Orf55), and a modular endolysin with a N-terminal glycoside hydrolase (GH_25) catalytic domain and two C-terminal LysM domains (Orf56, LysTP712). In this work, we aimed to study the mode of action of the endolysin LysTP712. Inducible expression of the holin-endolysin genes seriously impaired growth. The growth of lactococcal cells overproducing the endolysin LysTP712 alone was only inhibited upon the dissipation of the proton motive force by the pore-forming bacteriocin nisin. Processing of a 26-residues signal peptide is required for LysTP712 activation, since a truncated version without the signal peptide did not impair growth after membrane depolarization. Moreover, only the mature enzyme displayed lytic activity in zymograms, while no lytic bands were observed after treatment with the Sec inhibitor sodium azide. LysTP712 might belong to the growing family of multimeric endolysins. A C-terminal fragment was detected during the purification of LysTP712. It is likely to be synthesized from an alternative internal translational start site located upstream of the cell wall binding domain in the lysin gene. Fractions containing this fragment exhibited enhanced activity against lactococcal cells. However, under our experimental conditions, improved in vitro inhibitory activity of the enzyme was not observed upon the supplementation of additional cell wall binding domains in. Finally, our data pointed out that changes in the lactococcal cell wall, such as the degree of peptidoglycan O-acetylation, might hinder the activity of LysTP712. LysTP712 is the first secretory endolysin from a lactococcal phage described so far. The results also revealed how the activity of LysTP712 might be counteracted by modifications of the bacterial peptidoglycan, providing guidelines to exploit the biotechnological potential of phage endolysins within industrially relevant lactococci and, by extension, other bacteria.

scholarly journals In VitroCharacterization of PlySK1249, a Novel Phage Lysin, and Assessment of Its Antibacterial Activity in a Mouse Model of Streptococcus agalactiae Bacteremia

2013 ◽  
Vol 57 (12) ◽  
pp. 6276-6283 ◽  
Author(s):  
Frank Oechslin ◽  
Jean Daraspe ◽  
Marlyse Giddey ◽  
Philippe Moreillon ◽  
Grégory Resch
Keyword(s):  
Mouse Model ◽  
Streptococcus Agalactiae ◽  
Content Type ◽  
Cell Wall Binding ◽  
Gene Coding ◽  
Invasive Infections ◽  
Cell Wall Binding Domain ◽  
Bacterial Peptidoglycan

ABSTRACTBeta-hemolyticStreptococcus agalactiaeis the leading cause of bacteremia and invasive infections. These diseases are treated with β-lactams or macrolides, but the emergence of less susceptible and even fully resistant strains is a cause for concern. New bacteriophage lysins could be promising alternatives against such organisms. They hydrolyze the bacterial peptidoglycan at the end of the phage cycle, in order to release the phage progeny. By using a bioinformatic approach to screen several beta-hemolytic streptococci, a gene coding for a lysin was identified on a prophage carried byStreptococcus dysgalactiaesubsp.equisimilisSK1249. The gene product, named PlySK1249, harbored an original three-domain structure with a central cell wall-binding domain surrounded by an N-terminal amidase and a C-terminal CHAP domain. Purified PlySK1249 was highly lytic and bactericidal forS. dysgalactiae(2-log10CFU/ml decrease within 15 min). Moreover, it also efficiently killedS. agalactiae(1.5-log10CFU/ml decrease within 15 min) but not several streptococcal commensal species. We further investigated the activity of PlySK1249 in a mouse model ofS. agalactiaebacteremia. Eighty percent of the animals (n= 10) challenged intraperitoneally with 106CFU ofS. agalactiaedied within 72 h, whereas repeated injections of PlySK1249 (45 mg/kg 3 times within 24 h) significantly protected the mice (P< 0.01). Thus, PlySK1249, which was isolated fromS. dysgalactiae, demonstrated high cross-lytic activity againstS. agalactiaebothin vitroandin vivo. These encouraging results indicated that PlySK1249 might represent a good candidate to be developed as a new enzybiotic for the treatment of systemicS. agalactiaeinfections.

scholarly journals In-Vitro Analysis of FeMn-Si Smart Biodegradable Alloy

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 568
Author(s):  
Ana Maria Roman ◽  
Victor Geantă ◽  
Ramona Cimpoeșu ◽  
Corneliu Munteanu ◽  
Nicoleta Monica Lohan ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Memory Effect ◽  
Surface Condition ◽  
Special Property ◽  
Thermal Characterization ◽  
Scanning Calorimetry ◽  
Solution Ph ◽  
Arc Melting ◽  
Vitro Analysis

Special materials are required in many applications to fulfill specific medical or industrial necessities. Biodegradable metallic materials present many attractive properties, especially mechanical ones correlated with good biocompatibility with vivant bodies. A biodegradable iron-based material was realized through electric arc-melting and induction furnace homogenization. The new chemical composition obtained presented a special property named SME (shape memory effect) based on the martensite transformation. Preliminary results about this special biodegradable material with a new chemical composition were realized for the chemical composition and structural and thermal characterization. Corrosion resistance was evaluated in Ringer’s solution through immersion tests for 1, 3, and 7 days, the solution pH was measured in time for 3 days with values for each minute, and electro-corrosion was measured using a potentiostat and a three electrode cell. The mass loss of the samples during immersion and electro-corrosion was evaluated and the surface condition was studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). SME was highlighted with differential scanning calorimetry (DSC). The results confirm the possibility of a memory effect of the materials in the wrought case and a generalized corrosion (Tafel and cyclic potentiometry and EIS) with the formation of iron oxides and a corrosion rate favorable for applications that require a longer implantation period.

scholarly journals Design, Synthesis and Biological Assessment of Thiazole Derivatives as Possible Antioxidant and Antimicrobial Agents

2021 ◽  
pp. 24-32
Author(s):  
. Isha ◽  
Neetu Sachan
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Therapeutic Potential ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Molecular Structures ◽  
Biological Assessment ◽  
Thiazole Derivatives ◽  
Antioxidant And Antimicrobial Activity

Aims: To synthesize thiazole derivatives and evaluate their therapeutic potential to continue our quest for new antibacterial and antioxidant drugs. Place and Duration of Study: Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, between January 2021 and July 2021. Methodology: The target compounds in this investigation were synthesized in the search for new molecules having antioxidant and antimicrobial activity. Physicochemical and spectroanalytical studies validated the derivatives molecular structures. Antioxidant and antimicrobial properties of the synthesized molecules were evaluated in vitro using the DPPH and tube dilution methods, respectively. Results: The majority of the synthesized derivatives displayed antioxidant and antimicrobial activity. The efficacy of the derivatives varied based upon the substituent. Compound 7c exhibited significant antioxidant and antibacterial activity, according to the results of the study. Conclusion: Our results showed the antioxidant and antibacterial properties of novel thiazole compounds, implying the probability of their utilization in the development of new therapeutics.

scholarly journals EVALUATION OF THE CLINICAL EFFECTIVENESS OF TOOTHPASTE CONTAINING GRAPEFRUIT EXTRACT AND LYSOTECH AND PROTELYSE LYSATES IN THE COMPLEX TREATMENT OF INFLAMMATORY PERIODONTAL DISEASES

2021 ◽  
Vol 16 (4) ◽  
pp. 58-63
Author(s):  
Svetlana Tokmakova ◽  
Olga Bondarenko ◽  
Yuliya Lunitsyna
Keyword(s):  
Laboratory Study ◽  
Oral Hygiene ◽  
Therapeutic Potential ◽  
Inflammatory Diseases ◽  
Periodontal Diseases ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Complex Treatment ◽  
Periodontal Tissues

The preventive direction in dentistry is the leading one today. Individual oral hygiene plays a significant role in preventing the development of inflammatory periodontal diseases. The use of therapeutic and prophylactic toothpastes containing natural components with antibacterial properties is promising. Among plant extracts, grapefruit extract has the most pronounced antimicrobial activity. LysoTech and ProteLyse lysates, which have antimicrobial and immunomodulatory effects, have long been used in dentistry in the form of tablets for resorption in the complex treatment of various diseases. Their introduction into toothpastes is also considered a promising direction for the prevention and treatment of oral pathology. The aim of our study was to clinically evaluate the effectiveness of therapeutic and prophylactic toothpaste, which contains grapefruit extract and LysoTech and ProteLyse lysates, in patients with inflammatory diseases of periodontal tissues. A clinical and laboratory comparative study of two therapeutic and prophylactic toothpastes was conducted. The composition of the samples was identical, except for two components: grapefruit extract and LysoTech and ProteLyse lysates. The study involved 60 volunteers who were divided into two groups depending on the toothpastes used. The purifying and anti-inflammatory effects of the samples were evaluated for one month. An in vitro laboratory study was also conducted to identify the antimicrobial properties of toothpastes. During the work, high clinical results were noted in a group of volunteers using toothpaste with grapefruit seed extract and bacterial lysates, which are expressed in a decrease in PMA and SBI indices, and an improvement in oral hygiene. According to a laboratory study, the toothpaste containing grapefruit extract and LysoTech and ProteLyse lysates has a more pronounced antimicrobial and antifungal effect, which indicates a high preventive and therapeutic potential of the test sample.

scholarly journals CHEWING GUM CONTAINING PROPOLIS WAX FROM APIS MELLIFERA BEES FOR PREVENTION OF DENTAL CARIES DISEASE

2019 ◽  
pp. 141-145
Author(s):  
SRI ANGKY SOEKANTO ◽  
ASTRID LEVINA ◽  
EKA NURIN SHARFINA IRIANTO ◽  
ACHMAD HUDA FAUZI ADZIMA ◽  
HERI HERMANSYAH ◽  
...  
Keyword(s):  
Dental Caries ◽  
Biofilm Formation ◽  
Antibacterial Properties ◽  
Salivary Flow ◽  
Disease Stage ◽  
Tooth Surface ◽  
Chewing Gum ◽  
Scanning Calorimetry ◽  
Negative Controls

Objective: Dental caries is caused by demineralization of the tooth surface by organic acids as a result of metabolism of cariogenic bacteria, especiallyStreptococcus mutans. Chewing gum has been proven to help prevent dental caries formation by stimulating salivary flow and thus reducing theavailability of nutrients for cariogenic bacteria.Methods: In this study, sugar-free chewing gum was formulated using latex from the jelutong tree (Dyera costuata) with the addition of propolis wax(1–5%) as an antibacterial agent to inhibit the activity of S. mutans and prevent biofilm formation, which is an early disease stage of dental caries.Characterization of jelutong latex using differential scanning calorimetry and thermogravimetric analysis shows that the latex has glass transitiontemperatures of −22.46°C and 33.86°C, and it contains volatile (14.96%), polymer (84.43%), organic (0.36%), and inorganic (0.25%) components.The propolis wax used in this formulation mostly contains resin and wax and is a purification by-product of raw propolis obtained from Apis mellifera.Results: Flavonoids acting as antibacterial compounds are found in propolis, and presumably are also found in propolis wax; thus, probably thiscompound also has the antibacterial properties of propolis. The in vitro testing showed that 5% propolis wax in sugar-free chewing gum can preventthe formation of dental caries by inhibiting biofilm formation with up to 80% more effectiveness relative to negative controls (without chewing gum).Conclusion: Propolis wax chewing gum can inhibit the formation of dental caries disease.

scholarly journals Bottom-Up Development of Nanoimprinted PLLA Composite Films with Enhanced Antibacterial Properties for Smart Packaging Applications

Macromol ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 49-63
Author(s):  
Eleni Psochia ◽  
Lazaros Papadopoulos ◽  
Dimitrios J. Gkiliopoulos ◽  
Achille Francone ◽  
Maria-Eirini Grigora ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Thermal Properties ◽  
Nanoimprint Lithography ◽  
Mesoporous Silica Nanoparticles ◽  
Antibacterial Properties ◽  
Nanocomposite Films ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Smart Packaging

In this work, polymer nanocomposite films based on poly(L-lactic acid) (PLLA) were reinforced with mesoporous silica nanoparticles, mesoporous cellular foam (MCF) and Santa Barbara amorphous-15 (SBA). PLLA is a biobased aliphatic polyester, that possesses excellent thermomechanical properties, and has already been commercialized for packaging applications. The aim was to utilize nanoparticles that have already been established as nanocarriers to enhance the mechanical and thermal properties of PLLA. Since the introduction of antibacterial properties has become an emerging trend in packaging applications, to achieve an effective antimicrobial activity, micro/nano 3D micropillars decorated with cone- and needle-shaped nanostructures were implemented on the surface of the films by means of thermal nanoimprint lithography (t-NIL), a novel and feasible fabrication technique with multiple industrial applications. The materials were characterized regarding their composition and crystallinity using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), respectively, and their thermal properties using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Their mechanical properties were examined by the nanoindentation technique, while the films’ antimicrobial activity against the bacteria Escherichia coli and Staphylococcus aureus strains was tested in vitro. The results demonstrated the successful production of nanocomposite PLLA films, which exhibited improved mechanical and thermal properties compared to the pristine material, as well as notable antibacterial activity, setting new groundwork for the potential development of biobased smart packaging materials.

scholarly journals Evaluating Anti-Inflammatory Potential of Etodolac Co-Crystals: Nitric Oxide, IL-6 And TNF-a As Potential Markers

2021 ◽  
Author(s):  
Poonam Parashar ◽  
Shalini Gautam ◽  
Neelu Singh ◽  
Jovita Kanoujia ◽  
Abhishek Yadav ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Citric Acid ◽  
Therapeutic Potential ◽  
Solubility Enhancement ◽  
Paw Edema ◽  
Scanning Calorimetry ◽  
Fold Reduction ◽  
Grinding Technique

Abstract The present investigation deals with solubility enhancement of Etodolac (ETD) through co-crystals technique utilizing various co-formers and to evaluate their therapeutic efficacy against carrageenan-induced inflammation. Co-formers citric acid anhydrous and tartaric acid were selected to formulate ETD co-crystals to improve solubility and dissolution employing neat grinding technique. The prepared co-crystals were characterized for solubility enhancement, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), in vitro dissolution and stability studies. The co-crystals were further investigated for in vivo studies to assess their potential to cure paw edema in mice. The outcome of the study illustrated significantly improved solubility and dissolution of ETD up to 6.15 folds using citric acid. Approximately a two-fold reduction in nitric oxide and cytokines levels was observed with optimized formulation. Also, substantial inhibition of inflammation was observed in paw edema induced animals. In sight of the above results the co-crystal approach could be an alternative for enhanced therapeutic potential.

Cytotoxic Effect of the Combination of Gemcitabine and Atorvastatin Loaded in Microemulsion on the HCT116 Colon Cancer Cells

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Mayson H. Alkhatib ◽  
Dalal Al-Saedi ◽  
Wadiah S. Backer
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Anticancer Drugs ◽  
Therapeutic Potential ◽  
Morphological Changes ◽  
In Vitro Study ◽  
Colon Cancer Cells ◽  
Apoptosis Detection ◽  
Hct116 Cells

The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize efficacies by eradicating resistant, reduce the dosage of the drug and minimize toxicities on the normal cells. Gemcitabine (GEM), a nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some limitations. The objective of this in vitro study was to evaluate the antitumor activity of the combination therapy of GEM and ATVencapsulated in a microemulsion (ME) formulation in the HCT116 colon cancer cells. The cytotoxicity and efficacy of the formulation were assessed by the 3- (4,5dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT) assay. The mechanism of cell death was examined by observing the morphological changes of treated cells under light microscope, identifying apoptosis by using the ApopNexin apoptosis detection kit, and viewing the morphological changes in the chromatin structure stained with 4′,6-diamidino-2-phenylindole (DAPI) under the inverted fluorescence microscope. It has been found that reducing the concentration of GEM loaded on ME (GEM-ME) from 5μM to 1.67μM by combining it with 3.33μM of ATV in a ME formulation (GEM/2ATV-ME) has preserved the strong cytotoxicity of GEM-ME against HCT116 cells. The current study proved that formulating GEM with ATV in ME has improved the therapeutic potential of GEM and ATV as anticancer drugs.

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