scholarly journals Titanium Dioxide Nanoparticles Induce Inhibitory Effects against Planktonic Cells and Biofilms of Human Oral Cavity Isolates of Rothia mucilaginosa, Georgenia sp. and Staphylococcus saprophyticus

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1564
Author(s):  
Saher Fatima ◽  
Khursheed Ali ◽  
Bilal Ahmed ◽  
Abdulaziz A. Al Kheraif ◽  
Asad Syed ◽  
...  
Keyword(s):  
Titanium Dioxide Nanoparticles ◽  
Anatase Phase ◽  
Spherical Shape ◽  
Rrna Gene ◽  
Dependent Manner ◽  
Bacterial Cells ◽  
Gram Positive ◽  
Concentration Dependent Manner ◽  
Staphylococcus Saprophyticus ◽  
Rothia Mucilaginosa

Multi-drug resistant (MDR) bacterial cells embedded in biofilm matrices can lead to the development of chronic cariogenesis. Here, we isolated and identified three Gram-positive MDR oral cocci, (1) SJM-04, (2) SJM-38, and (3) SJM-65, and characterized them morphologically, biochemically, and by 16S rRNA gene-based phylogenetic analysis as Georgenia sp., Staphylococcus saprophyticus, and Rothia mucilaginosa, respectively. These three oral isolates exhibited antibiotic-resistance against nalidixic acid, tetracycline, cefuroxime, methicillin, and ceftazidime. Furthermore, these Gram positive MDR oral cocci showed significant (p < 0.05) variations in their biofilm forming ability under different physicochemical conditions, that is, at temperatures of 28, 30, and 42 °C, pH of 6.4, 7.4, and 8.4, and NaCl concentrations from 200 to 1000 µg/mL. Exposure of oral isolates to TiO2NPs (14.7 nm) significantly (p < 0.05) reduced planktonic cell viability and biofilm formation in a concentration-dependent manner, which was confirmed by observing biofilm architecture by scanning electron microscopy (SEM) and optical microscopy. Overall, these results have important implications for the use of tetragonal anatase phase TiO2NPs (size range 5–25 nm, crystalline size 13.7 nm, and spherical shape) as an oral antibiofilm agent against Gram positive cocci infections. We suggest that TiO2NPs pave the way for further applications in oral mouthwash formulations and antibiofilm dental coatings.

scholarly journals Synthesis and Characterization of Sulfur and Sulfur-Selenium Nanoparticles Loaded on Reduced Graphene Oxide and Their Antibacterial Activity against Gram-Positive Pathogens

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 191
Author(s):  
Rashmi Niranjan ◽  
Saad Zafar ◽  
Bimlesh Lochab ◽  
Richa Priyadarshini
Keyword(s):  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Spherical Shape ◽  
Dependent Manner ◽  
Gram Positive ◽  
Concentration Dependent Manner ◽  
Reduced Graphene

Resistance to antimicrobial agents in Gram-positive bacteria has become a major concern in the last decade. Recently, nanoparticles (NP) have emerged as a potential solution to antibiotic resistance. We synthesized three reduced graphene oxide (rGO) nanoparticles, namely rGO, rGO-S, and rGO-S/Se, and characterized them using X-ray diffraction (PXRD), Raman analysis, and thermogravimetric analysis. Transmission electron microscopy confirmed spherical shape nanometer size S and S/Se NPs on the rGO surface. Antibacterial properties of all three nanomaterials were probed against Gram-positive pathogens Staphylococcus aureus and Enterococcus faecalis, using turbidometeric and CFU assays. Among the synthesized nanomaterials, rGO-S/Se exhibited relatively strong antibacterial activity against both Gram-positive microorganism tested in a concentration dependent manner (growth inhibition >90% at 200 μg/mL). Atomic force microscopy of rGO-S/Se treated cells displayed morphological aberrations. Our studies also revealed that rGO composite NPs are able to deposit on the bacterial cell surface, resulting in membrane perturbation and oxidative stress. Taken together, our results suggest a possible three-pronged approach of bacterial cytotoxicity by these graphene-based materials.

scholarly journals Inter-α inhibitor proteins maintain neutrophils in a resting state by regulating shape and reducing ROS production

2018 ◽  
Vol 2 (15) ◽  
pp. 1923-1934 ◽  
Author(s):  
Soe Soe Htwe ◽  
Hidenori Wake ◽  
Keyue Liu ◽  
Kiyoshi Teshigawara ◽  
Barbara S. Stonestreet ◽  
...  
Keyword(s):  
Resting State ◽  
Smooth Surface ◽  
Spherical Shape ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Ros Production ◽  
Concentration Dependent Manner ◽  
Key Points

Key Points IAIP, but not bikunin, maintains spherical shape, small size, and smooth surface of human neutrophils and supports capillary passage. IAIP reduced ROS production from neutrophils in a concentration-dependent manner probably through the p47phox phosphorylation on Ser328.

scholarly journals Impact of Antibiotic Gut Exposure on the Temporal Changes in Microbiome Diversity

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Charles Burdet ◽  
Thu Thuy Nguyen ◽  
Xavier Duval ◽  
Stéphanie Ferreira ◽  
Antoine Andremont ◽  
...  
Keyword(s):  
Bacterial Diversity ◽  
Day Treatment ◽  
Temporal Changes ◽  
Shannon Index ◽  
Gene Profiling ◽  
Intestinal Microbiome ◽  
Rrna Gene ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Mixed Effect

ABSTRACT Although the global deleterious impact of antibiotics on the intestinal microbiota is well known, temporal changes in microbial diversity during and after an antibiotic treatment are still poorly characterized. We used plasma and fecal samples collected frequently during treatment and up to one month after from 22 healthy volunteers assigned to a 5-day treatment by moxifloxacin (n = 14) or no intervention (n = 8). Moxifloxacin concentrations were measured in both plasma and feces, and bacterial diversity was determined in feces by 16S rRNA gene profiling and quantified using the Shannon index and number of operational taxonomic units (OTUs). Nonlinear mixed effect models were used to relate drug pharmacokinetics and bacterial diversity over time. Moxifloxacin reduced bacterial diversity in a concentration-dependent manner, with a median maximal loss of 27.5% of the Shannon index (minimum [min], 17.5; maximum [max], 27.7) and 47.4% of the number of OTUs (min, 30.4; max, 48.3). As a consequence of both the long fecal half-life of moxifloxacin and the susceptibility of the gut microbiota to moxifloxacin, bacterial diversity indices did not return to their pretreatment levels until days 16 and 21, respectively. Finally, the model characterized the effect of moxifloxacin on bacterial diversity biomarkers and provides a novel framework for analyzing antibiotic effects on the intestinal microbiome.

scholarly journals In VitroEffects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm

2015 ◽  
Vol 60 (2) ◽  
pp. 818-826 ◽  
Author(s):  
Eun-Young Jang ◽  
Minjung Kim ◽  
Mi Hee Noh ◽  
Ji-Hoi Moon ◽  
Jin-Yong Lee
Keyword(s):  
Biofilm Formation ◽  
Sodium Tripolyphosphate ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Prevotella Intermedia ◽  
Dependent Manner ◽  
Bacterial Cells ◽  
Concentration Dependent Manner ◽  
Content Type ◽  
Planktonic Phase

ABSTRACTPolyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells ofPrevotella intermedia, a major oral pathogen. The MIC of polyP3 againstP. intermediaATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal againstP. intermediain time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation byP. intermediashowed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers ofP. intermediacells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced byP. intermediawere decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent againstP. intermediain biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium.

scholarly journals In vitroandin vivoactivities of a bi-aryl oxazolidinone RBx 11760 against Gram positive bacteria

2016 ◽  
pp. AAC.00453-16 ◽  
Author(s):  
Tarani Kanta Barman ◽  
Manoj Kumar ◽  
Tarun Mathur ◽  
Tridib Chaira ◽  
G. Ramkumar ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
High Dose ◽  
Dependent Manner ◽  
Gram Positive ◽  
Concentration Dependent Manner ◽  
Gram Positive Bacteria ◽  
Initial Control ◽  
The Difference ◽  
Time Kill ◽  
Groin Abscess

RBx 11760, a bi-aryl oxazolidinone was investigated for antibacterial activity against Gram positive bacteria. The MIC90(mg/L) of RBx 11760 and linezolid againstStaphylococcus aureuswere: 2 and 4,Staphylococcus epidermidis: 0.5 and 2,Enterococcus: 1 and 4, respectively. Similarly againstStreptococcus pneumoniaeMIC90was: 0.5 and 2, respectively. In time-kill studies, RBx 11760, tedizolid and linezolid exhibited bacteriostatic effect exceptS. pneumoniae. RBx 11760 showed 2-log10kill at 4 X MIC while tedizolid and linezolid showed 2 log10and 1.4-log10kill at 16 X MIC, respectively against MRSA H-29. AgainstS. pneumoniae5051, RBx 11760 showed bactericidal activity with 4.6 log10kill at 4 X MIC compared to 2.42 log10and 1.95 log10kill of tedizolid and linezolid at 16 X MIC. RBx 11760 showed 3 h post antibiotic effects (PAE) at 4 mg/L against MRSA H-29 and linezolid showed same effect at 16mg/L. RBx 11760 inhibited the biofilm production against MRSE ATCC 35984 in concentration dependent manner. In foreign body model, linezolid and rifampicin resulted in no advantage over stasis, while same dose of RBx 11760 demonstrated a significant killing from initial control againstS. aureus(*p<0.05) and MRSE (**p<0.01). The difference in killing was statistically significant for the lower dose of RBx 11760 (*p<0.05) versus high dose of linezolid (nsp>0.05) in groin abscess model. In neutropenic mouse thigh infection, RBx 11760 showed stasis at 20 mg/kg whereas tedizolid showed same effect at 40 mg/kg. These data support the RBx 11760 as a promising investigational candidate.

scholarly journals Titanium dioxide nanoparticles induce in vitro autophagy

2018 ◽  
Vol 38 (1) ◽  
pp. 56-64 ◽  
Author(s):  
X Dai ◽  
R Liu ◽  
N Li ◽  
J Yi
Keyword(s):  
Titanium Dioxide ◽  
Messenger Rna ◽  
Titanium Dioxide Nanoparticles ◽  
Beclin 1 ◽  
Raw 264.7 Cells ◽  
Phagocytic Index ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Aim: Concerns about the possible toxicity to environment and human health of titanium dioxide nanoparticles (TiO2 NPs) are increasing. The aim of this study was to investigate the relationship between toxicology and autophage in vitro. Methods: RAW 264.7 cells were exposed to five concentrations (50, 100, 200, 300, and 400 μg/mL) and two particle size of TiO2 NPs (30 and 100 nm) for 24 h. Results: The results showed that TiO2 NPs decreased cell viability, phagocytic rate, and phagocytic index in a concentration-dependent manner, thereby inducing autophagy. TiO2 NPs-induced autophagy was indicated by monodansyl cadaverine staining and transmission electron microscopy. TiO2 NPs-induced messenger RNA expression of autophagy-related proteins LC3 and Beclin-1 was also significantly increased compared with those of the unexposed control cells. LC3 and Beclin-1 protein expression levels were markedly increased with the increase of TiO2 NPs concentrations. Conclusion: These results suggest the possibility that TiO2 NPs-induced toxicology probably plays a key role in autophagy in RAW 264.7 cells, and further exhaustive research on the harmful effects of these NPs in relevant organisms is needed for their safe application.

scholarly journals S-PRG Filler Eluate Induces Oxidative Stress in Oral Microorganism: Suppression of Growth and Pathogenicity, and Possible Clinical Application

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 816
Author(s):  
Yu Kono ◽  
Muneaki Tamura ◽  
Marni E. Cueno ◽  
Morio Tonogi ◽  
Kenichi Imai
Keyword(s):  
Oxidative Stress ◽  
Bacterial Flora ◽  
Oral Care ◽  
Oral Bacteria ◽  
Ion Concentration ◽  
Dependent Manner ◽  
Bacterial Cells ◽  
Oral Diseases ◽  
Concentration Dependent Manner ◽  
Culture Growth

Controlling the oral microbial flora is putatively thought to prevent not only oral diseases, but also systemic diseases caused by oral diseases. This study establishes the antibacterial effect of the novel bioactive substance “S-PRG filler” on oral bacteria. We examined the state of oxidative stress caused by the six types of ions released in eluate from the S-PRG filler in oral bacterial cells. Moreover, we investigated the effects of these ions on the growth and pathogenicity of Gram-positive and Gram-negative bacteria. We found that the released ions affected SOD amount and hydrogen peroxide in bacterial cells insinuating oxidative stress occurrence. In bacterial culture, growth inhibition was observed depending on the ion concentration in the medium. Additionally, released ions suppressed Streptococcus mutans adhesion to hydroxyapatite, S. oralis neuraminidase activity, and Porphyromonas gingivalis hemagglutination and gingipain activity in a concentration-dependent manner. From these results, it was suggested that the ions released from the S-PRG filler may suppress the growth and pathogenicity of the oral bacterial flora. This bioactive material is potentially useful to prevent the onset of diseases inside and outside of the oral cavity, which in turn may have possible applications for oral care and QOL improvement.

scholarly journals Adhesive Surface Proteins of Erysipelothrix rhusiopathiae Bind to Polystyrene, Fibronectin, and Type I and IV Collagens

2003 ◽  
Vol 185 (9) ◽  
pp. 2739-2748 ◽  
Author(s):  
Yoshihiro Shimoji ◽  
Yohsuke Ogawa ◽  
Makoto Osaki ◽  
Hidenori Kabeya ◽  
Soichi Maruyama ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Solid Phase ◽  
Amino Acid Sequences ◽  
Surface Proteins ◽  
Type I ◽  
Dependent Manner ◽  
Bacterial Cells ◽  
Erysipelothrix Rhusiopathiae ◽  
Gram Positive ◽  
Adhesive Surface

ABSTRACT Erysipelothrix rhusiopathiae is a gram-positive bacterium that causes erysipelas in animals and erysipeloid in humans. We found two adhesive surface proteins of E. rhusiopathiae and determined the nucleotide sequences of the genes, which were colocalized and designated rspA and rspB. The two genes were present in all of the serovars of E. rhusiopathiae strains examined. The deduced RspA and RspB proteins contain the C-terminal anchoring motif, LPXTG, which is preceded by repeats of consensus amino acid sequences. The consensus sequences are composed of 78 to 92 amino acids and repeat 16 and 3 times in RspA and RspB, respectively. Adhesive surface proteins of other gram-positive bacteria, including Listeria monocytogenes adhesin-like protein, Streptococcus pyogenes protein F2 and F2-like protein, Streptococcus dysgalactiae FnBB, and Staphylococcus aureus Cna, share the same consensus repeats. Furthermore, the N-terminal regions of RspA and RspB showed characteristics of the collagen-binding domain that was described for Cna. RspA and RspB were expressed in Escherichia coli as histidine-tagged fusion proteins and purified. The recombinant proteins showed a high degree of capacity to bind to polystyrene and inhibited the binding of E. rhusiopathiae onto the abiotic surface in a dose dependent manner. In a solid-phase binding assay, both of the recombinant proteins bound to fibronectin, type I and IV collagens, indicating broad spectrum of their binding ability. It was suggested that both RspA and RspB were exposed on the cell surface of E. rhusiopathiae, as were the bacterial cells agglutinated by the anti-RspA immunoglobulin G (IgG) and anti-RspB IgG. RspA and RspB were present both in surface-antigen extracts and the culture supernatants of E. rhusiopathiae Fujisawa-SmR (serovar 1a) and SE-9 (serovar 2). The recombinant RspA, but not RspB, elicited protection in mice against experimental challenge. These results suggest that RspA and RspB participate in initiation of biofilm formation through their binding abilities to abiotic and biotic surfaces.

scholarly journals Dissecting and Tuning Primer Editing by Proofreading Polymerases

2021 ◽  
Author(s):  
Daryl M Gohl ◽  
Benjamin Auch ◽  
Amanda Certano ◽  
Brice LeFrancois ◽  
Anne Bouevitch ◽  
...  
Keyword(s):  
Dna Amplification ◽  
Pcr Primers ◽  
Drop Out ◽  
Rrna Gene ◽  
Dependent Manner ◽  
Skin Microbiome ◽  
Sequence Specificity ◽  
Concentration Dependent Manner ◽  
Synthetic Dna ◽  
Editing Activity

Proofreading polymerases have 3' to 5' exonuclease activity that allows the excision and correction of mis-incorporated bases during DNA replication. In a previous study, we demonstrated that in addition to correcting substitution errors and lowering the error rate of DNA amplification, proofreading polymerases can also edit PCR primers to match template sequences. Primer editing is a feature that can be advantageous in certain experimental contexts, such as amplicon-based microbiome profiling. Here we develop a set of synthetic DNA standards to report on primer editing activity and use these standards to dissect this phenomenon. The primer editing standards allow next-generation sequencing-based enzymological measurements, reveal the extent of editing, and allow the comparison of different polymerases and cycling conditions. We demonstrate that proofreading polymerases edit PCR primers in a concentration-dependent manner, and we examine whether primer editing exhibits any sequence specificity. In addition, we use these standards to show that primer editing is tunable through the incorporation of phosphorothioate linkages. Finally, we demonstrate the ability of primer editing to robustly rescue the drop-out of taxa with 16S rRNA gene-targeting primer mismatches using mock communities and human skin microbiome samples.

The Anti-Atherogenic Properties of Sesamin are Mediated via Improved Macrophage Cholesterol Efflux Through PPARγ1-LXRα and MAPK Signaling

2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro
Keyword(s):  
Cholesterol Efflux ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Foam Cell ◽  
Mapk Signaling ◽  
Luciferase Reporter ◽  
Foam Cell Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Macrophage Cholesterol Efflux

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.

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