Capsule Independent Antimicrobial Activity Induced by Nanochitosan against Streptococcus pneumoniae

Background: Streptococcus pneumoniae remains a major cause of community-acquired pneumonia, meningitis, and other diseases, contributing significantly to high morbidity and mortality worldwide. Although it responds to antibiotics, their use is becoming limited due to the rise in antibiotic resistance, which necessitates the development of new therapeutics. Nanotechnology is used to counteract antimicrobial resistance. In this regard, polymeric nanoparticles (NPs) made of natural, biodegradable, biocompatible, and cationic polymers such as Chitosan (CNPs) exhibit wide-spectrum antimicrobial activity. Therefore, this study aimed to prepare CNPs, characterize their physiochemical characteristics: particle size (PZ), polydispersity index (PDI), and zeta potential (ZP), and investigate their antimicrobial activity against Streptococcus pneumoniae TIGR4 (virulent serotype 4) and its capsular mutant (∆cps). Methods: CNPs were prepared at 1, 2.5, and 5 mg/mL concentrations using the ion gelation method. Then, PZ, PDI, and ZP were characterized using a Zetasizer. Transmission electron microscopy (TEM) was used to visualize the CNP’s morphology. Broth and agar dilution methods were used to assess their antimicrobial activity. Cytotoxicity of prepared NPs on A549 cells and their effect on pneumococcal hemolysis were also investigated. Results: Spherical CNPs were produced with PZ ranging from 133.3 nm ± 0.57 to 423 nm ± 12.93 PDI < 0.35, and ZP from 19 ± 0.115 to 27 ± 0.819. The prepared CNPs exhibited antibacterial activity against TIGR4 and its capsule mutant with a minimum inhibitory concentration (MIC90) of 0.5 to 2.5 mg/mL in a non-acidic environment. The hemolysis assay results revealed that CNPs reduced bacterial hemolysis in a concentration-dependent manner. Their mammalian cytotoxicity results indicated that CNPs formed from low concentrations of Chitosan (Cs) were cytocompatible. Conclusion: Nanochitosan particles showed anti-pneumococcal activity regardless of the presence of capsules. They resulted in a concentration-dependent reduction in bacterial hemolysis and were cytocompatible at a lower concentration of Cs. These findings highlight the potential of CNPs in the treatment of pneumococcal diseases.

Download Full-text

Modulatory Effects of Osthole on Lipopolysaccharides-Induced Inflammation in Caco-2 Cell Monolayer and Co-Cultures with THP-1 and THP-1-Derived Macrophages

Nutrients ◽

10.3390/nu13010123 ◽

2020 ◽

Vol 13 (1) ◽

pp. 123

Author(s):

Natalia K. Kordulewska ◽

Justyna Topa ◽

Małgorzata Tańska ◽

Anna Cieślińska ◽

Ewa Fiedorowicz ◽

...

Keyword(s):

Gene Expression ◽

Inflammatory Reaction ◽

Wide Spectrum ◽

Cell Monolayer ◽

In Vivo Studies ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Tnf Α

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.

Download Full-text

Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽

10.3390/biom11050745 ◽

2021 ◽

Vol 11 (5) ◽

pp. 745

Author(s):

Melaine González-García ◽

Fidel Morales-Vicente ◽

Erbio Díaz Pico ◽

Hilda Garay ◽

Daniel G. Rivera ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Antifungal Activity ◽

Multidrug Resistant ◽

Moderate Activity ◽

Dependent Manner ◽

Bacterial Strains ◽

Acinetobacter Baumanii ◽

Concentration Dependent Manner ◽

Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

Download Full-text

Serum S100A8 as an early diagnostic biomarker in patients with community-acquired pneumonia

10.21203/rs.3.rs-56033/v1 ◽

2020 ◽

Author(s):

Ling Zheng ◽

Jun Fei ◽

Zheng Xu ◽

Chun-Mei Feng ◽

Se-Ruo Li ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Inflammatory Cytokines ◽

Demographic Data ◽

A549 Cells ◽

Community Acquired Pneumonia ◽

Diagnostic Biomarker ◽

Cross Sectional ◽

Neutrophil Lymphocyte Ratio ◽

Lymphocyte Ratio ◽

Severity Scores

Abstract Background and Objectives Limited studies suggested that calprotectin may take part in the pathophysiology of community-acquired pneumonia (CAP). Nevertheless, there is no clinical study to analyze the role of S100A8 in CAP patients. The objective of this study was to analyze the association of serum S100A8 with the severity of CAP based on a cross-sectional study. Methods Entire 200 CAP patients and 100 normal subjects were recruited. Demographic data, clinical information and serum were collected on admission. Serum S100A8 and inflammatory cytokines were detected. Results Serum S100A8 was increased in CAP patients on admission. Serum S100A8 was gradually increased in parallel with the CAP severity scores. Serum S100A8 was positively correlated with CAP severity scores (CURB-65, CRB-65, PSI, CURXO and SMART-COP), blood routine parameters (WBC, neutrophil-lymphocyte ratio and monocyte-lymphocyte ratio) and inflammatory cytokines (TNFα, IL-1β and CRP). Furtherly, univariate and multivariate logistical regression analysis revealed that there was a positive association between serum S100A8 with CRB-65, PSI and CURXO. Moreover, the predictive capacity of serum S100A8 was performed by receiver operating characteristic area under the curve (AUC) analysis. The AUCs of S100A8 for CAP and CAP severity were 0.855 and 0.893, respectively. Mechanistic analysis found that S100A8 knockdown alleviated streptococcus pneumoniae-evoked inflammatory cytokines in A549 cells. Conclusion Serum S100A8 on admission was positively associated with the severity of CAP. S100A8 knockdown alleviates streptococcus pneumoniae- evoked inflammatory cytokines in A549 cells, indicating that S100A8 may exert an important role in the pathophysiology of CAP and be an early serum diagnostic biomarker for CAP.

Download Full-text

Cytotoxic Effects of Flubendazole in Human Lung Cancer Cell Line A549

Jentashapir Journal of Cellular and Molecular Biology ◽

10.5812/jjcmb.108923 ◽

2020 ◽

Vol 11 (4) ◽

Author(s):

Elham Hoveizi ◽

Fatemeh Fakharzadeh Jahromi

Keyword(s):

Lung Cancer ◽

Cell Viability ◽

Human Lung ◽

A549 Cells ◽

Beclin 1 ◽

Human Lung Cancer ◽

Pcr Analysis ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Acridine Orange Staining

Background: The development of effective anticancer drugs is a significant health issue. Previous studies showed that members of the benzimidazole family have anticancer effects on several cancers Objectives: The present study investigated the cytotoxic effect of flubendazole on A549 human lung cancer cells. Methods: The A549 cells were treated with flubendazole at 1, 2, 5, and 10 µM concentrations for three days. Cell viability was measured by the MTT assay and Acridine orange staining. Also, the expressions of P62 and Beclin -1 were analyzed by qRT-PCR analysis. Results: Cell viability of A549 cells, in a concentration-dependent manner, showed significant differences between the treatment and control groups, and the IC50 value was determined to be 2 µM. Also, flubendazole reduced the expression of P62 and increased the expression of Beclin 1 in treated cells. Conclusions: Flubendazole induces cell death in A549 cells in a dose and time-dependent manner and can offer new factors in lung cancer therapeutic strategies.

Download Full-text

ANTIMICROBIAL ACTIVITY STUDY OF NEW QUINAZOLIN-4(3H)-ONES AGAINST STAPHYLOCOCCUS AUREUS AND STREPTOCOCCUS PNEUMONIAE

Pharmacy & Pharmacology ◽

10.19163/2307-9266-2021-9-4-318-329 ◽

2021 ◽

Vol 9 (4) ◽

pp. 318-329

Author(s):

M. A. Samotrueva ◽

A. A. Ozerov ◽

A. A. Starikova ◽

N. M. Gabitova ◽

D. V. Merezhkina ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Streptococcus Pneumoniae ◽

Active Sites ◽

Wide Spectrum ◽

Experimental Studies ◽

Amide Group ◽

Pharmacological Effect ◽

Dilution Method

Quinazolin-4(3H)-one derivatives exhibiting a wide spectrum of a pharmacological activity, represent a promising class of substances used to obtain antibacterial agents, which is especially important in the context of the emergence of pathogenic microorganisms’ resistance to drugs used in medicine. It has been proved that compounds having a naphthyl radical in the molecule, as well as an amide group bound to the benzene ring as quinazolinone substituents, are characterized by a pronounced antimicrobial activity against Staphylococcus aureus and Streptococcus pneumoniae.The aim of the research is a primary microbiological screening of the in vitro antimicrobial activity of new quinazolin-4(3H)-one derivatives against Staphylococcus aureus and Streptococcus pneumoniae, as well as the assessment of the relationship between the pharmacological effect and the structural transformation of the substance molecule, lipophilicity and the possibility of forming resistance to them.Materials and methods. The experimental studies have been carried out using well-known nosocomial pathogens of infectious and inflammatory diseases Staphylococcus aureus and Streptococcus pneumoniae by a serial dilution method.Results. A compound containing a naphthyl radical in its structure, which contributes to an increase in the hydrophobicity of the substance and its solubility in the membrane of a bacterial cell, has a bacteriostatic effect against both Staphylococcus aureus and Streptococcus pneumoniae. A similar pharmacological effect is exhibited by a derivative with an amide group as a substituent of the quinazolinone nucleus linked to a phenyl radical, which probably contributes to an increase in the degree of binding to active sites of enzymes involved in the DNA replication, and protein synthesis. Obviously, the increased lipophilicity, which promotes better binding to the efflux protein, cannot serve as objective characteristics of the emergence possibility of the pathogen’s resistance to this substance.Conclusion. Among the synthesized compounds, the leading substances that exhibit an antimicrobial activity against Staphylococcus aureus and Streptococcus pneumonia, have been identified. The assessment of the chemical structure made it possible to substantiate their pharmacological action and draw conclusions about the possibility of developing resistance to it in microbial cells.

Download Full-text

Synthesis and Biological Evaluation of Novel 4-Phenylaminobenzofuro[2,3-d]pyrimidine Derivatives

Journal of the chemical society of pakistan ◽

10.52568/000659 ◽

2020 ◽

Vol 42 (4) ◽

pp. 564-564

Author(s):

Ju liu Ju liu ◽

Jun Li Jun Li ◽

Jian tao Shi Jian tao Shi ◽

Jie Li Jie Li ◽

Xue chen Hao Xue chen Hao ◽

...

Keyword(s):

Cell Lines ◽

A549 Cells ◽

Positive Control ◽

Biological Evaluation ◽

Dependent Manner ◽

Pyrimidine Derivatives ◽

Concentration Dependent Manner ◽

Ic50 Value ◽

Synthesis And Biological Evaluation

A series of novel 4-phenylaminobenzofuro[2,3-d]pyrimidine derivatives had been prepared and assessed for their in vitro antiproliferative activities against three lung cancer cell lines (A549, H460 and H1975). The bioassay results showed most of the designed compounds exhibited potential antiproliferation activities. Among them, compound 8f exhibited remarkable inhibitory activity against A549 and H460 cell lines with IC50 value of 2.54 μM and 2.68 μM, respectively, which was comparable to that of the positive control sorafenib (IC50 = 2.69 μM for A549 and 3.71 μM for H460). AO/EB staining suggests that compound 8f could induce apoptosis in A549 cells. Furthermore, cell cycle analyses show that compound 8f increased G0/G1 A549 cells arrest in a concentration-dependent manner. The preliminary structure-activity relationships (SARs) studies indicated that mono-electron-withdrawing groups (mono-EWGs) on the phenyl ring are positive on the antitumor activity.

Download Full-text

Design, Synthesis and Biological Evaluation of a New Series of 1-Aryl-3-{4-[(pyridin-2-ylmethyl)thio]phenyl}urea Derivatives as Antiproliferative Agents

Molecules ◽

10.3390/molecules24112108 ◽

2019 ◽

Vol 24 (11) ◽

pp. 2108 ◽

Cited By ~ 1

Author(s):

Chuanming Zhang ◽

Xiaoyu Tan ◽

Jian Feng ◽

Ning Ding ◽

Yongpeng Li ◽

...

Keyword(s):

Cell Lines ◽

Cancer Cell ◽

A549 Cells ◽

Cancer Cell Lines ◽

Biological Evaluation ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Urea Derivatives ◽

Antiproliferative Agents

To discover new antiproliferative agents with high efficacy and selectivity, a new series of 1-aryl-3-{4-[(pyridin-2-ylmethyl)thio]phenyl}urea derivatives (7a–7t) were designed, synthesized and evaluated for their antiproliferative activity against A549, HCT-116 and PC-3 cancer cell lines in vitro. Most of the target compounds demonstrated significant antiproliferative effects on all the selective cancer cell lines. Among them, the target compound, 1-[4-chloro-3-(trifluoromethyl)phenyl]-3-{4-{{[3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl]methyl}thio}phenyl}urea (7i) was identified to be the most active one against three cell lines, which was more potent than the positive control with an IC50 value of 1.53 ± 0.46, 1.11 ± 0.34 and 1.98 ± 1.27 μM, respectively. Further cellular mechanism studies confirmed that compound 7i could induce the apoptosis of A549 cells in a concentration-dependent manner and elucidated compound 7i arrests cell cycle at G1 phase by flow cytometry analysis. Herein, the studies suggested that the 1-aryl-3-{4-[(pyridin-2-ylmethyl)thio]phenyl}urea skeleton might be regarded as new chemotypes for designing effective antiproliferative agents.

Download Full-text

Essential Oils of Aromatic Plants with Antibacterial, Anti-Biofilm and Anti-Quorum Sensing Activities against Pathogenic Bacteria

Antibiotics ◽

10.3390/antibiotics9040147 ◽

2020 ◽

Vol 9 (4) ◽

pp. 147 ◽

Cited By ~ 5

Author(s):

Marlon Cáceres ◽

William Hidalgo ◽

Elena Stashenko ◽

Rodrigo Torres ◽

Claudia Ortiz

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Quorum Sensing ◽

Essential Oils ◽

Pathogenic Bacteria ◽

Bacterial Resistance ◽

Thymus Vulgaris ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Biofilm Inhibition

Both the ability of bacteria to form biofilms and communicate through quorum sensing allows them to develop different survival or virulence traits that lead to increased bacterial resistance against conventional antibiotic therapy. Here, seventeen essential oils (EOs) were investigated for the antimicrobial, antibiofilm, and anti-quorum sensing activities on Escherichia. coli O157:H7, Escherichia coli O33, and Staphylococcus epidermidis ATCC 12228. All essential oils were isolated from plant material by using hydrodistillation and analyzed by GC-MS. The antimicrobial activity was performed by using the microdilution technique. Subinhibitory concentrations of each EO were assayed for biofilm inhibition in both bacterial strains. Quantification of violacein in Chromobacterium violaceum CV026 was performed for the anti-quorum sensing activity. The cytotoxicity activity of the EOs was evaluated on Vero cell line by using MTT method. Thymol-carvacrol-chemotype (I and II) oils from Lippia origanoides and Thymus vulgaris oil exhibited the higher antimicrobial activity with MIC values of 0.37–0.75 mg/mL. In addition, these EOs strongly inhibited the biofilm formation and violacein (QS) production in a concentration-dependent manner, highlighting thymol-carvacrol-chemotype (II) oil as the best candidate for further studies in antibiotic design and development against bacterial resistance.

Download Full-text

Glucosamine Hydrochloride Specifically Inhibits COX-2 by Preventing COX-2 N-Glycosylation and by Increasing COX-2 Protein Turnover in a Proteasome-dependent Manner

Journal of Biological Chemistry ◽

10.1074/jbc.m610778200 ◽

2007 ◽

Vol 282 (38) ◽

pp. 27622-27632 ◽

Cited By ~ 37

Author(s):

Byeong-Churl Jang ◽

Su-Haeng Sung ◽

Jong-Gu Park ◽

Jong-Wook Park ◽

Jae Hoon Bae ◽

...

Keyword(s):

Molecular Mass ◽

Protein Turnover ◽

A549 Cells ◽

Lung Epithelial Cells ◽

Prostaglandin E ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Glucosamine Hydrochloride ◽

Cox 2 ◽

Factor Α

COX-2 and its products, including prostaglandin E2, are involved in many inflammatory processes. Glucosamine (GS) is an amino monosaccharide and has been widely used for alternative regimen of (osteo) arthritis. However, the mechanism of action of GS on COX-2 expression remains unclear. Here we describe a new action mechanism of glucosamine hydrochloride (GS-HCl) to tackle endogenous and agonistdriven COX-2 at protein level. GS-HCl (but not GS sulfate, N-acetyl GS, or galactosamine HCl) resulted in a shift in the molecular mass of COX-2 from 72–74 to 66–70 kDa and concomitant inhibition of prostaglandin E2 production in a concentration-dependent manner in interleukin (IL)-1β-treated A549 human lung epithelial cells. Remarkably, GS-HCl-mediated decrease in COX-2 molecular mass was associated with inhibition of COX-2 N-glycosylation during translation, as assessed by the effect of tunicamycin, the protein N-glycosylation inhibitor, or of cycloheximide, the translation inhibitor, on COX-2 modification. Specifically, the effect of low concentration of GS-HCl (1 mm) or of tunicamycin (0.1 μg/ml) to produce the aglycosylated COX-2 was rescued by the proteasomal inhibitor MG132 but not by the lysosomal or caspase inhibitors. However, the proteasomal inhibitors did not show an effect at 5 mm GS-HCl, which produced the aglycosylated or completely deglycosylated form of COX-2. Notably, GS-HCl (5 mm) also facilitated degradation of the higher molecular species of COX-2 in IL-1β-treated A549 cells that was retarded by MG132. GS-HCl (5 mm) was also able to decrease the molecular mass of endogenous and IL-1β- or tumor necrosis factor-α-driven COX-2 in different human cell lines, including Hep2 (bronchial) and H292 (laryngeal). However, GS-HCl did not affect COX-1 protein expression. These results demonstrate for the first time that GS-HCl inhibits COX-2 activity by preventing COX-2 co-translational N-glycosylation and by facilitating COX-2 protein turnover during translation in a proteasome-dependent manner.

Download Full-text

Identification of a Human Anti-Alpha-Toxin Monoclonal Antibody Against Staphylococcus aureus Infection

Frontiers in Microbiology ◽

10.3389/fmicb.2021.692279 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fangjie Liu ◽

Zhangchun Guan ◽

Yu Liu ◽

Jingjing Li ◽

Chenghua Liu ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Monoclonal Antibody ◽

A549 Cells ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Phage Display Technology ◽

Alpha Hemolysin ◽

Protective Strategy ◽

Display Technology ◽

Hla Binding

Staphylococcus aureus is a major pathogenic bacterium that causes a variety of clinical infections. The emergence of multi-drug resistant mechanisms requires novel strategies to mitigate S. aureus infection. Alpha-hemolysin (Hla) is a key virulence factor that is believed to play a significant role in the pathogenesis of S. aureus infections. In this study, we screened a naïve human Fab library for identification of monoclonal antibodies targeting Hla by phage display technology. We found that the monoclonal antibody YG1 blocked the Hla-mediated lysis of rabbit red blood cells and inhibited Hla binding to A549 cells in a concentration-dependent manner. YG1 also provided protection against acute peritoneal infection, bacteremia, and pneumonia in murine models. We further characterized its epitope using different Hla variants and found that the amino acids N209 and F210 of Hla were functionally and structurally important for YG1 binding. Overall, these results indicated that targeting Hla with YG1 could serve as a promising protective strategy against S. aureus infection.

Download Full-text