scholarly journals New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 274 ◽  
Author(s):  
Anna Carbone ◽  
Barbara Parrino ◽  
Maria Cusimano ◽  
Virginia Spanò ◽  
Alessandra Montalbano ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Microbial Growth ◽  
Bacterial Biofilm ◽  
Dependent Manner ◽  
Gram Negative ◽  
Ic50 Values ◽  
Planktonic Form ◽  
New Compounds ◽  
Dose Dependent

New thiazole nortopsentin analogues were conveniently synthesized and evaluated for their activity as inhibitors of biofilm formation of relevant Gram-positive and Gram-negative pathogens. All compounds were able to interfere with the first step of biofilm formation in a dose-dependent manner, showing a selectivity against the staphylococcal strains. The most active derivatives elicited IC50 values against Staphylococcus aureus ATCC 25923, ranging from 0.40–2.03 µM. The new compounds showed a typical anti-virulence profile, being able to inhibit the biofilm formation without affecting the microbial growth in the planktonic form.

scholarly journals Influence of Nisin-Biogel at Subinhibitory Concentrations on Virulence Expression in Staphylococcus aureus Isolates from Diabetic Foot Infections

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1501
Author(s):  
Carolina Jesus ◽  
Rui Soares ◽  
Eva Cunha ◽  
Miguel Grilo ◽  
Luís Tavares ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Diabetic Foot ◽  
Biofilm Formation ◽  
Guar Gum ◽  
Dependent Manner ◽  
Accessory Gene ◽  
Diabetic Foot Infections ◽  
Subinhibitory Concentrations ◽  
Dose Dependent

A new approach to diabetic foot infections (DFIs) has been investigated, using a nisin-biogel combining the antimicrobial peptide (AMP) nisin with the natural polysaccharide guar-gum. Since in in vivo conditions bacteria may be exposed to decreased antimicrobial concentrations, known as subinhibitory concentrations (sub-MICs), effects of nisin-biogel sub-MIC values corresponding to 1/2, 1/4 and 1/8 of nisin’s minimum inhibitory concentration (MIC) on virulence expression by six Staphylococcus aureus DFI isolates was evaluated by determining bacteria growth rate; expression of genes encoding for staphylococcal protein A (spA), coagulase (coa), clumping factor A (clfA), autolysin (atl), intracellular adhesin A (icaA), intracellular adhesin D (icaD), and the accessory gene regulator I (agrI); biofilm formation; Coa production; and SpA release. Nisin-biogel sub-MICs decreased bacterial growth in a strain- and dose-dependent manner, decreased agrI, atl and clfA expression, and increased spA, coa, icaA and icaD expression. Biofilm formation increased in the presence of nisin-biogel at 1/4 and 1/8 MIC, whereas 1/2 MIC had no effect. Finally, nisin-biogel at sub-MICs did not affect coagulase production, but decreased SpA production in a dose-dependent manner. Results highlight the importance of optimizing nisin-biogel doses before proceeding to in vivo trials, to reduce the risk of virulence factor’s up-regulation due to the presence of inappropriate antimicrobial concentrations.

scholarly journals Activity of Gallidermin on Staphylococcus aureus and Staphylococcus epidermidis Biofilms

2012 ◽  
Vol 56 (11) ◽  
pp. 5804-5810 ◽  
Author(s):  
Jongkon Saising ◽  
Linda Dube ◽  
Anne-Kathrin Ziebandt ◽  
Supayang Piyawan Voravuthikunchai ◽  
Mulugeta Nega ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune System ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Physiological State ◽  
Dependent Manner ◽  
Persister Cells ◽  
Content Type ◽  
Killing Activity ◽  
Dose Dependent

ABSTRACTDue to their abilities to form strong biofilms,Staphylococcus aureusandStaphylococcus epidermidisare the most frequently isolated pathogens in persistent and chronic implant-associated infections. As biofilm-embedded bacteria are more resistant to antibiotics and the immune system, they are extremely difficult to treat. Therefore, biofilm-active antibiotics are a major challenge. Here we investigated the effect of the lantibiotic gallidermin on two representative biofilm-forming staphylococcal species. Gallidermin inhibits not only the growth of staphylococci in a dose-dependent manner but also efficiently prevents biofilm formation by both species. The effect on biofilm might be due to repression of biofilm-related targets, such asica(intercellular adhesin) andatl(major autolysin). However, gallidermin's killing activity on 24-h and 5-day-old biofilms was significantly decreased. A subpopulation of 0.1 to 1.0% of cells survived, comprising “persister” cells of an unknown genetic and physiological state. Like many other antibiotics, gallidermin showed only limited activity on cells within mature biofilms.

scholarly journals Antibiotics Enhance Prevention and Eradication Efficacy of Cathodic-Voltage-Controlled Electrical Stimulation against Titanium-Associated Methicillin-ResistantStaphylococcus aureusandPseudomonas aeruginosaBiofilms

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Mary K. Canty ◽  
Lisa A. Hansen ◽  
Menachem Tobias ◽  
Sandy Spencer ◽  
Terry Henry ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Electrical Stimulation ◽  
Antibiotic Treatment ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Dependent Manner ◽  
Methicillin Resistant ◽  
Content Type ◽  
Cathodic Voltage

ABSTRACTPeriprosthetic joint infection (PJI) develops clinically, even with antibiotic treatment, and methicillin-resistantStaphylococcus aureus(MRSA) andPseudomonas aeruginosaare predominant causes of these infections. Due to biofilm formation, antibiotic treatment for patients with PJI can perpetuate resistance, further complicating the use of noninvasive treatments. This study evaluated cathodic-voltage-controlled electrical stimulation (CVCES) of titanium, in combination with a clinically relevant antibiotic, to synergistically prevent MRSA andP. aeruginosaPJIs by inhibiting bacterial adherence or as a treatment for eradicating established biofilms. CVCES of −1.0 V, −1.5 V, or −1.8 V (versus Ag/AgCl), with or without vancomycin for MRSA or gentamicin forP. aeruginosa, was applied to sterile titanium incubated with cultures to evaluate prevention of attachment or eradication of preestablished biofilms. Treatments were 24 h long and included open-circuit potential controls, antibiotic alone, CVCES, and CVCES plus antibiotic. Biofilm-associated and planktonic CFU were enumerated. In general, CVCES at −1.8 V alone or with antibiotic completely eradicated biofilm-associated CFU for both strains, and these parameters were also highly effective against planktonic bacteria, resulting in a >6-log reduction in MRSA and no detectable planktonicP. aeruginosa. All CFU were reduced ∼3 to 5 logs from controls for prevention CVCES plus antibiotics at −1.0 V and −1.5 V against MRSA. Remarkably, there were no detectableP. aeruginosaCFU following prevention CVCES at −1.0 V or −1.5 V with gentamicin. Our results suggest that CVCES in combination with antibiotics may be an effective approach for prevention and treatment of PJI.IMPORTANCEPeriprosthetic joint infections (PJIs) develop clinically in the presence of antibiotic therapies and are responsible for increased patient morbidity and rising health care costs. Many of these infections involve bacterial biofilm formation on orthopedic hardware, and it has been well established that these biofilms are refractory to most antibiotic treatments. Recent studies have focused on novel methods to prevent and eradicate infection. Cathodic-voltage-controlled electrical stimulation (CVCES) has previously been shown to be effective as a method for prevention and eradication of Gram-positive and Gram-negative infections. The present study revealed that the utility of CVCES for prevention and eradication of methicillin-resistantStaphylococcus aureusandPseudomonas aeruginosais enhanced in the presence of clinically relevant antibiotics. The synergistic effects of CVCES and antibiotics are effective in a magnitude-dependent manner. The results of this study indicate a promising alternative method to current PJI mitigation techniques.

Synthesis and Assessment of Novel Anti-chlamydial Benzylidene Acylhydrazides Derivatives

2018 ◽  
Vol 15 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Xiaofeng Bao ◽  
Ying Xue ◽  
Chao Xia ◽  
Yin Lu ◽  
Ningjing Yang ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Dependent Manner ◽  
Iron Starvation ◽  
Hydrochloride Salt ◽  
Obligate Intracellular ◽  
Biphasic Life Cycle ◽  
Ic50 Value ◽  
Ic50 Values ◽  
Dose Dependent ◽  
Better Than

Background: Chlamydiae, characterized by a unique biphasic life cycle, are a group of Gram-negative obligate intracellular bacterial pathogens responsible for diseases in a range of hosts including humans. Benzylidene acylhydrazide CF0001 could inhibit chlamydiae independent of iron starvation and T3SS inhibition. This finding promoted us to design and synthesize more benzylidene acylhydrazides to find novel anti-chlamydial agents. Methods: The carboxylic acids 1a-1d were coupled with Boc-hydrazide inpresence of EDCI and DMAP to obtain the intermediate 2a-2d in 60-62% yields. N-Boc deprotections were performed to obtain hydrazide hydrochloride salt 3a-3d. Nextly, the hydrazides were subjected to condensation with aldehydes to obtain benzylidene acylhydrazides 4a-4g in 30-52% yields in two steps. Results: Compound 4d exhibited best inhibitory effect on the formation and growth of chlamydial inclusions. The IC50 value of compound 4d for infectious progenies was 3.55 µM, better than 7.30 µM of CF0001. Conclusion: To find novel anti-chlamydial agents, we have designed and synthesized benzylidene acylhydrazides 4a-4g. Compounds 4a, 4d, 4g showed inhibitory activity on C. muridarum with the IC50 values from 3.55-12 µM. The 3,5-dibromo-4-hydroxyl substitutes on ring B are critical to keep their anti-chlamydial activity. Compound 4d inhibited C. muridarum in a dose-dependent manner without apparent cytotoxicity.

scholarly journals Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 81
Author(s):  
Anna Carbone ◽  
Stella Cascioferro ◽  
Barbara Parrino ◽  
Daniela Carbone ◽  
Camilla Pecoraro ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Thiazole Derivatives ◽  
Gram Positive ◽  
Lead Compounds ◽  
New Class ◽  
Marked Selectivity ◽  
Global Threat ◽  
New Compounds ◽  
Reference Strains

Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 and the Gram-negative strain Pseudomonas aeruginosa ATCC 15442. Most of the new compounds showed a marked selectivity against the Gram-positive strains. Remarkably, five compounds exhibited BIC50 values against S. aureus ATCC 25923 ranging from 1.0 to 9.1 µM. The new compounds, affecting the biofilm formation without any interference on microbial growth, can be considered promising lead compounds for the development of a new class of anti-virulence agents.

scholarly journals Targeting BMI-1 with PLGA–PEG nanoparticle-containing PTC209 modulates the behavior of human glioblastoma stem cells and cancer cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elham Poonaki ◽  
Fatemeh Ariakia ◽  
Mohammad Jalili-Nik ◽  
Mehdi Shafiee Ardestani ◽  
Gholamhossein Tondro ◽  
...  
Keyword(s):  
Drug Loading ◽  
Polycomb Group ◽  
Dependent Manner ◽  
Migration Ability ◽  
Jnk Signaling ◽  
Human Glioblastoma ◽  
Core Member ◽  
Ic50 Values ◽  
Human Gbm ◽  
Dose Dependent

AbstractDespite advances in glioblastoma (GBM) treatments, current approaches have failed to improve the overall survival of patients. The oncogene BMI-1, a core member of the polycomb group proteins, is a potential novel therapeutic target for GBM. To enhance the efficacy and reduce the toxicity, PTC209, a BMI-1 inhibitor, was loaded into a PLGA–PEG nanoparticle conjugated with CD133 antibody (Nano-PTC209) and its effect on the behavior of human GBM stem-like cells (GSCs) and the human glioblastoma cell line (U87MG) was assessed. Nano-PTC209 has a diameter of ~ 75 nm with efficient drug loading and controlled release. The IC50 values of Nano-PTC209 for GSCs and U87MG cells were considerably lower than PTC209. Nano-PTC209 significantly decreased the viability of both GSCs and U87MG cells in a dose-dependent manner and caused a significant enhancement of apoptosis and p53 levels as well as inhibition of AKT and JNK signaling pathways. Furthermore, Nano-PTC209 significantly inhibited the migration ability, decreased the activity of metalloproteinase-2 and -9, and increased the generation of reactive oxygen species in both GSCs and U87MG cells. Our data indicate that PLGA–PEG nanoparticle conjugated with CD133 antibody could be an ideal nanocarrier to deliver PTC209 and effectively target BMI-1 for potential approaches in the treatment of GBM.

scholarly journals A Pilot Study on Antimalarial Effects of Moringa oleifera Leaf Extract in Plasmodium berghei Infection in Mice

2017 ◽  
Vol 15 (2) ◽  
pp. 151-156
Author(s):  
Somrudee NAKINCHAT ◽  
Voravuth SOMSAK
Keyword(s):  
Plasma Glucose ◽  
Crude Extract ◽  
Plasmodium Berghei ◽  
Leaf Extract ◽  
Moringa Oleifera ◽  
Dependent Manner ◽  
Glucose Levels ◽  
New Compounds ◽  
Dose Dependent

The emergence and spread of antimalarial drug resistance of Plasmodium parasites, as well as hypoglycemia, during malaria infection, and subsequent death, are critical problems in malaria-endemic areas. Hence, finding new compounds, especially plant extracts having antimalarial and anti-hypoglycemic activities, are urgently needed. The present study aimed to investigate the antimalarial and anti-hypoglycemic effects of Moringa oleifera leaf extract in Plasmodium berghei infection in mice. Aqueous crude extract of M. oleifera leaves was freshly prepared and used for an efficacy test in vivo. Groups of ICR mice (5 mice in each) were infected with 1´107 infected red blood cells of P. berghei ANKA by intraperitoneal injection and given the extract orally with doses of 100, 500, and 1000 mg/kg for 4 consecutive days. Parasitemia and plasma glucose levels were subsequently measured. The results showed that M. oleifera leaf extract presented significant (p < 0.001) inhibition of parasitemia in a dose-dependent manner. Moreover, this extract exerted anti-hypoglycemia effects in infected mice in a dose-dependent manner. The highest degrees of activity were found at a dose of 1000 mg/kg of the extract. Additionally, no effect on plasma glucose was found in normal mice treated with this extract. It can be concluded that aqueous crude extract of M. oleifera leaves exerted antimalarial and anti-hypoglycemic effects in P. berghei infection in mice.

scholarly journals Microbial Warfare on Three Fronts: Mixed Biofilm of Aspergillus fumigatus and Staphylococcus aureus on Primary Cultures of Human Limbo-Corneal Fibroblasts

2021 ◽  
Vol 11 ◽  
Author(s):  
Adrián Ramírez-Granillo ◽  
Luis Antonio Bautista-Hernández ◽  
Víctor Manuel Bautista-De Lucío ◽  
Fátima Sofía Magaña-Guerrero ◽  
Alfredo Domínguez-López ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Aspergillus Fumigatus ◽  
Biofilm Formation ◽  
Primary Cultures ◽  
Morphological Characterization ◽  
Fibroblast Culture ◽  
Bacterial Biofilm ◽  
Corneal Fibroblast ◽  
Corneal Fibroblasts ◽  
Fibroblast Monolayer

BackgroundCoinfections with fungi and bacteria in ocular pathologies are increasing at an alarming rate. Two of the main etiologic agents of infections on the corneal surface, such as Aspergillus fumigatus and Staphylococcus aureus, can form a biofilm. However, mixed fungal–bacterial biofilms are rarely reported in ocular infections. The implementation of cell cultures as a study model related to biofilm microbial keratitis will allow understanding the pathogenesis in the cornea. The cornea maintains a pathogen-free ocular surface in which human limbo-corneal fibroblast cells are part of its cell regeneration process. There are no reports of biofilm formation assays on limbo-corneal fibroblasts, as well as their behavior with a polymicrobial infection.ObjectiveTo determine the capacity of biofilm formation during this fungal–bacterial interaction on primary limbo-corneal fibroblast monolayers.ResultsThe biofilm on the limbo-corneal fibroblast culture was analyzed by assessing biomass production and determining metabolic activity. Furthermore, the mixed biofilm effect on this cell culture was observed with several microscopy techniques. The single and mixed biofilm was higher on the limbo-corneal fibroblast monolayer than on abiotic surfaces. The A. fumigatus biofilm on the human limbo-corneal fibroblast culture showed a considerable decrease compared to the S. aureus biofilm on the limbo-corneal fibroblast monolayer. Moreover, the mixed biofilm had a lower density than that of the single biofilm. Antibiosis between A. fumigatus and S. aureus persisted during the challenge to limbo-corneal fibroblasts, but it seems that the fungus was more effectively inhibited.ConclusionThis is the first report of mixed fungal–bacterial biofilm production and morphological characterization on the limbo-corneal fibroblast monolayer. Three antibiosis behaviors were observed between fungi, bacteria, and limbo-corneal fibroblasts. The mycophagy effect over A. fumigatus by S. aureus was exacerbated on the limbo-corneal fibroblast monolayer. During fungal–bacterial interactions, it appears that limbo-corneal fibroblasts showed some phagocytic activity, demonstrating tripartite relationships during coinfection.

An Alanine-Rich Peptide Attenuates Quorum Sensing-Regulated Virulence and Biofilm Formation in Staphylococcus aureus

2019 ◽  
Vol 102 (4) ◽  
pp. 1228-1234 ◽  
Author(s):  
Raid Al Akeel ◽  
Ayesha Mateen ◽  
Rabbani Syed
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Bacterial Attachment ◽  
The Body ◽  
Dependent Manner ◽  
Virulence Determinants ◽  
Microarray Gene Expression ◽  
Concentration Dependent Manner

Abstract Background: Alanine-rich proteins/peptides (ARP), with bioactivity of up to 20 amino acid residues, can be observed by the body easily during gastrointestinal digestion. Objective: Populus trichocarpa extract’s capability to attenuate quorum sensing-regulated virulence and biofilm formation in Staphylococcus aureus is described. Methods: PT13, an ARP obtained from P. trichocarpa, was tested for its activity against S. aureus using the broth microdilution test; a crystal-violet biofilm assay was performed under a scanning electron microscope. The production of various virulence factors was estimated with PT13 treatment. Microarray gene expression profiling of PT13-treated S. aureus was conducted and compared with an untreated control. Exopolysaccharides (EPS) was estimated to observe the PT13 inhibition activity. Results: PT13 was antimicrobial toward S. aureus at different concentrations and showed a similar growth rate in the presence and absence of PT13 at concentrations ≤8 μg/mL. Biofilm production was interrupted even at low concentrations, and biofilm-related genes were down-regulated when exposed to PT13. The genes encoding cell adhesion and bacterial attachment protein were the major genes suppressed by PT13. In addition, hemolysins, clumping activity, and EPS production of S. aureus decreased after treatment in a concentration-dependent manner. Conclusions: A long-chain PT13 with effective actions that, even at low concentration levels, not only regulated the gene expression in the producer organism but also blocked the virulence gene expression in this Gram-positive human pathogen is described. Highlights: We identified a PT13 as a potential antivirulence agent that regulated production of bacterial virulence determinants (e.g., toxins, enzymes and biofilm), downwards and it may be a promising anti-virulence agent to be further developed as an anti-infective agent.

scholarly journals Virulence of methicillin-resistant Staphylococcus aureus modulated by the YycFG two-component pathway in a rat model of osteomyelitis

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Shizhou Wu ◽  
Yunjie Liu ◽  
Lei Lei ◽  
Hui Zhang
Keyword(s):  
Staphylococcus Aureus ◽  
Western Blot ◽  
Rat Model ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Invasive Ability ◽  
Methicillin Resistant ◽  
Two Component ◽  
Mrsa Strains

Abstract Objectives Methicillin-resistant Staphylococcus aureus (MRSA) strains present an urgent medical problem in osteomyelitis cases. Our previous study indicated that the YycFG two-component regulatory pathway is associated with the bacterial biofilm organization of MRSA strains. The aim of this study was to investigate the regulatory roles of ASyycG in the bacterial biofilm formation and the pathogenicity of MRSA strains using an antisense RNA strategy. Methods An ASyycG-overexpressing MRSA clinical isolate was constructed. The bacterial growth was monitored, and the biofilm biomass on bone specimens was examined using scanning electron microscopy and confocal laser scanning microscopy. Furthermore, quantitative RT-PCR (QRT-PCR) analysis was used to measure the expression of yycF/G/H and icaA/D in the MRSA and ASyycG strains. The expression of the YycG protein was quantified by Western blot assays. We validated the role of ASyycG in the invasive ability and pathogenicity of the strains in vivo using histology and peptide nucleic acid fluorescent in situ hybridization. Results The results showed that overexpression of ASyycG lead to a reduction in biofilm formation and exopolysaccharide (EPS) synthesis compared to the control MRSA strains. The ASyycG strains exhibited decreased expression of the yycF/G/H and icaA/D genes. Furthermore, Western blot data showed that the production of the YycG protein was inhibited in the ASyycG strains. In addition, we demonstrated that ASyycG suppressed the invasive ability and pathogenicity of the strain in vivo using an SPF (specific pathogen free) rat model. Conclusion In summary, the overexpression of ASyycG leads to a reduction in biofilm formation and bacterial pathogenicity in vivo, which provides a potential target for the management of MRSA-induced osteomyelitis.

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