scholarly journals Strategies to Prevent Biofilm Infections on Biomaterials: Effect of Novel Naturally-Derived Biofilm Inhibitors on a Competitive Colonization Model of Titanium by Staphylococcus aureus and SaOS-2 Cells

2020 ◽  
Vol 8 (3) ◽  
pp. 345 ◽  
Author(s):  
Inés Reigada ◽  
Ramón Pérez-Tanoira ◽  
Jayendra Z. Patel ◽  
Kirsi Savijoki ◽  
Jari Yli-Kauhaluoma ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mammalian Cells ◽  
Experimental Models ◽  
High Serum ◽  
Clinical Scenario ◽  
Implanted Medical Devices ◽  
Potential Applicability ◽  
Colonization Model ◽  
The One

Biofilm-mediated infection is a major cause of bone prosthesis failure. The lack of molecules able to act in biofilms has driven research aimed at identifying new anti-biofilm agents via chemical screens. However, to be able to accommodate a large number of compounds, the testing conditions of these screenings end up being typically far from the clinical scenario. In this study, we assess the potential applicability of three previously discovered anti-biofilm compounds to be part of implanted medical devices by testing them on in vitro systems that more closely resemble the clinical scenario. To that end, we used a competition model based on the co-culture of SaOS-2 mammalian cells and Staphylococcus aureus (collection and clinical strains) on a titanium surface, as well as titanium pre-conditioned with high serum protein concentration. Additionally, we studied whether these compounds enhance the previously proven protective effect of pre-incubating titanium with SaOS-2 cells. Out of the three, DHA1 was the one with the highest potential, showing a preventive effect on bacterial adherence in all tested conditions, making it the most promising agent for incorporation into bone implants. This study emphasizes and demonstrates the importance of using meaningful experimental models, where potential antimicrobials ought to be tested for the protection of biomaterials in translational applications.

scholarly journals Strategies to Prevent Biofilm Infections on Biomaterials: Effect of Novel Naturally-Derived Biofilm Inhibitors on a Competitive Colonization Model of Titanium by Staphylococcus aureus and Human Cells

2019 ◽  
Author(s):  
Ines Reigada ◽  
Ramón Pérez-Tanoira ◽  
Jayendrakumar Patel ◽  
Kirsi Savijoki ◽  
Jari Yli-Kauhaluoma ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mammalian Cells ◽  
Titanium Surface ◽  
Natural Compounds ◽  
Experimental Models ◽  
Clinical Scenario ◽  
Implanted Medical Devices ◽  
Potential Applicability ◽  
Colonization Model

Biofilm-mediated infection is a major cause of bone prosthesis failure. The lack of molecules able to act in biofilms has driven research aimed at identifying new anti-biofilm agents via chemical screens. However, to be able to accommodate a large number of compounds, the testing conditions of these screenings end up being typically far from the clinical scenario. In this study, we assess the potential applicability of three anti-biofilm compounds (based on natural compounds) as part of implanted medical devices by testing them on in vitro systems that more faithfully resemble the clinical scenario. To that end, we used a competition model based on the co-culture of SaOS-2 mammalian cells and Staphylococcus aureus (collection and clinical strains) on a titanium surface. Additionally, we studied whether these derivatives of natural compounds enhance the previously proven protective effect of pre-incubating the titanium surface with SaOS-2 cells. Out of the three tested leads, one showed the highest potential, and can be regarded as a promising agent for incorporation into bone implants. This study emphasizes and demonstrates the importance of using meaningful experimental models, where potential antimicrobials ought to be tested for protection of biomaterials in translational applications.

scholarly journals Dalbavancin, Vancomycin and Daptomycin Alone and in Combination with Cefazolin against Resistant Phenotypes of Staphylococcus aureus in a Pharmacokinetic/Pharmacodynamic Model

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 696 ◽  
Author(s):  
Jacinda C. Abdul-Mutakabbir ◽  
Razieh Kebriaei ◽  
Kyle C. Stamper ◽  
Zain Sheikh ◽  
Philip T. Maassen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Inhibitory Concentration ◽  
Pharmacodynamic Model ◽  
In Vitro Tests ◽  
Beta Lactam ◽  
Fold Reduction ◽  
The One ◽  
Time Kill

The most efficacious antimicrobial therapy to aid in the successful elimination of resistant S. aureus infections is unknown. In this study, we evaluated varying phenotypes of S. aureus against dalbavancin (DAL), vancomycin (VAN), and daptomycin (DAP) alone and in combination with cefazolin (CFZ). The objective of this study was to observe whether there was a therapeutic improvement in adding a beta-lactam to a glycopeptide, lipopeptide, or a lipoglycopeptide. We completed a series of in vitro tests including minimum inhibitory concentration testing (MIC) of the antimicrobials in combination, time-kill analysis (TKA), and a 168 h (7-day) one-compartment pharmacokinetic/pharmacodynamic (PK/PD) model on two daptomycin non-susceptible (DNS), vancomycin intermediate S. aureus strains (VISA), D712 and 6913. Results from our MIC testing demonstrated a minimum 2-fold and a maximum 32-fold reduction in MIC values for DAL, VAN, and DAP in combination with CFZ, in contrast to either agent used alone. The TKAs completed on four strains paralleled the enhanced activity demonstrated via the combination MICs. In the one-compartment PK/PD models, the combination of DAP plus CFZ or VAN plus CFZ resulted in a significant (p < 0.001) improvement in bactericidal activity and overall reduction in CFU/ml over the 7-day period. While the addition of CFZ to DAL improved time to bactericidal activity, DAL alone demonstrated equal and more sustained overall activity compared to all other treatments. The use of DAL alone, with or without CFZ and the combinations of VAN or DAP with CFZ appear to result in increased bactericidal activity against various recalcitrant S. aureus phenotypes.

scholarly journals The Effects of Turmeric Infusion and Turmeric Juice (Curcuma Domestica) on The Staphylococcus Aureus Growth in Vitro

2021 ◽  
Vol 2 (2) ◽  
pp. 54-60
Author(s):  
Renny Novi Puspitasari ◽  
Handayani Handayani ◽  
Ratna Sofaria
Keyword(s):  
Staphylococcus Aureus ◽  
Pearson Correlation ◽  
Food Poisoning ◽  
Average Growth ◽  
Phenol Derivatives ◽  
Group I ◽  
The One ◽  
Insect Bites ◽  
Growth Of Bacteria

Background: Turmeric is a plant that grows in tropical areas and functions as medicine. The chemical compounds contained in turmeric have a role as antioxidants, antimicrobials, anti-cancer, indigestion, smallpox, insect bites. The curcumin content in turmeric has antibacterial activity against various types of Gram negative, Gram positive, antiviral and anti-tumor bacteria. Essential oils can be used as antibacterial because they contain hydroxyl and carbonyl functional groups which are phenol derivatives. Flavonoids can interfere with cell wall formation with peptidoglycan transpeptidase activity which will break down cell walls and damage cell membranes so that important components such as proteins, nucleic acids, nucleotides will be lysis. Staphylococcus bacteria are normal flora on the skin, respiratory tract, and digestive tract of food in humans. These bacteria can cause disease when they reach 1,000,000 or 106 per gram, an amount sufficient to produce the toxin. S. aureus bacteria can cause various types of infections ranging from minor skin infections, food poisoning to systemic infections. The aim of our study was to analyze the effects of infusion and turmeric juice (Curcuma domestica val) on the growth of bacteria Staphylococcus aureus through invitro. Method: This study is a laboratory experimental study with the aim of analyzing turmeric infusion (Curcuma domestica val) and turmeric juice effect on the growth of staphylococcus aureus by invitro. This research was conducted in an integrated laboratory, FK UNUSA. The samples in this study were 4 replications per treatment. The independent variables in this study were turmeric infusion and turmeric juice (with a concentration of 10%, 30%, 50% while the dependent variable in this study was the growth of Staphylococcus aureus bacteria. Data analysis used was the one way ANOVA test and Pearson correlation to determine the effect of giving turmeric infusion and turmeric juice on the growth of bacteria staphylococcus aureus through invitro. Result: The average growth of bacteria in the turmeric infusion in group I (control), 10%, 30% and 50% of turmeric infusion was 4.89 ± 0.4425 log CFU / ml, 3.07 ± 0.61330 log CFU / ml, 2.99 ± 0.63986 log CFU. / ml and 3.02 ± 0.22650 log CFU / ml. The average growth of this bacteria in giving turmeric juice in group I (control), giving 10%, 30% and 50% turmeric infusion was 4.89 ± 0.04425 log CFU / ml, 4.40 ± 0.18355log CFU / ml, 3.10 ± 0.58926 log CFU / ml and 3.02 ± 0.38206 log CFU / ml. Conclusion: In this study, found that there was an effect of giving turmeric infusion and turmeric juice (Curcuma domestica val) on Staphylococcus aureus growth and there was an effect of giving multilevel doses of turmeric infusion and turmeric juice (Curcuma domestica val) on Staphylococcus aureus growth through invitro.

Inhibition of cardiomyocytes late INa with ranolazine blunts anthracyclines-cardiotoxicity in experimental models in vitro and in vivo.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13539-e13539
Author(s):  
Nicola Maurea ◽  
Carmela Coppola ◽  
Domenica Rea ◽  
Giovanna Piscopo ◽  
Gennaro Riccio ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Cell Survival ◽  
Glucose Utilization ◽  
Experimental Models ◽  
In Vivo Studies ◽  
Myocardial Energetics ◽  
H9c2 Cardiomyoblasts ◽  
The One

e13539 Background: Anthracyclines produce a well-known cardiomyopathy through multiple mechanisms, which also include, among many, Ca2+ overload due to reduced SERCA2a activity and inappropriate opening of the RyR2, and impaired myocardial energetics. Anthracyclines generate Reactive Oxigen and Nitrogen Species (ROS and RNS), posing the heart at increased demand for oxygen, thus setting the stage for a metabolic ischemia that also activates late INa, the target of ranolazine (RAN). Here, we aim at assessing whether RAN, diminishing intracellular Ca2+ through its inhibition of late INa, and enhancing myocardial glucose utilization (and/or reverting impairment of glucose utilization caused by chemotherapy) blunts anthracyclines cardiotoxicity. Methods: To assess for toxicity in vitro, rat H9C2 cardiomyoblasts were pretreated with RAN (0.1-1mM) for 72 hours and then treated with doxorubicin (DOX, 0.1 mM) for additional 24 hours. Cells counts were assessed by Trypan exclusion test. To evaluate cardiac function in vivo, fractional shortening (FS) and ejection fraction (EF) were measured by echocardiography in C57BL6 mice, 2-4 mo old, pretreated with RAN (370mg/kg/day, a dose comparable to the one used in humans) per os for 3 days. RAN was then administered for additional 7 days, together with DOX (2.17mg/kg/day ip), according to our well established protocol. Results: After DOX, only 68% of the cells were viable. RAN alone did not affect cell survival, but blunted DOX toxicity, rescuing % cell survival to 87% (p=.01 vs DOX alone). In our in vivo studies, after 7 days with DOX, FS decreased to 50±2%, p=.002 vs 60±1% (sham), and EF to 81±2%, p=0.0001 vs 91±1% (sham). RAN alone did not change FS (59±2%) nor EF (89±1%). Interestingly, in mice treated with RAN and DOX, the reduction in cardiac function was milder: FS was 57±1%, EF was 89±1%, p=0.01 and 0.0009 respectively, vs DOX alone. Conclusions: RAN blunts DOX cardiotoxic effects in 2 different models, in vitro and in vivo. We plan to test RAN as a cardioprotective agent with other antineoplastic cardiotoxic drugs in our experimental models, and to better characterize the cardioprotective mechanisms of RAN in all these settings.

Inhibition of cardiomyocytes late INa with ranolazine to prevent anthracyclines cardiotoxicity in experimental models in vitro and in vivo.

2013 ◽  
Vol 31 (26_suppl) ◽  
pp. 170-170
Author(s):  
Nicola Maurea ◽  
Carmela Coppola ◽  
Giovanna Piscopo ◽  
Clemente Cipresso ◽  
Domenica Rea ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Cell Survival ◽  
Glucose Utilization ◽  
Experimental Models ◽  
In Vivo Studies ◽  
Myocardial Energetics ◽  
H9c2 Cardiomyoblasts ◽  
The One

170 Background: Anthracyclines are first line drugs against cancer, but produce a well-known cardiomyopathy through multiple mechanisms, which also include Ca2+ overload due to reduced SERCA2a activity and inappropriate opening of the RyR2, and impaired myocardial energetics. Anthracyclines generate Reactive Oxigen and Nitrogen Species, posing the heart at increased demand for oxygen, thus setting the stage for a metabolic ischemia that also activates late INa, the target of ranolazine (RAN). Here, we aim at assessing whether RAN, diminishing intracellular Ca2+ through its inhibition of late INa, and enhancing myocardial glucose utilization (and/or reverting impairment of glucose utilization caused by chemotherapy) blunts anthracyclines cardiotoxicity. Methods: To assess for cardiotoxicity in vitro, rat H9C2 cardiomyoblasts were pretreated with RAN (0.1-1µM) for 72 hours and then treated with doxorubicin (DOX, 0.1 µM)for additional 24 hours. Cells counts were assessed by Trypan exclusion test. To evaluate cardiac function in vivo, fractional shortening (FS) and ejection fraction (EF) were measured by echocardiography in C57BL6 mice, 2-4 mo old, pretreated with RAN (370mg/kg/day, a dose comparable to the one used in humans) per os for 3 days. RAN was then administered for additional 7 days, alone and together with DOX (2.17mg/kg/day ip), according to our well established protocol. Results: After DOX, only 68% of the cells were viable. RAN alone did not affected cell survival, but blunted DOX toxicity, rescuing % cell survival to 87% (p=.01 vs DOX alone). In our in vivo studies, after 7 days with DOX, FS decreased to 50±2%, p=.002 vs 60±1% (sham), and EF to 81+2%, p=0.0001 vs 91+1% (sham). RAN alone did not change FS (59±2%) nor EF 89+1%. Interestingly, in mice treated with RAN and DOX, the reduction in cardiac function was milder: FS was 57±1%, EF was 89+1%, p=0.01 and 0.0009, vs DOX alone. Conclusions: RAN blunts DOX cardiotoxic effects in 2 different models, in vitro and in vivo. We plan to test RAN as a cardioprotective agent with other antineoplastic cardiotoxic drugs in our experimental models, and to better characterize the cardioprotective mechanisms of RAN in all these settings.

Isolation of Phages and Study of their In vitro Efficacy on Staphylococcus aureus Isolates Originating from Bovine Subclinical Mastitis

2021 ◽  
Author(s):  
A.S. Srujana ◽  
J. Sonalika ◽  
D.S. Akhila ◽  
M.R. Juliet ◽  
P. Sheela
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Subclinical Mastitis ◽  
Global Market ◽  
Host Susceptibility ◽  
Health Concept ◽  
Disk Diffusion Assay ◽  
Potential Strategy ◽  
The One

Background: India leads the global market in milk production. However, bovine mastitis, which is the mammary gland inflammation in dairy cattle characterized by physical, chemical, bacteriological changes in milk results in commercial losses. Staphylococcus aureus, is the major causative agent. The treatment of mastitis caused by this pathogen is mainly by antibiotics. Emphasizing on the one health concept, phage therapy is an appropriate alternative to antibiotic. The present study was aimed to isolate and characterize bacteriophages against Staphylococcus aureus associated with bovine mastitis.Methods: Thirty two isolates of S. aureus obtained from the milk of mastitis cows were characterized by phenotypic and genotypic methods. Antibiotic susceptibility of the isolates was carried out by disk diffusion assay. Milk and cow shed wastewater were used for phage isolation. Phages were characterized by host susceptibility and RAPD assay.Result: Nineteen phages were isolated from the cowshed waste water. All the milk samples showed negative for the presence of phage. The phage 24 (A2) which had the broadest host range, was selected for the CFU drop assay. The phage was able to clear the lawn of S. aureus culture when grown on agar at different time points thus indicating that topical application of this phage would be a potential strategy to control S. aureus infection leading to mastitis. This study provides a basis to continue the exploration of the potential of PSA2 phage as a candidate for the treatment of Staphylococcal mastitis.

Development of a Novel Zinc Oxide/Polyvinyl Chloride Nanocomposite Material for Medical Implant Applications

2014 ◽  
Vol 1626 ◽  
Author(s):  
Benjamin M. Geilich ◽  
Thomas J. Webster
Keyword(s):  
Zinc Oxide ◽  
Polyvinyl Chloride ◽  
Mammalian Cells ◽  
In Vitro Study ◽  
Nanocomposite Material ◽  
Functional Surface ◽  
Mechanisms Of Toxicity ◽  
Implanted Medical Devices ◽  
Genetic Tolerance

ABSTRACTIn hospitals and clinics worldwide, medical device surfaces have become a rapidly growing source of nosocomial infections. Almost immediately after adhering to a device surface, bacteria can begin to form a biofilm, which makes the infection especially difficult to treat and often necessitates device removal. Adding to the severity of this problem is the spread of bacterial genetic tolerance to antibiotics, in part demonstrated by the recent and significant increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA).Nanomaterials are beginning to be used for a wide variety of biomedical applications due to their unique surface properties which have the ability to control initial protein adsorption and subsequent cell behavior. This “nanoroughness” gives nanomaterials a greater functional surface area than conventional materials, which do not have significant features on the nanoscale. In addition, it is theorized that nanoparticles may also have general mechanisms of toxicity towards bacteria that do not cause problems for mammalian cells.The objective of the present in vitro study was to develop a nanocomposite material by embedding conventional polyvinyl chloride (PVC) with zinc oxide nanoparticles through a simple and inexpensive procedure. The effect of different nanoparticle sizes and %wts were investigated. Results demonstrated that this technique significantly decreased S. aureus density and biofilm formation without the incorporation of antibiotics or other pharmaceuticals, as well as increased the adhesion of human fibroblast cells. Thus, this material could have much promise for use in the manufacture of common implanted medical devices.

scholarly journals The NS5A/NS5 Proteins of Viruses from Three Genera of the Family Flaviviridae Are Phosphorylated by Associated Serine/Threonine Kinases

1998 ◽  
Vol 72 (7) ◽  
pp. 6199-6206 ◽  
Author(s):  
Karen E. Reed ◽  
Alexander E. Gorbalenya ◽  
Charles M. Rice
Keyword(s):  
Mammalian Cells ◽  
Yellow Fever Virus ◽  
Diarrhea Virus ◽  
The Family ◽  
A Cell ◽  
Infected Cells ◽  
Threonine Kinases ◽  
The One ◽  
Viral Diarrhea Virus

ABSTRACT Phosphorylation of the expressed NS5A protein of hepatitis C virus (HCV), a member of the Hepacivirus genus of the familyFlaviviridae, has been demonstrated in mammalian cells and in a cell-free assay by an associated kinase activity. In this report, phosphorylation is also shown for the NS5A and NS5 proteins, respectively, of bovine viral diarrhea virus (BVDV) and yellow fever virus (YF), members of the other two established genera in this family. Phosphorylation of BVDV NS5A and YF NS5 was observed in infected cells, transient expression experiments, and a cell-free assay similar to the one developed for HCV NS5A. Phosphoamino acid analyses indicated that all three proteins were phosphorylated by serine/threonine kinases. Similarities in the properties of BVDV NS5A, YF NS5, and HCV NS5A phosphorylation in vitro further suggested that closely related kinases or the same kinase may phosphorylate these viral proteins. Conservation of this trait among three quite distantly related viruses representing three separate genera suggests that phosphorylation of the NS5A/NS5 proteins or their association with cellular kinases may play an important role in the flavivirus life cycle.

scholarly journals Purification and characterization of diacetyl-reducing enzymes from Staphylococcus aureus

1988 ◽  
Vol 251 (2) ◽  
pp. 461-466 ◽  
Author(s):  
I Vidal ◽  
J González ◽  
A Bernardo ◽  
R Martín
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
The Other ◽  
Purification And Characterization ◽  
High Affinity ◽  
Optimum Ph ◽  
Nad Oxidoreductase ◽  
The One

A method was developed to purify diacetyl-reducing enzymes from Staphylococcus aureus. Two enzymes capable of catalysing diacetyl reduction were isolated, neither of which turned out to be a specific diacetyl reductase. One of them is a lactate dehydrogenase similar to the one from Staphylococcus epidermidis, which accepts diacetyl, although poorly. The other one uses as coenzyme beta-NAD and reduces uncharged alpha-dicarbonyls with more than three carbon atoms (especially the alpha-diketones diacetyl and pentane-2,3-dione), producing the L(+) form of the corresponding alpha-hydroxycarbonyls. This enzyme has an Mr of 68,000 and is, most probably, a monomer. Its optimum pH is 6.0. Its shows a high affinity for NADH and a rather low one for diacetyl, which, at least in vitro, does not seem to be as good a substrate as pentane-2,3-dione. We propose for it the systematic name L-alpha-hydroxyketone: NAD+ oxidoreductase and the recommended name of alpha-diketone reductase (NAD). We also suggest that the diacetyl reductase entry in the I.U.B. classification be suppressed.

scholarly journals Chemerin-Derived Peptide Val66-Pro85 Is Effective in Limiting Methicillin-Resistant S. aureus Skin Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Aneta Zegar ◽  
Urszula Godlewska ◽  
Dorota Kozłowska-Chmielewska ◽  
Pawel Majewski ◽  
Brian A. Zabel ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Skin Infection ◽  
Inflammatory Diseases ◽  
Experimental Models ◽  
Associated Bacteria ◽  
Methicillin Resistant ◽  
Endogenous Peptides ◽  
Growth Of A Variety

Chemerin-derived peptide Val66-Pro85 (p4) restricts the growth of a variety of skin-associated bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). To better understand the antimicrobial potential of chemerin peptide, we compared p4 activity against MRSA in vitro to cathelicidin LL-37, one of the key endogenous peptides implicated in controlling the growth of S. aureus. The efficacy of p4 was also validated in relevant experimental models of skin pathology, such as topical skin infection with community-acquired MRSA, and in the context of skin inflammatory diseases commonly associated with colonization with S. aureus, such as atopic dermatitis (AD). We showed that p4 collaborates additively with LL-37 in inhibiting the growth of S. aureus, including MRSA, and that p4 was effective in vivo in reducing MRSA burden. p4 was also effective in reducing levels of skin-infiltrating leukocytes in S. aureus-infected AD-like skin. Taken together, our data suggest that p4 is effective in limiting S. aureus and, in particular, MRSA skin infection.

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