scholarly journals Manganese complex [Mn(CO)3(tpa-κ3N)]Br increases antibiotic sensitivity in multidrug resistant Streptococcus pneumoniae

2020 ◽  
Author(s):  
Apostolos Liakopoulos ◽  
Roberto M. La Ragione ◽  
Christoph Nagel ◽  
Ulrich Schatzschneider ◽  
Daniel E. Rozen ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistance ◽  
Streptococcus Pneumoniae ◽  
Treatment Strategies ◽  
Antibiotic Sensitivity ◽  
Multidrug Resistant ◽  
Novel Treatment ◽  
Novel Treatment Strategies

AbstractThe emergence of multidrug-resistance (MDR) in Streptococcus pneumoniae clones and non-vaccine serotypes is of increasing concern, necessitating the development of novel treatment strategies. Here, we determined the efficacy of the Mn complex [Mn(CO)3(tpa-κ3N)]Br against MDR S. pneumoniae strains. Our data showed that [Mn(CO)3(tpa-κ3N)]Br has in vitro and in vivo antibacterial activity and has the potential to be used in combination with currently available antibiotics to increase their effectiveness against MDR S. pneumoniae.

scholarly journals Fluoxetine Can Inhibit SARS-CoV-2 In Vitro

2021 ◽  
Vol 9 (2) ◽  
pp. 339
Author(s):  
Arthur Dechaumes ◽  
Magloire Pandoua Nekoua ◽  
Sandrine Belouzard ◽  
Famara Sane ◽  
Ilka Engelmann ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Limit Of Detection ◽  
Acute Infection ◽  
Treatment Strategies ◽  
Potential Value ◽  
Novel Treatment ◽  
Novel Treatment Strategies ◽  
Antiviral Mechanism

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in the coronavirus disease pandemic, drastically affecting global health and economy. Though the understanding of the disease has improved, fighting the virus remains challenging. One of the strategies is repurposing existing drugs as inhibitors of SARS-CoV-2. Fluoxetine (FLX), a selective serotonin reuptake inhibitor, reportedly inhibits the replication of RNA viruses, especially Coxsackieviruses B (CVB), such as CV-B4 in vitro and in vivo. Therefore, in this study, we investigated the in vitro antiviral activity of FLX against SARS-CoV-2 in a model of acute infection. When 10 μM of FLX was added to SARS-CoV-2-infected Vero E6 cells, the virus-induced cytopathic effect was not observed. In this model, the level of infectious particles in the supernatant was lower than that in controls. The level was below the limit of detection of the assay up to day 3 post-infection when FLX was administered before viral inoculation or simultaneously followed by daily inoculation. In conclusion, FLX can inhibit SARS-CoV-2 in vitro. Further studies are needed to investigate the potential value of FLX to combat SARS-CoV-2 infections, treat SARS-CoV-2-induced diseases, and explain the antiviral mechanism of this molecule to pave way for novel treatment strategies.

scholarly journals Molecular mechanisms underpinning sarcomas and implications for current and future therapy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Victoria Damerell ◽  
Michael S. Pepper ◽  
Sharon Prince
Keyword(s):  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Treatment Strategies ◽  
Mesenchymal Transition ◽  
Mesenchymal To Epithelial Transition ◽  
Cells Of Origin ◽  
Novel Treatment Strategies ◽  
Future Therapy

AbstractSarcomas are complex mesenchymal neoplasms with a poor prognosis. Their clinical management is highly challenging due to their heterogeneity and insensitivity to current treatments. Although there have been advances in understanding specific genomic alterations and genetic mutations driving sarcomagenesis, the underlying molecular mechanisms, which are likely to be unique for each sarcoma subtype, are not fully understood. This is in part due to a lack of consensus on the cells of origin, but there is now mounting evidence that they originate from mesenchymal stromal/stem cells (MSCs). To identify novel treatment strategies for sarcomas, research in recent years has adopted a mechanism-based search for molecular markers for targeted therapy which has included recapitulating sarcomagenesis using in vitro and in vivo MSC models. This review provides a comprehensive up to date overview of the molecular mechanisms that underpin sarcomagenesis, the contribution of MSCs to modelling sarcomagenesis in vivo, as well as novel topics such as the role of epithelial-to-mesenchymal-transition (EMT)/mesenchymal-to-epithelial-transition (MET) plasticity, exosomes, and microRNAs in sarcomagenesis. It also reviews current therapeutic options including ongoing pre-clinical and clinical studies for targeted sarcoma therapy and discusses new therapeutic avenues such as targeting recently identified molecular pathways and key transcription factors.

scholarly journals Overcoming multidrug-resistance in vitro and in vivo using the novel P-glycoprotein inhibitor 1416

2012 ◽  
Vol 32 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Yan Xu ◽  
Feng Zhi ◽  
Guangming Xu ◽  
Xiaolei Tang ◽  
Sheng Lu ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Cancer Chemotherapy ◽  
Antitumour Activity ◽  
Multidrug Resistant ◽  
The Novel ◽  
Mice Model ◽  
P Glycoprotein ◽  
Channel Currents

MDR (multidrug-resistance) represents a major obstacle to successful cancer chemotherapy and is usually accomplished by overexpression of P-gp (P-glycoprotein). Much effort has been devoted to developing P-gp inhibitors to modulate MDR. However, none of the inhibitors on the market have been successful. 1416 [1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (phenoprolamine hydrochloride)] is a new VER (verapamil) analogue with a higher IC50 for blocking calcium channel currents than VER. In the present paper, we examined the inhibition effect of 1416 on P-gp both in vitro and in vivo. 1416 significantly enhanced cytotoxicity of VBL (vinblastine) in P-gp-overexpressed human multidrug-resistant K562/ADM (adriamycin) and KBV cells, but had no such effect on the parent K562 and KB cells. The MDR-modulating function of 1416 was further confirmed by increasing intracellular Rh123 (rhodanmine123) content in MDR cells. Human K562/ADM xenograft-nude mice model verified that 1416 potentiates the antitumour activity of VBL in vivo. RT-PCR (reverse transcriptase-PCR) and FACS analysis demonstrated that the expression of MDR1/P-gp was not affected by 1416 treatment. All these observations suggest that 1416 could be a promising agent for overcoming MDR in cancer chemotherapy.

scholarly journals In VitroDrug Combination Studies of Letermovir (AIC246, MK-8228) with Approved Anti-Human Cytomegalovirus (HCMV) and Anti-HIV Compounds in Inhibition of HCMV and HIV Replication

2015 ◽  
Vol 59 (6) ◽  
pp. 3140-3148 ◽  
Author(s):  
Steffen Wildum ◽  
Holger Zimmermann ◽  
Peter Lischka
Keyword(s):  
Human Cytomegalovirus ◽  
Treatment Strategies ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Severe Toxicity ◽  
Transplant Recipients ◽  
Hiv Drugs ◽  
Anti Hiv

ABSTRACTDespite modern prevention and treatment strategies, human cytomegalovirus (HCMV) remains a common opportunistic pathogen associated with serious morbidity and mortality in immunocompromised individuals, such as transplant recipients and AIDS patients. All drugs currently licensed for the treatment of HCMV infection target the viral DNA polymerase and are associated with severe toxicity issues and the emergence of drug resistance. Letermovir (AIC246, MK-8228) is a new anti-HCMV agent in clinical development that acts via a novel mode of action and has demonstrated anti-HCMV activityin vitroandin vivo. For the future, drug combination therapies, including letermovir, might be indicated under special medical conditions, such as the emergence of multidrug-resistant virus strains in transplant recipients or in HCMV-HIV-coinfected patients. Accordingly, knowledge of the compatibility of letermovir with other HCMV or HIV antivirals is of medical importance. Here, we evaluated the inhibition of HCMV replication by letermovir in combination with all currently approved HCMV antivirals using cell culture checkerboard assays. In addition, the effects of letermovir on the antiviral activities of selected HIV drugs, and vice versa, were analyzed. Using two different mathematical techniques to analyze the experimental data, (i) additive effects were observed for the combination of letermovir with anti-HCMV drugs and (ii) no interaction was found between letermovir and anti-HIV drugs. Since none of the tested drug combinations significantly antagonized letermovir efficacy (or vice versa), our findings suggest that letermovir may offer the potential for combination therapy with the tested HCMV and HIV drugs.

scholarly journals Antimicrobial activity of a novel bioengineered honey against non-typeable Haemophilus influenzae biofilms: an in vitro study

2018 ◽  
Vol 71 (6) ◽  
pp. 554-558 ◽  
Author(s):  
Rachel S Newby ◽  
Matthew Dryden ◽  
Raymond N Allan ◽  
Rami J Salib
Keyword(s):  
Haemophilus Influenzae ◽  
Treatment Strategies ◽  
In Vitro Study ◽  
Opportunistic Pathogen ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Chronic Respiratory Diseases ◽  
Novel Treatment ◽  
Novel Treatment Strategies

The opportunistic pathogen non-typeable Haemophilus influenzae (NTHi) plays an important role in many chronic respiratory diseases including otitis media, chronic rhinosinusitis, cystic fibrosis and chronic obstructive pulmonary disease. Biofilm formation has been implicated in NTHi colonisation, persistence of infection and recalcitrance towards antimicrobials. There is therefore a pressing need for the development of novel treatment strategies that are effective against NTHi biofilm-associated diseases. SurgihoneyRO is a honey-based product that has been bioengineered to enable the slow release of H2O2, a reactive oxygen species to which H. influenzae is susceptible. Treatment of established NTHi biofilms with SurgihoneyRO significantly reduced biofilm viability through enhanced H2O2 production and was shown to be more effective than the conventional antibiotic co-amoxiclav.

scholarly journals Therapeutic Effects of Curcumin—From Traditional Past to Present and Future Clinical Applications

2019 ◽  
Vol 20 (15) ◽  
pp. 3757 ◽  
Author(s):  
Beatrice Bachmeier ◽  
Dieter Melchart
Keyword(s):  
Molecular Mechanisms ◽  
Malignant Tumors ◽  
Scientific Evidence ◽  
Treatment Strategies ◽  
Therapeutic Effects ◽  
Microbial Infection ◽  
Therapeutic Benefits ◽  
Novel Treatment Strategies

The efficacy of the plant-derived polyphenol curcumin, in various aspects of health and wellbeing, is matter of public interest. An internet search of the term “Curcumin” displays about 12 million hits. Among the multitudinous information presented on partly doubtful websites, there are reports attracting the reader with promises ranging from eternal youth to cures for incurable diseases. Unfortunately, many of these reports are not based on scientific evidence, but they feed the desideratum of the reader for a “miracle cure”. This circumstance makes it very difficult for researchers, who work in a scientifically sound and evidence-based manner on the therapeutic benefits (or side effects) of curcumin, to demarcate their results from sensational reports that circulate in the web and in other media. This is only one of many obstacles making it difficult to pave curcumin’s way into clinical application; others are its nonpatentability and low economic usability. A further impediment comes from scientists who never worked with curcumin or any other natural plant-derived compound in their own labs. They have never tested these compounds in any scientific assay, neither in vitro nor in vivo; however, they claim, in a sometimes polemic manner, that everything that has so far been published on curcumin’s molecular effects is based on artefacts. The here presented Special Issue comprises a collection of five scientifically sound articles and nine reviews reporting on the therapeutic benefits and the molecular mechanisms of curcumin or of chemically modified curcumin in various diseases ranging from malignant tumors to chronic diseases, microbial infection, and even neurodegenerative diseases. The excellent results of the scientific projects that underlie the five original papers give reason to hope that curcumin will be part of novel treatment strategies in the near future—either as monotherapy or in combination with other drugs or therapeutic applications.

Baicalin-induced Cytotoxicity and Apoptosis in Multidrug-resistant MC3/5FU Mucoepidermoid Carcinoma Cell Line

2019 ◽  
Vol 16 (12) ◽  
pp. 1339-1347 ◽  
Author(s):  
Xiaofang Xu ◽  
Qihong Li ◽  
Kaitao Yu ◽  
Ghulam Murtaza ◽  
Bin Liu
Keyword(s):  
Flow Cytometry ◽  
Multidrug Resistance ◽  
Nude Mice ◽  
Multidrug Resistant ◽  
Clinical Findings ◽  
Hoechst 33342 ◽  
Protein Levels ◽  
Transmission Electron

Background: Multidrug Resistance (MDR) is a serious hindrance to cancer chemotherapy and profoundly influences the clinical findings. Many Traditional Chinese Medicines (TCM) have been tested with the aim of developing effective resistance modulators or anticancer drugs to overcome the MDR of human cancers. Methods: The anticancer effect of baicalin on multidrug-resistant MC3/5FU (5-fluorouracil) cells was investigated by MTT test and xenografts in nude mice. Cell apoptosis was studied by transmission electron microscopy, Hoechst-33342 staining, DNA fragmentation detection, and flow cytometry. RT-PCR and Rhodamine 123 efflux assay was also used to detect its effect on ABC drug transporter proteins, ABCB1 (P-glycoprotein, P-gp) and ABCC1 (multidrug resistance protein 1, MRP1). Results: The results indicate that there was no significant effect of baicalin on ABC transporters expression or efflux function, although it induced potent growth inhibition in MC3/5FU cells. Flow cytometry, Hoechst 33342 staining and transmission electron microscope revealed that baicalin caused MC3/5FU cell death through the induction of apoptosis. It is demonstrated that baicalininduced apoptosis could be mediated by up-regulation of Bax and caspase-3 protein levels and downregulation of Bcl-2 protein levels. In addition, daily intraperitoneal injection of baicalin (100 and 200 mg/kg) for 2 weeks significantly inhibited the growth of MC3/5FU cells xenografts in nude mice. Conclusion: Our results suggest that baicalin possesses considerable cytotoxic activity in multidrug resistance MC3/5FU cells in vitro and in vivo.

scholarly journals Activity of Aztreonam in Combination with Avibactam, Clavulanate, Relebactam, and Vaborbactam against Multidrug-Resistant Stenotrophomonas maltophilia

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
M. Biagi ◽  
D. Lamm ◽  
K. Meyer ◽  
A. Vialichka ◽  
M. Jurkovic ◽  
...  
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Treatment Strategies ◽  
Multidrug Resistant ◽  
Content Type ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Novel Treatment Strategies

ABSTRACT The intrinsic L1 metallo- and L2 serine-β-lactamases in Stenotrophomonas maltophilia make it naturally multidrug resistant and difficult to treat. There is a need to identify novel treatment strategies for this pathogen, especially against isolates resistant to first-line agents. Aztreonam in combination with avibactam has demonstrated potential, although data on other aztreonam–β-lactamase inhibitor (BLI) combinations are lacking. Additionally, molecular mechanisms for reduced susceptibility to these combinations have not been explored. The objectives of this study were to evaluate and compare the in vitro activities and to understand the mechanisms of resistance to aztreonam in combination with avibactam, clavulanate, relebactam, and vaborbactam against S. maltophilia. A panel of 47 clinical S. maltophilia strains nonsusceptible to levofloxacin and/or trimethoprim-sulfamethoxazole were tested against each aztreonam-BLI combination via broth microdilution, and 6 isolates were then evaluated in time-kill analyses. Three isolates with various aztreonam-BLI MICs were subjected to whole-genome sequencing and quantitative reverse transcriptase PCR. Avibactam restored aztreonam susceptibility in 98% of aztreonam-resistant isolates, compared to 61, 71, and 15% with clavulanate, relebactam, and vaborbactam, respectively. The addition of avibactam to aztreonam resulted in a ≥2-log10-CFU/ml decrease at 24 h versus aztreonam alone against 5/6 isolates compared to 1/6 with clavulanate, 4/6 with relebactam, and 2/6 with vaborbactam. Molecular analyses revealed that decreased susceptibility to aztreonam-avibactam was associated with increased expression of genes encoding L1 and L2, as well as the efflux pump (smeABC). Aztreonam-avibactam is the most promising BLI-combination against multidrug-resistant S. maltophilia. Decreased susceptibility may be due to the combination of overexpressed β-lactamases and efflux pumps. Further studies evaluating this combination against S. maltophilia are warranted.

scholarly journals Efficacy of Humanized Exposures of Cefiderocol (S-649266) against a Diverse Population of Gram-Negative Bacteria in a Murine Thigh Infection Model

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marguerite L. Monogue ◽  
Masakatsu Tsuji ◽  
Yoshinori Yamano ◽  
Roger Echols ◽  
David P. Nicolau
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Diverse Population ◽  
Gram Negative ◽  
Content Type ◽  
Log Reduction

ABSTRACT Cefiderocol (S-649266) is a novel siderophore cephalosporin with potent in vitro activity against clinically encountered multidrug-resistant (MDR) Gram-negative isolates; however, its spectrum of antibacterial activity against these difficult-to-treat isolates remains to be fully explored in vivo. Here, we evaluated the efficacy of cefiderocol humanized exposures in a neutropenic murine thigh model to support a suitable MIC breakpoint. Furthermore, we compared cefiderocol's efficacy with humanized exposures of meropenem and cefepime against a subset of these phenotypically diverse isolates. Ninety-five Gram-negative isolates were studied. Efficacy was determined as the change in log10 CFU at 24 h compared with 0-h controls. Bacterial stasis or ≥1 log reduction in 67 isolates with MICs of ≤4 μg/ml was noted in 77, 88, and 85% of Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa, respectively. For isolates with MICs of ≥8 μg/ml, bacterial stasis or ≥1 log10 reduction was observed in only 2 of 28 (8 Enterobacteriaceae, 19 A. baumannii, and 1 P. aeruginosa) strains. Against highly resistant meropenem and cefepime organisms, cefiderocol maintained its in vivo efficacy. Overall, humanized exposures of cefiderocol produced similar reductions in bacterial density for organisms with MICs of ≤4 μg/ml, whereas isolates with MICs of ≥8 μg/ml generally displayed bacterial growth in the presence of the compound. Data derived in the current study will assist with the delineation of MIC susceptibility breakpoints for cefiderocol against these important nosocomial Gram-negative pathogens; however, additional clinical data are required to substantiate these observations.

scholarly journals The search for novel treatment strategies for Streptococcus pneumoniae infections

2021 ◽  
Author(s):  
F Cools ◽  
P Delputte ◽  
P Cos
Keyword(s):  
Immune System ◽  
Streptococcus Pneumoniae ◽  
Treatment Strategies ◽  
Host Immune System ◽  
Pneumococcal Infections ◽  
Enzymatic Assays ◽  
Novel Treatment ◽  
Development Costs ◽  
Life Threatening ◽  
Novel Treatment Strategies

Abstract This review provides an overview of the most important novel treatment strategies against Streptococcus pneumoniae infections published over the past 10 years. The pneumococcus causes the majority of community-acquired bacterial pneumonia cases, and it is one of the prime pathogens in bacterial meningitis. Over the last 10 years, extensive research has been conducted to prevent severe pneumococcal infections, with a major focus on i) boosting the host immune system and ii) discovering novel antibacterials. Boosting the immune system can be done in two ways, either by actively modulating host immunity, mostly through administration of selective antibodies, or by interfering with pneumococcal virulence factors, thereby supporting the host immune system to effectively overcome an infection. While several of such experimental therapies are promising, few have evolved to clinical trials. The discovery of novel antibacterials is hampered by the high research and development costs versus the relatively low revenues for the pharmaceutical industry. Nevertheless, novel enzymatic assays and target-based drug design, allow the identification of targets and the development of novel molecules to effectively treat this life-threatening pathogen.

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