Pathogens and disease
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Pathogens and disease · Aug 2015
Interference of quorum sensing in urinary pathogen Serratia marcescens by Anethum graveolens.
Serratia marcescens is an opportunistic turned obligate pathogen frequently associated with urinary tract infections (UTI) and are multidrug resistant at most instances. Quorum sensing (QS) system, a population-dependent global regulatory system, controls the pathogenesis machinery of S. marcescens as it does in other pathogens. In the present study, methanol extract of a common herb and spice, Anethum graveolens (AGME) was assessed for its anti-QS potential against the clinical isolate of S. marcescens. ⋯ LC-MS analysis of AGME revealed 3-O-methyl ellagic acid (3-O-ME) as one of its active principles having nearly similar antibiofilm activity and a reduced inhibition of prodigiosin (27%) and protease (15%) compared to AGME [prodigiosin (47%) and protease (50%)]. UFLC analysis revealed that 0.355 mg g(-1) of 3-O-ME was present in the AGME. AGME and the 3-O-ME significantly interfered the QS system of a QS model strain S. marcescens MG1 and its mutant S. marcescens MG44 which in turn corroborates the anti-QS mechanism of AGME.
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Pathogens and disease · Jul 2015
Amiodarone and metabolite MDEA inhibit Ebola virus infection by interfering with the viral entry process.
Ebola virus disease (EVD) is one of the most lethal transmissible infections characterized by a high fatality rate, and a treatment has not been developed yet. Recently, it has been shown that cationic amphiphiles, among them the antiarrhythmic drug amiodarone, inhibit filovirus infection. In the present work, we investigated how amiodarone interferes with Ebola virus infection. ⋯ We also show that MDEA, the main amiodarone metabolite, contributes to the antiviral activity. Finally, studies with amiodarone analogues indicate that the antiviral activity is correlated with drug ability to accumulate into and interfere with the endocytic pathway. Considering that it is well tolerated, especially in the acute setting, amiodarone appears to deserve consideration for clinical use in EVD.
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Pathogens and disease · Nov 2014
Low-dose cisplatin administration to septic mice improves bacterial clearance and programs peritoneal macrophage polarization to M1 phenotype.
Sepsis is a systemic inflammatory response to infection, and early responses of macrophages are vital in controlling the infected microorganisms. We used a cecal ligation and puncture (CLP) model of sepsis to determine the role of cisplatin (0.1, 0.5 and 1 mg kg(-1)) with respect to peritoneal macrophages, controlling peritoneal/blood bacterial infection, and systemic inflammation. We found that mice which received low-dose (0.1 and 0.5 mg kg(-1)) i.p. cisplatin had lower mortality rate and improved clinical scores compared with mice in normal saline-treated group, and the level of IL-6 and TNF-α was significantly reduced after cisplatin administration in peritoneal fluid of mice underwent CLP. ⋯ Besides, in vivo phagocytosis and killing assay showed that the ability of macrophage derived from peritoneum was significantly increased with cisplatin treatment (5, 10, and 15 μM) for both gram-positive (Enterococcus faecalis) and gram-negative (Escherichia coli) bacteria. This was associated with the macrophage phenotype polarization from CD11b(+) F4/80(high) CD206(-) to CD11b(+) F4/80(low) CD206(-) M1 group. These findings underscore the importance of low-dose cisplatin in the treatment of sepsis.
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Pathogens and disease · Apr 2014
ReviewTreatment of microbial biofilms in the post-antibiotic era: prophylactic and therapeutic use of antimicrobial peptides and their design by bioinformatics tools.
The treatment for biofilm infections is particularly challenging because bacteria in these conditions become refractory to antibiotic drugs. The reduced effectiveness of current therapies spurs research for the identification of novel molecules endowed with antimicrobial activities and new mechanisms of antibiofilm action. Antimicrobial peptides (AMPs) have been receiving increasing attention as potential therapeutic agents, because they represent a novel class of antibiotics with a wide spectrum of activity and a low rate in inducing bacterial resistance. ⋯ Recent studies have shown the ability of some AMPs to act against microbial biofilms, in particular during early phases of biofilm development. Here, we provide a review of the antimicrobial peptides tested on biofilms, highlighting their advantages and disadvantages for prophylactic and therapeutic applications. In addition, we describe the strategies and methods for de novo design of potentially active AMPs and discuss how informatics and computational tools may be exploited to improve antibiofilm effectiveness.