Efficacy of Cryptdin-2 as an Adjunct to Antibiotics from Various Generations Against Salmonella

Emerging drug resistance in Salmonella coupled with the recent poor success rate of antibiotic discovery programs of the pharmaceutical industry is a cause for significant concern. It has forced the scientific community to look for alternative new classes of antimicrobial compounds. In this context, combinations of antimicrobial peptides (AMPs) and conventional antibiotics have gained interest owing to their versatile applications. The present study was therefore planned to evaluate the synergistic effects, if any, of cryptdin-2, a mouse Paneth cell alpha-defensin, in combination with four different antibiotics i.e. ciprofloxacin, ceftriaxone, cefotaxime and chloramphenicol, which are conventionally used against Salmonella. Minimum bactericidal concentrations of the selected antimicrobial agents were determined by micro and macro broth dilution assays. In-vitro synergy between the agents was evaluated by fractional bactericidal concentration index (checkerboard test) and time-kill assay. Cryptdin-2-ciprofloxacin, cryptdin-2-ceftriaxone and cryptdin-2-cefotaxime combinations were found synergistic as evident by in vitro assays. This synergism provides an additional therapeutic choice by allowing the use of conventional antibiotics in conjunction with AMPs against MDR Salmonella.     

Dimethylarginine Levels in Cerebrospinal Fluid of Hyperacute Ischemic Stroke Patients are Associated with Stroke Severity

We hypothesise that asymmetric and symmetric dimethylarginine (ADMA, SDMA) are released in cerebrospinal fluid (CSF) due to ischemia-induced proteolysis and that CSF dimethylarginines are related to stroke severity. ADMA and SDMA were measured in CSF of 88 patients with ischemic stroke or TIA within 24 h after stroke onset (mean 8.6 h) and in 24 controls. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score at admission. Outcome was evaluated by institutionalization due to stroke and the modified Rankin scale. Dimethylarginine levels were higher in patients with stroke than in TIA patients, who had higher levels than controls and correlated with the NIHSS. Logistic regression analysis confirmed that dimethylarginines were independently associated with stroke severity. The SDMA/ADMA ratio did not differ significantly between controls and stroke patients. CSF dimethylarginine levels are increased in hyperacute ischemic stroke and are associated with stroke severity. R. Brouns is a research assistant of the Fund for Scientific research Flanders (FWO-Vlaanderen).     

In vitro identification and characterisation of iron chelating catechol-containing natural products and derivatives

BioMetals - Iron is an essential component for multiple biological processes. Its regulation within the body is thus tightly controlled. Dysregulation of iron levels within the body can result in...     

Oxylipin biosynthesis reinforces cellular senescence and allows detection of senolysis

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