Catalytic polymersomes to produce strong and long-lasting bioluminescence

Polymersome-based bioluminescent nanocompartment to achieve enzyme protection and switch kinetics to produce a persistent light signal.

Alternative Enzyme Protection Assay To Overcome the Drawbacks of the Gentamicin Protection Assay for Measuring Entry and Intracellular Survival of Staphylococci

ABSTRACTPrecise enumeration of living intracellular bacteria is the key step to estimate the invasion potential of pathogens and host immune responses to understand the mechanism and kinetics of bacterial pathogenesis. Therefore, quantitative assessment of host-pathogen interactions is essential for development of novel antibacterial therapeutics for infectious disease. The gentamicin protection assay (GPA) is the most widely used method for these estimations by counting the CFU of intracellular living pathogens. Here, we assess the longstanding drawbacks of the GPA by employing an antistaphylococcal endopeptidase as a bactericidal agent to kill extracellularStaphylococcus aureus. We found that the difference between the two methods for the recovery of intracellular CFU ofS. aureuswas about 5 times. We prove that the accurate number of intracellular CFU could not be precisely determined by the GPA due to the internalization of gentamicin into host cells during extracellular bacterial killing. We further demonstrate that lysostaphin-mediated extracellular bacterial clearance has advantages for measuring the kinetics of bacterial internalization on a minute time scale due to the fast and tunable activity and the inability of protein to permeate the host cell membrane. From these results, we propose that accurate quantification of intracellular bacteria and measurement of internalization kinetics can be achieved by employing enzyme-mediated killing of extracellular bacteria (enzyme protection assay [EPA]) rather than the host-permeative drug gentamicin, which is known to alter host physiology.

The Influence of Continuous and Interval Aerobic Training on the Oxidative Status of Woman Basketball Players

ABSTRACT Oxidative stress is a state of disturbed balance between reactive oxygen species and reactive nitrogen species on the one hand and on the other antioxidant protection. Increased oxygen consumption during exercise could be the cause of oxidative stress. Th e aim of this study was to monitoring the parameters of oxidative stress and components of antioxidative defense during the training process, establish oxidative status basketball players in standby mode after the load caused by two types of aerobic training - continuous aerobic and interval (HIIT) training. As part of a longitudinal experimental study selected a sample of 12 basketball players during the training process. All respondents were female, age 14 to 27 years. Th e study was conducted in preparatory stage. Oxidative status was determined through the index of lipid peroxidation (measured as TBARS), nitric oxide (NO) in the form of nitrite (NO2) levels of superoxide anion radicals (O2) and hydrogen peroxide (H2O2), while the activity of the enzyme protection from oxidative damage was determined through superoxide dismutase (SOD), catalase (CAT) and reduction glutathione (GSH). Th e group analyzed in relation to the type of the training intervention was signifi cantly diff erent from the results in the test in the parameters of NO and TBARS. When the enzyme activity of protection against oxidative damage statistically signifi cant diff erences between groups arise for CAT and GSH. Th e emergence of oxidative stress is not necessary phenomenon of high aerobic training load, training leads to the maintenance of physiological balance in the body.