Measuring the Metabolic Activity of Mature Mycobacterial Biofilms Using Isothermal Microcalorimetry

Measuring metabolic activity and response of biofilm to different conditions or compounds is of general interest but is also expected to help in developing new antibiofilm compounds and potentially new treatments. Current culture-based and microscopic methods although of much use have several drawbacks. Isothermal calorimetry can be useful in this context by allowing measurements of the metabolic activity of biofilm grown and maintained on solid medium. Biofilms prepared on membranes were placed in calorimetry vials containing solid medium. Sealed vials were introduced in an isothermal calorimeter, and the rate of metabolic heat production was monitored over time. We chose mycobacteria as an example for this paper as working with mycobacterial biofilms is notoriously difficult

Treatment of prosthetic vascular graft infections

International audienceProsthetic vascular graft infections require a medico-surgical treatment. A first-line, empirical, antimicrobial treatment could be administered in cases of severe sepsis, septic shock or mechanical complications such as aneurysm rupture or anastomotic leakage. A broad-spectrum combination (glycopeptide, beta-lactams, and aminoglycoside) is usually proposed. When bacteriological samples have identified the causal agent(s) and its antibiotics susceptibility, a treatment with a narrow spectrum will be prescribed during the 6 weeks following surgical treatment.When surgical treatment is suboptimal, a suppressive antibiotic therapy is administered lifelong. The surgical treatment for these patients is complex. It depends on the mechanism of infection, location of prosthetic graft, causal bacteria, and underlying diseases

Nanoscale Effects in Water Splitting Photocatalysis.

From a conceptual standpoint, the water photoelectrolysis reaction is the simplest way to convert solar energy into fuel. It is widely believed that nanostructured photocatalysts can improve the efficiency of the process and lower the costs. Indeed, nanostructured light absorbers have several advantages over traditional materials. This includes shorter charge transport pathways and larger redox active surface areas. It is also possible to adjust the energetics of small particles via the quantum size effect or with adsorbed ions. At the same time, nanostructured absorbers have significant disadvantages over conventional ones. The larger surface area promotes defect recombination and reduces the photovoltage that can be drawn from the absorber. The smaller size of the particles also makes electron-hole separation more difficult to achieve. This chapter discusses these issues using selected examples from the literature and from the laboratory of the author