Visualizing adhesion-induced agglutination of Escherichia coli with mannosylated nanoparticles.

Polymeric nanoparticles covalently functionalized with derivatized D-mannose molecules were synthesized and characterized. These nanoparticles have an average size of approximately 160 nm in diameter, thus bearing a large number of surface-tethered mannose moieties for multivalent interactions with adhesins on bacterial cells. Specifically, the mannosylated nanoparticles bind strongly with Escherichia coli, allowing the convenient visualization of adhesion interactions under a conventional electron microscope. Since a single nanoparticle is capable of binding more than one cell, the adhesion interactions result in significant nanoparticle-mediated cell agglutination according to electron microscopy imaging. Potential applications of the mannosylated nanoparticles in the inhibition of enteropathogenic infections are discussed.

Use of a Disposable Syringe as a Novel Economic Breath-Collection Chamber for Mice.

We modified commercially available 50-ml syringes to allow their use as breath-collection chambers for mice. By drilling holes at the flanged end and applying 3-way valves to the opposite (tip) end, a syringe can be ventilated, then quickly and simply converted to a closed chamber for collection of breath samples. We evaluated the influence of sample collection time on CO2 content of breath samples and found that 30 sec was required to obtain a CO2 concentration of 3 to 5%. We believe this is an economic, simple, and safe alternative to conventional breath-collection chambers.