AIM To quantify the effect of enrichment, immunomagnetic separation (IMS), and selective plating procedures on isolation of Shiga-toxigenic Escherichia coli O157 (STEC O157) and non-Shiga-toxigenic Escherichia coli O157 (non-STEC O157) from naturally contaminated bovine faeces. METHODS AND RESULTS Two broth enrichment times, two IMS strategies, and two selective plating media were evaluated. ...

The objective of the study was the structural analysis of the 70TeO2-5XO-10P2O5-10ZnO-5PbF2 (X = Mg, Bi2, Ti) tellurite glasses doped with ions of the rare-earth elements Er3+, based on the PALS (positron annihilation lifetime spectroscopy) method of measuring positron lifetimes. Values of positron lifetimes and the corresponding intensities may be connected with the sizes and number of structu...

This communication is concerned with the formation of spheroidal bodies from Bacillus megaterium strain KM, by the action of potassium tellurite in a hypertonic sucrose medium. Cells grown in sucrose-casein hydrolyzate broth (Lederberg and St. Clair, J. Bacteriol., 75, 143, 1958) were inoculated into fresh broth and aerated at 37 C for 3 to 4 hr. Potassium tellurite (final concentration 0.05 pe...

Biochemical, genetic, enzymatic and molecular approaches were used to demonstrate, for the first time, that tellurite (TeO(3) (2-)) toxicity in E. coli involves superoxide formation. This radical is derived, at least in part, from enzymatic TeO(3) (2-) reduction. This conclusion is supported by the following observations made in K(2)TeO(3)-treated E. coli BW25113: i) induction of the ibpA gene ...

In Bacillus subtilis the reduction of potassium tellurite and of tetranitro-blue tetrazolium (TNBT) give comparable results: reduced products appear deposited in particular membranous organelles. For this reason these specialized organelles are considered to be chondrioids (1-3). In the Gram-negative Proteus vulgaris similar membranous structures were never observed by us (4, 5). Therefore it i...

This letter is aiming to develop a full-color glass for the three-dimensional and three-color display. The Yb/Tm/Er codoped lead–germanate–tellurite bulk glass has been fabricated and the upconversion emissions have been investigated. The reduced blue and green emission intensity suggests that it is difficult to achieve three-color display in the multiple-rare-earth ions doped glass. Then a two...

Multimaterial optical fibers combining tellurite with chalcogenide glasses and featuring thin polymer structures are fabricated via the thermal drawing process. It is demonstrated that micrometric polyethersulfone films can be embedded within larger elongated tellurite/chalcogenide glass architectures. Taking advantage of strong chemical reactivity contrasts which exist in considered fiber geom...

In this paper we calculated, for the first time to the best of our knowledge, the cross relaxation parameter of Tm(3+) ions in tellurite glasses over a wide range of concentrations: from 0.36 mol% up to 10 mol%. A new measurement approach based on emission spectra monitoring is proposed. This method is very simple and allows to measure even very highly doped samples. The obtained values of cros...