Multilocus Characterization Scheme for Shiga Toxin-Encoding Bacteriophages▿

Shiga toxin-producing Escherichia coli (STEC) strains are food-borne pathogens whose ability to produce Shiga toxin (Stx) is due to integration of Stx-encoding lambdoid bacteriophages. These Stx phages are both genetically and morphologically heterogeneous, and here we report the design and validation of a PCR-based multilocus typing scheme. PCR primer sets were designed for database variants of a range of key lambdoid bacteriophage genes and applied to control phages and 70 stx+ phage preparations induced from a collection of STEC isolates. The genetic diversity residing within these populations could be described, and observations were made on the heterogeneity of individual gene targets, including the unexpected predominance of short-tailed phages with a highly conserved tail spike protein gene. Purified Stx phages can be profiled using this scheme, and the lambdoid phage-borne genes in induced STEC preparations can be identified as well as those residing in the noninducible prophage complement. The ultimate goal is to enable robust and realistically applicable epidemiological studies of Stx phages and their traits. The impact of Stx phage on STEC epidemiology is currently unknown

Effects of three plant growth regulators on growth, morphology, water relations, and frost resistance in lemonwood ( Pittosporum eugenioides

Pittosporum eugenioides is a native ornamental species with a wide distribution throughout New Zealand. The effects of the application of two plant hormones (gibberellic acid and abscisic acid) and a gibberellin biosynthesis inhibitor (paclobutrazol) on the growth and development, frost resistance, and water loss on two-year old seedlings of P. eugenioides were studied.Gibberellic acid increased plant growth, stem diameter, and shoot succulence, while also inducing leaf hyponasty and vegetative bud break of apices. Abscisic acid induced growth suppression while being effective in promoting leaf epinasty and inhibiting bud break. Paclobutrazol induced growth suppression, promoted epinasty, decreased shoot succulence, inhibited bud break in apices, and increased foliar frost resistance. The effects of paclobutrazol were also overcome by the addition of gibberellic acid. The results are compared with those gained from species not native to New Zealand, and indicate the potential for the application of plant growth regulators to a New Zealand species of ornamental value

Systems for prediction and monitoring of ice shedding, anti-icing and de-icing for power line conductors and ground wires

This TB presents some operational or potential anti- and deicing systems (AI/DI). However, for a better understanding and appropriate application of the recommended techniques, the TB also informs on some fundamental aspects of ice accretion and its mechanical and thermodynamic behaviour. The promising potential of new materials such as AI coatings and the role of modern meteorological forecasting models for reliable use of AI/DI techniques are also discussed