Portions of the hemagglutinin neuraminidase (HN) gene of Newcastle disease virus (NDV) isolates from two recent outbreaks were sequenced to investigate epidemiology of this disease in Taiwan. These NDV isolates were all viscerotropic velogenic according to the clinical lesions produced in chickens. Sequence data were obtained from 14 NDV isolates (12 from 1995 and 2 from 1984). All isolates differed in their nucleotide sequences (from 0.3 to 15.3%), and represented potentially different strains of NDV. Phylogenetic analysis revealed that these isolates are closely related to viruses isolated from Japan and Malaysia. Some viruses isolated in 1995 appeared to evolve from viruses isolated in 1984. The results suggest that the 1995 outbreak of Newcastle disease (ND) in Taiwan may have been caused by multiple strains of velogenic NDV that have cocirculated in Taiwan for some time. Moreover, NDV isolates from racing pigeons were very similar to isolates from chickens in the same period, suggesting that both domestic and free-living birds were involved in the spread of ND in Taiwan.
An electrochemical latent redox probe, SAF 5 was designed, synthesized and characterized. A rapid and sensitive solution-based assay was demonstrated for salicylate hydroxylase (SHL). In presence of NADH at aerobic conditions, SHL catalyzed the decarboxylative hydroxylation of SAF and released a redox reporter amino ferrocene (AF 6). The release of AF 6 was monitored at interference free potential region (-50 mV vs. Ag|AgCl) using differential pulse voltammetry as signal read-out. The current signal generated by this process is highly specific, and insensitive to other biological interfering compounds. Next, the SAF incorporated SHL assay was extended to fabricate immobilization-free biosensors for rapid sensing of salicylic acid (SA) and β-hydroxybutyrate (β-HB) in whole blood. The described method rapidly detects SA in a linear range of 35-560 μM with detection limit of 5.0 μM. For β-HB determination, the linear range was 10-600 μM and detection limit was 2.0 μM. Besides, the assay protocols are simple, fast, reliable, selective, sensitive and advantageous over existing methods. The whole blood assay did not required cumbersome steps such as, enzyme immobilization, pre-treatments and holds great practical potential in clinical diagnosis.