Characterization of Erysipelothrix rhusiopathiae strains isolated from recent swine erysipelas outbreaks in Japan

The objective of the present study was to characterize Erysipelothrix sp. strains from recent erysipelas outbreaks in Japan. Eighty-three (100%) strains were identified as E. rhusiopathiae, based on serotyping and spaA PCR. Fifty (60.3%), 5 (6.0%), and 28 (33.7%) strains were isolated from animals with acute, subacute and chronic outbreaks, respectively, of which 79 (95.2%), 1 (1.2%), and 3 (3.6%) belonged to serotypes 1a, 2a, and untypeable, respectively. Fifteen strains (including 3, 2, and 10 from acute, subacute, and chronic cases, respectively) were sensitive to acriflavine, and showed high levels of virulence in mice; of which strains from acute cases, and from subacute and chronic cases killed 100%, and 80 to 100% mice, respectively at challenge doses of 10(2) CFU per mouse. Based on sequence analysis of a 432-bp hypervariable region in spaA gene, 83 strains could be divided into 3 groups: (i) group 1 (3 strains of serotype 1a) had Ala-195 and Ile-203; (ii) group 2 (76 strains of serotype 1a and 3 of untypeable) had Asp-195 and Met-203; and (iii) group 3 (one strain of serotype 2a) had Asn-195 and Ile-203. The results of the present study suggest that the serotype 1a strains belonging to the group 2 might be widespread in pig populations in Japan.     

Factors determining the distribution of a keystone understory taxon, dwarf bamboo of the section Crassinodi, on a national scale: application to impact assessment of climate change in Japan

The objective of this study was to identify climatic factors determining the distribution of a keystone understory taxon, section Crassinodi of the genus Sasa, and assess the impacts of climate change on the taxon. Relationships between the distribution of sect. Crassinodi and five climatic variables were explored using classification tree analysis. Potential habitats under current climate and future climate in 2081–2100 were predicted. Potential habitats were further divided into suitable and marginal habitats. The predictive accuracy of the model was assessed using receiver operating characteristic analysis and by comparing model predictions with an independent dataset. The model was reasonably accurate. It showed that the warmth index (WI) and snow cover were the most important climatic variables for Crassinodi distribution. Potential habitats were limited to cooler regions with WI <102.7°C month. Suitable habitats were limited to even cooler regions with WI <84.8°C month. The model also showed that areas with deeper snow than previously reported would provide suitable habitats for Crassinodi under some climatic conditions. In 2081–2100, 37.4% of current potential habitats are predicted to become non-habitats because of increases in WI. Most currently suitable habitats are predicted to vanish from western Japan by 2081–2100. Meanwhile, Hokkaido and high-elevation areas of eastern Honshu will sustain suitable habitats. Sect. Crassinodi, which is adapted to less snowy climates, is predicted to be more affected by climate change than sect. Sasa and Macrochlamys, which are adapted to snowy climates.     

First report of raspberry yellows disease caused by raspberry bushy dwarf virus in Japan

Severe yellowing of leaves was observed on red raspberry in Akita Prefecture. When inoculated with sap from symptomatic raspberry leaves, Chenopodium quinoa plants developed chlorotic ringspot and mottling that are typical of raspberry bushy dwarf virus (RBDV) infection. In western blot analysis, an antibody to the coat protein (CP) of RBDV reacted against ca. 30-kDa protein specific to the diseased trees. In RT-PCR testing for RBDV, single DNA fragments were amplified from total RNA samples of the diseased trees. The nucleotide sequences of the DNA fragments covering the entire CP region revealed 87–97?% identities with those of RBDV isolates.     

Purification and characterization of polyphenol oxidase from cauliflower (Brassica oleracea L.)

Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).     

A time-series data analysis to examine effects of subsidies to fishery productions in Japan

A cointegration analysis is conducted to examine the effect of fishery subsidies on fisheries production using data compiled over more than 30 years in Japan. The results illustrate that one fishery production indicator (production value per fishermen) shows a positive relationship with one particular group of government financial transfer (GFT) (that is, government general service expenditures including cost for fishery managements, scientific researches, and other administrative activities). No other tested results between GFTs and fishery indicators showed a real relationship. Although further scrutiny is awaited, this study could provide an empirical basis for an argument that, under an effective fishing management system, fisheries subsidies do not necessarily cause production increases or negative impact on fishing stocks.