Tetsuya Horikita

Sensitive and Specific Detection of Yersinia pseudotuberculosis by Loop-Mediated Isothermal Amplification

ABSTRACT We developed a loop-mediated isothermal amplification method able to detect Yersinia pseudotuberculosis strains in 30 min by using six primers designed by targeting the inv gene. This method is more sensitive than PCR and might be a useful tool for detecting and identifying Y. pseudotuberculosis.

Pulsed-Field Gel Electrophoresis in Differentiation of Erysipelothrix Species Strains

ABSTRACT We report here the first analysis of Erysipelothrixspp. using pulsed-field gel electrophoresis (PFGE). Seventy strains of Erysipelothrix spp. were analyzed.SmaI, AscI, and NotI were tested for the ability to cleave the DNA extracted from those strains, and among them, SmaI was the most reliable enzyme. Sixty-three distinct PFGE patterns were produced, and no DNA degradation was observed, allowing the identification of all of the strains. Based on these results and on those of a previous analysis using randomly amplified polymorphic DNA and ribotyping, PFGE withSmaI might be considered to be more sensitive than those methods and to be the best method for epidemiological studies of strains of this genus.

Isolation of bovine foamy virus in Japan

Bovine foamy virus (BFV) is endemic in many countries, but has not been reported in Japan. A syncytium-forming virus was isolated from peripheral blood leukocytes of clinically healthy cattle on a farm in Kanagawa prefecture during a periodic epidemiological survey of viral diseases. The isolate was propagated in primary fetal bovine muscle cells and subsequently passaged in Madin–Darby bovine kidney cells. Since the isolate appeared to be distinct from the viruses with syncytium-forming ability previously isolated in Japan, we attempted to identify it using genomic analyses and electron microscopy. A phylogenetic analysis revealed that the isolate belongs to the bovine foamy virus cluster and is highly similar to a BFV strain isolated in China. A sero-epidemiological survey was performed using agar gel immunodiffusion test with the isolated virus as the antigen, and five of the 57 cattle tested were found to be seropositive.

A Field Investigation on Hind Feet and Leg Condition of Sows in Commercial Pig Farms in Chiba, Japan

豚の運動器疾患は年間死廃頭数の約20％を占める重要な疾患である。運動器疾患のうち，関節炎や脚弱などの研究はあるが，蹄底面（蹄球部および蹄底部）についての研究は少ない。そこで蹄底面に注目し，その病変に関する実態を調査した。