Lida Tetsuya, Park Kwon-Sam, Suthienkul Orasa, Kozawa Junji, Yamaichi Yoshiharu, Yamamoto Koichiro, Honda Takeshi
Department of Bacterial Infections, Research Institute for Microbial Diseases, Osaka University3-1 Yamadaoka, Suita, Osaka 565Japan.
Microbiology (Reading). 1998 Sep;144 ( Pt 9):2517-2523. doi: 10.1099/00221287-144-9-2517.
The distribution and location of the virulence-factor genes of Vibrio parahaemolyticus, tdh and trh, and the structural gene of urease, ureC, were examined on the genomic DNAs of 115 clinical isolates of V. parahaemolyticus. The majority of strains (81%) had two copies of tdh on the chromosome, and no copies of trh or ure. Southern hybridization with a tdh probe, after pulsed-field gel electrophoresis of Notl-digested genomic DNA of each strain revealed only single bands, suggesting that the two copies of the exist on single Notl fragments in each strain. Of the 115 strains, 7% had the tdh, trh and ure genes on chromosomal DNA. The three genes were also detected on single Notl fragments in these strains. More detailed analysis revealed that the three genes were localized within 40 kb. By long and accurate polymerase chain reactions (LA-PCR) the distance between trh and ure was shown to be less than 8.5 kb. These results reveal a close proximity of the tdh, trh and ure genes on the chromosome of pathogenic V. parahaemolyticus strains.
对115株副溶血性弧菌临床分离株的基因组DNA进行检测，分析副溶血性弧菌毒力因子基因tdh和trh以及脲酶结构基因ureC的分布和定位情况。大多数菌株（81%）在染色体上有两个tdh拷贝，没有trh或ure拷贝。对各菌株经Notl酶切的基因组DNA进行脉冲场凝胶电泳后，用tdh探针进行Southern杂交，结果显示仅出现单一条带，这表明每个菌株中的两个tdh拷贝存在于单个Notl片段上。在115株菌株中，7%的菌株在染色体DNA上同时存在tdh、trh和ure基因。在这些菌株的单个Notl片段上也检测到了这三个基因。更详细的分析表明，这三个基因定位在40 kb范围内。通过长片段精确聚合酶链反应（LA-PCR）显示，trh和ure之间的距离小于8.5 kb。这些结果揭示了致病性副溶血性弧菌菌株染色体上tdh、trh和ure基因紧密相邻。
