Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
Ecotoxicology. 2012 Aug;21(6):1661-8. doi: 10.1007/s10646-012-0939-7. Epub 2012 Jun 9.
Mai Po Nature Reserve is the largest mangrove ecosystem and the most polluted coastal water body in Hong Kong. Plasmids screening of 100 Vibrio isolates randomly showed 45 % of them contained 1-3 plasmids. These plasmid(s)-bearing isolates could be divided into 12 groups based on their plasmid profiles. Phylogenetic analysis of the partial 16S rRNA gene sequences confirmed that all plasmid(s)-bearing isolates belonged to Vibrio cholerae. Full DNA sequences of the plasmids in Groups I (pVCG1.1 and pVCG1.2), II (pVCG2.1), III (pVCG3.2) and IV (pVCG4.1) have been determined and the results showed that pVCG1.1, pVCG2.1 and pVCG3.2 were almost identical. Plasmids pVCG1.1, pVCG1.2 and pVCG4.1 are comprised of 4,439, 2,357 and 2,163 bp with the overall G+C content of 45.57, 53.54 and 43.09 %, respectively. pVCG1.1 is a novel plasmid, and plasmids pVCG1.2 and pVCG4.1 showed homology of replication initiation proteins to that of the theta type replicons. Attempts to cure the plasmids from their hosts were unsuccessful. These data suggest that plasmids of Vibrio spp. are a significant gene reservoir in the marine ecosystem.
米埔自然保护区是香港最大的红树林生态系统和污染最严重的沿海水域。随机筛选 100 个弧菌分离株的质粒显示，其中 45%携带 1-3 个质粒。根据质粒图谱，这些携带质粒的分离株可分为 12 组。部分 16S rRNA 基因序列的系统发育分析证实，所有携带质粒的分离株均属于霍乱弧菌。已确定 I 组（pVCG1.1 和 pVCG1.2）、II 组（pVCG2.1）、III 组（pVCG3.2）和 IV 组（pVCG4.1）质粒的全长 DNA 序列，结果表明 pVCG1.1、pVCG2.1 和 pVCG3.2 几乎相同。质粒 pVCG1.1、pVCG1.2 和 pVCG4.1 分别由 4439、2357 和 2163 bp 组成，GC 含量分别为 45.57%、53.54%和 43.09%。pVCG1.1 是一种新型质粒，质粒 pVCG1.2 和 pVCG4.1 的复制起始蛋白与θ型复制子同源。从宿主中去除质粒的尝试均未成功。这些数据表明，弧菌属质粒是海洋生态系统中重要的基因库。
