Lin Guifang, Chen Wenbo, Su Yongquan, Qin Yingxue, Huang Lixing, Yan Qingpi
State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China.
Key Laboratory of Healthy Mariculture for the East China Sea, Fisheries College, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China.
Microbiologyopen. 2017 Aug;6(4). doi: 10.1002/mbo3.451. Epub 2017 Jan 27.
The characterization of adhesion between pathogenic bacteria and the host is critical. Pathogenic Aeromonas hydrophila was shown to adhere in vitro to the mucus of Anguilla japonica. To further investigate the adhesion mechanisms of A. hydrophila, a mini-Tn10 transposon mutagenesis system was used to generate an insertion mutant library by cell conjugation. Seven mutants that were impaired in adhesion to mucus were selected out of 332 individual colonies, and mutant M196 was the most severely impaired strain. National Center for Biotechnology Information (NCBI) blast analysis showed that mutant M196 was inserted by mini-Tn10 with an ORF of approximately 1,005 bp (GenBank accession numbers KP280172). This ORF is predicted to encode a protein consist of 334 amino acid, which displays the highest identity (98%) with the RbsR of A. hydrophila ATCC 7966. Random inactivation of rbsR gene affected the pleiotropic phenotypes of A. hydrophila. The adhesion ability and the survival level of the rbsR gene mutant (M196) were attenuated compared with the wild-type and rbsR complementary type. The findings of this study indicated that RbsR plays roles in the bacterial adhesion and intracellular survival of A. hydrophila.
致病性细菌与宿主之间黏附作用的特性至关重要。已证明致病性嗜水气单胞菌在体外可黏附于日本鳗鲡的黏液。为进一步研究嗜水气单胞菌的黏附机制，利用mini-Tn10转座子诱变系统通过细胞接合产生插入突变体文库。从332个单菌落中筛选出7个黏附黏液能力受损的突变体，其中突变体M196是受损最严重的菌株。美国国立生物技术信息中心（NCBI）的blast分析表明，突变体M196被mini-Tn10插入，插入位点的开放阅读框（ORF）约为1005 bp（GenBank登录号KP280172）。该ORF预计编码一个由334个氨基酸组成的蛋白质，与嗜水气单胞菌ATCC 7966的RbsR具有最高的同一性（98%）。rbsR基因的随机失活影响了嗜水气单胞菌的多效性表型。与野生型和rbsR互补型相比，rbsR基因突变体（M196）的黏附能力和存活水平均有所减弱。本研究结果表明，RbsR在嗜水气单胞菌的细菌黏附和细胞内存活中发挥作用。
