无乳链球菌鱼源株10kb基因序列对细菌致病力的影响

发布时间：2018-04-29 22:13

本文选题：无乳链球菌 + kb基因序列　；参考：《微生物学报》2016年01期

【摘要】：【目的】在前期比较基因组学分析中,我们发现中国无乳链球菌鱼源株GD201008-001基因组中有一段10 kb基因序列,内含11个未知功能的开放阅读框。为了研究该段基因序列与细菌的致病力的关系,本研究将这段基因进行了全段缺失。【方法】运用链球菌-大肠杆菌穿梭质粒p SET4s,构建了10 kb基因缺失株(Δ10 kb),并通过生物学性状的比较,细胞粘附试验,斑马鱼攻毒试验和缺失前后毒力相关基因转录水平的检测,评价该序列对无乳链球菌毒力的影响。【结果】经测序证明缺失株Δ10 kb构建成功,与亲本株GD201008-001相比较,缺失株Δ10 kb在细菌染色形态、对HEp-2细胞的粘附能力无明显差异,但在培养液中的生长速度略慢;缺失株Δ10 kb对斑马鱼的毒力明显增强,LD_(50)有极其显著的差异(P0.001);编码菌毛骨架蛋白2b的基因(PI-2b)和唾液酸酶基因(neul)在缺失株中的转录水平明显上升。【结论】该序列对无乳链球菌GD201008-001的毒力有显著的影响,可能调控某些毒力基因的转录表达,使细菌的毒力减弱。
[Abstract]:[objective] in the previous comparative genomics analysis, we found that there is a 10kb gene sequence in the GD201008-001 genome of Streptococcus lactis, which contains 11 open reading frames with unknown functions. In order to study the relationship between the gene sequence and the pathogenicity of bacteria, In this study, the complete deletion of this gene was carried out. [methods] A 10 kb gene deletion strain (螖 10 kb) was constructed by using streptococc-Escherichia coli shuttle plasmid pSET4s. the cell adhesion test was performed by comparing biological characters. Zebrafish attack test and the detection of transcriptional level of virulence related genes before and after deletion were used to evaluate the effect of the sequence on the virulence of Streptococcus acuminata. [results] the deletion strain 螖 10kb was successfully constructed by sequencing, and compared with parent strain GD201008-001. There was no significant difference in the adhesion ability of the missing strain 螖 10 kb to HEp-2 cells in bacterial staining, but the growth rate of the missing strain in the culture medium was a little slow. The virulence of missing strain 螖 10 kb to zebrafish was significantly increased (P 0.001), and the transcription level of PI-2b and sialidase gene was significantly increased in the missing strain. [conclusion] The virulence of Streptococcus lactis GD201008-001 was significant. It may regulate the transcriptional expression of some virulence genes and weaken the virulence of bacteria.
【作者单位】：农业部动物细菌学重点实验室南京农业大学动物医学院;农业部淡水渔业和种质资源利用重点实验室中国水产科学研究院淡水渔业研究中心;
【基金】：江苏省自然科学基金青年科学基金(BK20140703) 国家自然科学基金青年科学基金(31502085) 农业部淡水渔业与种质资源利用重点实验室开放课题(KF201301) 江苏省优势学科项目(PAPD)~~
【分类号】：S941.4

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