pvdQ基因对铜绿假单胞菌群集运动的作用

The effect of pvdQ gene on Pseudomonas aeruginosa swarming motility

目的探讨铜绿假单胞菌pvdQ（PA2385）基因对群集运动的作用。方法构建pvdQ基因表达质粒pME6032-pvdQ并鉴定，采用电穿孔法将带有pvdQ基因的质粒转入铜绿假单胞菌野生株PA01中，构建pvdQ-高表达株。同时将空质粒pME6032采用电穿孔法转入PA01中，构建pME6032空质粒株。选择含有反向筛选基因sacB的pEX18Gm质粒作为自杀载体，构建缺失pvdQ基因的铜绿假单胞菌无痕缺失突变株，溶菌肉汤（LB）液过夜培养，观察菌株的直径变化。统计学处理采用单因素方差分析。结果经鉴定，成功构建pvdQ-高表达株和pvdQ突变株，比较4株菌的群集运动直径变化：PAO1为（20．52±1.80）mm，pME6032空质粒株为（19．39±2．10）mm，pvdQ高表达株为（51．20±2．16）mm，pvdQ突变株为（3．30±0．55）mm。pME6032空质粒株与野生株PA01相比，直径无显著变化（t=-0．1493，P〉0．05），pvdQ突变株与野生株PAO1相比，直径减小（t=2．8525，P〈0．05），pvdQ高表达株与野生株PAO1相比，直径增大（t=1．4230，P〈0．05）。结论pvdQ基因参与调控铜绿假单胞菌群集运动，且能促进铜绿假单胞菌群集运动。

Objective To investigate the effect of pvdQ （PA2385） gene on Pseudornonas aeruginosa swarming motility. Methods The plasmid pME6032 with pvdQ gene was constructed and identified, then transformed into Pseudomonas aeruginosa PAO1 using the electroporation to build pvdQ-overexpression strain. The pME6032-PAO1 strain was constructed with the same method. The cloning plasmid pEXl8Gm containing sacB was successfully used to construct unmarked deletion mutant of pvdQ gene and pvdQ-mutant strain. Bacteria were inoculated in LB and were cultured overnight. The clones were measured for the diameter of the swarming zone. The statistical analysis was done using one factor ANOVA. Results Strains of pvdQ-overexpression and pvdQ-mutant were successfully constructed and confirmed by polymerase chain reaction （PCR）. The four strains were compared for the swarming motility by changes in diameter： PAO1 （20.52±1.80） mm, pME6032- PAO1 strain （19. 39 ± 2. 10） mm, pvdQ-overexpression strain （51. 20± 2. 16） mm, pvdQ-mutant strain （3.30±0.55） mm. The diameter of pME6032-PAO1 strain was not significantly different from that of wild strain PAO1 （t=-0. 1493, P〉0.05）. However, the diameter of pvdQ-mutant strain was significantly shorter than that of wild strain PAO1 （t=2. 8525,P〈0.05）, while the diameter of pvdQ-overexpression strain was longer than that of the wild strain PAO1 （t=1. 4230, P〈0. 05）. Conclusions pvdQ gene may be involved in regulating the swarming motility of Pseudornonas aeruginosa, which can promote Pseudomonas aeruginosa swarming motility.