观察铜绿假单胞菌pvdQ基因对群集游动中抗生素抗性的影响

Effects of Pseudomonas aeruginosa pvdQ gene on altering antibiotic susceptibility under swarming conditions

目的 探讨铜绿假单胞菌pvdQ（PA2385）基因在群集游动中对几种常用抗生素抗性的影响.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PAO1中,构建pvdQ高表达株.同时将空质粒pME6032采用电穿孔法转入PAO1中,构建pME6032空质粒株.在不同浓度抗生素中,通过比较群集游动直径的大小,观察PAO1和pvdQ高表达株对抗生素抗性的改变.结果 经鉴定成功构建pvdQ高表达株,比较两株菌群集游动直径大小：抗生素浓度成倍增加,但群集游动直径不是成倍下降而是成不规则增加,说明PAO1和pvdQ高表达株均能提高抗生素抗性 pvdQ高表达株对头孢他啶、环丙沙星、美罗培南和多黏菌素B几种抗生素与PAO1相比抗性提高了2～4倍.结论 铜绿假单胞菌pvdQ高表达株能够提高抗生素的抗性,说明pvdQ基因在此过程中发挥重要作用,可能通过参与群集细胞的分化来提高抗生素的抗性.

Objective To investigate whether Pseudomonas aeruginosa pvdQ（ PA2385 ） gene reveals altered antibiotic susceptibility under swarming conditions. Methods The plasmid pME6032 with pvdQ gene was constructed and identified, then transformed into Pseudomonas aeruginosa PAO1 by the electroporation, building pvdQ overexpression strain. Using the same method building pME6032-PAO1 strain.Bacteria were inoculated in LB overnight , measuring the colony diameter of the swarming zone . Results Strains of pvdQ overexpression was successfully constructed by real-time PCR. Comparison of two strains of the swarming motility of change in diameter： The result showed that PAO1 and pvdQ overexpression strains can both improve the antibiotics resistance. Swarmer cells of pvdQ overexpression strain exhibited a 2- to 4-fold increase in antibiotic resistance toward ceftazidime,ciprofloxacin, meropenem and polymyxin B compared to PAO1 on BM2-swarming agar plates. Conclusion pvdQ gene played an important role in elevating the antibiotics resistance, which through prarticipated in the swarmer cell differentiation.