一株奇异变形杆菌对铜绿假单胞菌多细胞行为的抑制作用*

摘要目的：抗生素耐药性成为了全球性的健康问题。研究发现病原菌的多细胞行为在抗生素的耐药性中起着至关重要的作用 （尤其是生物膜），因而通过抑制多细胞行为而控制耐药性成为当务之急。本文以奇异变形杆菌（Proteus Mirabilis ）为研究对象，考 察它的发酵滤液对一种机会致病菌———铜绿假单胞菌（ Pseudomonas aeruginose）多细胞行为的作用，以期得到一株多细胞行为抑 制菌：在不影响 P.aeruginosa 生长的前提下，抑制生物膜形成、EPS 产生以及定向丛集运动，解除保护，减缓扩散，为降低P.aeruginosa 耐药性，增强抗生素作用效果提供可能。方法：采用结晶紫生物膜测定法、蒽酮-硫酸法、平板检测法，探究P.aeruginosa 发酵滤 液对P.aeruginosa 生物膜、胞外多聚物、定向丛集运动和生长的影响。结果： P.aeruginosa 发酵滤液能显著抑制生物膜 量，在体积百分比浓度为1 %时，抑制率可达60.9 %。该菌的发酵滤液还能阻碍的定向丛集运动，减弱它的吸附和扩 散运动；同时，也减少了P.aeruginosa 胞外多聚物的产量，在滤液体积百分比浓度为1 %时，抑制率达到45.9%。更重要的是，固体 平板实验证明该发酵滤液对P.aeruginosa 的生长没有影响。结论： 在不影响病原菌生长的前提下，对病原菌的多细胞 行为有一定的控制作用。其发酵滤液中存在着抑制微生物膜、定向丛集运动等的成分，在治疗细菌感染性疾病和降低抗生素耐药 性方面有潜在应用价值。

Inhibition of Multicellular Behaviors of by a Pseudomonas by a Proteus Mirabilis *

ABSTRACT Objective:Antibiotic resistance of pathogens has become a global healthcare problem. Many studies have demonstrated that multicellular behaviors are important in the antibiotic resistance of the encased bacteria. Thus it is urgent to control antibiotic resistance by inhibiting the multicellular behaviors. The filtrate of cultured Proteus Mirabilis isolated froma freshwater environment, to inhibit the multicellular behaviors (biofilmformation, swarming motility) of an opportunity pathogen- were investigated in this study. We expect to acquire a multicellular behavior inhibitor, which will decrease the biofilm formation, EPS production and swarming motility of P.aeruginosa With the loss of protection and retardation of diffusion, it is possible to control antibiotic resistance and enhance the effect of antibiotic to P.aeruginosa . Methods:According to crystal violet (CV) method, anthrone-H2SO4 assay, plates assay, the effects of filtrate of cultured Proteus mirabilis on biofilm, swarming, extracellular polymeric substances were determined. Results:The cultured P.aeruginosa filtrate could effectively inhibit the formation of biofilms of with P.aeruginosa different concentrations (0.1%, 0.5 %, 1%), and at the concentration of 1%, the inhibition rate reached 60.9%. The filtrate could also suppress the swarming motility of P. aeruginosa, and the dispersal of P.aeruginosa slew down. Moreover, the production of extracellular polymeric substances were significantly decreased, and the highest inhibition rate in this study was 45.9% at the concentration of 1% . Furthermore, the addition of P.aeruginosa filtrate did not influence the growth of P.aeruginosa .Conclusion: P.aeruginosa can control the multicellular behaviors of P.aeruginosa without inhibiting its growth, and may act as a biofilm inhibitor with potential value in infectious disease treatment and bacterial antibiotic resistance.