Quorum-sensing mutations affect attachment and stability of Burkholderia cenocepacia biofilms
Quorum-sensing mutations affect attachment and stability of Burkholderia cenocepacia biofilms
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DOI：
10.1128/aem.71.9.5208-5218.2005
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发表时间：
2005-09-01
影响因子：
4.4
通讯作者：
Ceri, H
中科院分区：
文献类型：
--
作者：
Tomlin, KL;Malott, RJ;Ceri, H
新洋葱伯克霍尔德菌生物膜的形成部分依赖于酰基高丝氨酸内酯的群体感应。对于许多其他细菌物种，当群体感应途径被抑制时，生物膜成熟的初始粘附和后期阶段似乎都受到影响。在这项研究中，我们研究了新洋葱伯克霍尔德氏菌K56-2的cepIR和cciIR群体感应系统突变对生物膜附着和抗生素耐药性的影响。我们还研究了cepIR系统在生物膜稳定性和结构发育中的作用。使用高通量MBEC测定系统产生多个等效生物膜，通过结晶紫染色测量的cepI和cepR突变生物膜的生物量小于野生型菌株观察到的值的一半。通过多拷贝表达载体提供功能性基因拷贝后，附着部分恢复。令人惊讶的是，无论是cciI突变体，也不是双cciI cepI突变体是缺乏附着，和cciI基因的恢复导致较少的附着比突变体。同时，cciR突变体确实显示出附着的显著减少，cciR cepIR突变体也是如此。虽然有没有变化的抗生素敏感性与个人cepIR和cciIR突变体，cepI cciI突变体生物膜更敏感的环丙沙星。cepI和cepR突变体对十二烷基硫酸钠去除的敏感性显着增加。单个cepIR突变体生物膜的流动细胞分析表明，它们在附着和发育方面都在结构上和时间上受损。这些结果表明，生物膜结构缺陷可能存在于群体感应突变体的B。cenocepacia影响粘附细胞团的稳定性和抗性，为未来的研究提供了基础，以设计针对该物种生物膜形成的预防措施，这是囊性纤维化患者的重要肺部病原体。
Biofilm formation in Burkholderia cenocepacia has been shown to rely in part on acylhomoserine lactone-based quorum sensing. For many other bacterial species, it appears that both the initial adherence and the later stages of biofilm maturation are affected when quorum sensing pathways are inhibited. In this study, we examined the effects of mutations in the cepIR and cciIR quorum-sensing systems of Burkholderia cenocepacia K56-2 with respect to biofilm attachment and antibiotic resistance. We also examined the role of the cepIR system in biofilm stability and structural development. Using the high-throughput MBEC assay system to produce multiple equivalent biofilms, the biomasses of both the cepI and cepR mutant biofilms, measured by crystal violet staining, were less than half of the value observed for the wild-type strain. Attachment was partially restored upon providing functional gene copies via multicopy expression vectors. Surprisingly, neither the cciI mutant nor the double cciI cepI mutant was deficient in attachment, and restoration of the cciI gene resulted in less attachment than for the mutants. Meanwhile, the cciR mutant did show a significant reduction in attachment, as did the cciR cepIR mutant. While there was no change in antibiotic susceptibility with the individual cepIR and cciIR mutants, the cepI cciI mutant biofilms were more sensitive to ciprofloxacin. A significant increase in sensitivity to removal by sodium dodecyl sulfate was seen for the cepI and cepR mutants. Flow cell analysis of the individual cepIR mutant biofilms indicated that they were both structurally and temporally impaired in attachment and development. These results suggest that biofilm structural defects might be present in quorum-sensing mutants of B. cenocepacia that affect the stability and resistance of the adherent cell mass, providing a basis for future studies to design preventative measures against biofilm formation in this species, an important lung pathogen of cystic fibrosis patients.