Proteomic and Functional Analyses Reveal a Unique Lifestyle for Acinetobacter baumannii Biofilms and a Key Role for Histidine Metabolism

作者：Cabral Maria P; Soares Nelson C; Aranda Jesus; Parreira Jose R; Rumbo Carlos; Poza Margarita; Valle Jaione; Calamia Valentina; Lasa Inigo; Bou German^*

来源：Journal of Proteome Research, 2011, 10(8): 3399-3417.

DOI：10.1021/pr101299j

• proteomics
• Acinetobacter baumannii
• biofilms
• histidine
• salicylate
• 2DE
• iTRAQ
• MALDI-TOF/TOF

Biofilm formation is one of the main causes for the persistence of Acinetobacter baumannii, a pathogen associated with severe infections and outbreaks in hospitals. Here, we performed comparative proteomic analyses (2D-DIGE and MALDI-TOF/TOF and iTRAQ/SCX-LC-MS/MS) of cells at three different conditions: exponential, late stationary phase, and biofilms. These results were compared with alterations in the proteome resulting from exposure to a biofilm inhibitory compound (salicylate). Using this multiple-approach strategy, proteomic patterns showed a unique lifestyle for A. baumannii biofilms and novel associated proteins. Several cell surface proteins (such as CarO, OmpA, OprD-like, DcaP-like, PstS, LysM, and Omp33), as well as those involved in histidine metabolism (like Urocanase), were found to be implicated in biofilm formation, this being confirmed by gene disruption. Although L-His uptake triggered biofilms efficiently in wild-type A. baumannii, no effect was observed in Urocanase and OmpA mutants, while a slight increase was observed in a Car deficient strain. We conclude that Urocanase plays a crucial role in histidine metabolism leading to biofilm formation and that OmpA and Car can act as channels for L-His uptake. Finally, we propose a model in which novel proteins are suggested for the first time as targets for preventing the formation of A. baumannii biofilms.

• 出版日期2011-8