title: Systematic Mutational Analysis of Histidine Kinase Genes in the Nosocomial Pathogen Stenotrophomonas maltophilia Identifies BfmAK System Control of Biofilm Development.
abstract: The Gram-negative bacterium Stenotrophomonas maltophilialives in diverse ecological niches. As a result of its formidable capabilities of forming biofilm and its resistance to multiple antibiotic agents, the bacterium is also a nosocomial pathogen of serious threat to the health of patients whose immune systems are suppressed or compromised. Besides the histidine kinase RpfC, the two-component signal transduction system (TCS), which is the canonical regulatory machinery used by most bacterial pathogens, has never been experimentally investigated inS. maltophilia Here, we annotated 62 putative histidine kinase genes in the S. maltophilia genome and successfully obtained 51 mutants by systematical insertional inactivation. Phenotypic characterization identified a series of mutants with deficiencies in bacterial growth, swimming motility, and biofilm development. A TCS, named here BfmA-BfmK (Smlt4209-Smlt4208), was genetically confirmed to regulate biofilm formation inS. maltophilia Together with interacting partner prediction and chromatin immunoprecipitation screens, six candidate promoter regions bound by BfmA in vivo were identified. We demonstrated that, among them, BfmA acts as a transcription factor that binds directly to the promoter regions of bfmA-bfmK and Smlt0800(acoT), a gene encoding an acyl coenzyme A thioesterase that is associated with biofilm development, and positively controls their transcription. Genome-scale mutational analyses of histidine kinase genes and functional dissection of BfmK-BfmA regulation in biofilm provide genetic information to support more in-depth studies on cellular signaling inS. maltophilia, in the context of developing novel approaches to fight this important bacterial pathogen.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China.|State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Bao-Zhen
authors.initials: BZ
authors.lastname: Ren
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China.|State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China liuzhong@sjtu.edu.cn qianw@im.ac.cn.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China liuzhong@sjtu.edu.cn qianw@im.ac.cn.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0002-7041-5354
authors.initials: W
authors.lastname: Qian
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D004252:DNA Mutational Analysis; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase / Q000235:genetics / Q000378:metabolism*; D008124:Locomotion; D016254:Mutagenesis, Insertional; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020615:Stenotrophomonas maltophilia / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D014157:Transcription Factors; D000071677:Histidine Kinase