title: Role of Burkholderia cenocepacia afcE and afcF genes in determining lipid-metabolism-associated phenotypes.
abstract: Burkholderia cenocepacia is an opportunistic pathogen that primarily infects cystic fibrosis patients. Previously we have reported that mutations in shvR, a LysR-type transcriptional regulator, and ShvR-regulated genes BCAS0208 and BCAS0201 (designated afcE and afcF, respectively) affect colony morphotype, biofilm and pellicle formation and virulence in B. cenocepacia. In this study we investigated the role of afcE and afcF in influencing lipid-metabolism-associated phenotypes. As previously reported for K56-2ΔshvR, the Δ2afcE and afcF : : lux mutants had no antifungal activity against Fusarium and Rhizoctonia solani, suggesting that these genes are involved in synthesis of a membrane-associated antifungal lipopeptide. Strains Δ2afcE and afcF : : lux had reduced swarming motility and altered cell membrane morphology, both of which were restored to wild-type levels upon providing these genes in trans. Both K56-2ΔshvR and Δ2afcE showed increased uptake of the hydrophobic fluorescent probe N-phenylnaphthylamine (NPN), indicating altered outer membrane properties. Total lipid profiles determined by TLC revealed distinct differences in cellular lipid compositions of K56-2ΔshvR, Δ2afcE and afcF : : lux compared with K56-2. Taken together, these results indicate that afcE and afcF are involved in metabolic pathway(s) influencing lipid profiles and affect both cell surface and antifungal properties of B. cenocepacia.
authors.affiliation: Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Subramoni
authors.affiliation: Department of Microbiology, Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Agnoli
authors.affiliation: Department of Microbiology, Institute of Plant Biology, University of Zürich, Zürich, Switzerland.
authors.forename: Leo
authors.initials: L
authors.lastname: Eberl
authors.affiliation: Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.
authors.forename: Shawn
authors.initials: S
authors.lastname: Lewenza
authors.affiliation: Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Sokol
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism; D057508:Burkholderia cenocepacia / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology; D002855:Chromatography, Thin Layer; D005670:Fusarium / Q000187:drug effects; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000032:analysis; D055666:Lipopeptides / Q000378:metabolism; D008124:Locomotion; D010641:Phenotype; D012232:Rhizoctonia / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D008055:Lipids; D055666:Lipopeptides; D014157:Transcription Factors