title: Bacillus cereus G9241 S-layer assembly contributes to the pathogenesis of anthrax-like disease in mice.
abstract: Bacillus cereus G9241, the causative agent of anthrax-like disease, harbors virulence plasmids encoding anthrax toxins as well as hyaluronic acid (HA) and B. cereus exopolysaccharide (BPS) capsules. B. cereus G9241 also harbors S-layer genes, including homologs of Bacillus anthracis surface array protein (Sap), extractable antigen 1 (EA1), and the S-layer-associated proteins (BSLs). In B. anthracis, S-layer proteins and BSLs attach via their S-layer homology domains (SLH) to the secondary cell wall polysaccharide (SCWP) in a manner requiring csaB, a predicted ketalpyruvate transferase. Here we used a genetic approach to analyze B. cereus G9241 S-layer assembly and function. Variants lacking the csaB gene synthesized SCWP but failed to retain Sap, EA1, and BSLs in the bacterial envelope. The B. cereus G9241 csaB mutant assembled capsular polysaccharides but displayed an increase in chain length relative to the wild-type strain. This phenotype is likely due to its inability to deposit BslO murein hydrolase at divisional septa. During growth under capsule-inducing conditions, B. cereus G9241 assembled BSLs (BslA and BslO) and the Sap S-layer protein, but not EA1, in the envelope. Finally, csaB-mediated assembly of S-layer proteins and BSLs in B. cereus G9241 contributes to the pathogenesis of anthrax-like disease in mice.
authors.affiliation: Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Argonne, Illinois, USA.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Wang
authors.forename: So-Young
authors.initials: SY
authors.lastname: Oh
authors.forename: Antoni P A
authors.initials: AP
authors.lastname: Hendrickx
authors.forename: J M
authors.initials: JM
authors.lastname: Lunderberg
authors.forename: Olaf
authors.initials: O
authors.lastname: Schneewind
mesh_terms: D000818:Animals; D016863:Bacillaceae Infections / Q000382:microbiology*; D001409:Bacillus cereus / Q000378:metabolism* / Q000472:pathogenicity* / Q000648:ultrastructure; D016667:Bacterial Capsules; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins; D009238:N-Acetylmuramoyl-L-alanine Amidase