title: Role of overexpressed CFA/I fimbriae in bacterial swimming.
abstract: Enterotoxigenic Escherichia coli CFA/I is a protective antigen and has been overexpressed in bacterial vectors, such as Salmonella Typhimurium H683, to generate vaccines. Effects that overexpressed CFA/I may engender on the bacterial host remain largely unexplored. To investigate, we constructed a high CFA/I expression strain, H683-pC2, and compared it to a low CFA/I expression strain, H683-pC, and to a non-CFA/I expression strain, H683-pY. The results showed that H683-pC2 was less able to migrate into semisolid agar (0.35%) than either H683-pC or H683-pY. Bacteria that migrated showed motility halo sizes of H683-pC2 < H683-pC < H683-pY. In the liquid culture media, H683-pC2 cells precipitated to the bottom of the tube, while those of H683-pY did not. In situ imaging revealed that H683-pC2 bacilli tended to auto-agglutinate within the semisolid agar, while H683-pY bacilli did not. When the cfaBE fimbrial fiber encoding genes were deleted from pC2, the new plasmid, pC2(-), significantly recovered bacterial swimming capability. Our study highlights the negative impact of overexpressed CFA/I fimbriae on bacterial swimming motility.
authors.affiliation: Immunology & Infectious Diseases, Montana State University, Bozeman, MT 59717-3610, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Cao
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Suo
authors.forename: Timothy
authors.initials: T
authors.lastname: Lim
authors.forename: Sangmu
authors.initials: S
authors.lastname: Jun
authors.forename: Muhammedin
authors.initials: M
authors.lastname: Deliorman
authors.forename: Carol
authors.initials: C
authors.lastname: Riccardi
authors.forename: Laura
authors.initials: L
authors.lastname: Kellerman
authors.forename: Recep
authors.initials: R
authors.lastname: Avci
authors.forename: Xinghong
authors.initials: X
authors.lastname: Yang
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D018407:Bacterial Physiological Phenomena; D004926:Escherichia coli / Q000235:genetics; D036781:Fimbriae Proteins / Q000235:genetics*; D010861:Fimbriae, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D012486:Salmonella typhimurium / Q000166:cytology / Q000235:genetics*; D015854:Up-Regulation
chemical_list: D000942:Antigens, Bacterial; C022924:colonization factor antigens; D036781:Fimbriae Proteins