Premium
A phase‐variable capsule is involved in virulence of Campylobacter jejuni 81‐176
Author(s) -
Bacon David J.,
Szymanski Christine M.,
Burr Don H.,
Silver Richard P.,
Alm Richard A.,
Guerry Patricia
Publication year - 2001
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2001.02431.x
Subject(s) - biology , campylobacter jejuni , glycan , mutant , virulence , polysialic acid , phase variation , escherichia coli , microbiology and biotechnology , biochemistry , gene , bacteria , cell , genetics , glycoprotein , cell adhesion , neural cell adhesion molecule
Campylobacter jejuni strain 81‐176 (HS36, 23) synthesizes two distinct glycan structures, as visualized by immunoblotting of proteinase K‐digested whole‐cell preparations. A site‐specific insertional mutant in the kpsM gene results in loss of expression of a high‐molecular‐weight (HMW) glycan (apparent M r 26 kDa to > 85 kDa) and increased resolution of a second ladder‐like glycan (apparent M r 26–50 kDa). The kpsM mutant of 81‐176 is no longer typeable in either HS23 or HS36 antisera, indicating that the HMW glycan structure is the serodeterminant of HS23 and HS36. Both the kpsM ‐dependent HMW glycan and the kpsM ‐independent ladder‐like structure appear to be capsular in nature, as both are attached to phospholipid rather than lipid A. Additionally, the 81‐176 kpsM gene can complement a deletion in Escherichia coli kpsM , allowing the expression of an α2,8 polysialic acid capsule in E. coli . Loss of the HMW glycan in 81‐176 kpsM also increases the surface hydrophobicity and serum sensitivity of the bacterium. The kpsM mutant is also significantly reduced in invasion of INT407 cells and reduced in virulence in a ferret diarrhoeal disease model. The expression of the kpsM ‐dependent capsule undergoes phase variation at a high frequency.