Genome sequence of the hyperinvasive Campylobacter jejuni strains

Campylobacter jejuni is the world’s major cause of gastroenteritis in humans. Although motility, toxin production, adhesion and invasion are some of the key factors associated with C. jejuni pathogenesis, their mechanism in the disease process remains unclear. The key aim of this project is to study the genetic basis of hyperinvasiveness in a group of six C. jejuni strains which have been reported as hyperinvasive into human intestinal cell lines. Here, genomotyping of the hyperinvasive C. jejuni was performed by comparative genomic hybridization (CGH) against four low invasive C. jejuni strains. A group of 67 genes were identified as being present or highly divergent/absent in the hyperinvasive versus low invasive C. jejuni strains. Of these, nine genes were present and six genes were highly divergent/absent in all hyperinvasive C. jejuni. The PCR screening of these 15 genes in nine additional low invasive C. jejuni strains showed a significant association with the hyperinvasive phenotype. The majority of identified genes encoded proteins with essential cellular and metabolic functions along with some genes with known virulence related roles. Thus, the hyperinvasive phenotype is characterised by different functional networks rather than a single gene or gene cluster. All strains showed an overall genetic variability and the capsule, lipooligosaccharide, flagellar biosynthesis and restriction modification regions were the most diverse. The hierarchical clustering based on comparative genomic hybridization (CGH) did not group together the hyperinvasive C. jejuni as a single group and these strains possessed different MLST profiles.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Nottingham Trent University

Year dc:date.issued

2012

Author dc:creator

• Baig, A

Language dc:language

en