Three molecular typing methods, pulsed-field gel electrophoresis (PFGE), ribotyping, and
flagellin (flaA) gene typing, were used to discriminate within a group of 28 Campylobacter
jejuni, heat-stable serotype 55 (HS55) isolates derived from cases of campylobacter enteritis
occurring throughout Scotland, including 9 isolates associated with an outbreak. PFGE was
found to be most discriminatory, identifying 6 distinct profiles, followed by ribotyping (5
profiles), and then flagellin gene typing (4 profiles). The coincidence of all three genotypic
markers identified a dominant clonal line within the HS55 group, accounting for each of the
outbreak strains, and for 9 of the 19 sporadic strains. A second, closely related, clonal line
accounted for a further 5 of the sporadic strains, and also included the HS55 reference strain.
Identification and monitoring of such clonal lines should facilitate more effective future
epidemiological surveillance of C. jejuni.