PFGE and PCR/RFLP typing of Campylobacter jejuni strains from poultry

1. Pulsed-field gel electrophoresis (PFGE) and PCR-restriction fragment length polymorphisms of the flagellin gene (fla-RFLP) were used to analyse 92 poultry and 110 human strains of Campylobacter jejuni. 2. Among poultry strains, 11 fla-RFLP and 11 PFGE subtypes were found, while human strains could be divided into 23 fla-RFLP and 32 PFGE subtypes. Altogether, 31 fla-RFLP and 32 PFGE subtypes were found. 3. The results show that individual flocks in farms are mostly infected with a single C. jejuni clone, while during subsequent colonisation their genotypes altered. fla-RFLP and PFGE profiles in poultry and humans were identical in less than 6% of cases. The results found so far confirm previous findings that chicken meat does not represent as important a source of campylobacteriosis as was previously believed. 4. The typing of Campylobacter sp. forms the basis for an evaluation of the current state and risk assessment of various Campylobacter sp. sources in relation to humans. Examination of samples with only one method is insufficient for epidemiology studies, because apparently different clones identified with one method could originate from a single clone, which could be proved with the other method.