Comparative fingerprinting analysis of Campylobacter jejuni subsp jejuni strains by amplified-fragment length polymorphism genotyping

Amplified-fragment length polymorphism (AFLP) analysis with the endonucleas es BglII and MfeI was used to genotype 91 Campylobacter jejuni subsp. jejun i strains from outbreaks and sporadic cases. AFLP-generated fragments were labeled with fluorescent dye and separated by capillary electrophoresis. Th e software packages GeneScan and GelCompar II were used to calculate AFLP p attern similarities and to investigate phylogenetic relationships among the genotyped strains. The AFLP method was compared with two additional DNA-ba sed typing methods, pulsed-field gel electrophoresis (PFGE) using SmaI and restriction fragment Length polymorphism analysis on PCR products (PCR-RFLP ) of the flaA and flaB genes. We found that AFLP analysis of C. jejuni stra ins is a rapid method that offers better discriminatory power than do both PFGE and PCR-RFLP. AFLP and, to a lesser extent, PCR-RFLP could differentia te strains within the same PFGE profiles, which also makes PCR-RFLP an alte rnative to PFGE. We were able to clearly distinguish 9 of 10 recognized out breaks by AFLP and to identify similarities among outbreak and sporadic str ains. Therefore, AFLP is suitable for epidemiological surveillance of C. je juni and will be an excellent tool for source identification in outbreak si tuations.