Stability of related human and chicken Campylobacter jejuni genotypes after passage through chick intestine studied by pulsed-field gel electrophoresis

The genomic stability of 12 Campylobacter jejuni strains consisting of two groups of human and chicken isolates was studied by analysis of their PFGE (pulsed-field gel electrophoresis) patterns after passage through newly hat ched chicks' intestines. The patterns of SmaI, SalI, and SacII digests rema ined stable after intestinal passage, except for those of two strains. One originally human strain, FB 6371, changed its genotype from IIIA (SmaI/SacI I) to IIB. Another strain, BTI, originally isolated from a chicken, changed its genotype from I/B to a new genotype. The genomic instability of the st rains was further confirmed by San: digestion and ribotyping of the HaeIII digests. In addition, heat-stable serotype 57 of strain FB 6371 changed to serotype 27 in all isolates with new genotypes but remained unchanged in an isolate with the original genotype. Serotype 27 of strain BTI remained sta ble. Our study suggests that during intestinal colonization, genomic rearra ngement, as demonstrated by changed PFGE and ribopatterns, may occur.