Fig. 1.

Unrooted neighbor-joining tree of 255 Campylobacter 16S rRNA gene sequences obtained in this study. The sequences were obtained from individual clone libraries developed from excreta collected at 15 different dates. The tree was built using MEGA 4.1 with representative California gull fecal sequences of different operation taxonomic units (97% identity for clade A and 99% identity for other clades) and sequences from bacterial reference strains. The number of sequences for each group is included within parentheses (n). Bootstrap values were obtained from 1,000 bootstrap replicates and are reported as percentages greater than 50%. The scale bar corresponds to 0.01 changes per nucleotide.