Differential Distribution of the and Genes, Associated with Guillain-Barré Syndrome, in Isolates from Humans, Broiler Chickens, and Wild Birds.

causes campylobacteriosis, a bacterial gastroenteritis with high incidence worldwide. Moreover, infection can trigger the polyneuropathic disorder denominated Guillain-Barré syndrome (GBS). The strains that can elicit GBS carry either or coding both genes for a β-1,3-galactosyltransferase enzyme that is required for the production of sialylated lipooligosaccharide (LOS). We described a differential prevalence of the genes and in isolates from three different ecological niches: humans, broiler chickens, and wild birds. The distribution of both genes, which is similar between broiler chicken and human isolates and distinct when compared to the wild bird isolates, suggests a host-dependent distribution. Moreover, the prevalence of the and genes seems to be restricted to some clonal complexes. Gene sequencing identified the presence of new variants of the G- homopolymeric tract within the gene. Furthermore, we detected two variants of a G rich region within the gene, suggesting that, similarly to , the G-tract in the gene mediates the phase variation control of expression. Caco-2 cell invasion assays indicate that there is no evident correlation between the production of LOS and the ability to invade eukaryotic cells.