Lineage: Bacteria[3914]; Proteobacteria[1644]; Epsilonproteobacteria[69]; Campylobacterales[63]; Campylobacteraceae[38]; Campylobacter[22]; Campylobacter jejuni[1]Campylobacter jejuni. This organism is the leading cause of bacterial food poisoning (campylobacteriosis) in the world, and is more prevalent than Salmonella enteritis (salmonellosis). Severe health and economic problems are a result of widespread infections that affect up to 1% of the population. Found throughout nature, it can colonize the intestines of both mammals and birds, and transmission to humans occurs via contaminated food products. This organism can invade the epithelial layer by first attaching to epithelial cells, then penetrating through them. Diarrhea results from damage to the epithelial cells. Systemic infections can also occur causing more severe illnesses. [Source: NCBI Genome ]