The acronym "HACEK" stands for Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella and Kingella : all HACEK members are fastidious Gram-negative bacteria associated with infectious endocarditis.
The HACEK group is not based on taxonomic relationships but on the ability of these bacteria to induce endocarditis. All members of the HACEK group are commensals of the human oropharynx, but the way they move to distal sites to cause the disease is not fully established.
