Question

To weave a common theme this week between this post and Wednesday’s eponym:

1. What are the HACEK bugs?
2. What disease are they associate with?
3. Why are they important?

Answer

The HACEK pathogens is an acronym for the fastidious, gram-negative bacteria that are implicated in 5-10% of infective endocarditis cases. The bugs are:

• Haemophilus species
• Aggregatibacter species
• Cardiobacterium species
• Eikenella species
• Kingella species

These pathogens are normal oropharyngeal flora, but can take up to 14 days to grow in the laboratory and are often referred to as
culture-negative” endocarditis cases.  It is important to discuss with your lab if you are worried about HACEK pathogens so they can plate the blood cultures on the appropriate agar plates and keep past the typical 3-5 days if there is no growth.

References

1. Sharara SL, Tayyar R, Kanafani ZA, Kanj SS. HACEK endocarditis: a review. Expert review of anti-infective therapy. 2016; 14(6):539-45. [pubmed]
2. Chambers ST, Murdoch D, Morris A, et al. HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort. PloS one. 2013; 8(5):e63181. [pubmed]
3. Yew HS, Chambers ST, Roberts SA, et al. Association between HACEK bacteraemia and endocarditis. Journal of medical microbiology. 2014; 63(Pt 6):892-5. [pubmed]
4. Wassef N, Rizkalla E, Shaukat N, Sluka M. HACEK-induced endocarditis. BMJ case reports. 2013; 2013:. [pubmed]