A HACEK organism is one of a set of slow-growing Gram negative bacteria that form a normal part of the human flora. Gram-negative bacteria are those Bacteria that do not retain Crystal violet dye in the Gram staining protocol The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have The human flora is the Microrganisms that constantly inhabit the Human body. They are a frequent cause of endocarditis in children. Endocarditis is an Inflammation of the inner layer of the Heart, the Endocardium. Pediatrics (also spelled paediatrics) is the branch of Medicine that deals with the medical care of Infants Children and Adolescents
The name is formed from their initials:
- Haemophilus aphrophilus, Haemophilus parainfluenzae and Haemophilus paraphrophilus
- Actinobacillus actinomycetemcomitans
- Cardiobacterium hominis
- Eikenella corrodens
- Kingella kingae
All of these organisms are part of the normal oropharyngeal flora which grow slowly, prefer a carbon dioxide–enriched atmosphere and share an enhanced capacity to produce endocardial infections, especially in young children. Actinobacillus is a genus of gram-negative immotile and nonspore-forming oval to rod-shaped bacteria occurring as parasites or pathogens in mammals birds and reptiles Eikenella corrodens is a fastidious Gram-negative facultative anaerobic bacillus Collectivelly, they account for 5-10% of cases of infective endocarditis involving native valves and are the most common gram-negative cause of endocarditis among people who do not use IV drugs. Because of their fastidious growth requirements, they have been a frequent cause of culture-negative endocarditis. Culture negative refers to its inability to produce a colony on regular agar plates, this is because they are fastidious (require a specific nutrient).
In addition to valvular infections in the heart, they can also produce other infections such as bacteremia, abscess, peritonitis, otitis media, conjunctivitis, pneumonia, arthritis and osteomyelitis, and periodontal infections.
The treatment of choice for HACEK organisms in endocarditis is ceftriaxone, a cephalosporin antibiotic. Ceftriaxone ( INN) (ˌsɛftraɪˈæksoʊn/ /ˌkɛf- is a third-generation Cephalosporin Antibiotic. The cephalosporins (ˌsɛfələˈspɔrən/ /ˌkɛfə- are a class of β-lactam antibiotics.