What is bacterial group HACEK?
The HACEK group of bacteria (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) are a small, heterogeneous group of fastidious, gram-negative bacteria that frequently colonize the oropharynx and have long been recognised as a cause of infective endocarditis …
What does the acronym HACEK stand for?
The acronym stands for Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella: all HACEK members are fastidious Gram-negative bacteria associated with infective endocarditis.
Are HACEK culture negative?
The HACEK organisms are a group of fastidious Gram-negative bacteria that are an unusual cause of infective endocarditis, which is an inflammation of the heart due to bacterial infection.
How do you treat hacek?
Ceftriaxone or ampicillin/sulbactam is the therapy of choice for patients with HACEK endocarditis. Fluoroquinolones may be considered as alternative therapy. Regardless of the agent chosen, treatment should last 4 to 6 weeks, depending upon the type of valve involved.
What are examples of encapsulated bacteria?
Examples of encapsulated bacteria
- Haemophilus influenzae type B (Hib)
- Streptococcus pneumoniae (pneumococcus)
- Neisseria meningitides (meningococcus)
- Group B streptococcus (GBS)
- Salmonella typhi.
Can you have endocarditis with negative blood cultures?
Blood culture-negative endocarditis (BCNE), that is, endocarditis in which blood cultures using usual laboratory methods remain sterile, may account for 2.5% to 70% of all cases of endocarditis, depending on countries.
How is hacek endocarditis treated?
HACEK ORGANISMS Patients with endocarditis of a native valve caused by an organism in the HACEK group should be treated with ceftriaxone in a dosage of 2 g daily intravenously or intramuscularly for four weeks. Patients with infection of a prosthetic valve should be treated with ceftriaxone for six weeks.
Are gram positive bacteria encapsulated?
Most of Gram positive bacteria do not have so called capsules. Exo polysaccharide (EPS) or polypeptide capsules are mostly property of Gram negative bacteria even though some Gram positive bacteria may display capsules.
How long does it take to detect HACEK in blood culture?
This was attributed to slow growth in old formulations of blood culture bottles and resulted in recommendations for extended incubation (>5 days) when the presence of these organisms was suspected. However, modern blood culture instruments reliably detect HACEK organisms within a 5-day incubation period.
Can a HACEK organism grow on chocolate agar?
HACEK organisms can be isolated on routinely used non-selective media, often growing better on chocolate agar than on blood agar. They cannot be isolated from selective media designed for enterics such as MacConkey agar. Identification can be performed by automated systems but performance may be suboptimal.
Who are the HACEK group of Gram negative bacilli?
US Pharm. 2011;36(8):HS-2-HS-8. HACEK is an acronym for a group of organisms that are small, fastidious gram-negative bacilli. 1 The HACEK organisms include Haemophilus species, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae.
How long does it take for HACEK organisms to grow?
However, modern blood culture instruments reliably detect HACEK organisms within a 5-day incubation period. HACEK organisms can be isolated on routinely used non-selective media, often growing better on chocolate agar than on blood agar. They cannot be isolated from selective media designed for enterics such as MacConkey agar.
