The HACEK Group of Gram-Negative Bacilli

Christina F. Burger, PharmD; Marcus W. Brown, PharmD; Jeffrey A. Kyle, PharmD, BCPS

US Pharmacist

Abstract and Introduction

Introduction

ACEK 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.^[2,3] These organisms commonly colonize the human oropharynx as normal, indigenous flora that could cause mouth infections.^[4] HACEK organisms are most often associated with infective endocarditis, accounting for up to 10% of cases.^[1,5–7] Rarely, HACEK organisms may cause severe systemic infections.^[4] This article will briefly review the HACEK pathogens, resulting infections, and common treatment approaches.

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Cite this: The HACEK Group of Gram-Negative Bacilli - Medscape - Aug 01, 2011.

Table 1. Therapy for Endocarditis Caused by HACEK Organisms
Antibiotic Regimen	Dosage^a and Route	Duration^b	Comments
Ceftriaxone sodium	2 g/24 h IV/IM × 1 dose	4 wk	May substitute cefotaxime or other 3rd- or 4th-generation cephalosporin
Ampicillin/sulbactam	12 g/24 h IV in 4 equal doses	4 wk
Ciprofloxacin	1,000 mg/24 h po or 800 mg/24 h IV in 2 equal doses Pediatric dose: ceftriaxone 100 mg/kg per 24 h IV/IM once daily; ampicillin/sulbactam 300 mg/kg per 24 h IV divided into 4 or 6 equal doses; ciprofloxacin 20-30 mg/kg per 24 h IV/po in 2 equal doses; dose not to exceed that of normal adult	4 wk	Fluoroquinolones recommended only for pts unable to tolerate ampicillin and cephalosporin; may substitute levofloxacin, gatifloxacin, moxifloxacin; fluoroquinolones generally not recommended for pts <18 y

^a Recommended for pts with normal renal function.
^b Treat pts with endocarditis involving prosthetic cardiac valves or other prosthetic cardiac material for 6 wk.
HACEK: Haemophilus parainfluenzae, Haemophilus aphrophilus, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae; IM: intramuscular; pt: patient. Source: Reference 3.

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The HACEK Group of Gram-Negative Bacilli

Abstract and Introduction

Introduction

Tables

References

Authors and Disclosures

Authors and Disclosures

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