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Organisms: Monkbot/task 21: Replace page(s) with article-number;

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	==Organisms==		==Organisms==
	HACEK originally referred to ''[[Haemophilus parainfluenzae]]'', ''[[Haemophilus aphrophilus]]'', ''[[Actinobacillus actinomycetemcomitans]]'', ''[[Cardiobacterium hominis]]'', ''[[Eikenella corrodens]]'', and ''[[Kingella kingae]]''. However, taxonomic rearrangements have changed the A to ''[[Aggregatibacter]]'' species and the '''H''' to ''[[Haemophilus]]'' species to reflect the recategorization and novel identification of many of the species in these [[genera]].<ref name="Reclassification of HACEK organisms" /> Some reviews of medical literature on HACEK organisms use the older classification,<ref>{{cite journal\|last1=Raza\|first1=SS\|last2=Sultan\|first2=OW\|last3=Sohail\|first3=MR\|title=Gram-negative bacterial endocarditis in adults: state-of-the-heart.\|journal=Expert Review of Anti-infective Therapy\|date=Aug 2010\|volume=8\|issue=8\|pages=879–85\|pmid=20695743\|doi=10.1586/eri.10.76\|s2cid=48457}}</ref> but recent papers are using the new classification.<ref>{{cite journal\|last1=Chambers\|first1=ST\|last2=Murdoch\|first2=D\|last3=Morris\|first3=A\|last4=Holland\|first4=D\|last5=Pappas\|first5=P\|last6=Almela\|first6=M\|last7=Fernández-Hidalgo\|first7=N\|last8=Almirante\|first8=B\|last9=Bouza\|first9=E\|last10=Forno\|first10=D\|last11=del Rio\|first11=A\|last12=Hannan\|first12=MM\|last13=Harkness\|first13=J\|last14=Kanafani\|first14=ZA\|last15=Lalani\|first15=T\|last16=Lang\|first16=S\|last17=Raymond\|first17=N\|last18=Read\|first18=K\|last19=Vinogradova\|first19=T\|last20=Woods\|first20=CW\|last21=Wray\|first21=D\|last22=Corey\|first22=GR\|last23=Chu\|first23=VH\|last24=International Collaboration on Endocarditis Prospective Cohort Study\|first24=Investigators\|title=HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort.\|journal=PLOS ONE\|date=2013\|volume=8\|issue=5\|~~pages~~=e63181\|pmid=23690995\|doi=10.1371/journal.pone.0063181\|pmc=3656887\|bibcode=2013PLoSO...863181C\|doi-access=free}}</ref><ref name="primary source on HACEK endocarditis"/><ref name="pmid 23682079"/>		HACEK originally referred to ''[[Haemophilus parainfluenzae]]'', ''[[Haemophilus aphrophilus]]'', ''[[Actinobacillus actinomycetemcomitans]]'', ''[[Cardiobacterium hominis]]'', ''[[Eikenella corrodens]]'', and ''[[Kingella kingae]]''. However, taxonomic rearrangements have changed the A to ''[[Aggregatibacter]]'' species and the '''H''' to ''[[Haemophilus]]'' species to reflect the recategorization and novel identification of many of the species in these [[genera]].<ref name="Reclassification of HACEK organisms" /> Some reviews of medical literature on HACEK organisms use the older classification,<ref>{{cite journal\|last1=Raza\|first1=SS\|last2=Sultan\|first2=OW\|last3=Sohail\|first3=MR\|title=Gram-negative bacterial endocarditis in adults: state-of-the-heart.\|journal=Expert Review of Anti-infective Therapy\|date=Aug 2010\|volume=8\|issue=8\|pages=879–85\|pmid=20695743\|doi=10.1586/eri.10.76\|s2cid=48457}}</ref> but recent papers are using the new classification.<ref>{{cite journal\|last1=Chambers\|first1=ST\|last2=Murdoch\|first2=D\|last3=Morris\|first3=A\|last4=Holland\|first4=D\|last5=Pappas\|first5=P\|last6=Almela\|first6=M\|last7=Fernández-Hidalgo\|first7=N\|last8=Almirante\|first8=B\|last9=Bouza\|first9=E\|last10=Forno\|first10=D\|last11=del Rio\|first11=A\|last12=Hannan\|first12=MM\|last13=Harkness\|first13=J\|last14=Kanafani\|first14=ZA\|last15=Lalani\|first15=T\|last16=Lang\|first16=S\|last17=Raymond\|first17=N\|last18=Read\|first18=K\|last19=Vinogradova\|first19=T\|last20=Woods\|first20=CW\|last21=Wray\|first21=D\|last22=Corey\|first22=GR\|last23=Chu\|first23=VH\|last24=International Collaboration on Endocarditis Prospective Cohort Study\|first24=Investigators\|title=HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort.\|journal=PLOS ONE\|date=2013\|volume=8\|issue=5\|article-number=e63181\|pmid=23690995\|doi=10.1371/journal.pone.0063181\|pmc=3656887\|bibcode=2013PLoSO...863181C\|doi-access=free}}</ref><ref name="primary source on HACEK endocarditis"/><ref name="pmid 23682079"/>

	A list of HACEK organisms:		A list of HACEK organisms:

2601:86:4380:8FC0:A52A:13F6:3A04:946F at 13:46, 7 May 2025

2025-05-07T13:46:44Z

New page

{{short description|Group of bacteria}}
{{redirect|HACEK|the diacritical mark known as háček|Caron}}
The '''HACEK organisms''' are a group of [[fastidious organism|fastidious]] [[Gram-negative]] [[bacteria]] that are an unusual cause of [[infective endocarditis]], which is an inflammation of the heart due to bacterial infection.<ref name="Reclassification of HACEK organisms">{{cite journal|last1=Nørskov-Lauritsen|first1=N|title=Classification, identification, and clinical significance of haemophilus and aggregatibacter species with host specificity for humans|journal=Clinical Microbiology Reviews|date=Apr 2014|volume=27|issue=2|pages=214–40|pmid=24696434|pmc=3993099|doi=10.1128/CMR.00103-13}}</ref> HACEK is an abbreviation of the initials of the [[genera]] of this group of bacteria: ''[[Haemophilus]]'', ''[[Aggregatibacter]]'' (previously ''[[Actinobacillus]]''), ''[[Cardiobacterium]]'', ''[[Eikenella]]'', ''[[Kingella]]''.<ref name="Reclassification of HACEK organisms" /> The HACEK organisms are a normal part of the [[human microbiota]], living in the [[Mouth|oral]]-[[pharynx|pharyngeal]] region.<ref name="HACEK in kids">{{cite journal|last1=Feder HM|first1=Jr|last2=Roberts|first2=JC|last3=Salazar|first3=J|last4=Leopold|first4=HB|last5=Toro-Salazar|first5=O|title=HACEK endocarditis in infants and children: two cases and a literature review.|journal=The Pediatric Infectious Disease Journal|date=Jun 2003|volume=22|issue=6|pages=557–62|pmid=12799515|doi=10.1097/01.inf.0000069795.12338.cf|s2cid=3238233}}</ref>

The bacteria were originally grouped because they were thought to be a significant cause of infective endocarditis, but recent research has shown that they are rare and only responsible for 1.4–3.0% of all cases of this disease.<ref name="Reclassification of HACEK organisms" />

==Organisms==
HACEK originally referred to ''[[Haemophilus parainfluenzae]]'', ''[[Haemophilus aphrophilus]]'', ''[[Actinobacillus actinomycetemcomitans]]'', ''[[Cardiobacterium hominis]]'', ''[[Eikenella corrodens]]'', and ''[[Kingella kingae]]''. However, taxonomic rearrangements have changed the A to ''[[Aggregatibacter]]'' species and the '''H''' to ''[[Haemophilus]]'' species to reflect the recategorization and novel identification of many of the species in these [[genera]].<ref name="Reclassification of HACEK organisms" /> Some reviews of medical literature on HACEK organisms use the older classification,<ref>{{cite journal|last1=Raza|first1=SS|last2=Sultan|first2=OW|last3=Sohail|first3=MR|title=Gram-negative bacterial endocarditis in adults: state-of-the-heart.|journal=Expert Review of Anti-infective Therapy|date=Aug 2010|volume=8|issue=8|pages=879–85|pmid=20695743|doi=10.1586/eri.10.76|s2cid=48457}}</ref> but recent papers are using the new classification.<ref>{{cite journal|last1=Chambers|first1=ST|last2=Murdoch|first2=D|last3=Morris|first3=A|last4=Holland|first4=D|last5=Pappas|first5=P|last6=Almela|first6=M|last7=Fernández-Hidalgo|first7=N|last8=Almirante|first8=B|last9=Bouza|first9=E|last10=Forno|first10=D|last11=del Rio|first11=A|last12=Hannan|first12=MM|last13=Harkness|first13=J|last14=Kanafani|first14=ZA|last15=Lalani|first15=T|last16=Lang|first16=S|last17=Raymond|first17=N|last18=Read|first18=K|last19=Vinogradova|first19=T|last20=Woods|first20=CW|last21=Wray|first21=D|last22=Corey|first22=GR|last23=Chu|first23=VH|last24=International Collaboration on Endocarditis Prospective Cohort Study|first24=Investigators|title=HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort.|journal=PLOS ONE|date=2013|volume=8|issue=5|pages=e63181|pmid=23690995|doi=10.1371/journal.pone.0063181|pmc=3656887|bibcode=2013PLoSO...863181C|doi-access=free}}</ref><ref name="primary source on HACEK endocarditis"/><ref name="pmid 23682079"/>

A list of HACEK organisms:
*''[[Haemophilus]] ''species
**''[[Haemophilus haemolyticus]]''<ref name="pmid 23682079">{{cite journal|last1=Wassef|first1=N|last2=Rizkalla|first2=E|last3=Shaukat|first3=N|last4=Sluka|first4=M|title=HACEK-induced endocarditis|journal=BMJ Case Reports|date=May 15, 2013|volume=2013|pages=bcr2012007359|pmid=23682079|doi=10.1136/bcr-2012-007359|pmc=3670033}}</ref>
**''[[Haemophilus influenzae]]'': The incidence of endocarditis due to ''H. influenzae'' declined after the introduction of the [[Hib vaccine]].<ref name="Reclassification of HACEK organisms" />
**''[[Haemophilus parahaemolyticus]]''<ref name="pmid 23682079" />
**''[[Haemophilus parainfluenzae]]''<ref name="primary source on HACEK endocarditis"/>

*''[[Aggregatibacter]]''
**''[[Aggregatibacter actinomycetemcomitans]]'' (previously ''[[Actinobacillus actinomycetemcomitans]]'')
**''[[Aggregatibacter aphrophilus]]'' (previously ''[[Haemophilus aphrophilus]]'')
**''[[Aggregatibacter paraphrophilus]]'' (previously ''[[Haemophilus aphrophilus]]'')
**''[[Haemophilus segnis|Aggregatibacter segnis]]''

*''[[Cardiobacterium]]''
**''[[Cardiobacterium hominis]]'': This is the most common species in the genus ''Cardiobacterium''.
**''[[Cardiobacterium valvarum]]''

*''[[Eikenella]]''
**''[[Eikenella corrodens]]''<ref name="primary source on HACEK endocarditis">{{cite journal|last1=Sen Yew|first1=H|last2=Chambers|first2=ST|last3=Roberts|first3=SA|last4=Holland|first4=DJ|last5=Julian|first5=KA|last6=Raymond|first6=NJ|last7=Beardsley|first7=J|last8=Read|first8=KM|last9=Murdoch|first9=DR|title=Association between HACEK bacteraemia and endocarditis|journal=Journal of Medical Microbiology|date=Jun 2014|volume=63|issue=Pt 6|pages=892–5|pmid=24681996|doi=10.1099/jmm.0.070060-0|s2cid=206195338|doi-access=free}}</ref>

*''[[Kingella]]''
**''[[Kingella denitrificans]]''<ref name="primary source on HACEK endocarditis" />
**''[[Kingella kingae]]'': This is the most common species in the genus ''Kingella''.

==Presentation==
All of these organisms are part of the normal oropharyngeal flora, which grow slowly (up to 14 days), prefer a carbon dioxide–enriched atmosphere, and share an enhanced capacity to produce endocardial infections, especially in young children. Collectively, 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 drugs intravenously. They have been a frequent cause of culture-negative endocarditis. Culture-negative refers to an inability to produce a colony on regular agar plates because these bacteria 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]], [[osteomyelitis]], and [[Periodontitis|periodontal infections]].

==Treatment==
The treatment of choice for HACEK organisms in endocarditis is the third-generation [[cephalosporin]] and [[β-Lactam]] antibiotic [[ceftriaxone]]. [[Ampicillin]] (a [[penicillin]]), combined with low-dose [[gentamicin]] (an [[aminoglycoside]]) is another therapeutic option.<ref>[http://emedicine.medscape.com/article/218158-treatment], eMedicine, HACEK organism infection. June 2005.</ref>

==References==
{{reflist|2}}

{{Gram-negative proteobacterial diseases}}
{{Heart diseases}}

{{DEFAULTSORT:Hacek Endocarditis}}
[[Category:Bacteria]]
[[Category:Pathogenic bacteria]]

HACEK organisms - Revision history

imported>Monkbot: /* Organisms */ Monkbot/task 21: Replace page(s) with article-number;

2601:86:4380:8FC0:A52A:13F6:3A04:946F at 13:46, 7 May 2025