RT Book, Section
A1 Barlam, Tamar F.
A1 Kasper, Dennis L.
A2 Jameson, J. Larry
A2 Fauci, Anthony S.
A2 Kasper, Dennis L.
A2 Hauser, Stephen L.
A2 Longo, Dan L.
A2 Loscalzo, Joseph
SR Print(0)
ID 1159154182
T1 Infections Due to the HACEK Group and Miscellaneous Gram-Negative Bacteria
T2 Harrison's Principles of Internal Medicine, 20e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259644016
LK accessmedicine.mhmedical.com/content.aspx?aid=1159154182
RD 2024/04/20
AB HACEK  organisms  are  a  group  of  fastidious,  slow-growing,  gram-negative  bacteria  whose  growth  requires  an  atmosphere  of  carbon  dioxide.  These  organisms  do  not  grow  on  media  routinely  used  for  enteric  bacteria  (e.g.,  MacConkey  agar).  Species  belonging  to  this  group  include  several  Haemophilus  species,  Aggregatibacter  (formerly  Actinobacillus)  species,  Cardiobacterium  species,  Eikenella  corrodens,  and  Kingella  kingae.  HACEK  bacteria  normally  reside  in  the  oral  cavity  and  have  been  associated  with  local  infections  in  the  mouth.  They  are  also  known  to  cause  severe  systemic  infections—most  often  bacterial  endocarditis,  which  can  develop  on  either  native  or  prosthetic  valves  (Chap.  123).  HACEK  bacteremia  is  strongly  predictive  of  underlying  infective  endocarditis  (overall  positive  predictive  value,  60%).  However,  this  association  varies  significantly  by  organism.  For  example,  in  one  study,  infective  endocarditis  was  diagnosed  in  100%  of  patients  with  Aggregatibacter  actinomycetemcomitans  bacteremia  but  in  no  patients  with  Eikenella  bacteremia.