RT Book, Section
A1 Rapini, Ronald P.
A2 Barnhill, Raymond L.
A2 Crowson, A. Neil
A2 Magro, Cynthia M.
A2 Piepkorn, Michael W.
A2 Kutzner, Heinz
A2 Desman, Garrett T.
SR Print(0)
ID 1178393772
T1 Bacterial Infections
T2 Barnhill's Dermatopathology, 4e
YR 2020
FD 2020
PB McGraw Hill Education
PP New York, NY
SN 9780071828222
LK dermatology.mhmedical.com/content.aspx?aid=1178393772
RD 2024/04/19
AB Definitive  diagnosis  of  most  bacterial  diseases  depends  on  specific  identification  of  the  pathogenic  organisms.  This  must  often  be  accomplished  by  appropriate  cultures  or  molecular  techniques  because  special  bacterial  stains  frequently  fail  to  detect  sparse  numbers  of  bacteria.  Studies  of  infectious  cellulitis  show  that  even  cultures  yield  organisms  in  less  than  10%  of  cases.  Cultures  from  actual  biopsies  have  a  higher  yield  than  cultures  originating  from  injected  saline  aspirates.  Swab  cultures  from  pustules,  ulcers,  or  crusted  lesions  are  suitable  for  only  the  most  superficial  infections,  such  as  impetigo.  An  ideal  method  for  deeper  infections  is  to  send  half  of  the  biopsy  for  culture  and  the  other  half  for  hematoxylin  and  eosin  (H&E)  and  special  stains.  Before  biopsy,  excess  antiseptic,  such  as  chlorhexidine  or  povidone-iodine,  which  may  inhibit  the  culture,  should  be  wiped  off  the  skin.  Cultures  are  best  performed  on  tissue  that  is  rushed  to  the  laboratory  before  it  desiccates.  It  should  be  minced  and  added  immediately  to  the  culture  medium.  If  there  is  a  chance  that  a  biopsy  might  dry  during  transport,  the  biopsy  should  be  placed  on  sterile  gauze  soaked  in  normal  saline  (without  preservatives  such  as  benzyl  alcohol).