title: Oral bacteria and yeasts in relationship to oral ulcerations in hematopoietic stem cell transplant recipients.
abstract: BACKGROUND
  Oral mucositis is a serious and debilitating side effect of conditioning regimens for hematopoietic stem cell transplant (HSCT). Through HSCT, the homeostasis in the oral cavity is disrupted. The contribution of the oral microflora to mucositis remains to be clarified. The aim of our study was to investigate the relationship between yeasts, bacteria associated with periodontitis, and oral ulcerations in HSCT recipients.
  
  
  METHODS
  This prospective observational study included 49 adult HSCT recipients. Twice weekly, oral ulcerations were scored, and oral rinsing samples were obtained. Samples were evaluated for the total bacterial load; the Gram-negative bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra, Fusobacterium nucleatum, Tannerella forsythia, and Treponema denticola; and the yeasts: Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis using real-time polymerase chain reaction with specific primers and probes. Explanatory variables for oral ulcerations were calculated using the multilevel generalized estimated equations (GEE) technique.
  
  
  RESULTS
  None of the samples was positive for A. actinomycetemcomitans, while F. nucleatum was found most often (66 % of samples). C. albicans was the most isolated yeast (88 % of samples), whereas C. parapsilosis was found in only 8 % of the samples. Multivariate GEE analyses identified P. gingivalis, P. micra, T. denticola, F. nucleatum, C. glabrata, and C. kefyr as significant explanatory variables of oral ulcerations.
  
  
  CONCLUSIONS
  Our data indicate that P. gingivalis in particular, but also P. micra, T. denticola, F. nucleatum, C. glabrata, and C. kefyr may play a role in ulcerative oral mucositis in patients undergoing HSCT.
authors.affiliation: Department of Preventive Dentistry, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands. a.lahey@acta.nl.
authors.forename: Alexa M G A
authors.initials: AM
authors.lastname: Laheij
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: de Soet
authors.forename: Peter A
authors.initials: PA
authors.lastname: von dem Borne
authors.forename: Ed J
authors.initials: EJ
authors.lastname: Kuijper
authors.forename: Eefje A
authors.initials: EA
authors.lastname: Kraneveld
authors.forename: Cor
authors.initials: C
authors.lastname: van Loveren
authors.forename: Judith E
authors.initials: JE
authors.lastname: Raber-Durlacher
mesh_terms: D000328:Adult; D058491:Bacterial Load; D002175:Candida / Q000302:isolation & purification*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D019337:Hematologic Neoplasms / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D019226:Oral Ulcer / Q000209:etiology / Q000382:microbiology; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D013280:Stomatitis / Q000209:etiology / Q000382:microbiology; D019172:Transplantation Conditioning / Q000009:adverse effects*