title: Combinational approach using in situ hybridization targeting 23S ribosomal RNA genes and blood cultures for bacterial identification in patients with neutropenia and fever.
abstract: BACKGROUND
  A new 23S ribosomal RNA genes-targeted in situ hybridization (ISH) probe to detect global bacterial genomic DNA (59 species from 35 genera; referred to as the GB probe) phagocytized in leukocytes was recently developed. This method provided early and direct evidence of bacterial infection with high sensitivity and specificity in spontaneous bacterial peritonitis ascites. However, the utility of this method in febrile neutropenia (FN) is unknown.
  
  
  METHODS
  We prospectively evaluated the utility of the ISH approach using the GB probe and previously reported probes in patients with neutropenia and fever undergoing chemotherapy at our institution between June 2011 and July 2013. Blood samples for culture analysis and ISH tests were collected simultaneously at the onset of fever; the latter were performed repeatedly.
  
  
  RESULTS
  Fifty febrile episodes were evaluated. In 24 episodes of fever of unknown origin and 15 episodes of local infection (all negative for blood cultures), ISH tests identified causal bacteria in 21% and 13% of cases, respectively, at the onset of fever. In seven sepsis cases (all positive for blood culture), positive ISH test results at fever onset were achieved in 71%; for two patients with neutrophil counts of 0/μl and 171/μl, respectively, negative results were obtained.
  
  
  CONCLUSIONS
  This new ISH approach could prove useful for early detection of bacteria in patients with neutropenia and blood culture-negative, with fever of unknown etiology after chemotherapy. Using this method in combination with blood culture, even in cases with extremely low neutrophil counts, might contribute to better management of FN.
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan. Electronic address: hide_koh@med.osaka-cu.ac.jp.
authors: Hideo
authors: H
authors: Koh
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Mizuki
authors: M
authors: Aimoto
authors: Research and Development Center, Fuso Pharmaceutical Industries, Ltd., Osaka, Japan.
authors: Akio
authors: A
authors: Matsuhisa
authors: Research and Development Center, Fuso Pharmaceutical Industries, Ltd., Osaka, Japan.
authors: Shin-Ichi
authors: S
authors: Inoue
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Takako
authors: T
authors: Katayama
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Hiroshi
authors: H
authors: Okamura
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Takuro
authors: T
authors: Yoshimura
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Shiro
authors: S
authors: Koh
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Satoru
authors: S
authors: Nanno
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Mitsutaka
authors: M
authors: Nishimoto
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Yasuhiro
authors: Y
authors: Nakashima
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Asao
authors: A
authors: Hirose
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Mika
authors: M
authors: Nakamae
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Takahiko
authors: T
authors: Nakane
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Masayuki
authors: M
authors: Hino
authors: Hematology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
authors: Hirohisa
authors: H
authors: Nakamae
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D000071997:Blood Culture / Q000379:methods*; D002116:Calcitonin / Q000097:blood; D064146:Chemotherapy-Induced Febrile Neutropenia / Q000150:complications*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D020459:Genes, rRNA; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis / Q000382:microbiology; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D015415:Biomarkers; C508606:CXCL8 protein, human; D004269:DNA, Bacterial; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D002116:Calcitonin
keywords: 23S ribosomal RNA genes; Bacterial identification; Blood cultures; Febrile neutropenia; In situ hybridization