title: Bacteraemia due to Streptococcus gallolyticus subspecies pasteurianus is associated with digestive tract malignancies and resistance to macrolides and clindamycin.
abstract: OBJECTIVE
  This study was intended to delineate the association between digestive tract malignancies and bacteraemia due to Streptococcus gallolyticus subspecies pasteurianus.
  
  
  METHODS
  We reviewed the medical records and microbiological results of patients with bacteraemia due to Streptococcus bovis during the period 2000-2012. Species and subspecies identification of isolates originally classified as S. bovis was confirmed by 16S rRNA sequencing and PCR restriction fragment length polymorphism (PCR-RFLP) assays. Minimum inhibitory concentrations of antimicrobial agents were determined by the broth microdilution method.
  
  
  RESULTS
  Of the 172 S. bovis complex isolates obtained from 172 patients (age range, <1-94 years, median age, 66) with bacteraemia, 31 isolates were identified to be S. gallolyticus subspecies gallolyticus, 126 were S. gallolyticus subspecies pasteurianus, and 15 were shown to be Streptococcus infantarius. The majority (n = 104, 60%) of patients were male and had underlying malignancies (n = 87, 51%). Bacteraemia due to S. gallolyticus subspecies gallolyticus was significantly associated with endocarditis while S. gallolyticus subspecies pasteurianus was more likely to be associated with malignancies of the digestive tract, including gastric, pancreatic, hepatobiliary and colorectal cancers. Septic shock at presentation was the only factor associated with mortality among patients with bacteraemia due to either subspecies of S. bovis. Isolates of S. gallolyticus subspecies pasteurianus had higher rates of resistance to macrolides and clindamycin than isolates of S. gallolyticus subspecies gallolyticus.
  
  
  CONCLUSIONS
  Extensive diagnostic work-up for digestive tract malignancies and trans-esophageal echocardiogram should be investigated in patients with bacteraemia caused by S. gallolyticus.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wang-Huei
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Chuang
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Lee-Jene
authors.initials: LJ
authors.lastname: Teng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: hsporen@ntu.edu.tw.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000150:complications / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D002981:Clindamycin / Q000627:therapeutic use; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology / Q000473:pathology*; D006801:Humans; D007223:Infant; D016015:Logistic Models; D018942:Macrolides / Q000627:therapeutic use; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D010406:Penicillins / Q000627:therapeutic use; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012189:Retrospective Studies; D013291:Streptococcus / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D010406:Penicillins; D012336:RNA, Ribosomal, 16S; D002981:Clindamycin
keywords: Bacteraemia; Digestive tract malignancies; Endocarditis; Macrolide and clindamycin resistance; Streptococcus bovis; Streptococcus gallolyticus; Streptococcus infantarius