title: Dynamics of fecal microbial communities in children with diarrhea of unknown etiology and genomic analysis of associated Streptococcus lutetiensis.
abstract: BACKGROUND
  The sequences of the 16S rRNA genes extracted from fecal samples provide insights into the dynamics of fecal microflora. This potentially gives valuable etiological information for patients whose conditions have been ascribed to unknown pathogens, which cannot be accomplished using routine culture methods. We studied 33 children with diarrhea who were admitted to the Children's Hospital in Shanxi Province during 2006.
  
  
  RESULTS
  Nineteen of 33 children with diarrhea could not be etiologically diagnosed by routine culture and polymerase chain reaction methods. Eleven of 19 children with diarrhea of unknown etiology had Streptococcus as the most dominant fecal bacterial genus at admission. Eight of nine children whom three consecutive fecal samples were collected had Streptococcus as the dominant fecal bacterial genus, including three in the Streptococcus bovis group and three Streptococcus sp., which was reduced during and after recovery. We isolated strains that were possibly from the S. bovis group from feces sampled at admission, which were then identified as Streptococcus lutetiensis from one child and Streptococcus gallolyticus subsp. pasteurianus from two children. We sequenced the genome of S. lutetiensis and identified five antibiotic islands, two pathogenicity islands, and five unique genomic islands. The identified virulence genes included hemolytic toxin cylZ of Streptococcus agalactiae and sortase associated with colonization of pathogenic streptococci.
  
  
  CONCLUSIONS
  We identified S. lutetiensis and S. gallolyticus subsp. pasteurianus from children with diarrhea of unknown etiology, and found pathogenic islands and virulence genes in the genome of S. lutetiensis.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Jin
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Lianqing
authors.initials: L
authors.lastname: Li
authors.forename: Shan
authors.initials: S
authors.lastname: Lu
authors.forename: Zhenjun
authors.initials: Z
authors.lastname: Li
authors.forename: Zhemin
authors.initials: Z
authors.lastname: Zhou
authors.forename: Huaiqi
authors.initials: H
authors.lastname: Jing
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Xu
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.forename: Haiyin
authors.initials: H
authors.lastname: Wang
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Xiong
authors.forename: Han
authors.initials: H
authors.lastname: Zheng
authors.forename: Xuemei
authors.initials: X
authors.lastname: Bai
authors.forename: Hui
authors.initials: H
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Changyun
authors.initials: C
authors.lastname: Ye
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
mesh_terms: D058448:Biota; D002675:Child, Preschool; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D044404:Genomic Islands; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013291:Streptococcus / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S