The full length of the 16S rRNA gene sequence was obtained for confirmation of identification. Pulsed-field gel electrophoresis was performed according to the protocol for Streptococcus suis[12]. The DNA was digested with 40 U SmaI (TaKaRa, Dalian, China). A dendrogram of isolates was drawn using BioNumerics

software (version 4.0, Applied Maths BVBA, Belgium). Clustering of patterns was performed using the unweighted pair group with arithmetic averaging (UPGMA). Genome sequencing and analysis of Streptococcus lutetiensis The genome of S. lutetiensis 033 isolated from Patient 033 was sequenced using a combination of selleck screening library 454 sequencings with a Roche 454 FLX and paired end sequencing BAY 11-7082 derived from the pUC18 library using an ABI 3730 Automated DNA Analyzer (Applied Biosystems, Foster City, CA, USA). The genome was predicted using Glimmer software [13]. All putative open reading frames (ORFs) were annotated using non-redundant nucleotides and proteins in the NCBI, Swissport and KEGG databases. BLASTN and Artemis Comparison Tool (ACT) were

used for the pair alignment. Orthologous gene clusters were searched for using the orthoMCL pipeline. We clustered these orthologous genes according to their presence or absence in different genome sequences among Streptococcus spp., and then a phylogenic tree was constructed using the neighbor-joining method. Genome islands were defined as having abnormal GC content with at least five continuous genes. The homologous genes within each island were compared with the references using BLASTN with an e-value cutoff at 1×10–5. Nucleotide sequence accession numbers The GenBank accession numbers reported in this study are CP003025 for

the genome sequence of S. lutetiensis strain Sodium butyrate 033; and JN581988 and JN581989 for the 16S rRNA gene sequences of S. gallolyticus subsp. pasteurianus strains 017 and 035, respectively. Ethics statement Feces samples were acquired with the written informed consent from the parents of the children with diarrhea and normal children. This study was reviewed and approved by the ethics committee of the National Institute for Communicable Disease Control and Prevention, China CDC, according to the medical research regulations of the Ministry of Health, China (permit number 2006-16-3). Results Detection of enteric pathogens in feces of children with diarrhea From August 17 to 30, 2006, fecal samples were obtained from 33 children with diarrhea admitted to the Children’s Hospital, Shanxi Province, China (Additional file 1: Table S1). Thirty-two of 33 children with diarrhea yielded negative culture for common enteric bacterial pathogens, such as Salmonella, Vibrio or diarrheagenic E. coli. Shigella sonnei was isolated from one patient (selleckchem Figure 1). The 16S rRNA gene sequences of fecal samples were also negative for Salmonella, Vibrio or Yersinia spp.