| The sequences of the16S rRNA genes extracted from fecal samples provide insights into the dynamics of fecal microbial flora. This potentially gives valuable etiological information for patients whose conditions have been ascribed to unknown pathogens. This cannot be accomplished using routine culture methods. We studied33diarrheal patients hospitalized at Children’s Hospital in Shanxi Province during2006using this strategy. Out of33patients,11were diagnosed as infected with diarrheagenic Escherichia coli or Shigella. The conditions of22patients were ascribed to an unknown etiology. Ten of these patients provided three consecutive feces specimens for analysis:one at admission, one during recovery and one after recovery. E. coli and Klebsiella sp. were the dominant bacterial species at admission in two patients; Streptococcus salivarius in two patients; and Streptococcus sp. and the Streptococcus bovis group in three patients, respectively. For eight of the ten patients analyzed in depth, the fecal flora ratio of the dominant bacterial species at admission was reduced during and after recovery.According the clue of16S rRNA gene analysis, we tried to islolate the dominated species in the diarrhea children. In the dominant S. bovis group species from the16S rRNA gene analysis, we found three patients; one with Streptococcus lutetiensis and two with Streptococcus gallolyticus subsp. pasteurianus. The genome of the S. lutetiensis strain revealed a total of20genomic islands, including2putative pathogenicity islands18and7. They were found to encode an adhesion associated pilus and glycosyl transferase, respectively. We report here for the first time S. lutetiensis as the dominant strain in children with diarrhea of unknown etiology and we analyzed its genome. We isolated the Streptococcus bovis group strains from diarrhea patients and animal reservoir and used the molecular epidemiological technology to analyze those strains. |
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