title: [Construction and in vitro assay of the sortase BCD geneknock-out mutant of Streptococcus suis 2].
abstract: OBJECTIVE
  Streptococcus suis 2 is an emerging zoonotic pathogen responsible for a wide range of life-threatening diseases in pigs and humans. In this study, we investigated the functionality of one of Streptococcus suis 2 sortases, known as the srtBCD.
  
  
  METHODS
  To obtain the isogenic mutant srtBCD, the competent cells of 05ZYH33 were subjected to electrotrans formation with recombinant plasmid based on the principle of homologous recombination. The resulting mutant strains was further confirmed by a series of PCR and reverse transcription PCR. To better assess the role of srtBCD gene in the virulence of 05ZYH33, cell adherence assays and experimental infection of mice was adopted.
  
  
  RESULTS
  A SrtBCD defective mutant of 05ZYH33 was found to be associated with growth curve upon cultivation in standard laboratory used in our in vitro assays. Furthermore, abolishment of the expression of srtBCD result in impaired interactions of S. suis with human laryngeal epithelial cell line. However, there is no differences when infection mice by the WT and mutant strain.
  
  
  CONCLUSIONS
  These results suggest that srtBCD are critical for the pathogen-host interaction of S. suis 2, but abolishment of srtBCD does not impair the full virulence of 05ZYH33. It is to expect that future study carried out with S. suis 2 to verification the conclusions.
authors: Institute of Military Medical Sciences, Nanjing Command, Nanjing 210002, China. chenhaoqi@yahoo.com.cn
authors: Hongna
authors: H
authors: Chen
authors: Hui
authors: H
authors: Liao
authors: Changjun
authors: C
authors: Wang
authors: Xiuzhen
authors: X
authors: Pan
authors: Jiaqi
authors: J
authors: Tang