title: [Influence of lysozyme-like protein on virulence and capsular polysaccharide synthesis of Streptococcus pneumoniae].
abstract: OBJECTIVE
  To study the biological character and pathogenic effect of a lysozyme-like protein in Streptococcus pneumoniae.
  
  
  METHODS
  The gene knockout mutant was constructed by the long flanking homology polymerase chain reaction. The mutant containing rescue plasmid to complement the lysozyme-like gene was also constructed. The differences in biology and pathogenicity in D39 wild strain, gene knockout mutant and gene knockout mutant containing rescue plasmid were observed to identify the functions of the lysozyme-like gene.
  
  
  RESULTS
  Compared with the wild strain, the gene knockout mutant had the characteristics of slower growth, declining virulence, and obviously reduced capsule polysaccharide synthesis. Complement experiment showed when the rescue plasmid was transformed into the mutant strain, the mRNA level of hypothetical lysozyme-like gene in the gene knockout mutant containing rescue plasmid was higher than that of the wild strain. Although the levels of virulence and capsule polysaccharide synthesis could be partly complemented compared with those of the gene knockout mutant, but not reached the levels in the wild strain.
  
  
  CONCLUSIONS
  The lysozyme-like protein, a new Streptococcus pneumoniae virulence factor, may regulate the proliferation and the capsular polysaccharides synthesis of Streptococcus pneumoniae to affect expression of virulence.
authors.affiliation: Key Laboratory of Laboratory Medical Diagnostics of Ministry of Education, University of Medical sciences, Chongqing 400016, China. zmchj2001@163.com
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Jiang
authors.forename: Meirong
authors.initials: M
authors.lastname: Huang
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Yangi
authors.forename: Mingwei
authors.initials: M
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Jianping
authors.initials: J
authors.lastname: Meng
mesh_terms: D000818:Animals; D016667:Bacterial Capsules / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009113:Muramidase / Q000235:genetics / Q000378:metabolism*; D011008:Pneumococcal Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D009113:Muramidase