title: The virulence of Streptococcus pneumoniae partially depends on dprA.
abstract: Streptococcus pneumoniae is one of the most frequent opportunistic pathogens worldwide. DNA processing protein A (DprA) is an important factor involved in bacterial uptake and DNA integration into bacterial genome, but its role in S. pneumoniae virulence remains unclear. The aim of this study was to characterize the effects of the pneumococcal dprA gene on the pathogenesis of S. pneumoniae. To construct a dprA-deficient pneumococcal strain, the dprA gene of the S. pneumoniae strain D39 was inactivated. The virulence of this dprA-deficient strain, designated ΔD39, was compared with that of the wild-type strain by evaluating their respective capabilities to adhere to human pulmonary epithelial cells (PEC-A549) and by analyzing their choline-binding protein expression levels. In addition, the expression profiles of genes associated with virulence and host survival assays were also conducted with the mutant and the wild-type strain. Our results indicate that the capability of ΔD39 to adhere to the PEC-A549 airway cells was significantly lower (p<0.01) compared with D39. Additionally, the 100-KD choline-binding protein was not detected in ΔD39. The addition of competence-stimulating peptide (CSP) lead to a significantly reduction of psaA mRNA expression in the dprA-deficient mutant and an increased level of psaA transcripts in the wild-type strain (p<0.01). The median survival time of mice intraperitoneally infected with ΔD39 was significantly higher (p<0.01) than that of mice infected with D39. The results of this study suggest that DprA has a significant effect on virulence characteristics of S. pneumoniae by influencing the expression of choline-binding protein and PsaA.
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China; General Hospital of Chinese People's Armed Police Forces, Department of Respiratory Medicine, Beijing, China.
authors.forename: De
authors.lastname: Chang
authors.affiliation: National Institute for Food and Drug Control, Institute for Medical Device Standardization Administration, Beijing, China.
authors.forename: Huiwen
authors.initials: H
authors.lastname: Xu
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Xuelin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Pan
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Chou
authors.initials: C
authors.lastname: Xu
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Guo
authors.affiliation: Chinese PLA General Hospital, Nanlou Respiratory Diseases Department, Beijing, China. Electronic address: liuchangt@foxmail.com.
authors.forename: Changting
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000382:microbiology; D055786:Gene Knockout Techniques; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D011008:Pneumococcal Infections / Q000382:microbiology / Q000473:pathology*; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000472:pathogenicity*; D016019:Survival Analysis; D037521:Virulence Factors / Q000032:analysis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C093815:DprA protein, bacteria; D008565:Membrane Proteins; C110344:SpsA protein, Streptococcus pneumoniae; D037521:Virulence Factors
keywords: DprA; Streptococcus pneumoniae; Transformation; Virulence