title: Identification of PblB mediating galactose-specific adhesion in a successful Streptococcus pneumoniae clone.
abstract: The pneumococcal genome is variable and there are minimal data on the influence of the accessory genome on phenotype. Pneumococcal serotype 14 sequence type (ST) 46 had been the most prevalent clone causing pneumonia in children in Taiwan. A microarray was constructed using the genomic DNA of a clinical strain (NTUH-P15) of serotype 14 ST46. Using DNA hybridization, genomic variations in NTUH-P15 were compared to those of 3 control strains. Microarray analysis identified 7 genomic regions that had significant increases in hybridization signals in the NTUH-P15 strain compared to control strains. One of these regions encoded PblB, a phage-encoded virulence factor implicated (in Streptococcus mitis) in infective endocarditis. The isogenic pblB mutant decreased adherence to A549 human lung epithelial cell compared to wild-type NTUH-P15 strain (P = 0.01). Complementation with pblB restored the adherence. PblB is predicted to contain a galactose-binding domain-like region. Preincubation of NTUH-P15 with D-galactose resulted in decreases of adherence to A549 cell in a dose-dependent manner. Challenge of mice with NTUH-P15, isogenic pblB mutant and pblB complementation strains determined that PblB was required for bacterial persistence in the nasopharynx and lung. PblB, as an adhesin mediating the galactose-specific adhesion activity of pneumococci, promote pneumococcal clonal success.
authors.affiliation: Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Yu-Chia
authors.initials: YC
authors.lastname: Hsieh
authors.affiliation: Departments of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Tzu-Lung
authors.initials: TL
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Che-Ming
authors.initials: CM
authors.lastname: Lin
authors.affiliation: 1] Departments of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan [2] Departments of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Jin-Town
authors.initials: JT
authors.lastname: Wang
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001792:Blood Platelets / Q000382:microbiology; D002460:Cell Line; D002648:Child; D002999:Clone Cells; D003124:Colorimetry; D005260:Female; D005690:Galactose / Q000378:metabolism*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006001:Glycoconjugates / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000382:microbiology; D008807:Mice, Inbred BALB C; D009154:Mutation / Q000235:genetics; D009305:Nasopharynx / Q000382:microbiology; D020411:Oligonucleotide Array Sequence Analysis; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D006001:Glycoconjugates; D005690:Galactose