title: The N3 subdomain in a domain of fibronectin-binding protein B isotype I is an independent risk determinant predictive for biofilm formation of Staphylococcus aureus clinical isolates.
abstract: Fibronectin-binding proteins (FnBP), FnBPA and FnBPB, are purported to be involved in biofilm formation of Staphylococcus aureus. This study was performed to find which of three consecutive N subdomains of the A domain in the FnBP is the key domain in FnBP. A total of 465 clinical isolates of S. aureus were examined for the biofilm forming capacity and the presence of N subdomains of FnBP. In the biofilm-positive strains, N2 and N3 subdomains of FnBPA, and N1 and N3 subdomains of FnBPB were significantly more prevalent. Multivariate logistic regression analysis of 246 biofilm-positive and 123 biofilm-negative strains identified only the FnBPB-N3 subdomain as an independent risk determinant predictive for biofilm-positive strains of S. aureus (Odds ratio [OR], 13.174; P<0.001). We also attempted to delete each of the fnbA-N2 and -N3 and fnbB-N1 and -N3 from S. aureus strain 8325-4 and examined the biofilm forming capacity in the derivative mutants. In agreement with the results of the multivariate regression analysis, deletion of either the fnbA-N2 or -N3, or fnbB-N1 did not significantly diminish the capacity of strain 8325-4 to develop a biofilm, while deletion of the fnbB-N3 did. Therefore, it is suggested that the FnBPB-N3 subdomain of isotype I may be a key domain in FnBP which is responsible for the causing biofilm formation in S. aureus clinical isolates.
authors.affiliation: Department of Microbiology, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: An Sung
authors.initials: AS
authors.lastname: Kwon
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Lim
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Shin
authors.forename: Geon
authors.initials: G
authors.lastname: Park
authors.forename: Jong H
authors.initials: JH
authors.lastname: Reu
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Jungmin
authors.initials: J
authors.lastname: Kim
authors.forename: Yong
authors.initials: Y
authors.lastname: Lim
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms; D023061:Gene Order; D006801:Humans; D054730:Protein Interaction Domains and Motifs; D020033:Protein Isoforms; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D018829:Adhesins, Bacterial; D020033:Protein Isoforms; C078635:fibronectin-binding proteins, bacterial