title: Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization.
abstract: Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.
authors.affiliation: Department of Bacteriology, The Jikei University School of Medicine, Tokyo, 105-8461 Japan. iwase.tadayuki@jikei.ac.jp
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Iwase
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Uehara
authors.forename: Hitomi
authors.initials: H
authors.lastname: Shinji
authors.forename: Akiko
authors.initials: A
authors.lastname: Tajima
authors.forename: Hiromi
authors.initials: H
authors.lastname: Seo
authors.forename: Koji
authors.initials: K
authors.lastname: Takada
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Agata
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Mizunoe
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D018441:Biofilms / Q000254:growth & development*; D005260:Female; D006801:Humans; D008297:Male; D009666:Nose / Q000382:microbiology*; D016017:Odds Ratio; D057057:Serine Proteases / Q000737:chemistry / Q000172:deficiency / Q000302:isolation & purification / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control / Q000628:therapy; D013211:Staphylococcus aureus / Q000254:growth & development* / Q000276:immunology; D013212:Staphylococcus epidermidis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D015163:Superinfection / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000628:therapy; D055815:Young Adult; D023083:beta-Defensins / Q000276:immunology / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; C106641:DEFB4A protein, human; D023083:beta-Defensins; D057057:Serine Proteases