title: Detachment and killing of Aggregatibacter actinomycetemcomitans biofilms by dispersin B and SDS.
abstract: The periodontopathogen Aggregatibacter actinomycetemcomitans forms tenacious biofilms on abiotic surfaces in vitro. The objective of the present study was to measure the susceptibility of A. actinomycetemcomitans biofilms to detachment and killing by the anionic surfactant sodium dodecyl sulfate (SDS). We found that biofilms formed by a wild-type strain were resistant to detachment by SDS. In contrast, biofilms formed by an isogenic mutant strain that was deficient in the production of PGA (poly-N-acetyl-glucosamine), a biofilm matrix polysaccharide, were sensitive to detachment by SDS. Pre-treatment of wild-type biofilms with dispersin B, a PGA-degrading enzyme, rendered them sensitive to detachment by SDS and resulted in a > 99% increase in SDS-mediated cell killing. We concluded that PGA protects A. actinomycetemcomitans cells from detachment and killing by SDS. Dispersin B and SDS may be useful agents for treating chronic infections caused by A. actinomycetemcomitans and other PGA-producing bacteria.
authors.affiliation: Department of Oral Biology, New Jersey Dental School, Medical Science Building, Newark, NJ 07103, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Izano
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Ragunath
authors.forename: N
authors.initials: N
authors.lastname: Ramasubbu
authors.forename: J B
authors.initials: JB
authors.lastname: Kaplan
mesh_terms: D000117:Acetylglucosamine / Q000502:physiology*; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects* / Q000378:metabolism; D001422:Bacterial Adhesion / Q000187:drug effects; D001426:Bacterial Proteins / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D015169:Colony Count, Microbial; D006026:Glycoside Hydrolases / Q000494:pharmacology*; D008823:Micelles; D008826:Microbial Sensitivity Tests; D011994:Recombinant Proteins / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology*; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D008823:Micelles; D011994:Recombinant Proteins; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D006026:Glycoside Hydrolases; C501330:dispersin B, Actinobacillus actinomycetemcomitans; D000117:Acetylglucosamine