title: Targeted killing of Streptococcus mutans by a pheromone-guided "smart" antimicrobial peptide.
abstract: Within the repertoire of antibiotics available to a prescribing clinician, the majority affect a broad range of microorganisms, including the normal flora. The ecological disruption resulting from antibiotic treatment frequently results in secondary infections or other negative clinical consequences. To address this problem, our laboratory has recently developed a new class of pathogen-selective molecules, called specifically (or selectively) targeted antimicrobial peptides (STAMPs), based on the fusion of a species-specific targeting peptide domain with a wide-spectrum antimicrobial peptide domain. In the current study, we focused on achieving targeted killing of Streptococcus mutans, a cavity-causing bacterium that resides in a multispecies microbial community (dental plaque). In particular, we explored the possibility of utilizing a pheromone produced by S. mutans, namely, the competence stimulating peptide (CSP), as a STAMP targeting domain to mediate S. mutans-specific delivery of an antimicrobial peptide domain. We discovered that STAMPs constructed with peptides derived from CSP were potent against S. mutans grown in liquid or biofilm states but did not affect other oral streptococci tested. Further studies showed that an 8-amino-acid region within the CSP sequence is sufficient for targeted delivery of the antimicrobial peptide domain to S. mutans. The STAMPs presented here are capable of eliminating S. mutans from multispecies biofilms without affecting closely related noncariogenic oral streptococci, indicating the potential of these molecules to be developed into "probiotic" antibiotics which could selectively eliminate pathogens while preserving the protective benefits of a healthy normal flora.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics,1 School of Dentistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Randal
authors.initials: R
authors.lastname: Eckert
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Yarbrough
authors.forename: Fengxia
authors.initials: F
authors.lastname: Qi
authors.forename: Maxwell H
authors.initials: MH
authors.lastname: Anderson
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D003731:Dental Caries / Q000382:microbiology; D005456:Fluorescent Dyes; D006801:Humans; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008856:Microscopy, Fluorescence; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D010675:Pheromones / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology; D013045:Species Specificity; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D010455:Peptides; D010675:Pheromones