title: Evaluation and insights into chitosan antimicrobial activity against anaerobic oral pathogens.
abstract: The objective of this study was to assess the antimicrobial capability of non-chemically altered chitosan as an alternative to traditional antimicrobials used in the treatment of oral infections. The action mechanism of chitosan was also ascertained. High and low molecular weight chitosan showed antimicrobial activity at low concentrations for all tested bacteria with the MICs varying between 1 and 7 mg/ml with a drop of efficacy relatively to the action of LMW chitosan. In addition chitosan showed also to be an effective bactericidal presenting bactericidal effect within 8 h at the latest. Additionally the evaluation of chitosan's action mechanism showed that both MWs acted upon the bacterial cell wall and were not capable of interacting with the intracellular substances, as showed by the inefficacy obtained in the flocculation assay.
authors.affiliation: CBQF, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal.
authors.forename: E M
authors.initials: EM
authors.lastname: Costa
authors.forename: S
authors.initials: S
authors.lastname: Silva
authors.forename: C
authors.initials: C
authors.lastname: Pina
authors.forename: F K
authors.initials: FK
authors.lastname: Tavaria
authors.forename: M M
authors.initials: MM
authors.lastname: Pintado
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016866:Bacteroidaceae Infections / Q000382:microbiology; D041963:Bacteroidetes / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D002462:Cell Membrane / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D048271:Chitosan / Q000494:pharmacology*; D005427:Flocculation / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008970:Molecular Weight; D015661:Pasteurellaceae / Q000187:drug effects* / Q000254:growth & development; D010510:Periodontal Diseases / Q000382:microbiology*; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D048271:Chitosan