Evaluating biofilm growth of two oral pathogens.
OBJECTIVE
To determine the expediency of a microtitre assay system for establishing, quantifying and antimicrobial testing of two representative oral pathogens.


RESULTS
Streptococcus mutans and Porphyromonas gingivalis were used. Morphological characteristics of the attached population were evaluated. Biofilm growth was evaluated spectrophotometrically (undisturbed and 1 N NaOH dissipated biofilm). The minimum concentration of chlorhexidine gluconate that inhibited biofilm growth was determined. Growth of the biofilms was successfully monitored by direct optical density measurements or those re-suspended in 1 N NaOH. The latter was necessary when glucans were present in Strep. mutans biofilms. The minimum concentration of chlorhexidine gluconate that inhibited biofilm growth was 1.25 microg ml(-1) for both species. The attached bacteria exhibited common biofilm characteristics.


CONCLUSIONS
The assay system developed was especially useful for monitoring the growth of adherent Strep. mutans in the presence of glucans, which is particularly significant for the study of anti-plaque chemicals.
Roberts
S K
SK
Department of Periodontics, College of Dentistry, University of Illinois-Chicago, Chicago, IL 60612, USA.
Wei
G X
GX
Wu
C D
CD
D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D001422:Bacterial Adhesion; D001431:Bacteriological Techniques; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002710:Chlorhexidine / Q000494:pharmacology; D003773:Dental Plaque / Q000382:microbiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008826:Microbial Sensitivity Tests; D010510:Periodontal Diseases / Q000382:microbiology; D011137:Polystyrenes; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000254:growth & development*; D013295:Streptococcus mutans / Q000187:drug effects / Q000254:growth & development*
D000891:Anti-Infective Agents, Local; D011137:Polystyrenes; D002710:Chlorhexidine