Effects of Triclosan-Containing Rinse on the Dynamics and Antimicrobial Susceptibility of In Vitro Plaque Ecosystems

Abstract

Dental plaque microcosms were established under a feast-famine regimen within constant-depth film fermentors and exposed four times daily postfeeding to a triclosan (TR)-containing rinse (dentifrice) (TRD). This was diluted so that the antimicrobial content was 0.6 mg/ml. Microcosms were characterized by heterotrophic plate counts and PCR-denaturing gradient gel electrophoresis (DGGE) with primers specific for the V2-V3 region of the eubacterial 16S rRNA gene (rDNA). Dominant isolates and PCR amplicons were identified by partial sequencing of 16S rDNA. TRD caused considerable decreases in the counts of both gram-negative organisms and total anaerobic cells, transiently lowered the numbers of streptococci and actinomycetes, and markedly increased the proportion of lactobacilli. DGGE indicated the presence of putatively unculturable bacteria and showed that a Porphyromonas sp. and Selenomonas infelix had been inhibited by TRD. Pure culture studies of 10 oral bacteria (eight genera) showed that Neisseria subflava, Prevotella nigrescens, and Porphyromonas gingivalis were highly susceptible to TR, while the lactobacilli and streptococci were the least susceptible. Clonal expansion of the lactobacilli in the pulsed microcosm could be explained on the basis of TR activity. The mean MICs of TR, chlorhexidine, erythromycin, penicillin V, and vancomycin for the population before and after 5 days of exposure to TRD showed few significant changes. In conclusion, changes in plaque microcosm populations following repeated exposure to TRD showed inhibition of the most susceptible flora and clonal expansion of less susceptible species.

Antimicrobial efficacy of Curcuma zedoaria extract as assessed by linear regression compared with commercial mouthrinses

“…Although the minimum inhibitory concentration (MIC) has been used for evaluating the antimicrobial activity, McBain et al (11) and McDonnell and Russel (12) observed that triclosan and chlorhexidine presented high antimicrobial potential against oral bacteria and, MIC obtained for triclosan was lower than the one obtained for chlorexidine. Pan et al (19), Riep et al (22), and Pitten and Kramer (20) evaluated the rate of microbial death after contact with antiseptic mouthrinses and observed that products containing essential oils were more effective.…”

Oral Bacterial Communities in Individuals with Type 2 Diabetes Who Live in Southern Thailand

“…PCRs were performed in sterile, nuclease-free, 0. (29,30). Gels were polymerized by adding tetramethylenediamide (50 l) and ammonium persulphate (1% [wt/vol], 100 l) immediately prior to pouring.…”

Bacteriological Effects of Dentifrices with and without Active Ingredients of Natural Origin

“…Glass slides were partially submerged in artificial saliva medium (40 ml) (24,25) supplemented with cysteine (26). The broth was inoculated with saliva from healthy volunteers, mixed briefly, and incubated statically at 37°C in an anaerobic cabinet for 48 h. Slides were then immersed in 1% slurries of test dentifrices (50 ml) for 60 s and gently agitated.…”