An ex-vivo multiplexed antibacterial test on oral microflora

Characterized clinical strains of oral bacteria are utilized to examine the antimicrobial efficacy of oral care formulations. A demonstration of antimicrobial effects of formulations on microbial samples obtained from the human mouth offers advantages, i.e. incorporates the considerable microbial diversity of this environment with bacteria harvested from naturally occurring biofilms to form the focus of this investigation.

Samples of oral flora from each adult subject were briefly treated (2 min) with test and control formulations and plated on appropriate agar for multiplexed antimicrobial effects on functional groups of oral bacteria associated with specific conditions.

Ex-vivo treatments of oral samples with the triclosan/copolymer dentifrice demonstrated significant dose-dependent antimicrobial effects compared with a control formulation on anaerobic and facultative oral bacteria from a group of 16 volunteers (P < 0.05) with reproducible effects observed in three separate trials (P < 0.05). Similarly, significant dose-dependent effects were noted with chlorhexidine mouthrinses (P < 0.05). A simultaneous assessment of the effects of these formulations on several functional classes of oral bacteria associated with specific oral conditions such as dental caries and oral malodor demonstrated multiplexed antimicrobial activity (P < 0.05).

A rapid procedure using small volumes of human oral samples and well-known formulations demonstrates ex-vivo multiplexed antimicrobial effects on functional groups of bacteria with both dentifrices and mouthrinses. Modifications of this approach may include antibacterial effects over time with formulations at clinically relevant concentrations, effects of novel agents or samples from subjects stratified on the basis of their clinical status.