Actinomyces viscosus colonization of mouse teeth.

Area of Science:

• Microbiology
• Immunology
• Dental Research

Background:

• Actinomyces viscosus is a significant oral bacterium implicated in dental caries and periodontal disease.
• Understanding the factors influencing Actinomyces colonization is crucial for developing preventive strategies.

Purpose of the Study:

• To establish and characterize an in vivo mouse model for Actinomyces viscosus implantation.
• To determine the optimal age and infectious dose for successful colonization.
• To evaluate the model's utility in testing interventions against Actinomyces colonization.

Main Methods:

• Inoculation of Actinomyces viscosus strain T14V-J1 into mice of varying ages.
• Determination of the minimum infective dose (ID100) for colonization.
• Assessment of transmission between infected and non-infected mice.
• Evaluation of the indigenous Actinomyces population on mouse teeth.

Main Results:

• The optimal age range for implantation was 40 to 80 days.
• The minimum infective dose (ID100) varied with age, ranging from 5 x 10^8 CFU to 1 x 10^9 CFU.
• Actinomyces colonization was not detected in indigenous mouse oral flora.
• Infection was transmissible to co-housed, non-infected mice.

Conclusions:

• An effective in vivo mouse model for Actinomyces viscosus colonization was developed.
• The model's parameters (age, infectious dose) were defined.
• This model provides a platform for evaluating the efficacy of vaccines targeting fimbrial adhesins to prevent Actinomyces colonization on teeth.