Actinomyces naeslundii (A. naeslundii)

Actinomyces naeslundii is a Gram-positive, facultatively anaerobic bacterium that is a primary colonizer in the human oral cavity (BacDive [4]). It plays a pivotal role in the initiation of dental plaque by adhering to salivary pellicle proteins on tooth surfaces via specialized Type 1 and Type 2 fimbriae (PubMed [6]). These fimbriae also facilitate coaggregation with other oral microorganisms, such as streptococci, helping to establish the complex architecture of mature biofilms (NIH [10]). While usually a commensal organism, A. naeslundii is an opportunistic pathogen associated with dental caries, periodontal disease, and occasionally systemic infections like actinomycosis (PMC [12]). It is typically targeted by broad-spectrum antibiotics, including penicillins and tetracyclines, which inhibit essential bacterial processes like cell wall synthesis and protein translation (PubMed [5]). Clinical management also frequently utilizes oral antiseptics like chlorhexidine to disrupt biofilm formation and reduce the overall bacterial load within the mouth (PMC [11]).

Other names

Actinomyces naeslundii genospecies 1Actinomyces naeslundii sensu stricto

Antibiotics targeting this organism typically inhibit bacterial cell wall synthesis, protein synthesis, or DNA replication, while antiseptics disrupt the bacterial cell membrane and disrupt biofilm formation.