Periodontitis is a chronic infectious inflammatory disease characterized by the destruction of teeth.The contribution of bacteria to the disease progression is poorly understood probably due to the multifactorial background of this disease.Aggregatibacter actinomycetemcomitans is part of the normal flora in many healthy individuals,but is also a major etiologic agent in some aggressive forms of periodontitis.The genetic diversity among different isolates of Aggregatibacter actinomycetemcomitans is great & its ability to express and release virulence factors varies.Aggregatibacter actinomycetemcomitans,a pathogen not only in periodontal but also in some nonoral infections,possesses several virulence determinants which contribute to its ability to colonize the oral cavity,persist in the periodontal pocket,resist and evade host defenses,cause destruction of soft and hard tooth-supporting tissues and interfere with host tissue repair after infection.Our understanding of this organism still lags behind as methods for genetic manipulation have just become available.More Exploration is needed to provide more insight into the evolution of the association between this bacteria & its host.
