Aggregatibacter actinomycetemcomitans (Aa) Under the Radar: Myths and Misunderstandings of Aa and Its Role in Aggressive Periodontitis

Conclusions Current data indicates that Aa can colonize tooth surfaces above the gum-line and that this is an early event. In the section below we will describe how Aa can compete for nutritional elements with a multitude of rival bacteria in order to survive. Misconception 2: Nutritional Fastidious Nature of Aa Clinical Aa has been characterized as a fastidious microbe that requires CO2, serum, and specific carbohydrates such as glucose for its growth (34). It has been reported that Aa has a mandatory requirement for 5% CO2 for primary isolation, and that its growth is purported to be boosted by addition of serum (34). The difficult recovery of the microbe from potentially diseased sites throughout the body has been attributed to Aa's fastidious nature and its slow and inconsistent growth after initial isolation. These characteristics have suggested that the organism is difficult to isolate from human sites and difficult to grow in the laboratory. These features coupled with the aggregative nature of the microbe when grown in the laboratory has made quantitative assessment of the microbe problematic. Further, these features have discouraged a more intense investigation of the genetic traits of Aa (13). More recently genetic methodologies have made it easier to do quantitative assessment of the microbe from individual periodontal sites of interest. Molecular In 2007, Brown and Whiteley demonstrated that Aa preferentially metabolizes lactate over other more readi...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research