Aggregatibacter actinomycetemcomitans

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Classification

Kingdom: Bacteria; Phylum: Proteobacteria; Class: Gammaproteobacteria; Order: Pasteurellales; Family: Pasteurellaceae; Genus: Aggregatibacter; Species: Actinomycetemcomitans.

Species

NCBI: Taxonomy

Description and Significance

Aggregatibacter actinomycetmcomitans is composed of fimbriae, vesicles, and extracellular amorphous materials. These vesicles (blebs) are lipopolysaccharide structures which contain endotoxin. Endotoxin acts as bone resorption and contains actinobacillin, a gram-negative bacterium. Vescicles also serve adhesive properties, allowing the delivery of toxic materials. Fimbriae are small filamentous hair-like appendages that bundle together. They form two types of colonies: fimbriated strains which are star-positive (with a star shape interior) and non-fimbriated strains which are start-negative.

Periodontitis is a serious gum infection, damaging the soft tissue around teeth. Without treatment, periodontitis can lead to tooth loss as well as gum recession. A. actinomycetemcomitans causes rapid progression of localized aggressive periodontitis (LAP). LAP specifically affects incisors and molars, leading to the breakdown of supporting tooth structures if left untreated. For this learson, A. actinomycetemcomitans is considered a systemic pathogen.

Genome Structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?

Cell Structure, Metabolism and Life Cycle

Interesting features of cell structure; how it gains energy; what important molecules it produces.