Porphyromonas gingivalis oral bacterium, computer illustration. P. gingivalis (formerly known as Bacteroides gingivalis) is part of the normal flora of the mouth, intestine and urogenital tract. It is a rod shaped, Gram-negative, anaerobe found in periodontal lesions and associated with adult periodontal diseases such as: gingivitis (gum disease), periodontal infections, ulcerative gingivitis and mouth abscesses. Approximately 70-90% of young adults and older have associated Porphyromonas gingivalis gingivitis, an oral inflammatory process and a possible precursor to adult periodontal disease. Porphyromonas gingivalis utilizes heme, transferrin and haemoglobin efficiently as sources of iron for growth, and has the ability to store heme on its cell surface. However, little is known about intracellular iron storage in this organism.