Periodontal Pathogens

all bacteria are bod and any accumulation of microbes at or below gingival margin causes inflammation

specific organisms are etiological agents and microbial composition is different between healthy and disease

Type I and V fimA genotypes

Type II and IV

colonization of beneficial species to dilute the level of pathogens

S. cristatus can inhibit fimA expression

• 1. veillonella uses lactate made by streptococci
• 2. campylobacter uses formate made by Selenomonas
• 3. Porphyromonas uses hemin from blood in sulcus

S. sanguinis produces hydrogen peroxide that inhibits AA

• 1. desquamation of epithelium: bacteria invade underlying epithelials
• 2. IgG and IgA proteases
• 3. leukotoxins attack phagocytes

• 1. Gm-
• 2. Capnophilic (requires CO₂)
• 3. star-shaped colonies

• 1. high numbers in LAP
• 2. elimination = successful therapy
• 3. Tissue invasive and fibroblast inhibiting factor
• 4. Inhibits growth of commensals (S. sanguis)

• 1. not seen in all cases of LAP
• 2. Seen in healthy subjects
• 3. AA with 530bp deletion is 23x more likely to be disease-associated

• 1. Serotype A: health-associated in finland but disease associated in japan
• 2. Serotype B: most common in LAP in USA

• 1. Gm-
• 2. Anaerobic
• 3. black pigmented bacteriodes

its cysteine proteinases are important in protein degradation and in the maturation of cell surface proteins such as fimA fimbrillin

• 1. Gm-
• 2. anaerobic
• 3. spindle shaped
• 4. requires NAM
• 5. cultivated with F nucleatum
• 6. Serrated S-layer on cell surface mediates adhesion

Gm-, anaerobic, highly motile

• 1. Gm-
• 2. anaerobic
• 3. black pigmented bacteriodes
• 4. Luxuriant growth in naphthoquinone, a vitamin K derivative from estrogen
• 5. associated with puberty/pregnancy gingivitis

• 1. Gm-, anaerobic
• 2. early colonizer
• 3. bridging organism
• 4. isolated in subgingival health and disease
• 5. can induce cell death in leukoctyes

700 oral species present with 60-80% cultured