ABP Periodontal Pathogenesis and Host Response

Question 1

Which bacterium is considered the 'keystone pathogen' in periodontal disease because it disrupts host immunity disproportionate to its low abundance?

Accepted Answer

Porphyromonas gingivalis

Answer

Tannerella forsythia

Answer

Treponema denticola

Answer

Aggregatibacter actinomycetemcomitans

Question 2

Socransky's 'red complex,' the bacterial group most strongly associated with severe periodontitis, consists of which three organisms?

Accepted Answer

P. gingivalis, T. forsythia, T. denticola

Answer

P. gingivalis, A. actinomycetemcomitans, T. denticola

Answer

F. nucleatum, P. intermedia, P. gingivalis

Answer

A. actinomycetemcomitans, E. corrodens, C. rectus

Question 3

What is the primary role of Fusobacterium nucleatum within the subgingival biofilm community?

Accepted Answer

Bridge organism linking early colonizers to late-colonizing pathogens

Answer

Primary initiator of alveolar bone resorption

Answer

Keystone pathogen that suppresses innate immunity

Answer

Producer of gingipains that degrade host defense proteins

Question 4

Leukotoxin A (LtxA), a major virulence factor that lyses PMNs and macrophages, is uniquely produced by which periodontal pathogen?

Accepted Answer

Aggregatibacter actinomycetemcomitans

Answer

Porphyromonas gingivalis

Answer

Treponema denticola

Answer

Tannerella forsythia

Question 5

Which feature of the subgingival biofilm most contributes to its resistance to systemic antimicrobial agents?

Accepted Answer

Extracellular polysaccharide matrix that limits drug penetration and shields bacteria

Answer

Primarily aerobic bacterial composition that excludes anaerobes

Answer

Absence of quorum sensing communication among species

Answer

High oxygen tension creating an inhospitable environment for pathogens

Question 6

Gingipains produced by Porphyromonas gingivalis primarily function to:

Accepted Answer

Degrade host defense proteins and cleave complement to evade immunity

Answer

Stimulate osteoblast matrix synthesis

Answer

Produce volatile sulfur compounds causing halitosis

Answer

Bridge early and late microbial colonizers in the biofilm

Question 7

In Socransky's microbial complexes, which complex serves as the 'bridge' between early colonizers and the pathogenic red complex?

Accepted Answer

Orange complex

Answer

Yellow complex

Answer

Purple complex

Answer

Green complex