National Board Dental Hygiene Examination (NBDHE) Dental Hygienist Practice Test

Most periodontal pathogens are characterized as which of the following?

1. Gram positive, motile

2. Gram negative, nonmotile

3. Gram positive, nonmotile

4. Gram negative, motile

The correct answer is: Gram negative, nonmotile

The correct characterization of most periodontal pathogens is that they are primarily gram-negative and nonmotile. This is significant because gram-negative bacteria have a unique cell wall structure that includes an outer membrane containing lipopolysaccharides, which contributes to their virulence and ability to evade the host's immune responses. In the context of periodontal disease, many of these pathogens, such as Porphyromonas gingivalis and Tannerella forsythia, are indeed gram-negative rods that are not typically motile; they often rely on adhesion and colonization of the periodontal tissues to establish infection rather than movement. Understanding the characteristics of these pathogens is crucial, as it lays the groundwork for diagnosing and treating periodontal diseases effectively. Treatments and interventions may target specific features of these gram-negative bacteria to help control their growth and undermining impact on periodontal health.