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

What is the main characteristic of gram-negative periodontal pathogens?

1. They are motile

2. They are less virulent

3. They produce more toxins

4. They are more susceptible to antibiotics

The correct answer is: They produce more toxins

The main characteristic of gram-negative periodontal pathogens is that they produce more toxins. Gram-negative bacteria possess an outer membrane that contains lipopolysaccharides (LPS), which can act as potent endotoxins. These endotoxins are significant contributors to the pathogenicity of these bacteria, leading to inflammation and tissue damage. The toxins can provoke strong immune responses, which, while attempting to eliminate the pathogens, can also result in collateral damage to the host’s tissues, exacerbating periodontal disease. In terms of pathogenicity, gram-negative bacteria are often linked with more severe forms of periodontal disease compared to gram-positive bacteria. This increased virulence aids in their ability to thrive in the subgingival environment of the periodontal pocket. Other characteristics of gram-negative periodontal pathogens, such as being motile, may also contribute to their ability to colonize, but the production of prolific toxins is a defining feature that impacts their role in periodontal disease. While susceptibility to antibiotics varies among different bacteria, gram-negative pathogens are often inherently more resistant due to their protective outer membrane, making them less susceptible overall in terms of treatment.