A bacterium that forms biofilms gains virulence by
A. attaching to the host.
B. forming toxins.
C. inhibiting lysosomes.
D. inhibiting macrophages.
The Correct Answer and Explanation is :
The correct answer is A. attaching to the host.
Explanation:
A bacterium that forms biofilms gains virulence primarily through the process of attachment to the host. Biofilms are structured communities of bacterial cells that are embedded in a self-produced extracellular matrix, typically composed of polysaccharides, proteins, and nucleic acids. This biofilm matrix allows bacteria to adhere firmly to surfaces, including host tissues, medical devices, or mucosal surfaces.
1. Attachment to the host:
Biofilms increase the ability of bacteria to adhere to tissues and medical devices, which is a critical first step in establishing infection. The attachment provides a protected environment where bacteria can persist and resist host immune responses. In addition, the biofilm structure can act as a physical barrier, limiting the effectiveness of antibiotics and immune cells. As bacteria are more protected in biofilms, they can survive longer in the host, contributing to chronic infections.
2. Formation of toxins:
While some biofilm-forming bacteria may produce toxins, the ability to form toxins is not the primary mechanism through which biofilms enhance virulence. Toxins can contribute to damage in tissues, but they are not the key factor in biofilm-associated virulence.
3. Inhibiting lysosomes:
Inhibition of lysosomes, which are cellular organelles involved in digestion of pathogens, is not a characteristic action of biofilm formation itself. While biofilm bacteria may be less susceptible to phagocytosis by immune cells (such as macrophages), biofilm formation itself is not directly involved in inhibiting lysosomal function.
4. Inhibiting macrophages:
While biofilm formation can contribute to immune evasion by reducing the activity of macrophages and other immune cells, this is an indirect effect. The primary action is the physical protection provided by the biofilm matrix, which limits the ability of immune cells to clear the infection.
In summary, attachment to the host is the most significant aspect of biofilm-associated virulence, as it facilitates bacterial persistence and resistance to host defenses.