Introduction to Infection Flashcards
Infectious agents and normal flora
What are the main types of infectious agents?
Bacteria, viruses, fungi, parasites, and prions.
What is normal flora?
The community of microorganisms that normally inhabit various parts of the human body without causing disease.
How do infectious agents differ from normal flora?
Infectious agents can cause disease, while normal flora usually do not; they can provide benefits, such as aiding digestion and preventing pathogen colonization.
What is the role of bacteria in the human microbiome?
They help with digestion, produce vitamins, and protect against pathogenic microbes.
What are opportunistic pathogens?
Normally harmless microorganisms that can cause disease when the host’s immune system is compromised.
How can normal flora become pathogenic?
Through mechanisms such as disruption of normal barriers (e.g., skin breaks), immunosuppression, or changes in the host environment.
What is colonization?
The establishment and growth of microorganisms on a host’s tissues without causing disease.
What factors influence the balance of normal flora?
Diet, hygiene, age, medication (e.g., antibiotics), and health status.
What are some common locations of normal flora in the body?
Skin, gastrointestinal tract, respiratory tract, urogenital tract, and mouth.
How do infectious agents enter the human body?
Through various routes such as respiratory tract, gastrointestinal tract, breaks in the skin, or urogenital tract.
What is the significance of the skin as a barrier against infection?
The skin acts as a physical and immune barrier that prevents pathogens from entering the body.
What role does the immune system play in infection?
It detects and responds to infectious agents, helping to eliminate them and prevent disease.
What are the common transmission routes for infectious agents?
Direct contact, airborne, vector-borne (e.g., insects), and contaminated surfaces.
What is the concept of infectious dose?
The minimum number of microorganisms required to establish an infection in the host.
How do antibiotics affect normal flora?
Antibiotics can disrupt the balance of normal flora, leading to potential overgrowth of pathogenic organisms (e.g., C. difficile).
