Infection (Bailey) Flashcards
What is the most common reason people seek treatment for infectious disease?
Oral infections
What are the six steps in the infectious disease process?
- Encounter
- Entry
- Colonization and/or invasion
- Multiplication and/or spread
- Damage
- Outcome
Does encountering an infectious microbe always result in infection?
No.
Some diseases are grown from within
Although the oral cavity and alimentary canal are inside the body, what is special about this canal?
It is connected to the outside world on both ends
What are the two major ways a pathogen will adhere to a host tissue?
- Nonspecific adherence: reversible docking
2. Specific adherence: irreversible anchoring with adhesins
Why does streptococcus mutans bind to the tooth pellicle?
It has an adhesin that specifically binds to tooth pellicle (specific adherence)
What is needed for a pathogen to colonize?
Must be able to live in the environment it wants to colonize
What are three ways bacteria take up nutrients?
- Carrier-mediated diffusion
- Phosphorylation-linked transport
- Active transport
What allows a pathogen to invade after colonization?
Specific virulence factors that allow for invasions
What are the two major mechanisms for disease multiplication?
- Lateral propagation to contiguous tissues (multiply -> spread)
- Dissemination to distant sites (spread -> multiply)
What are two major types of toxins during infection?
- Endotoxins: component of cell wall
2. Soluble substances secreted into host tissues
What makes a microbe a pathogen?
- Adheres
- Colonizes
- Replicates in given niche
- Causes damage
T/F: No microorganism is intrinsically benign or pathogenic
TRUE
T/F: Obligate anaerobes are bacteria that must have oxygen to grow.
FALSE.
Obligate anaerobes: cannot tolerate oxygen
Strict aerobes: must have oxygen to grow
Which bacteria can grow with or without oxygen?
Facultative anaerobes
What is unique about oligotrophs?
Can grow with limited nutrients