Exam 1 Lecture 5 Flashcards
Pathogen
organism that can cause disease in a particular host
opportunistic pathogen
infects compromised host
- loss of specific defense mechanisms
- loss of non-specific defense mechanisms
Rubor
Redness
Calor
Heat/warmth at the site of inflammation
Dolor
Pain
What is the formula for finding attack rate?
infected / # susceptible and exposed * 100
Primary pathogen
infects competent host
Example of non-specific defense mechanism(s)
Skin
Carrier state/latency
successful colonization WITHOUT sufficient multiplication to evoke the changes characteristic of the disease state
What are 3 things needed for a pathogen to colonize?
- adherence
- motility
- survival or fitness in an environment outside host
What can pathogens use for adherence?
Pili
ex. PAP pili of uropathogenic E. coli
What can pathogens use for motility?
Flagella and chemotaxis (ex. many enteric organisms)
- he briefly describes concept of run and tumble
What 2 things are necessary for a pathogen to multiply?
- Nutrition
2. Avoiding host immune surveillance
What nutrient do pathogens need to multiply? How can they acquire it?
Iron!! However, in the human body, there is little to no free iron. Bacteria have thus evolved mechanisms to take our iron
Can be acquired through siderophores, lactoferrin/transferrin receptors
How do pathogens avoid immune response?
- Live intracellularly.
- Live in phagolysosome through modification or blocking fusion after macrophage uptake.
-Can also break out of phagolysosome or live in cytoplasm (Listeria, Shigella)
Salmonella has Type __ SS
Type 3
Also known as an “injectosome” or “molecular syringe”
Why is the interaction between human, microbes, and diseases, not the same for all of us?
Depends on exposure, some people may have autoimmune diseases or other factors that may affect how their body responds to a pathogen (differing susceptibility)
Smoking lead to…
- Heart attack
- Stroke
- Lower respiratory tract infection
- Cancer
Normal functioning anatomy allows for?
Resistance to getting infected by opportunistic pathogens
Inflammation involves: (5 things)
- Rubor
- Tumor
- Calor
- Dolor
- Loss of function
Infamous example of Carrier state/latency?
Typhoid Mary
Virulence determinant
unique attributes that permit a microbe to successfully establish infection and cause subsequent disease
Virulence
Quantitative measure of pathogenicity or likelihood of causing disease (experimentally determined)
Infectivity
quantitative measure of a pathogen’s ability to infect another susceptible host, calculated with attack rate %
Ways we can be resistant to infectious disease
Get vaccinated, limiting exposure, presence of antibiotics
Why is it a fitness advantage to survive outside of the host?
To compensate for low transmission rates, increases likelihood of spreading to multiple other people
Characteristics of phagolysosomes
There are oxygen radicals, low pH, toxic space for pathogens
