Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
4 Potential outcomes from bacterial encounters. |
a) Pass through the body b) Colonize body as part of microbiota c) Establish infection d) Establish infection and cause disease |
|
|
What is infection? |
Invasion of the body by pathogen. |
|
|
What is disease? |
Damage to the body that impairs function. |
|
|
What is pathogenicity? |
The ability for a pathogen to cause disease. |
|
|
What are the 2 factors that affect the outcome of encounters to a pathogen? |
1. Pathogenicity of the microbe. 2. Susceptibility of the host. |
|
|
A strain is... |
A population of bacteria descended from a single organism. |
|
|
What is an opportunistic pathogen? |
A bacterium that harms compromised hosts. |
|
|
What is virulence? |
A measure of pathogenicity expressed as the number of bacterial cells required to illicit a host response in a given time period. |
|
|
Pathogenicity is a genetic component of the pathogen. |
Enough said. |
|
|
Virulence can be affected by... (3) |
1. Ability of pathogen to multiply in the host. 2. Route of entry of microorganism. 3. State of host's immune system. |
|
|
What is a primary infection? |
An initial, acute infection. |
|
|
What is a secondary infection? |
A second infection caused by an opportunistic bacterium when host defences are weakened. |
|
|
What is a subclinical infection? |
An infection where the host shows no symptoms of disease. |
|
|
What is a subclinical infection? |
An infection where the host shows no symptoms of disease. |
|
|
What is a nosocomial infection? |
An infection obtained during hospitalisation. |
|
|
What is invasiveness? |
The ability of the bacteria to spread from the initial site of infection. |
|
|
What is a local infection? |
An infection of a relatively small area of the body. Caused by noninvasive bacteria. |
|
|
What is a systemic infection? |
An infection that is spread throughout the body. Caused by invasive bacteria. |
|
|
What is a focal infection? |
An infection that begins in a restricted area, but spreads out to other parts of the body. |
|
|
What 6 factors make a host more susceptible to infection? |
1. Underlying disease or infection 2. Stress 3. Poor nutrition 4. Age (old and young) 5. Immunosuppressive therapy 6. Genetic factors |
|
|
What is the microbiota? |
The microorganisms that inhabit certain parts of the human body. |
|
|
What does the microbiota consist of? |
Bacteria, archaea, eukaryotic fungi |
|
|
How do bacteria benefit from the host? |
1. Method of transportation 2. Supply of nutrients 3. Stable environment (protect from dessication and extreme temperatures) |
|
|
How do hosts benefit from bacteria? |
1. Microbiome prevents pathogens from colonizing 2. Bacteria produce nutrients for the body 3. Low level stimulation of host immune system |
|
|
How does the microbiota prevent pathogens from colonizing in host? |
1. Occupies adherence sites 2. Utilizes nutrients 3. Produces inhibitory by-products 4. Controls pH and oxygen levels |
|
|
What nutrients do the microbiota produce for the human body? |
1. Vitamins (eg. K and B12) 2. Steroids (from bile acids) 3. Organic acids (acetic and butyric) 4. Products of glycosidase reactions (sugar fermentation) |
|
|
How do microorganisms of the microbiota associate with the host? |
Bacterial ligands and adhesins bind to host cell receptors. |
|
|
What are 2 harmful host-microbiota interactions? |
1. Microbiota can be pathogenic when exposed to other parts of the body. 2. Microorganisms produce gases in intestine (300-400 mL/day) |
|
|
What is epidemiology? |
The study of how disease occurs and spreads. |
|
|
What is the incidence of disease? |
The fraction of a population that contracts disease in a given time period. |
|
|
What is the prevalence of disease? |
The fraction of people who have symptoms of disease. |
|
|
Defibe Sporadic disease |
Occurs occasionally. |
|
|
Describe Endemic disease. |
Occurs continuously at low level. |
|
|
Define Epidemic. |
Occurs sporadically at elevated level and continuously at low level. |
|
|
Define Pandemic. |
Epidemic that occurs worldwide. |
|
|
What is a disease outbreak? |
When an area experiencing only sporadic levels of disease sees an increase in the number of disease cases. |
|
|
What are zoonoses? |
Disease that primarily infects animals but can be transmitted to humans. |
