Exam 1 Flashcards
What does Virulence describe?
The level of harm caused by a pathogen following infection.
(Measured by
Lethal dose LD50
Infectious dose ID50
Invasion
the entry of a pathogen into a living cell, where it then lives
Invasiveness
The ability of a bacterial pathogen to spread rapidly through tissues
Disease
a disruption of the normal structure or function of any body part, organ, or system that can be recognized by a characteristic set of symptoms and signs.
Infectious Disease
a disease chased by a pathogen (bacterial, viral, or parasitic) that can be transferred from one host to another.
Signs of disease (objective)
can be observed by examination
- fluid filled rash
- fever of 102°F
Symptoms of disease (subjective)
experienced by the person
- pain
- fatigue
Syndrome
collection of signs and symptoms that occur together and collectively characterize a condition
Infection Cycle
the route of transmission from one person or animal to another
Horizontal Transmission
occurs when the infectious agent is transferred from one person or animal to the next
Vertical Transmission
occurs when the infectious agent is transferred from parent to offspring
Reservoir
an animal (including humans) or an environment that normally harbors the pathogen
ex. bat, mosquito, tick
Asymptomatic Carrier
harbors the potential disease agent but does not have the disease.
Endemic
Disease that is always present in a community at a low rate, often in an animal reservoir
ex. Flu
Epidemic
Disease in which the number of cases increases in a community in a short time
(it goes from like 100 cases to 1000 cases in a short period of time)
Pandemic
disease is an epidemic that spreads WORLDWIDE
ex. covid-19, HIV
Fecal-oral PORTAL
Portal is the mucosa of the GI tract.
Skin PORTAL
Portal is the skin epithelium.
Respiratory PORTAL
Portal is the mucosa of the respiratory tract.
Urogenital PORTAL
Portal is the mucosa of the genotype and urinary tracts
Parenteral PORTAL
Portal is through breaks in the skin
Entry via the Eye PORTAL
Portal is conjunctiva
Emerging disease
disease that recently appeared in the population
Are viruses alive?
NO
Viruses need a host cell to replicate (T or F)
TRUE
What information is learned from an inoculated blood agar plate?
Colony characteristic and hemolysis
What type of microscope should be used to observe the smear to look for stained cells?
Compound Light Microscope
Why is Heat fixing necessary during the staining procedure?
To adhere the specimen to the slide to prevent washing off.
Why is the spore stain method considered a differential stain rather than a simple stain?
Staining is done against a different background.
Why isn’t it possible to diagnose all infectious diseases by growing the disease-causing agent in culture and viewing it with a light microscope?
Viruses are too small to see.
Gram positive bacteria
Bacteria with thick peptidoglycan layer
Gram negative bacteria
Bacteria with thin peptidoglycan layer
Which type of microscopy shows a dark stained specimen against a light background?
Light Microscopy
