Transmission of infectious disease Flashcards
host-microbe interactions
- dynamic give and take between host and microbes
- can range from benign to serious causing disease
human microbiota
- mutualistic relationship
- the microbial population associated with the human body
- human provides nutrients
- promotes immune system maturation
- role of opportunistic pathogens; compete with bad pathogens for real estate; keep in check
tropism
preference for a specific host or tissue
dysbiosis
- disruption of microbiota
- ex. antibiotics can kill good bacteria as well
pathogenicity
ability of a microbe to cause disease
virulence
degree of extent of disease that a pathogen causes
virulence factors
ways pathogens overcome host defenses
ways to invade the immune system:
- toxins
- adhesion factors
- nutrient acquisition
- invasion strategies
attenuated
pathogen is still infectious but does not cause disease
- different for immunocompromised hosts
- attenuation is advantageous because virulence factors use energy to produce
infectious dose (ID50)
the number of bacterial cells or viral particles needed ti establish an infection in 50% of susceptible hosts
lethal dose (LD50)
the amount of toxin needed to kill 50% of untreated affected hosts
toxins
- molecules that generate adverse host effects in a low concentration
- can be tougher to destroy than the originating organism
toxigenic organisms
organisms that produce/generate toxins
toxemia
toxin in bloodstream
endotoxin
- released by gram negative bacteria when the cell is destroyed
- can lead to septic shock and death
- not readily neutralized
- no effective vaccines or therapies
exotoxins
- toxic soluble proteins made by gram negative and gram positive bacteria
- released by the cell into the envrionment