CHAPTER 13: PATHOGENS & TOXINS Flashcards
true pathogens
- cause infection in any host
influenza, plague bacillus, malaria protozoan
opportunistic pathogens
- rarely cause infection in hosts w healthy immune systems
- endogenous infections
pseudomonas and candida albicans
virulence
determines how severe the disease is
steps of infection
1) find entry (skin, gi, etc..)
2) attach (fibrae, surface proteins, hooks)
3) survive defenses (phagocyt, immune system)
4) cause DAMAGE
different forms of damage (2)
direct: toxins, enzymes, lysis
indirect: host responds excessively (inflammation)
how does microbe exit the host
skin, poop, blood
exogenous vs endogenous agent
exo: originate from source OUTSIDE the body
endo: already exists or in the body
STORCH infections
- when does it occur
- names
infection during pregnancy
- Syphilis
- Toxoplasmosis
- OTHER (hep A, aids, chlamydia)
- Rubella
- Cytomegalovirus
- Herpes simplex
infectious dose
- define
- connection to virulence
the minimum # of microbes needed for an infection to occur
SMALLER the ID, the GREATER the virulence
no ID? NO INFECTION!
Adhesion- when does it occur
after the point of entry, specific molecules bind between host and pathogen
methods of adhesion
- flagella
- glycocalyx
- cilia
- suckers
- hook
- barbs
- viral spikes
phagocytes
the initial response of host defenses
Anti-phagocytic factors (2)
let the microbe avoid phagocytosis
- leukocidins: toxic to WBC, made by strep and staphylococcus
- slime layer/capsule
Virulence Factor
trait that helps the microbe INVADE and ESTABLISH in the host
VF determine the degree of tissue damage and severity of the disease
Salmonella and E.coli virulence proteins
secretions insert specialized virulence proteins into the host cell
- host cell engulfs the microbe, an cells gets pulled into vacuole where it multiplies and moves into deeper tissue
