Chapters 22 And 23 For Final Flashcards
What is the word for a parasite growing and multiplying within or on a host that may or may not result in overt infectious disease?
Infection
What is a pathogen?
Any parasitic organism that causes infectious disease
What is a primary (frank) pathogen?
Causes disease by direct interaction with healthy host
What is an opportunistic pathogen?
May be part of normal flora and causes disease when it has gained access to other tissue sites or host is immunocompromised
What is Pathogenicity?
The ability of a parasite to cause disease
Who was Robert Koch?
The father of immunology that identified the causative agent of anthrax
What are Koch’s Postulates?
- The microorganism must be found in abundance in diseased individuals
- The microorganisms must be isolated from the diseased individual and grown in pure culture
- The cultured microorganisms must causes disease when re-introduced into a healthy organism (animal model)
- The microorganism must be re-isolated from that animal model
An infection with viruses, bacteria, fungi, or Protozoa is called what?
An infectious disease
What are signs (aka “read outs” of a patient)?
Objective changes in body that can be directly observed
What is the definition of symptoms?
Subjective changes experienced by patient
Disease syndrome definition
Set of characteristic signs and symptoms
Incubation period definition
Period after pathogen entry but before signs and symptoms appear
What is the prodromal stage?
- the onset of signs and symptoms
- not clear enough for diagnosis
What is the period of illness?
Disease is most severe and has characteristic signs and symptoms
What type of immunity is activated during the “period of illness”?
Adaptive immunity
What is convalescence?
When signs and symptoms begin to disappear
After which event does convalescence appear?
After class switching from IgM to IgG
What are the direct modes of spread of communicable infectious disease?
- Horizontal contact (kissing, sex)
- airborne droplets
- Vertical contact (mother to child)
- Vector ( flies and mosquitos)
What are examples of indirect (vehicles) of communicable infectious disease?
- contact fomites (solid surfaces)
- food, water, biological products (ex: Typhoid Mary)
- Airborne
What is the stain and shape of Neisseria gonorrhoeae?
Gram-negative diplococcus
What type of disease is N. gonorroeae?
An STD
Where does N. gonorhoeae colonize most commonly in males vs females?
Males: colonizes the urethra
Females: colonizes the cervix
Why is N. gonorrhoea called a superbug?
It is called “super” because of its resistance to azithromycin
What is a third generation cephalosporin that can be still be used to treat N. gonorrhoeae despite it being a superbug?
Ceftriaxone
What is the difference between Genetic Variation and Gene Regulation?
Genetic Variation -> Random switching -> Heterogeneous Population
Genetic Regulation -> Environmental stimulus -> Homogeneous population
In Pilin phase variation, which genes does the promotor control: PilE, pilS1, pilS2, or pil3?
PilE
What do pilS1, pilS2, and pilS3 have the tendency to do? What does this lead to?
They have the genetic tendency to recombine. This leads to mixed genes and Variability
By varying the pilin amino acid sequence, some N. gonorrhoeae can _______ the adaptive immune response.
Escape
What used to be used to treat gonorrhea that can no longer be used due to resistance?
- Penicillin (targets cell wal)
- Tetracyclines (targets ribosomes)
- Fluoroquinolones
What is the now recommended treatment for gonorrhea?
Ceftriaxone
What is the stain and shape of Staphylococcus aureus?
Gram-positive cocci
Where is staphylococcus aureus a huge threat since it is a major nosocomial pathogen?
Hospitals
What is the percentage of commensalism/Nasal carraiage of S. aureus?
20% stably colonized
60% intermittent carriers
(If you are in this 20% don’t handle for for others)
What type of pathogen is S. aureus?
An opportunistic pathogen
What are the features of S. aureus toxins?
- Apoptotic induction/Nutrient acquisition
- Resistance to oxidative burst killing
- Binding to host tissues
- Superantigens
- Cloaking of opsonins
- Host cell lysis
- Impairment of phagocyte recruitment
- Biofilm
Apoptotic induction/nutrient acquisition:
What three types of enzymes can cause cell degradation via apoptosis?
protease, nuclease, and lipase
resistance to oxidative burst killing: ______ catalase is resistant to hydrogen peroxide in the phagosome and has burst protection.
SodA
What does binding to host tissues in S. aureus?
MSCRAMMs are surface proteins for binding
What do Superantigens do in S. aureus?
They can make the immune system go crazy. an example is TSST-1
What is an IgG binding protein that can bind to flip antibody to the outside?
Protein A~
What accomplishes the cloaking of opsonins in S. aureus?
Capsules
What are capable of Host cell lysis for S. aureus? What symdrome toxin occurs as a result?
- alpha-toxin
- delta-toxin
- beta-toxin
scalded skin syndrome toxin
Impairment of phagocyte recruitment: impairs the recruitment of antibodies through ____, ____, and ____.
CHIPS, Sak, and Efb
What does biofilm allow?
It allows it to be resistant to antibiotics (like a little shield of protection)
Expression of S aureus hemolysis is controlled by what?
Cell density
What are the two components of the Two Component System?
Histidine Kinase + Response Regulator
What is Quorum sensing?
A mechanism where a bacterial population can determine the abundance of itself and others in an environment
Where was Quroum sensing originally discovered?
Vibrio fischeri
What does vibrio fischeri make to sense the levels of itself?
Autoinducing Peptide (AIP)
High AIP -> makes luciferase
how does Quorum sensing work?
When sufficient cells accumulate in an environment, they trigger gene expression and transmission of AIPs