Flashcards in Sketchy Micro Deck (46)
Where can the beta lactamase enzyme be found in gram negative microbes?
The periplasmic space
What structure is unique to the gram positive cell wall?
Gram negative microbes have endotoxin in the outer membrane.
this microbe cell wall structure protects against osmotic pressure
Gives rigid support
What does lipoteichoic acid in the gram positive cell walls induce in the host?
TNF alpha and IL-1 production.
This is inflammatory.
How does LPS in gram negative cells induce a host response
Lipid A induces TNF alpha and IL-1 production
O polysaccharide is the antigen.
It is found in the outer membrane of gram negatives only.
What are bacterial spores composed of?
Keratin like coat with dipliclonic acid and peptidoglycan.
What are plasmids composed of?
What is the glycocalyx?
Mediates adherence to surfaces, especially foreign surfaces such as indwelling catheters.
Composed of polysaccharides.
what shape is a coccus?
Bacillus is rod shaped.
What are the two pleomorphic microbes?
Chlamydia and Rickettsiae both visualized with giemsa staining.
What does PAS staining technique target?
Used to diagnose whipple disease
PAS the Sugar
Ziehl Neelsen staining
Also known as carbol fuchsin used to stain acid fast bacteria.
Chocolate agar with factor V (NAD) and factor X (hematin)
This is plating for H. influenza
Thayer martin Agar
For neisseria species
Has trimethoprim, colistin, and nystatin.
What compounds are in Thayer Martin Agar?
For neiseria species.
Bordet Gengou agar made from potatoes or regan lowe medium composed of charcoal, blood, and antibiotic are used for culturing.....
Used for culturing bordetella pertussis
Tellurite agar and Loffler Medium
Laughing child and big TV
Lowenstein Jensen Agar
Eaton Agar requiring cholesteron
For lactose fermenting
Produces acid causing colonies to turn pink.
Eosin-Methylene blue EMB agar
Will present with a green metallic sheen,
Charcoal yeast extract agar buffered with cysteine and iron
Used to culture legionella.
Binds Fc region of IgG preventing opsonization and phagocytosis.
S. Aureus uses this!!!
Enzyme cleaves IgA
S. pneumo (shield)
Neisseria (Ace card in hat)
Helps prevent phagocytosis by Strep Pyogenes.
Which type of bacteria generally produces ednotoxins?
Generally only be gram negative.
howevere some gram positive can as well. Its important to realize as well that endotoxin is not secreted where as exotoxin is.
When comparing endotoxin and exotoxin, which is normally encoded in the bacterial chromosome
Exotoxin is coded by plasmids usually.
When comparing endo and exotoxin, which needs only a small dose to be fatal
when making vaccines, can endotoxins or exotoxins be made into a vaccine?
Exotoxins can be used to make toxoid vaccines.
No vaccines can be made for endotoxins.
When comparing endotoxin and exotoxin, which is heat labile
Exotoxin is destroyed rapidly at high temperatures.
How does the shiga toxin work?
Inactivates the 60S ribosome by removing the adenine from rRNA
How does heat labile toxin from E.coli work?
Increases cAMP levels leading to watery diarhea via increased chloride secretion
How does heat stable toxin from E.coli work?
Heat stable works by creating too much cGMP causing resorption of NaCl and water in the gut.
How does edema factor work?
Causes increase cAMP
Causes the black escar.
How does the vibrio cholera work?
Overactivates Gs leading to increased Cl secretion in the gut and H2I efflux.
How does pertussis toxin work?
Increases cAMP by disabling Gi impairing phagocytosis.
How does Alpha toxin work?
Is a phospholipase that degrades cell membranes leading to gas gangrene and double zone hemolysis.
How does streptolysin work?
Degrades cell membrane lysing RBC and contributing to Beta hemolysis.
What is bacterial transformation?
Ability to take up naked DNA
Adding deocyribonuclease to the environment will degrade the nakd DNA.
What is bacterial conjugation?
Plasmid uptaken via sex!
F+ is plasmid gene require for sex pilus and conjugation
What is bacterial transposition?
Segment of DNA that can jump from one location to another.
Can transfer genes from plasmid to chromosomes and vice versa.
What is bacterial transduction?
A packaging event
Lytic phage infects bacterium leading to cleavage of bacterial DNA
Just think phages!!!
What causes genetic shift/antigenic shift?
Caused by reasortment of genome segments between different animals.
What causes genetic drift/ antigenic drift?
Changes based on random HA and NA mutations in the flu virus.