Micro...lol Flashcards
E. coli characteristics
Gram (-) Rod Facultative Anerobe Lactose fermenter *Nitrites* MacConkey agar -- select for gram negative, lactose = pink
What is the most important virulence factor that makes E. coli uropathogenic?
Type 1 or P fimbrae = attachment to eurothelial cells
E. coli cystitis treatment:
Trimethoprim-sulfamethoxazole = Bactrim
or Fluoroquinolone
As short as 3 days
E. coli polynephritis or sepsis treatment:
Fluoroqinolone, 3rd gen cephalosporine (cefotaxime)
7-14 days, Abx sensitivity testing, kidney fxn testing
Why does cranberry juice prevent E. coli
Tannins reduce fimbrae attachment
Enterobacteriaceae are [more/less] pathogenic than E. coli
Less, but more Abx resistant
Old guy with previous indwelling catheter is likely to get UTI by what pathogens?
Klebsiella/Enterobacter/Serratia
What UTI pathogen has siderophores?
Klebsiella – can bind iron
What UTI pathogen has an exotoxin?
Enterobacter – cytolysin to colonize tissue
What UTI pathogen can cause endocarditis and osteomyelitis in IV drug users?
Serratia
What do you see with Serratia urine culture?
Bright red (it’s the thing in your bath tub)
Patient with recent B-lactam use presents with UTI. What likely organism?
Proteus/Providencia/Morganella
Most Proteus/Providencia/Morganella are sensitive to these Abx:
Aminoglycosides
Trimethoprim/Sulfamethoxazole
Enterococcus characteristics
Gram (+) cocci, chains, facultative anaerobes, grow in high salt, catalase (-)
Patient with recent broad-spectrum antibiotic use (3rd gen cephalosporins) presents with UTI. What likely organism?
Enterococcus
Enterococcus treaments: Uncomplicated? Allergic? VRE? Endocarditis?
Uncomplicated = ampicillin Allergic = vancomycin VRE = nitrofurantoin Endocarditis = ampicillin/vanc + gentamycin/streptomycin/ceftriaxone
What antibodies are present in Type O blood?
Anti A
Anti B
What antibodies are present in Type B blood?
Anti A
What antibodies are present in Type AB blood?
NONE
How can erythroblastosis fetalis occur?
Mom Rh (-) has Rh (+) baby –> develops anti Rh Ab –> has another baby that is Rh (+) –> mother Ab attacks baby –> erythroblastosis fetalis
What is the strongest transplant antigen?
Blood group antigen
A person that has many transfusions will have [high/low] panel reactive antibody
High – more transplants = response to more MHCs
Acute rejection is mediated through what cell?
CD8 T cells reacting to MCH1 – stimulated by either MHC2 stimulation of CD4 T (TH1 or TH17,) or APC picking up dead cell antigens
Immune suppression in transplant is targeted towards what type of rejection?
Acute rejection
What is the strongest stimulating MHC?
DR
What pathological changes occur due to chronic rejection?
Thickening of vessel walls –> organ failure
MHC matching requires how many matches?
6 MHC1 matches (3 pairs) = 2A, 2B, 2C
Mixed Lymphocyte matching tests matching of MHC Class [1/2]
MHC Class 2
Positive Mixed Lymphocyte matching is [good/bad]
BAD – positive = T proliferation = mismatch
Daclizumab and Basiliximab target ____ and inhibit [activated/inactivated] T cells
IL-2 (stimulates CD8 cells)
Activated T cells
Common corticosteroids used for maintenance of immune suppression
Prednisone, prednisolone
What are commonly used cytotoxic drugs and when are they used?
Azathioprine, mycophenolic acid = interfere with rapid cell proliferation
Used to maintain immune suppression
What drugs block calcineurin signalling pathway for IL-2 secretion?
FK506 (tacrolimus), cyclosporine
