bact

Question 1

Innate Response

Answer 1

Alt Complement or inflamm

Question 2

Adaptive reponse general

Answer 2

Via pamps (peptidoglycan TLR 1,2,6; spore/endotoxin TLR 4; Flagella TLR 5; CpG DNA TLR 9)

Question 3

Extracell Response

Answer 3

Th2 - humoral response to external strains blocking adherence and exotoxins (Gram pos = no complement due to no OM)

Question 4

Intracell Response

Answer 4

TH1 to IFN-gamma increasing macros and DTH reponse (CD4 cells)

Question 5

Gram pos

Answer 5

ex: staph aureus; thick peptidoglycan lyr with teichoic and lipoteichoic acids

Question 6

Gram neg

Answer 6

ex e coli; Outer LPS (lipid A endotoxin), thin peptidoglycan, Porins

Question 7

Acid Fast

Answer 7

Peptidoglycans, mycolic acid, PM with PL bilayer (Porins OM and permeases IM for ATP). ex: myco spp, nocadia spp

Question 8

Cell Wall Less

Answer 8

no peptidoglycans (myco spp and urea spp), sterols within PL bilyr to maintain fluidity, adhesins on neck

Question 9

External bact structures

Answer 9

Flagella, Pilus and Fimbria (adhesion, cell comm, virulent factor), Sex Pili (used for conjugation = Ag variation for gram neg), capsules (poor immunogens), biofilms (adhesion and protection made of mucopolysaccs)

Question 10

Exotoxins

Answer 10

secreted by type 3 transport in gram -

1. AB toxins - B binds receptor, A is toxicity
2. Membrane disrupting - pore formation and bilayer destruction
3. Super AGs - bridge btwn MHC 2 and TCR leading to increased cytokine lvls = inflamm

Question 11

Genetic Recombination

Answer 11

Reassortment btwn chromosomes

1. Homologous recomb, DNA repair process. Stabs genes introduced by transfer. Incorporation of DNA and recombinase required
2. Site specific - Rqrs homology, rqrs circular foreign DNA and restriction endonuclease. Results in integrated DNA and none is lost

Question 12

Antigenic Variation

Answer 12

evasion of host IR

1. Serotypes - change polysacc capsule therefore Ag
2. Mutations - sub nucleotides
3. Phase variation - switch genes on and off via transC regulators (e coli with mvmt of Lrp for Pap expression; off = Lrp occupying binding site)
4. Cassette switch - DNA reinserted in reverse (salmonella flagella H1 or H2 genes)

Question 13

Transposons

Answer 13

Jumping genes, indirect repeats cleaved by transposons therefore disrupting normal gene expression. Path Islands = mod’d transposons, inserts virulence factors

Question 14

Transformation

Answer 14

uptake of naked DNA for gram pos (strep pneu), under extracell competence factor, ss transported and increases virulence

Question 15

Conjugation

Answer 15

Cell to cell transfer via plasmid, fertility factor and sex pili and oriT and is able to transfer resistance. Hfr is transfer of DNA and recipient remains F -

Question 16

Transduction

Answer 16

transfer via phage (accidental with lytic phase)

Question 17

Transposition

Answer 17

Mvmt of transposons