BIOL41 Exam 4

lactose fermentation

phenol red broth

• eosin methylene blue
• encourages Gram (-) growth
• dyed colonies if lactose fermented
• contains peptone, lactose, sucrose, and eosin Y and methylene blue

• differential test
• distinguishes Enterobacteriacceae from other Gram(-) rods
• shows fermentation by pH change and gas production

glucose and sucrose were used in lab

• determines what can live on electron transport chain and Krebs cycle alone
• citrate as sole C source
• ammonium phosphate as sole nitrogen source
• green -> blue : POSITIVE 
• growth -> citrate being utilized

• Sulfur reduction (black ppt from sodium thiosulfate)
• Indole production from tryptophan (red layer after Kovacs' reagent -> presence of tryptophanase)
• Motility (movement from stab location)

• cysteine desulfurase
• thiosulfate reductase

tryptophanase (tryptophan -> pyruvate, ammonia, indole)

• 1) fermentation
• 2) decarboxylase
• 3) deamination
• 4) utilization
• 5) hydrolytic
• 6) reduction

• pH indicator for acid production from fermentation
• includes VP test

• pH indicator
• breakdown of R, K, ornithine

tryptophan -- (tryptophan deaminase)--> product+FeCl₃ -> color change

• breakdown with enzyme+water
• 1) -gal
• 2) urease
• 3) indole
• 4) gelatinase

bacteria can hydrolyze lactose

bacteria can hydrolyze tryptophan

bacteria can hydrolyze gelatin

• red : POSITIVE
• reduces nitrate to nitrite
• anaerobic

yellow after Zn : reduces nitrate to N₂ gas

• black : POSITIVE
• organism reduces sulfur

• 1) Gram (-) bacilli
• 2) ferment glucose
• 3) reduce nitrate
• 4) oxidase (-)

10%

• 1.5M deaths of children/year
• 2B cases per year

• lactose fermenters
• "like E. coli"
• normal intestinal flora

• 1) Escherichia
• 2) Enterobacter
• 3) Klebsiella
• 4) Serratia
• 5) Citrobacter

E. coli

outer antigen

flagellar protein

• dangerous pathogen with virulence plasmids
• causes hemorrhagic colitis, hemolytic uremic syndrome
• damage due to toxin produced

• 1) Salmonella
• 2) Shigella
• 3) Yersinia

• 1) typhoid fever
• 2) gastroenteritis (diarrhea)

• 1) dysentery
• 2) gastroenteritis?

• 1) gastroenteritis
• 2) tuberculosis-like sickness

• causes bubonic plague
• spread by flea bites

• 1) thermophiles
• 2) mesophiles
• 3) psychrophiles

all dead vs all dangerous dead

• 1) endospores
• 2) mycobacteria
• 3) protozoan cysts

proteins are denatured

how long it takes to get the microbe # to 0 at a certain T

• dry heat takes longer, requires higher T
• moist heat takes lower T, & is more penetrating

only kills vegetative cells

• sterilizes
• kills all but prions

kills some bacteria & viruses but not all

can sterilize, but takes longer, with higher T

burns all organisms to ash

drying so microbes don't grow

freeze-drying

WBCs

• 1) neutrophil
• 2) basophil
• 3) eosinophil
• 4) monocyte
• 5) lymphocyte

• 1) neutrophils
• 2) basophils
• 3) eosinophils

• 1) monocytes
• 2) lymphocytes

• segmented lobes of nucleus, neutral-staining granules
• phagocytize bacteria
• 55-65%

• 2 lobes in nucleus, granules stain red
• allergic, parasitic reactions
• 1-3%

• dark staining granules
• similar to mast cells, inflammatory response
• 0.5-1%

• largest of leukocytes, horseshoe-shaped nucleus
• blood form of macrophages (phagocytosis)
• 3-7%

• spherical nucleus that takes up most of the cell
• specific acquired immunity (T/B cells)
• 25-33%

bacterial infection

parasitic infection

• 1) tears (mech)
• 2) blinking (mech)
• 3) salt (chem)
• 4) lysozyme (chem)
• 5) peptides (chem)

• most common eye infection
• leading cause of blindness
• repeated infections cause scarring that scratches cornea

swelling (inflammation) or infection of the tissue lining the eyelids in a newborn

substance that evokes the production of one or more antibodies

the part of an antigen that is recognised by the immune system

bacterial capsular antigen, a surface antigen external to the cell wall

one occurring in the lipopolysaccharide layer of the wall of gram-negative bacteria

• 1. a bacterial flagellar antigen important in the serological classification of enteric bacilli.
• 2. the precursor of the A and B blood group antigens; normal type O individuals lack the enzyme to convert it to A or B antigens.

Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses

• fragment antigen-binding
• region on an antibody that binds to antigens
• composed of one constant and one variable domain of each of the heavy and the light chain

• fragment crystallizable region
• tail region of an antibody that interacts with cell surface receptors
• allows antibodies to activate the immune system
• composed of two identical protein fragments, derived from the second and third constant domains of the antibody's two heavy chains

specific type of biochemical test that measures the presence or concentration of a substance in solutions that frequently contain a complex mixture of substances

study of blood serum and other bodily fluids

occur between soluble antigens and homologous antibodies precipitate forms when the two are at concentrations that allow maximum crosslinking in the antigen–antibody complex that forms

In one well is the antiserum; in the other is the sample with unknown antigen composition. The two diffuse out of their respective wells toward each other. If the sample has an antigen that will react with the antibody, then a precipitation line will form at the region of optimal proportions as their diffusion paths pass.

If no precipitation line forms, the test is considered negative. That is, the sample has no antigen that will react with the antibodies.

Particulate antigens (such as whole cells) may combine with homologous antibodies to form visible clumps (agglutinates)

used for blood typing

Enzyme Linked ImmunoSorbant Assay

• 1) specific Ag coated onto wells, unbound washed off, well blocked
• 2) sample w/ unknown Ab added to wells
• 3) secondary Ab added to react with primary Ab, unbound washed off
• 4) substrate added to react w/ secondary Ab (peroxidase) for color change