antimicrobial enzymes that degrade the beta 1-4 bond between amino sugar molecules in peptidoglycan. Found in human tears and saliva and also egg whites of hen's eggs.

Weakens the cell walls. As a result the solute pressure of the cytoplasm can cause the cell membrane to rupture resulting in cell lysis and death. Gram neg bacteria usually more resistant to lysozymes because of outer membrane.

to know which antibiotics are most effective in treating the bacteria.

compounds that kill or inhibit microbes

antimicrobials produced by microbes that kiss or inhibit other microbes

measurement of the diameter around the disc in mm to determine the microbes susceptibility to the antibiotic.

1. swab the entire surface of the plate with the organism to be tested.
2. allow the agar surface to dry.
3. either use an automatic dispenser or you can use forceps to place the antibiotic discs onto the medium.
4. invert and incubate for 18 hours.
5. measure the zones of inhibition in mm.
6. Significance of zones determined by Kirby-Bauer chart.

Enterobacteriaceae

gram negative

oxidase negative with only a few exeptions

the production of gas

1. Remove organism from well isolated colony
2. inoculate each compartment by first twisting the wire and then withdrawing it all the way out through the 12 compartments, using a turning movement.
3. Reinsert the wire (without sterilizing), using a turning motion through all 12 compartments until the notch on the wire is aligned with the opening of the tube.
4. break wire at notch by bending.
5. Punch holes with borken off part of wire through the thin plastic covering over the last 8 compartments. Replace caps and incubate for 18-24 hours.
6. after interpreting and recording positive results on the sides of the tube, perform the indole test by injecting 2 drops of Kovac's reagent into indole compartment
7. perform the Voges-Proskauer test if needed for confirmation.

1. Escherichia coli
2. Pseudomonas aeruginosa
3. Staphylococcus species

more than 100,000 CFU

???

1. collect urine sample
2. transfer to sterile shake bottle and shake
3. using calibrated inoculating loops .01 and .001 ml of urine are dispensed to liquefied TSA pours
4. after completly mixing TSA pours between palms, content is poured into petri plates and cooled.
5. After incubation colonies on the 2 plates are counted

to make sure the antibiotic being used is effective.

No.

feces

1. Streptococci occur in chains rather than clusters
2. lack the enzyme catalase

1. Possess enzyme catalase
2. can cause mixed infections with Streptococcus
3. Pyogenic gram positive cocci
4. responsible for nosocomial infections
5. developed resistance to antibiotics
6. exhibits hemolytic capabilities

pus forming

any degree of coagulation from a loose clot suspended in plasma to a solid immovable clot is considered positive.

1. With a wire loop inoculate plasma tube with organisms. use several loop fulls
2. place tubes in 37 degree C water bath
3. check for soidification of the plasma every 30 minutes

Staphylococcus aureus

Stahpylococcus epidermidis

1. Staphylococcus aureus
2. Staphylococcus epidermidis
3. Staphylococcus saprophyticus

tooth decay is the break down of enamel and dentin. occurs in presence of high levels of sugar.

Streptococcus mutans

1. collect saliva
2. add .2 ml to liquified snyder test agar
3. mix saliva and medium
4. incubate for 24-72 hours
5. green = negative
6. yellow = positive

1. part of the normal flora in our body
2. gram positive cocci in pairs or chains
3. facultative anaerobes (makes ATP w/o oxygen)
4. separated into groups by hemolytic pattern and serotype

1. partial helomysis
2. shows greenish and faint halo around colonies
3. discoloration due to loss of potassium from RBCs

1. complete hemolysis
2. clear distinct halo around colonies

no hemolysis

Streptococcus pyogenes

Streptococcus pneumoniae

1. hemolytic patterns
2. serotypes

antibodies specific for protein A

1. positive = clumpin
2. negative = no clumping