micro lab final

Example negative bacteria in a gelatin hydrolysis?

E.coli

Are coliforms usually pathogenic?

no but can be opportunistic 

can a colony be used to start a pure culter ?

yes

Describe a gram -

thin peptidoglycan layer which lose crystal viole and take the safranin in

describe what a slant media is 

helps save space 
helps maintain and prevent contamination 

describe what borth is ?

high concentration of bacteria 

Describe what deep media is for

study bacteria growth in low oxygen enviroments and test motillity 

Describe what plate media is?

large surface that can help grow individual colonies 
we are able to count and view the bacteria colonies 

Example negative bacteria in a Urease test?

E.coli

Example negative bacteria in Amino Acid Metabolims?

Ecoli

Example negative bacteria in citrate test?

E.coli

Example negative bacteria in DNase test?

E.coli

Example of postive bacteria in a citrate test?

Enterobacter a

Example positive bacteria in a gelatin Hydrolysis test?

Serratia m

Example positive bacteria in a Urease test?

Proteus v

Example positive bacteria In amino acid metabolims test?

Proteus v

Example positive bacteria in DNase test?

Serratia m

Example positive bacteria In MIO indole test?

E.coli

Example positive bacteria Ion amino acid metabolims?

Proteus v

Give an example of acidic fermentation product 

acetic acid

Give and example of neutral fermentation products.

Ethyl alcohol

how are bacteria classified in this test?

susceptible (S)
intermediate (I)
resistant (R)

How are microorganism grouped based on temp?

Psychrophiles 
Mesophiles 
Thermophiles 
Hyperthermophiles 

how can we stain the edospore?

use heat to foce the stain to stay inside the endospore 

how can we view capsules ?

negative stain (nigrosin or congo red) make the background black and make the bacteria apear as a halo

how do you identify the MIC in broth dilution test?

the lowest concentration with no growth (clear tube)

How does bacteria look like?

cocci
rods
spirals 

How does staining help the bacteria ?

it colors the bacteria which makes it easier for bacteria to view and it imporve contrast 

How does the broth dilution test work?

bacteria are exposed to defferent concentration of an antibiotic in broth

how does the E test work?

use a strip of increased antibiotic concentration 

how is bacteria metabolism determined?

biochemical test 

If a microscope has a resolution of 0.5 nm, what does it mean?

It can distinguish separate point that are as close as 0.5 nm apart 

if the bacteria ferment lactose on the EMB what does it mean?

acid was produce 
colonies appear purple or metalic green

If you remove the antibiotic disk in a disk-diffusion test, will there be growth underneath it?

No the antibiotic is fully diffused into the agar 

in a {{_}} cells with {{_}} in their cell walls {{_}} the dye even after decoloracation with acid alcohol 

basic acid fast stain
high mycolic acid
retain

in a {{____}} cells with {{____} in their cell walls {{____}} the dye even after decoloracation with acid alcohol 

basic acid fast stain
high mycolic acid
retain

Microorganisms and Microbes cant be see without a 

microscope 

provide all teh types of selective media

EMB
MSA 
MacConkey
PEA

provide all the expamples of differential media

EMB 
MSA 
MacConkey 
Blood agar 

provide an examplae of a bacteria that has a capsule 

Staphylococcus. P

what is resolution

the ability to distinguish close points as separete 

Shorter wavelenght of light provide {{_____ }}

greater resolution

solve the following 
using a 1:40 diluted MB solution prepate a 5 of 10 fold serial dilution in a 10ml final volume using water as a dilution what is the dilution scheme?

40x10 = 1:400
4000 x 10 = ...

solve the following:
1:40 dilution in a 10ml final volume with water as a diluent from the 2mg/ml from MB what is the new concentration of MB

2/40 = 0.05 mg/mL

Specifically (what bacteria) do we use for the follwoing dyes ?
methylen blue 
safranin 
crystal violet 

Bacillus. M
Staphylococcus. E
E.coli

We use a microscope to look at 

Bacteria
fungi

what 2 bacteria can stay yellow in a OF glucose test?

Ecoli
P. aeruginosa.

what are common antimicrobial agents?

disinfectant
antiseptic 
antibiotics 

what are disinfectats ?

chemical used to kill micros on non living surfaces 

what are endospores?

resting structures that help bacteria survive harsh conditions 

What are indicator organisms?

micro that use to signal contaminantion 

what are mesophiles?

bacteria that grow at body room temp

What are psychrophiles?

bacteria that grow at low temp

what are the 2 types of radiation?

Ionizing (Xrays)
non ionizing (UV light)

what are the 3 mehods of isolation of bacteria ?

streak plate 
pour plate 
spread pate 

what are the 3 positistions of an endospore cell ?

central 
subterminal 
terminal 

what are the 4 phase of a bacteria growth ?

lag 
log 
stationary 
death phase

what are the different types of media

liquid 
solid 

what are the different types of simple stains?

direct (stains bacteria)
negative (indirect stain, stains the bacground)

what are the different types of stains ?

simple, differential, and structural

what bacteria are staine dwith crystal violet ?

gram +

what bacteria are used for negative staining ?

bacillus.M 
staphylococcus. E 

what bacteria can stay blue/gree in a OF glucose test?

Alcaligenes f

What bacteria can we use to stain with safranin?

gram -

what bacteria is mainly used in an acid fast stain?

mycobacterium 
nocardia 

What bacteria is more resistant to UV radiation?

Bacillus S bc it has endospore which is resistant to light 

what carries out metabolic reaction?

enzymes

what did acid fast stain discover ?

mycobacterium 
nocardia 

What do you do if theres no color after reagents in nitrate reduction test ?

add zinc 

What do you need to to when you move from the 10x to the 40x?

only use fine knob 

what do zones of inhibition show?

how effective an antibiotic is agaisnt a bacteria 

what does "obligate intracellular parasite" mean?

a virus must live and reproduce inside the host

What does a positive citrate test indicate?

the bacteria can trasport and use citrate for growth 

What does a positive H₂S test indicate in the amino acid metabolism test ?

bacteria can break down sulfure that has amino acids to produce hydrogen sulfide

What does a positive nitrate reduction test indicate in a nitrate reductiont test?

that bacteria can use nitrate in metabolism (reduce it)

What does a postive MR test show?

organims has strong stable acids

what does a postive VP test indicate?

the organims makes neutral end product like acetoin 

what does a steeper line on a death curve mean?

its faster at killing bacteria

What does absorbance (optical density) indicate?

the number of cells in the sample 

What does agar media have ?

has 1.5-3 % agar 

what does amylase do?

break down starch into glucose 

What does antimicrobial agent do?

they kill/inhibit the growth of microorganims 

what does bactericidal mean?

kills bacteria

what does bacteriostatic mean?

stop/slow bacteria growth

what does biochemical test measure?

the ability to break down carbohydrates, proteins and nucleic acids 

What does blue on top and green on bottom mean?) mean inOF glucose test?

no glucose used 

what does broth dilution test measure?

min of inhibitory concentration (MIC)

What does catalase do in a catalase test??

breaks down hydrogen peroxide into water and oxygen (bubbles).

What does DNase do in a DNase test?

breaks down DNA

what does eosin Y and methyle blue do?

they act as a pH indicator form purple in acid conditions 

What does gelatinase do in a gelatin hydrolysis test?

breaks down gelatin (protein) into smaler components

what does immersion oil do ?

increase the resolution of 100x lens 
refractive index of air= 1 oil=1.52 (same as glas)
preventing light from scattering 

What does it mean if bacteria dont grow on either tube in OF glucose test?

dont use glucose 

What does it mean if bacteria grow only in the open tube (no oil)

they oxidative (need oxygen)

What does it mean of bacteria grow in both tubes (with/without oil)

they fermentative

what does kirby-bauer method measure?

zone of inhibition arround antibiotic disk 

what does large zone of inbition mean?

bacteia is more susceptible to the antibiotic 

What does low tem do to bacteria?

make it bacteriostatic (slow/stop growth)

What does no color after zinc mean in nitrate reduction test mean?

postive (reduce gas)

what does ornithine decarbozylase test detect in amino acid metabolism?

show decarboxylate ornithine