Experiment 11-20

If a bacterium produced a metallic green sheen color when it grew on EMB agar, what does this tell you about the bacterium?

It has strong acid production due to lactose fermentation

Which of the following is NOT TRUE about SS agar?

• Lactose fermenting bacteria produce black colonies

• It can test for hydrogen sulfide production

• It inhibits gram-positive bacteria

• Non-fermenting bacteria produce colorless colonie

Lactose fermenting bacteria produce black colonies

What technique(s) were used for the Food lab experiment?

serial dilutions and spread plating

What is considered a positive test for the lactose fermentation tubes when testing for water contamination?

both acid and gas production

If a Lactose fermentation tube is positive for water contamination, what media would be used during the confirmation test?

MUG agar

The number of coliform is determined by a statistical estimation called: 

most probable number (MPN)

_____________________ results in decreased pH and removal of the amino group.

Deamination

A false positive test can result from a Gelatin hydrolysis test if it is not placed in the fridge before recording results. 

true

Phenylalanine Slant is a media used to test for _______________.

deaminase

A positive Ornithine Decarboxylase broth test will be yellow.

false

SIM agar tests for Sulfur reduction, Indole production, and Motility. The addition of what reagent will help determine the result for Indole production

kovacs reagent

Bacteria that have oxygen as the terminal electron acceptor are capable of _________________.

aerobic respiration

Bacteria that use other inorganic compounds as their terminal electron acceptor are capable of ______________.

anareobic respiration

Catalase is a detoxifying enzyme that helps protect bacteria from reactive oxygen intermediates. 

true

A positive oxidase test is visible with a blue/deep purple color. 

true

You inoculate a Thioglycollate broth tube with an unknown bacteria and after 24 hours of incubation you notice growth towards the top of the tube but below the surface. What is the oxygen needs for the unknown bacteria?

microaerophile

After incubation and addition of Nitrate reagent A and B, you notice the media turn a red color. What product is present in the tube?

nitrite

SS agar is selective for ________________ organisms

gram negative

A bacterium grew on SS agar and had clear colonies with black centers. Is the bacteria capable of lactose fermentation?

No

An unknown bacterium grew on EMB agar and produced green-metallic colonies. What type of characteristic results in this type of colony morphology?

strong acid production

What dilution must you use for the MUG agar plate for the confirmed test?

highest possible dilution

After inoculation, you notice that all your lactose fermentation tubes have turned yellow but no bubble is visible in the durham tube. Based on this set of tubes, which dilution will you use for the MUG agar?

none are positive, so none are used

After inoculation, you notice that the MUG agar plate is not fluorescent under a UV light but bacterial growth is present. Can you confirm that E. coli is present in the water sample?

No, the MUG agar did not have any fluorescent growth.

What cell structure will help bacteria survive high temperatures for long periods of time?

endospores

What are the three categories for the Zone of Inhibition?

Sensitive, Resistant, Intermediate

If the ZOI is large, the MIC will be __________.

low

Which of the following is not related to heat sensitivity for bacterial growth?

• halophilic

• psychrophilic

• hyperthermophilic

• mesophilic

halophilic

Antiseptics is used on ____________; disinfectants is used on _____________.

living tissue; inanimate objects

What do TDT stand for in the context of measuring heat effectiveness?

thermal death time

Which of the following is not a determination for ZOI?

• clear zone

• resistant

• intermediate

• sensitive

clear zone

What type of hemolysis produces a clearing around bacterial growth?

Beta

You inoculate a BAP with a strain of staphylococci and after incubation, the media has a greenish-brown color around the bacterial growth. Is this strain of staphylococci pathogenic?

No

Candle jars produce a _______.

CO2 rich environment

All strains of Streptococcus have the same colony morphology on MS plates. 

True or False

False

BEA agar is differential for _____________.

the ability to hydrolyze esculin

The most common cause of a UTI is __________. 

E. coli

Which of the following is not a proper method to collect a urine sample?

• cathteters

• clean catch

• suprapubic aspiration

• collecting from the toilet

collecting from the toilet