Bacterial Identification: Gram Positive Bacteria Tests - Lab Practical 5 Checklist

Which test is always performed first when identifying an unknown bacterium? It is the same answer as the first item for the Gram Negative Tests

• Gram stain

Using a dichotomous key and the result from a test, determine the next best to perform

• Catalase test

Using a dichotomous key and the result from a test, determine the unknown bacterial species like the Gram negative tests

• Streptococci

Be able to identify a positive result in a Catalase Test

• Bubbles

Be able to identify a negative result in a Catalase Test

• no bubbles

What reagent is used in a Catalase Test?

• hydrogen peroxide

Know which genus from lab tests positive in a catalase test

• Staphylococcus

Know which genus from lab tests negative in a catalase test

• Streptococcus

What kind of media is Mannitol salt agar (MSA)

• Selective and differential media

What is the selective property in a MSA?

• Salt

What type of bacteria grows on the MSA media?

• Staphylococcus (gram +)

What is the different property of MSA?

• Ferment mannitol

Know what is means if the media is red/ pink in MSA

• Doesn’t ferment mannitol

Know what is means if the media is yellow in MSA

• Ferments mannitol

Be able to identify a positive result in a coagulase test

• clot forms

Be able to identify a negative result in a coagulase test

• Plasma stays a liquid

Name the reagent in a coagulase test

• Rabbit plasma

Know the media for the bacitracin and optochin susceptibility test

• BAP

Be able to identify if the bacteria in NBC susceptibility test is resistant

• No zone of inhibition

Be able to identify if the bacteria in NBC susceptibility test is susceptible

• Has a zone of inhibition

What kind of media is used in a blood agar plate (BAP)

• Differential media only

Be able to identify if the result is beta hemolysis in BAP

• white around growth

Be able to identify if the result is beta alpha hemolysis in BAP

• Darker color around the growth