What biochemical tests are used to identify Staphylococcus?
3.1. Biochemical tests used to confirm S. aureus were coagulase test, catalase test, indole production, methyl red test, Voges-proskauer reaction, urease production, citrate utilization and sugar fermentation [12].
How is a dichotomous key used to identify sources of infection?
“Dichotomous” means divided into two parts, hence the dichotomous keys always present two choices based on the key characteristics of the organism in each step. By correctly selecting the right choice at each stage, the user will be able to identify the name of the organism at the end.
What is the main biochemical test used to distinguish between Staphylococcus species?
Coagulase test This test is performed on Gram-positive, catalase positive species to identify the coagulase positive Staphylococcus aureus.
What are biochemical tests in microbiology?
Biochemical tests are the tests used for the identification of bacteria species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one type of organism to another.
What is a dichotomous key used for in microbiology?
A dichotomous key is an important scientific tool, used to identify different organisms, based the organism’s observable traits. Dichotomous keys consist of a series of statements with two choices in each step that will lead users to the correct identification.
What should the first test in any dichotomous key do?
The first step in the identification of an unknown bacterium is often to determine its morphology and Gram stain reaction. This allows you to eliminate many possibilities (for example, a Gram negative bacillus is not Staphylococcus aureus or Bacillus subtilis).
What is the novobiocin test what is it used for?
To determine the susceptibility pattern of bacterium to antibiotic novobiocin.
What is biochemical test in microbiology lab?
Biochemical tests are the tests that are performed on different bacteria for their identification on the basis of their biochemical activities towards different biochemical compounds.
How do you perform a biochemical test?
Test Procedure
- Dilute your organism in a tube of sterile water to obtain a turbidity equivalent to the 0.5 McFarland test standard.
- Using a sterile 1mL pipette, place 1 mL of organism into the middle of the tube.
- Cap tightly; do not jostle.
- Incubate for 24 hours at 37°C.
What are the biochemical tests for Staphylococcus aureus?
BIOCHEMICAL TESTS FOR STAPHYLOCOCCUS AUREUS (S. aureus) TEST RESULT Coagulase +VE (POSITIVE) Catalase +VE (POSITIVE) Gelatin Hydrolysis +VE (POSITIVE) H2S production -VE (NEGATIVE)
How do you differentiate Staphylococcus from other organisms?
If red colour is formed then nitrate reduction test positive and no colour change then negative test results. Staphylococcus organism gives a positive reaction for nitrate reduction test. From the above biochemical test, we can easily differentiate Staphylococcus organism from other organism.
What is the reaction of Staphylococcus aureus in DNase test?
Staphylococcus gives a positive reaction for DNAse test.2 Prepare nitrate broth in test tube and inoculate the test organism in this under aseptic conditions. Then incubate it at required temperature for about 24-48 hours.
Is mannitol fermentation test useful for Staphylococcus aureus?
However, these sugar fermentation tests are of no diagnostic value in routine laboratory tests except Mannitol fermentation which is of great importance in differentiating Staphylococcus aureus which is mannitol positive from other non-pathogenic Staphylococci, especially from Staphylococcus epidermidis.