Staphylococcus Identification Tests

Tests To Know BAP MSA Mstaph broth Coagulase

BAP with Novobiocin Test How to Perform Test: Inoculate a BAP plate using streak plate method and incubate 24-48 hours. Place a novovbiocin disk in the first quadrant of the streak. Property it tests for: This test is used to determine two things: It determines if the organism is resistant or sensitive to Novobiocin It also determines if the organism can lyse red blood cells (hemolysis) Media and Reagents: Media contains nutrient agar with 5% sheep's blood added. A Novobiocin antibiotic disk is added after inoculation.

BAP with Novobiocin Possible test results: Non-hemolytic bacteria Hemolysis Hemolysis occurs if the media surrounding the colonies turns translucent or green in color Novobiocin resistance Measure the zone of clearing around the disk. If the zone of clearing is smaller than the manufacturers recommendations for sensitivity (see package instructions) then the organism is resistant. Non-hemolytic bacteria No hemolysis; Top streak is R for NB and bottom is S Hemolytic bacteria

Mannitol Salt Agar (MSA) How to Perform Test: Inoculate an MSA plate using streak plate method and incubate 24-48 hours. Property it tests for: This tests for the bacteria’s ability to tolerate 7% salt concentration and ferment mannitol. The media is selective because it selects for salt tolerant bacteria. The media is also differential because it differentiates the salt tolerant organisms on their ability to ferment mannitol. Media and Reagents: MSA media contains nutrient agar, mannitol, 7% sodium chloride and phenol red indicator.

MSA Results Reading Results: If the organism is tolerant to salt it will grow. If the organism is not tolerant to salt it will not grow. If the salt tolerant organism can ferment mannitol then there will be yellow zones around the colonies. If the salt tolerant organism cannot ferment mannitol then the media will remain pink. Growth with no mannitol fermentation. Growth with + mannitol fermentation.

Mstaph broth How to Perform Test: Inoculate broth and incubate for 24-48 hours. Property it tests for: This tests for the bacteria’s ability to tolerate 7% salt concentration and ferment mannitol. The media is selective because it selects for salt tolerant Staphylococcus. Media and Reagents: This media contains nutrients appropriate for growing Staphylococcus and 7% salt.

M-STAPH Results Reading Results: If the organism is tolerant to salt it will grow. If the organism is not tolerant to salt it will not grow. Tolerates Salt. Does not tolerate salt.

Coagulase How to Perform Test: Inoculate rabbit plasma with one single colony. Break up colony and stir until blended in plasma. Incubate at 37 degrees C for 24 hours. Property it tests for: This tests for the bacteria’s ability to clot blood plasma using the enzyme coagulase. If the organism has coagulase it will clump rabbit plasma. Media and Reagents: This media contains rabbit plasma dissolved in buffer.

Coagulase Results Reading Results: If the organism is has coagulase it will clump the plasma. If the organism does not have coagulase it will not clump the plasma.