How to Write a Summary of an Article? Metera Lab Report 3:
The MSA will select for organisms such as Staphylococcus species which can live in areas of high salt concentration plate on the left in the picture below.
This is in contrast to Streptococcus species, whose growth is selected against by this high salt agar plate on the right in the picture below. The differential ingredient in MSA is the sugar mannitol. Organisms capable of using mannitol as a food source will produce acidic byproducts of fermentation that will lower the pH of the media.
The acidity of the media will cause the pH indicator, phenol red, to turn yellow. Staphylococcus aureus is capable of fermenting mannitol left side of left plate while Staphylococcus epidermidis is not right side of left plate. It tests an organism's ability to ferment the sugar glucose as well as its ability to convert the end product of glycolysis, pyruvic acid into gaseous byproducts.
This is a test commonly used when trying to identify Gram-negative enteric bacteria, all of which are glucose fermenters but only some of which produce gas. Like MSA, this medium also contains the pH indicator, phenol red. If an organism is capable of fermenting the sugar glucose, then acidic byproducts are formed and the pH indicator turns yellow.
Escherichia coli is capable of fermenting glucose as are Proteus mirabilis far right and Shigella dysenteriae far left. Pseudomonas aeruginosa center is a nonfermenter. The end product of glycolysis is pyruvate.
Organisms that are capable of converting pyruvate to formic acid and formic acid to H2 g and CO2 gvia the action of the enzyme formic hydrogen lyase, emit gas.
This gas is trapped in the Durham tube and appears as a bubble at the top of the tube.
Escherichia coli and Proteus mirabilis far right are both gas producers. Notice that Shigella dysenteriae far left ferments glucose but does not produce gas.
The degree of hemolysis by these hemolysins is helpful in differentiating members of the genera Staphylococcus, Streptococcus and Enterococcus. Beta-hemolysis is complete hemolysis.
It is characterized by a clear transparent zone surrounding the colonies. Staphylococcus aureus, Streptococcus pyogenes and Streptococcus agalactiae are b-hemolytic the picture on the left below shows the beta-hemolysis of S.
Partial hemolysis is termed alpha-hemolysis. Colonies typically are surrounded by a green, opaque zone. Streptococcus pneumoniae and Streptococcus mitis are a-hemolytic the picture on the right below shows the a-hemolysis of S. If no hemolysis occurs, this is termed gamma-hemolysis.
There are no notable zones around the colonies. Staphylococcus epidermidis is gamma-hemolytic. What type of hemolysis is seen on each one of the following plates? TOP Streak-stab technique Often when inoculating a BAP to observe hemoloysis patterns, investigators will also stab several times through the agar using an inoculating loop.
This stab allows for the detection of streptolysin O, a specific hemolysin produced by Streptococcus pyogenes. This hemolysin is inactivated by O2 and is only seen subsurface in an anaerobic environment around the stab mark.
Note the oval-shaped areas of clearing around the stab marks in the picture below; these are caused by streptolysin O. Bile Esculin Agar This is a medium that is both selective and differential. It tests the ability of organisms to hydrolyze esculin in the presence of bile.
It is commonly used to identify members of the genus Enterococcus E faecalis and E. The first selective ingredient in this agar is bile, which inhibits the growth of Gram-positives other than enterococci and some streptococci species.Proteus mirabilis is a rapid hydrolyzer of urea (center tube pictured here).
The tube on the far right was inoculated with a urease negative organism and the tube on the far left was uninoculated. The tube on the far right was inoculated with a urease negative organism and the tube on the far left was uninoculated.
Identification of Proteus vulgaris from an Unknown Sample. Praise Selah G. Dagoc Mambajao, Camiguin Abstract Identification of microorganisms from unknown sample is a routine work for a Registered Medical Technologist assigned in the Microbiology section of the laboratory.
Microbiology 20 Biochemical Unknown – Spring (due May 14th) You should be prepared to turn in your notebook with your biochemical unknown identification completed after lab on Thursday May lausannecongress2018.com of a possible 70 points you.
Microbiology 20 Biochemical Unknown – Spring (due May 14th) You should be prepared to turn in your notebook with your biochemical unknown identification completed after lab on Thursday May lausannecongress2018.com of a possible 70 points you. "Proteus Vulgaris Unknown Lab Report" Essays and Research Papers Proteus Vulgaris Unknown Lab Report Unknown Lab Report Dr.
Nathan Cahoone Microbiology December 9, Introduction There are many reasons for knowing the identity of microorganisms.
The second unknown organism was identified as Proteus mirabilis. This organism was also first inoculated using the steak plate method, then a nutrient agar slant, and finally a gram strain was performed.4/4(2).