Serratia Marcescens


Physical Description:
Serratia Marcescens is a gram negative & rod shaped bacteria species.

Growth Conditions:

Gram Stain:
The gram stain is a procedure used to categorize & differentiate the different types of bacteria. The procedure was invented by the scientist Hans Christian Gram. The two different categories are gram positive and gram negative. Gram positive will appear purple under the microscope, and gram negative bacteria will appear pink under the microscope. The cell wall of a gram positive bacteria has a single layer of peptidoglycan. On the other hand, gram negative bacteria also have the layer of peptidoglycan, but has an extra cell wall layer made up of lipopolysaccharide.

Methyl Red test results:
The Methyl red test is conducted to see if the bacteria produces acidic waste or not. The methyl red tests results of S. marcescens was negative, so it doesn't produce acidic waste.

Motility Test results:
The motility test results showed that S. marcescens is motile. Motile means the ability of the bacteria to move around. The test was conducted by using a metal rod covered with the bacteria and then stuck into a nutrient tube. The bacteria was shown to be motile because it grew all over the tube. If the bacteria isn't motile, it will only grow around the area where the stab was made.

Hemolysis Test results

Aerobic, Anaerobic, or Facultative:
Tightly sealed in a pickle jar, S. marcescens grew reasonably well, proving that it can grow with or without oxygen. The growth of S. marcescens showed that it does not necessarily need air to grow, showing that it is anaerobic.

Bauer-Kirby test results
the Bauer-Kirby test results showed that S. marcescens was completely resistant to Penicillin and Tetracycline, but backed up by the hand sanitizer and the Amplicillin. Penicillin works by weakening the cell wall of the bacterium. Tetracycline prevents the introduction of new amino acids to the peptide chain of the bacteria. Amplicillin destroys the enzyme transpeptidase, which is needed by the bacteria to make their cell walls. Hand sanitizer just kills bacteria.

Environmental Habitats:
S. marcescens lives in dirt, sterile places, and the subgingival biofilm of teeth.

Diseases:
S. marcescens is associated with human infections. Many strains are resistant to multiple antibiotics.it is transmitted through human contact and contamination, and most symptoms show infections of the body.










Sibo Wang