What color is Serratia marcescens?

What color is Serratia marcescens?

red
Serratia marcescens is a gram-negative, facultatively-anaerobic bacterium and opportunistic pathogen which produces the red pigment prodigiosin.

When does S. marcescens turn red?

As you have observed, this bacterium produces a bright red pigment (which historically has even been mistaken for blood) when grown at temperatures below 35-37C, but does not produce this pigment at higher temperatures, resulting in a pale off-white color.

How do I know if I have Serratia marcescens?

marcescens to produce pyruvic acid, thus it can rely on citrate as a carbon source and test positive for citrate utilization. In identifying the organism, one may also perform a methyl red test, which determines if a microorganism performs mixed-acid fermentation. S. marcescens results in a negative test.

When does S. marcescens turn red and why?

Can Serratia marcescens make you sick?

S. marcescens has been shown to cause a wide range of infectious diseases, including urinary, respiratory, and biliary tract infections, peritonitis, wound infections, and intravenous catheter-related infections, which can also lead to life-threatening bacteremia.

What color is E coli?

Escherichia coli is a coliform lactose fermenter. It forms blue-black colonies with a metallic greenish sheen. The color of E. coli colonies on eosin- methylene blue agar according to Mahon appears blue-black.

What kind of dye does Serratia marcescens use?

Now, Serratia marcescens has a thin peptidoglycan layer, so it doesn’t retain the crystal violet dye during Gram staining. Instead, like any other Gram-negative bacteria, it stains pink with safranin dye. And since it’s a Gram-negative bacillus, it looks like a little pink rod under the microscope.

How many species of Serratia marcescens are there?

Serratia marcescens is a Gram-negative bacteria which belongs to a family of bacteria called the Enterobacteriaceae. Now, the genus consists of at least 20 species, of which eight are known to have caused infections in humans, with Serratia marcescens being the main human pathogen.

How is S.marcescens determined to be lactic acid?

S. marcescens results in a negative test. Another determination of S. marcescens is its capability to produce lactic acid by oxidative and fermentative metabolism. Therefore, S. marcescens is lactic acid O/F+.

What kind of Agar was used to grow Serratia marcescens?

The agar was a general enrichment agar and was not specific for the growth of Serratia marcescens . Growth on Macconkey’s agar . Since the gram stain of Serratia marcescens revealed that the organism was a gram negative bacteria, MacConkey’s agar served as a selective media.