Question

write about 600 words about a bacteria called Serratia marcescens. how is this microbe studied and why is it of interest to people?

Answer 1

1. About the bacteria

1. Serratia marcescens is a member of the genus Serratia and a part of the family Enterobacteriaceae. The species that are reported to cause disease are S. marcescens, S. liquefaciens and S. odorifera.
2. They are motile, non-endospore forming Gram-negative rods.
3. Serratia can produce extracellular DNase, gelatinase, lipaseand siderophores.
4. They are usually resistant to antibiotics colistin and cephalothin.
5. S. marcescens can cause infections including pneumonia, lower respiratory tract infection, urinary tract infection and meningitis.
6. It is an opportunistic pathogen. Isolates of S. marcescens are reported to secrete a pore-forming haemolysin that helps in release of inflammatory mediators. The toxin secreted assists tissue penetration and quorum sensing.
7. They are also capable of producing biofilm.
8. Serratia marcescens can be grown at 37°C, it can also grow at temperature range 5–40°C. The bacteria can grow in pH range 5 to 9.
9. Serratia marcescens produces red pigment called prodigiosin which is made up of three pyrrole rings.
10. The G+C content in the genome is close to 59.5%

2. Serratia marcescens is a Gram-negative bacillus that can be isolated from soil and water they can be studied in the naked eye as they are capable of producing a red pigment at a temperature around 30^oC.

3.Interest of people

(i) Serratia marcescens is an important opportunistic pathogen and causes nosocomial infection.

(ii) It is resistant to many antibiotics due to the presence of unique membrane (LPS) in the cell membrane.

(iii) Recent research has shown that the red pigment prodigiosin has an impact on cancer treatment.

(iv) Serratia marcescens is reported to serve as a probiotic and it can inhibit the growth of H.pylori, and thus it can prevent stomach ulcers.

(v) Serratia marcescens has a unique potential to produce extracellular enzymes which can be applied for industrial and agricultural purpose.