Pharmacy Courses

Pharmaceutical Microbiology Interview Questions and Answers


Q1. What is Sterilization?

The process which destroys all the forms of microbial life including Fungus,Viruses & viable cells micro-organisms along with their spores byusing Chemical as well as Physical methods is called sterilization.


Q2. What are the type of sterilization?

  • Physical methods: Heating (Dry heat and Moist heat), Radiation, Filtration (by 0.22 micron diameter cellulose filter)
  • Chemical: Formaldehyde, Ethylene oxide, Methanol etc.

Q3. What is the difference between HEPA filter and ULPA filter?

  • HEPA FILTERS (High efficiency particulate air): Removes 99.97% of contaminant particles about of 0.3um diamete rsize.
  • ULPA FILTERS (Ultra-low particulate air): More efficient than HEPA filter removes 99.999% of contaminants of 0.12um diameter size.

Q4. Give some examples of Gram +ve & Gram -ve Bacteria?

  • Gram +ve Bacteria: B. subtilis, B. megaterium, Clostridium botulinm, Mycobacterium tb, Staphylococcus, Streptococcus, Streptomyces
  • Gram -ve Bacteria: E. coli, Acetobacter, Pseudomonas, Salmonella, Rickttesia

Q5. What is Disinfection?

The process of removing or killing the all the form of microbial life except bacterial spores is called disinfection.

Q6. Why 70% Isopropyl alcohol is used as disinfectant in pharmaceutical industries,why not 100%?

The Bacterial cells have proteins in their cell wall and when this protein comes in contact with the 70%IPA during disinfectant application, coagulation of proteins takes places in which denaturation of proteins occurred and after that IPA penetrate in the interior of the cell which cause lysis or death of the cell. 
Protein coagulation also happens in case of 100% IPA but with very fast rate and because of this very fast protein coagulation process denatured protein forms protective layer outside of the cell. When this happens, 100% can not penetrate inside the cell and not able to kill the microbe.

Q7. What are antiseptics?

Antiseptics are the chemical substances which are used in destroying disease causing microorganisms (also called pathogens) externally on wounds or applied on skin surface to treat infection.

Q8. What is C.F.U?

A colony-forming unit(CFU) is a unit that is used to estimate the number of viable bacteria or fungal cells in a sample. Colony forming units are used as a measure of the number of micro-organisms present in or on surface of a sample.

Q9. What is Bioburden testing?

Bioburden testing is performed to determine the total number of aerobic viable microorganisms in or on a medical device, container or component after completion of all in-process steps prior to sterilization.

Q10. What is Enriched media?

These media support the growth of wide variety of microorganisms and doesn't inhibit the growth of microorganisms.

Q11. What is Nutrient media?

These media are also called general purpose media. These media are nonselective and they contain general nutrients which required for the growth of wide range of microorganisms.

Q12. What is BET test?

It is the Microbiological test which carried out to detect the presence of Bacterial endotoxin present in the given sample.

This endotoxin test is also called as LAL Test becuase in this test the 'Limulus Amebocyte Lysate' is used which is the aqueous extract of blood cells of Horse shoe crab.

Q13. What is pyrogen testing?

This method is carried out to detect the presence of pyrogen.(Ames test)

Q14. Who is the father of Microbiology?

Antonie Philips van Leeuwenhoek is known as 'The Father of Microbiology'.

Q15. Who is father of Modern Microbiology?

Louis Pasteur regarded as the father of modern microbiology.


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