Basic Pharmaceutical Microbiology Interview Questions and Answers

Basic Pharmaceutical Microbiology Interview Questions and Answers:

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

2. What are the type of sterilization?

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

3. 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 diameter size.
• ULPA FILTERS (Ultra-low particulate air): More efficient than HEPA filter removes 99.999% of contaminants of 0.12um diameter size.

4.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

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

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

70% isopropyl alcohol (IPA) is used as a disinfectant in pharmaceutical industries because it’s more effective than higher concentrations, safer to use, and easier to handle.

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.

7. 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.

8. 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.

9.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.

10. What is Enriched media?
These media support the growth of wide variety of microorganisms and doesn’t inhibit the growth of microorganisms.

11. Can you explain the difference between bacteria and viruses?

Answer: Bacteria are single-celled organisms with a cell wall and no nucleus. They differ from viruses, which are non-living entities requiring a host cell for replication. Bacterial cell wall is made up of peptidoglycan, Viruses do not contain a cell wall. Understanding this distinction is fundamental in microbiology.