Question

Effectiveness of Disinfectants Data Interpretation Please type the answers to the following questions below (double spaced) and attach the data collection sheets when you hand in this lab report. Answer the first 9 questions True or False 1. Disinfectants always remove all bacteria and fungal spores from an object. Antiseptic is another term for disinfectant. The presence of blood serum, skin tissue and other body fluids would interfere with the antimicrobial action of disinfectants. The use of carbolic acid as a germicide in an operating room provided the beginning of aseptic surgery. 5. Confluent growth is a thick growth of bacteria (a bacterial lawn) over the entire surface of the medium. The zone of inhibition is the clear zone around an antimicrobial agent in which no bacteria are growing. All disinfectants are equally effective against most microbes. Cutting instruments, thermometers, and plastic materials are best Sterilized by autoclaving. 9. Louis Pasteur first introduced aseptic surgery by using a disinfectant. 10. State your interpretation of these results (e.g., what conclusions Can you draw from the results? Be Careful not to restate your data. Summarize in 2 or 3 sentences.) 11. What factors can influence the activity of a disinfectant? 12.- Why do microorganisms differ in their response to disinfectants? 13. What microorganisms are most susceptible to disinfectants? Why? 14. Which microbial forms are most resistant to disinfectants? Why? 15. How can bacteriostatic and bacteriocidal disinfectants be distinguished?

Answer 1

1. False.

Explaination:

Disinfectants do not kill all microorganisms or fungal spores. The disinfectants act on the metabolism as well as cell wall of the cell and kills it. So, endospore containing microbes and fungal spores are resistant to disinfectants. The process of disinfection is said to be less effective than sterilization process.

2. False.

Explaination:

Antiseptics are the compounds which kill the germs from living tissues such as skin, wounds, mucus membranes, etc. whereas the disinfectants are also used to destroy the germs from non living surfaces such as tables, instruments, utensils, etc.

3. True.

Explaination:

The presence of blood, saliva, skin tissues or any body fluids inhibit the antimicrobial activity of disinfectants. Because they may change the pH of disinfectants and affects its efficacy.

4. True.

Explaination:

Dr. Joseph Lister introduced carbolic acid to clean surgical utensils and wounds. Carbolic acid is used as germicide to kill all germs prior to surgery. Now a days, carbolic acid is called as phenol in medical field and it is used to disinfect the skin and to get relief from itching at the beginning of the surgery in operation theaters,

5. True.

Explaination:

When the cells occupy the available surface area of the medium, the growth is called as confluent growth and concept is called as confluence. As the whole area is occupied, the cells grow one another and form a thick layer.