Assignment: Joliet Junior Effect of Disinfectants & Antibiotics on Growth of Microorganisms

testing the effect of disinfectants and antibiotics on the growth of microorganisms.  Please study the Exercise in the lab manual. In this exercise, a bacterial culture is spread over a plate completely and various paper discs, each saturated with a different disinfectant or antibiotic, are disposed on the plate in an equidistance fashion and the plate is incubated overnight. The plate is then analyzed for the growth of culture with respect to a given disc. If bacterial strain is sensitive, meaning it is killed/inhibited by what is in this disc, then bacteria will not grow around the disc forming a large “no-growth-zone” or “growth-inhibition-zone.” If the bacterial strain is resistant to the disinfectant/antibiotic, it will grow close to/into the disc forming a very small “no-growth-zone.” The diameter of this zone is then measured in millimeter (mm) and recorded. This data is then compared to a reference table to identify if the microorganism is resistant or sensitive to the disinfectant/antibiotic in that particular disc. See example-1 and example-2 plates.

In the lab, each group would culture a separate bacterial strain on 4 plates and dispense various discs on each plate: two plates would get 8 discs each with a different antibiotics and the other two plates would get 8 discs each with a different disinfectants (see the names of each antibiotic and disinfectant in the first two tables). For the assignment, download this Lab Exercise 10 worksheet,

Data Antibiotic B. sub. E. coli M. lut. P. aerug. S. aur. S. marc. Plate A (Antibiotic 1) 1 Ampicillin (10mcg, AM 10) 25 10.6 30 13 30 6 2 Neomycin (5 mcg, N 5) 15 6 14 13 7 13 3 Tobramycin (10 mcg, NN 10) 18 6 13 6 15 13 4 Carbenicillin (100 mcg, CB 100) 30 20.6 32 6

30 27 5 Penicillin G (10 units, P 10) 25 6 32 6 30 6 6 Amikacin (30 mcg, AN 30) 19 10.6 20 15 15 20 7 Tetracycline (30 mcg, TE 30) 20 20.4 32 15 30 11 8 Amoxicillin (20 mcg, AMC 20) 23 20 32 6 30 6 30 25 25 6 30 6 10 Streptomycin (10 mcg, S 10) 13 13 23 6 15 16 11 Erythromycin (15 mcg, E 15) 35 10 32 6 20 6 12 Vancomycin (30 mcg, VA 30) 25 6 22 6 18 10 13 Bacitracin (10 units, B 10) 15 6 27 9 20 6 14 Chloramphenicol (30 mcg, C 30) 30 27 32 6 25 13 15 Oxacillin (1 mcg, OX 1) 13 6 6 8 30 6 16 Polymyxin B (300 units, PB 300) 9 10 9 6 6 9 Plate B (Antibiotic 2) 9 Sulfamethoxazole/Trimethoprim( SXT) Ave. Zone of Inhibition Bacteria (mm) 1 Ave. Zone of inhibition Antibiotics (mm) Table 2. Antiseptics/Disinfectants Data Antiseptics/Disinfectants B. sub. E. coli M. lut. P. aerug. S. aur. S. marc. Ave. Zone of inhibition Antiseptics/Disinfectants (mm) Plate C (Antiseptics/ Disinfectants) 1 0.2 M Zinc Sulfate ZnSO4*7H2O 50 6 12 15 >50 13 2 20% Cupric Sulfate CuSO4 *5H2O 42 10 30 6 >50 23 3 0.1 M Mercuric Chloride HgCl2 36 10 24 6 >50 21 4 0.2 M Silver Nitrate AgNO3 26 20 20 6 >50 14 5 70% Ethanol (C2H5OH) >50 6 >50 6 >50 6 6 2% Sodium Azide >50 20 >50 6 15 >50 7 3% Hydrogen Peroxide (H2O2) >50 20 >50 6 >50 25 8 Betadine Sol. (10% PovidoneIodine) 32 15 >50 6 >50 20 36 22 36 25 20 14 10 Ci-Decon 16 10 28 6 23 6 11 Bleach 16 16 22 11 12 11 12 Anti-septic Hand Cleanser 14 6 14 6 10 6 13 Antibacterial Toilet Bowl Cleaner 36 23 40 14 30 9 14 Cepacol 15 6 16 6 8 6 15 Listerine 28 9 6 6 10 6 16 Scope 22 6 15 6 22 6 Plate D (Antiseptics/ Disinfectants) 9 Micro-Quat Germicidal Detergent Ave. Zone of Inhibition Bacteria (mm) Note: the smaller the ZOI (NGZ) the more resistant the bacteria to the given antibiotic/disinfectant is and the larger the ZOI (NGZ) the more sensitive the bacteria to the given antibiotic/disinfectant is. 2 Exercise 10 Questions. Name _________________________ Section # ______________________ 1. Name three specific pieces of information which may be determined from the disk diffusion method. 2. Explain minimal inhibitory concentration (MIC)? (1-2 sentences).

Top nursing paper writers on hand to assist you with assignment : Assignment: Joliet Junior Effect of Disinfectants & Antibiotics on Growth of Microorganisms

Can MIC be determined using the disk diffusion method? If not, then what method is used to determine MIC? (1-3 sentences) 3. Assume the chemical with the largest average zone of inhibition is the most effective of those tested. Complete this table by referring to the class data in Tables 1 and 2. Most effective antiseptic/disinfectant Least effective antiseptic/disinfectant Most effective antibiotic Least effective antibiotic 4. What are some of the limitations of our experiment in determining the “best” disinfectant/antiseptic? 5. Assume a bacterium shows a small zone of inhibition or none at all because it is resistant to the chemical tested. Complete this table by referring to Tables 1 and 2. Bacterium most resistant to antiseptics/ disinfectants tested. Bacterium least resistant (most sensitive) to antiseptics/ disinfectants tested Bacterium most resistant to antibiotics tested. Bacterium least resistant (most sensitive) to antibiotics tested 3