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  and 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 ,

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).

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

Important information for writing discussion questions and participation

Welcome to class

Hello class and welcome to the class and I will be your instructor for this course. This is a -week course and requires a lot of time commitment, organization, and a high level of dedication. Please use the class syllabus to guide you through all the assignments required for the course. I have also attached the classroom policies to this announcement to know your expectations for this course. Please review this document carefully and ask me any questions if you do. You could email me at any time or send me a message via the “message” icon in halo if you need to contact me. I check my email regularly, so you should get a response within 24 hours. If you have not heard from me within 24 hours and need to contact me urgently, please send a follow up text to

I strongly encourage that you do not wait until the very last minute to complete your assignments. Your assignments in weeks 4 and 5 require early planning as you would need to present a teaching plan and interview a community health provider. I advise you look at the requirements for these assignments at the beginning of the course and plan accordingly. I have posted the YouTube link that explains all the class assignments in detail. It is required that you watch this 32-minute video as the assignments from week 3 through 5 require that you follow the instructions to the letter to succeed. Failure to complete these assignments according to instructions might lead to a zero. After watching the video, please schedule a one-on-one with me to discuss your topic for your project by the second week of class. Use this link to schedule a 15-minute session. Please, call me at the time of your appointment on my number. Please note that I will NOT call you.

Please, be advised I do NOT accept any assignments by email. If you are having technical issues with uploading an assignment, contact the technical department and inform me of the issue. If you have any issues that would prevent you from getting your assignments to me by the deadline, please inform me to request a possible extension. Note that working fulltime or overtime is no excuse for late assignments. There is a 5%-point deduction for every day your assignment is late. This only applies to approved extensions. Late assignments will not be accepted.

If you think you would be needing accommodations due to any reasons, please contact the appropriate department to request accommodations.

Plagiarism is highly prohibited. Please ensure you are citing your sources correctly using APA 7th edition. All assignments including discussion posts should be formatted in APA with the appropriate spacing, font, margin, and indents. Any papers not well formatted would be returned back to you, hence, I advise you review APA formatting style. I have attached a sample paper in APA format and will also post sample discussion responses in subsequent announcements.

Your initial discussion post should be a minimum of 200 words and response posts should be a minimum of 150 words. Be advised that I grade based on quality and not necessarily the number of words you post. A minimum of TWO references should be used for your initial post. For your response post, you do not need references as personal experiences would count as response posts. If you however cite anything from the literature for your response post, it is required that you cite your reference. You should include a minimum of THREE references for papers in this course. Please note that references should be no more than 5 years old except recommended as a resource for the class. Furthermore, for each discussion board question, you need ONE initial substantive response and TWO substantive responses to either your classmates or your instructor for a total of THREE responses. There are TWO discussion questions each week, hence, you need a total minimum of SIX discussion posts for each week. I usually post a discussion question each week. You could also respond to these as it would count towards your required SIX discussion posts for the week.

I understand this is a lot of information to cover in 5 weeks, however, the Bible says in Philippians 4:13 that we can do all things through Christ that strengthens us. Even in times like this, we are encouraged by God’s word that we have that ability in us to succeed with His strength. I pray that each and every one of you receives strength for this course and life generally as we navigate through this pandemic that is shaking our world today. Relax and enjoy the course!

Hi Class,

Please read through the following information on writing a Discussion question response and participation posts.

Contact me if you have any questions.

Important information on Writing a Discussion Question

• Your response needs to be a minimum of 150 words (not including your list of references)
• There needs to be at least TWO references with ONE being a peer reviewed professional journal article.
• Include in-text citations in your response
• Do not include quotes—instead summarize and paraphrase the information
• Follow APA-7th edition
• Points will be deducted if the above is not followed

Participation –replies to your classmates or instructor

• A minimum of 6 responses per week, on at least 3 days of the week.
• Each response needs at least ONE reference with citations—best if it is a peer reviewed journal article
• Each response needs to be at least 75 words in length (does not include your list of references)
• Responses need to be substantive by bringing information to the discussion or further enhance the discussion. Responses of “I agree” or “great post” does not count for the word count.
• Follow APA 7th edition
• Points will be deducted if the above is not followed

• Remember to use and follow APA-7th edition for all weekly assignments, discussion questions, and participation points.
• Here are some helpful links
• The is a great resource