Kirby -Bauer Assay
Abstract:
In this Experiment, antibiotics will be applied to the bacteria to find out which antibiotic will be most effective in controlling the growth of the bacteria by comparing it to the control group.
Introduction:
This lab will help figure out which antibiotic is most effective in hindering the bacterial growth by measuring the zones of inhibition. The antibiotic that creates the greatest zone of inhibition is the most effective antibiotic in controlling bacterial growth. To show this, the experimental groups, which receive the treatment of the different antibiotics, will later be compared to the control group, and whichever antibiotic shows the greatest zone of inhibition will be the most effective.
Hypothesis:
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Clean the work area effectively.
2. Obtain three TSA plates and label as in video.
3. Obtain an inoculate plate and observe the different colonies growing on the plate and record your observations. Note their appearance and other features.
4. Choose one bacterial colony for experiment.
5. Follow the procedure for the experiment as shown in the video make bacterial lawn on the plates and allow to site for a few minutes.
6. Label the quadrants on the media containing half of the petri dish and apply a single antibiotic disc in each of the three test areas and a blank in the fourth. Each of the Kirby-Bauer plates should have one disc of each antibiotic on it.
7. Seal the plates and place them in the designated area for the GTA to collect and incubate at 28 C for 24 hours. GTA will place plates in refrigerator to halt further bacterial growth.
8. Dispose of plates and other materials and directed by instructor.
Week 2
1. Clean the work area properly with sanitizers.
2. Measure the zones of inhibition for each antibiotic and record the data in notebook.
3. Compare results to the guidelines in Table 1. These standardized values indicate whether the bacteria is resistant, intermediately susceptible, or fully susceptible to the antibiotic based on the size of the zone of
After the end of the experiment, the unknown 10 sample was Staphylococcus epidermidis. Come to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man-made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester, it was determined that the blood agar, MSA, and catalase tests are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria.
Bauer AW, Kirby WMM, Sherris JC, Turck M (1966) Antibiotic Susceptibility Testing by a Standardized Single Disk Method. Am J Clin Pathol. 45:493–496.
While completing this lab we used four liquids. We used water, milk, orange juice, and soda. To hold the liquids we used two q-tips. We used two petri dishes, one was to hold the pill bugs while they were not being used in the
After the addition of the media, we insert an aeration tube inside and cover the lid with a cotton plug and start giving them aeration. This preparation has to be put on for 3 days under proper sunlight and 25-30 degree Celsius to observe if the culture is healthy/ potent or not depending on the color each culture portrays (The nanochloropsis culture should have a grass-green color to be seen as potent and the isochrysis culture should have a dark brown color to be seen as potent), if the colors seem dull and light, then that might mean that the culture is impotent.
Kanamycin antibiotics must be further improve so that in the future, more stronger bacteria with more strains can be eliminated but the concentration of the active pharmaceutical ingredients must be controlled so that it will not exceed certain concentration that leads to harmful side effects on the consumer.
Antibiotics basically refer to chemical substances that can inhibit and destroy the growth of microorganisms (Gottileb,1976; Katz and Demain,1977). Antibiotic term was first used in 1942 by Selman Waksman to describe any substance produced by a microorganism which interfere with the growth of other microorganism (SA Waksman, 1947). Each antibiotic is produced by a relatively limited number of species and is inherited from specific set of genes. These are the products of secondary metabolism which can be produced commercially by microbial fermentation after active growth has declined. These compounds are generally synthesized in stationary phase especially idiophase (unbalanced growth phase) so these are sometimes called as idiolites(walker, 1974). Their formation is highly influenced not only by the growth conditions but also by the composition of the culture medium.
Antibiotics are powerful substances which are capable of inhibiting bacterial growth. Antibiotics can be consumed from any part of the body. Essentially there are two different types of antibiotics which perform different operations to the body. (Medical News, 1) The first discovered type is bactericidal, which not only inhibits but initially eliminates the bacterial or microbial organisms, this is done through exterminating the bacterium cell wall which furthermore erupts and causes the bacteria to be killed. The second type is bacteriostatic, as the name states. It aids to inhibit and limit bacterial growth. The antibiotic stops bacterial growth through stopping the process of protein synthesis, or bacterial reproduction. It is consumed to stop the growth of a microorganism permanently or temporarily. (Scientific American, 3) Patients consume antibiotics through the mouth. Antibiotics can also be directly injected into the body. Others can be applied on the infected area of the body, and physically cured or eliminated. (Medical News, 1)
Compounding all of these solutions, the pharmaceutical industry needs to conduct extensive research on developing new antibiotics for various pathogenic bacteria by studying the bacterial structure. This will help scientists to formulate ways of counteracting the functions of the various constituents of bacteria.
Bacteria can be prevented from growing and/or living with the use of antibiotics. Antibiotics combat bacteria several ways by preventing the cell wall from developing properly, protein synthesis hindrance, interferes with deoxyribonucleic acid (DNA) production by impeding cell division, interfering with outer-membrane and plasma function, killing the cell (Aziz, 2013).
6. Unscrew cap on Penicilium italicum culture tube with one hand and flame the mouth of the tube.
The medication of paracetamol can be administered in various ways and they are sold in different formulations. The common dosage comes in tablets form of 500 mg, in dispersible fizzy tablets (500 mg) and oral suspensions. It can also be bought in capsules as a mixture with other API like caffeine and codeine.
Step 1 -. Rub a small amount of sample onto a square of brown paper bag. Step 2 -. Brush off excess food and drink. Step 3 -.
The discovery of antibiotics is attributed to Alexander Fleming who discovered the first antibiotic to be commercially used (Penicillin) in approximately 1928. An antibiotic, also known as an antimicrobial, is a medication that is taken in order to either destroy or slow the growth rate of bacteria. Antibiotics are integral to the success of many medical practises, such as; surgical procedures, organ transplants, the treatment of cancer and the treatment of the critically ill. (Ramanan Laxminarayan, 2013)
4. Put milk samples into the beaker for about five and a half minutes and take samples out after time is up. 5. With the warm samples, open the pouch containing the gel cassette and remove the cassette.
Inconsistencies in this lab could have caused variations in data collecting. Collecting data from one petri dish was challenging because something could have been different on other petri dishes if this experiment was tested on several petri dishes. This could have been different because the other petri dishes could have had more micro-organisms in Section 2 instead of Section 1, or no bacteria could have grown at all in every section of the petri dish.- Second, nothing grew in section B even though there were no disinfectants in that section. The reason why the bacteria and mold might have grown in sections 1, 2, and 3 was because in the process of making the experiment, the coffee filter papers were touched with glove free hands and were not clean. If this lab was run again, some changes would be to wear rubber gloves, do not pour the hand sanitizers on the coffee filter paper but just pour one pump straight into the petri dish, have more than one petri dish to collect data off of, and check when the last time someone cleaned the door knob