Antibacterial Soap Discs

In order to determine which ones would be resistant, intermediate, and susceptible to our unknown strain of E. coli we had three antibiotics and one control per agar plate, and we replicated this twice. A lawn of the E. coli strand was spread evenly on each agar plate with a cotton swab. We then divided the agar plate into four halves and placed an antibiotic sample in each half with forceps. We incubated the dishes for forty-eight hours. Our independent variables are the different types of antibiotics with our known and unknown E. coli that we used to conduct the experiment and our dependent variables are the diameters of the zone of inhibition for each antibiotic.

In this lab experiment, two species of bacteria were cultured on tryptic soy agar (TSA) with the addition of four different antibiotics to demonstrate the effectiveness of each anti biotic. The two species grown were E. coli and Staphylococcus epidermidis, both very different in relation to size, shape, and gram state. The four antibiotic drugs tested on the TSA plate were Penicillin, Streptomycin, Kanamycin, and Erythromycin, each with a different function and effectiveness. The following information provided will review the two bacteria’s pathogenicity and the four antibiotics mechanism of action and application.

With this being said, the reason why E. coli was chosen specifically is because it grows at a quick pace and is readily available for observation in lab. During this experiment, the population growth of E. coli is measured overtime to observe which conditions allow for the most efficient growth of each culture. It was hypothesized that based upon prior knowledge of this form

Three of the four quadrants were labeled S, P, T, for streptomycin, penicillin, and tetracycline. One quadrant was left blank for the control (Figure 1.1) Having a control of no antibiotic was used to show the growth of the bacteria when it is uninhibited by antibiotics. Then, Escherichia coli K12 from VWR (catalog #470179-082) and Staphylococcus aureus from VWR (catalog #470179-208) were evenly swabbed across the surface of the agar plate with a cotton swab; ten plates, contained E. coli and the other ten plates contained S. aureus. Then, Streptomycin (10 μg/mL), Penicillin (10 U = ~10 μg/mL), and Tetracycline (30 μg/mL) were obtained and placed into the middle of their respective quadrants. After this, the agar plates were stacked into two stacks of five, for each bacteria, were wrapped with parafilm, and were incubated at 37°C for 48 hours (Figure 1.2). After 48 hours, the plates were moved to a refrigerator at 4°C, until they were taken out of the fridge approximately a week after the stacks of agar plates had initially been placed in the incubator. The diameters of the zones of inhibition were then measured with a ruler and recorded to the nearest millimeter. After measuring the zones of inhibition, a gram-staining technique was used to illustrate the difference in cell wall structure between S. aureus and E. coli. First, a small sample of each species of bacteria was transferred with a loop from the agar plate onto two different areas on a microscope slide that had previously been washed, wiped with alcohol, and dried. Then a drop of water was added to each bacterial sample, was smeared into a thin layer, then allowed to air dry. Once the bacterial samples were dry, the slide was held at one end and was passed through a Bunsen burner flame with the smeared-bacteria samples facing up.

The hypothesis was not supported because rubbing alcohol did not proved to be the household item with the largest zone of inhibition. Starting with the largest zone of inhibition and ending with the smallest, Betadine was the largest, then the Lysol cleanser, liquid hand soap, rubbing alcohol, Neosporin, Germ-X, and the smallest was the distilled water. Betadine had the largest zone of inhibition of 39.5mm and rubbing alcohol which does not have the largest zone of inhibition of 17.7mm, which rejects the hypothesis. Betadine had the largest zone of inhibition because the active ingredient was povidone-iodine. Povidone-iodine kills eukaryotic and prokaryotic cells and is an antiseptic. It penetrates the cell wall quickly and disrupts proteins

The purpose of this project was to determine the minimal inhibitory concentration of our given antibiotic called tetracycline. Tetracycline is a bacteriostatic agent and instead of directly killing the bacteria, it prevents the growth mainly by inhibiting the synthesis of proteins. We hypothesized that the minimal inhibitory concentration for our test would range from 4 g/mL to 8 g/mL. This process spanned across four lab meetings located in a biology lab at Duncan Hall of San José State University. The first lab introduced us to sterile and plating techniques as we prepared and plated a serial

In this experiment some mistakes and errors that could have impacted on the results. Firstly, it was really difficult to place the amoxicillin paper to the agar plant. Some amoxicillin was smeared some place of the agar plate by mistake, which would influence the result. Furthermore, the discs were put on the table, where are lot of different micro-organisms. Moreover, the agar plates were open when they were put on the disk for a long time after the E. coli have spread around them. Some micro-organisms that are floating in the air could have been place on the agar plates. One agar plate was damaged because smear the E. coli too hard. These kind of human mistakes were all caused by incaution of the operators. The experiment should be done more

Antiseptics play an important role in preventing microbial growth and killing microorganisms. They are used in many fields such as healthcare fields and hospitals as agents to prevent infections. To observe the effectiveness of disinfectants and antiseptics on certain organisms you would use the Kirby-Bauer. The Kirby-Bauer is used as disk diffusion method as seen in Figures 1 and 2. This experiment used filter discs that were immersed in the antiseptics and were placed on the Tryptic soy agar plate containing the organism to test the antibiotic susceptibility. This test is used to discover what antiseptics should be used to treat infections. The zone of inhibition is when bacteria who are vulnerable to the specific antiseptic form a clear

Purpose: To explore the effectiveness of different levels of concentration of antiseptic and antibacterial products’ prevention of bacterial growth.

9. The most effective antibiotic for Culture A is Chlorapherical. The zone of inhibition had a diameter of 31 millimeters. The larger the zone of inhibition the more effective the antibiotic is. The antibiotic is preventing the bacteria from growing, essentially inhibiting the growth and creating the circles. The clear circles around the antibiotic disks show the areas that the bacteria were not able to grow. The smaller the circle or zone of inhibition the less effective the antibiotic is against the culture of bacteria. The most effective antibiotic for Culture B is Tetracycline and Kanamycin. The zone of inhibition was 23 millimeters for both antibiotics. They had the largest diameter, thus the bacteria did not grow as much in comparison

In this experiment an agar diffusion test (Bauer-Kirby Test) will be conducted to determine if a sample of S. aureus is susceptible to any of the five antibiotic discs that were used in this experiment. To begin, with a sharpie divide the outside of the TSA plate into five sections. Once the TSA plate has been divided, inoculate the TSA plate by dipping a sterile swab into the liquid culture of S. aureus bacteria. Swab the entire plate making sure to cover the entire surface of the plate with the bacteria. Next, rotate the plate sixty degrees and swab the entire TSA plate again making sure to cover the entire surface of the plate including the edges of the plate. Next, using aseptic technique sterilize a set of tweezer using alcohol. Using

The materials that will be used for this experiment are. Overnight to 24-Hour culture of E.coli in TSB. T4 bacteriophage. We will have 8 screw cap tubes that contain 4.5ml of sterile agar that are melted and cooled in 55C water bath. 8 TSA plates were used. 1 tube containing 3ml of TSB was used. We had 2 screw cap tubes, they each contained 9.9ml of TSB. We also had 1ml pipettes with pipette pumps. We also had 1 15ml sterile centrifuge tube. A Bunsen burner. We also had a incubator that was set at 37C. Some micropipettes were used as well as a table top centrifuge.

Out of the three antibiotics tested on Staphylococcus aureus erythromycin had the largest zone of inhibition compared to amoxicillin and penicillin. Erythromycin had a 24mm large zone of inhibition, while penicillin had a zone of 9mm and amoxicillin had a zone of 12mm. However when testing Hemophilus influenzae penicillin had the largest zone of inhibition. For penicillin the diameter of the zone of inhibition was 28mm, amoxicillin had 27mm and erythromycin had 16mm. With that being said, for

Our hypothesis was supported by our results, in the fact that the zone of inhibition was created through the use of hand sanitizer against the gram-positive bacteria. Problems that could’ve occur during the experiment would be through the way the disks were soaked in the hand sanitizer, some of them had more of the hand sanitizer than others, which caused a significant difference in percentage covered for the zone of inhibition. This is significant because hand sanitizer does work in eliminating bacteria as well as viruses because it reduces the risk of infection and illness (Tamimi, 3340). Others should care about the results of this experiment because it does show that by using hand sanitizer will drop an individuals risk of contracting bad

The blood agar petri dish was stored in a refrigerator prior to the start of the experiment. Before the experiment could begin, the agar was left to sit in order to allow it to return to room temperature. Using a marker, four test tubes were then labeled A, B, C, and D. Using a syringe, 5 ml of whole milk was measured and poured into each test tube. Then, small samples of the e. Coli specimen were added to test tubes B, C, and D using a sterilized paper clip which was bent into the shape of a loop. After each use, the loop was promptly sterilized. Test tubes A, B, C, and D were then inverted three times. After inverting test tubes B, C, and D, half a teaspoon of raw, ground garlic was added to test tube C using a standardized measuring