Antibiotic Investigation

One person each in a team of four heavily inoculated two Mueller-Hinton agar plates with one of the cultures listed by aseptic transfer from a broth culture using a sterile cotton swab. Each plate was marked off into four segments, a total of eight sectors. One McFarland standard disk containing one of the eight antibiotics tested was placed, using

2. Which antibiotic was most effective in killing the bacterial lawn on each plate? Which was the least effective?

Physicians perform gram stains before prescribing an antibiotic to know if the cell wall type and the antibiotic sensitivity link.

The problem that this experiment is trying to solve is whether or not Staphylococcus epidermidis is resistant or susceptible to various antibiotics. The independent variable for the experiment is the type of antibiotic being used against the bacteria(Ampicillin, Streptomycin, Penicillin, and Tetracycline). The

The Kirby- Bauer method is used to test antibiotics sensitivity to the microbe. Some antibiotics have broad-spectrum effect, which means they inhibit the growth of more than one microbe; while narrow spectrum only have an effective on one group of microbe. In order for this test to be effective a lawn of bacteria has to be made on Mueller- Hinton agar. This agar does two amazing things in the world of science. It contains a starch that makes it test plate transparent (easy to read results) and it control the rate of diffusion of the tested drug. Ampicillin, Gentamicin, Gentamicin, penicillin, and vancomycin are the fours types of antibiotics that were use to test the sensitivity of the microbe to them. The microbe was resistant to Ampicillin;

E.coli outbreaks have steadily grown over the last few decades. An expansion in big farming has led to E. coli not only being found in meat, but vegetation as well, due to waste runoff. This has increased our need for adequate antibiotics that can fight bacteria, like E. coli. The best way to pinpoint which antibiotics work is by measuring their ability to create antimicrobial agents or zones of inhibition. When a paper disc that has been saturated in an antibiotic is inserted in a solution of E.coli and medium, the zone of inhibition will be noted as the clear ring that forms around the disk. The antibiotics efficacy is then determined by measuring each disk zone of inhibition, and comparing these measurements to the zone measurements of an untreated specimen. If an antibiotic is to be deemed sufficient for treating E. coli it should show a zone of inhibition that is at least double the size of the untreated specimen.

Although some agar plates were hard to see if the streptomycin had a definitive zone of inhibition. Ampicillin, erythro-mycin, penicillin, sulphafurazole was ineffective with no inhibition zone.

When investigating this experiment I found many different types of antiseptics all with different effects on bacteria and the effectiveness of all these antiseptics varied. I found

The main objective of this experiment is to investigate the effect of different types of antibiotics on bacteria Bacillus subtilis and Escherichia coli. Some of the main methods used in this experiment

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.

Antibiotics differ from many other drugs in the fact that the treatment is for a very short time compared to drugs used to treat hypertension, diabetes, Parkinson’s, or cancer. The latter disorders have in common that the treatment, from the moment of diagnosis, is life-long. The treatment period for antibiotics is only a few weeks, making the return of investment poor. Increasing demands of authorities in both development and marketing phase and in legislation increase the costs of new antibiotics.[1] [3]

The OR for curing the infection comparing drug with placebo, adjusting for the centers is 2.175, with a p-value of 0.011 which is less than 0.05 and therefore significant. We can conclude that the drug is 2.175 times better at curing the infections after adjusting for centers compared to the placebo.

The Kirby-Bauer disc diffusion method was used to examine sensitivity of antimicrobial agents, it fast and simple way to find an antibiotic to use for a treatment of some type of infection. This method uses a plate that has been cover with the testing bacteria and small disc covered in the antibiotic to see if the bacteria is able to around the disc, it will make an even circle around the disc which is the zone of inhibition. This zone of inhibition diameter can be measured and compared to the interpretation chart to find the antibiotic sensitivity or resistance. When the zone of inhibition is very small or nonexistent this shows that bacteria is resistant to the antibiotic and will not work against this bacterial infection. If the zone is

Antibiotics, composed of microorganisms such as streptomycin and penicillin, kill other infectious microorganisms in the human body. At one point, antibiotics were considered to have “basically wiped out infection in the United States”, but due to their overuse and evolutionary

Antibiotic resistance is when microorganisms, such as bacteria, are able to survive an exposure to antibiotics and these bacteria are now resistant to the effects of these antibiotics. Antibiotic resistance in bacteria has been an issue since antibiotics were discovered. The fact that bacteria can become resistant to our medical treatments such as antibiotics is a natural evolutionary process, but there are certain human contributions that definitely speed up the process. For example, one of the main contributions that will be discussed is the problem of over prescription of the antibiotic drugs. The