E. Coli Lab Report

1752 Words4 Pages

Ariel Nadler
The Effectiveness of the Antibiotics, Gentamycin, Neomycin, and Streptomycin on the Escherichia coli Bacteria

Introduction:
Escherichia coli, commonly known as E. coli, is a bacterium that is associated with food poisoning. Both in the medical community and the general public there are growing concerns about the health dangers that are associated with Escherichia coli. One major area of concern is its apparent resistance to certain core antibiotics. The bacterium Escherichia coli, is found in both foods and lakes. In terms of food it is mostly beef and dairy products, and sometimes in vegetables due to the fertilizer being partially cow feces. In terms of lakes, E coli can be in any of them. This bacterium causes humans to …show more content…

The slide was placed on a staining tray where the sample was stained using crystal violet. After a minute the sample was rinsed. After that Gram iodine was put on the sample and was rinsed again, after a minute. Following that a 95% alcohol/acetone was dropped on the sample until only a faint violet like color is seen. Immediately following that the slide was rinsed in order to prevent further destaining. Then the sample was covered with safranin for 45 seconds in order to restain the destained gram-negative bacteria making it have a purple-pinkish color. Following this the slide was rinsed and the sample was observed.

Results: The bacterial lawn of Escherichia coli consisted of the antibiotic saturated disks, very few white dot like structures, which are probably colonies of the bacteria, and the zones of inhibition of each of the antibiotics as shown in Figure 1. Each zone of inhibition had a different diameter showing which antibiotic is more effective. Figure 1. The zones of inhibition produced by the antibiotic disks in E. coli bacterial lawn. (Top right: Gentamycin, Top left:
Streptomycin, Bottom left: Neomycin, Bottom right: …show more content…

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