Bacteria In The Study Of Bacteria

Introduction

There were three bacteria that were studied during this experiment. Staphylococcus is a type of bacteria that is often found on the body of human beings and animals. It is found on the skin and hair as well as in the noses and throats. Staphylococcus can cause food poisoning when it is exposed to food and contaminated because the food is not properly refrigerated. (Food Safety) These bacteria are Gram-positive with a spherical shape that often group into clusters, much like grapes. (Bacteriology) The only way to kill these bacteria is by cooking and pasteurization. Bacillus cereus is a type of bacteria that produces toxins that can cause two types of illnesses. One type causes diarrhea and the other causes nausea and vomiting. These bacteria are found in foods and multiple rapidly at room temperature. (Food Safety) Bacillus cereus is also Gram-positive and is rod-shaped and very large. It can spread easily to many types of foods such as plants, eggs, meats, and dairy products. (MicrobeWiki) Escherichia coli is bacteria found in the gastrointestinal tract and are able to produce a toxin that can produce serious infections. This bacterium can be acquired by consuming contaminated food or water. (European Centre) E. coli is often used to help your body break down and digest certain foods. It becomes dangerous when the bacteria go from the intestines into the blood. (Kids Health) Escherichia coli, unlike any other bacteria that was studied, is Gram-negative. It is also rod shaped and is about average size. (Mansfield)

This experiment also tested four different antibiotics with these bacteria. Oxacillin is an antibiotic that is most commonly known to treat staphylococcal infection. This antibiotic ...

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... they will not move when the petri dishes are turned upside down during incubation. After every disk was pushed into the petri dish and looked like the one in Figure 1, the lid needed to be closed. It was very important to check and make sure each petri dish was labeled with the correct antibiotic. Once all the antibiotics were placed in each petri dish and they were sealed, one student from each group was to incubate them upside down in the incubator. After 24 hours, one student from each group was asked to return to the lab to check on their group’s petri dishes. Records of how large of a circle the antibiotics made around the bacteria were put into the Table. After completing the data, each plate was to be put in a tray for autoclave sterilization. The most important thing that was to be remembered was to wash hands, and everything that touched the dishes.