Bacillus Cereus Lab Report Answers

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1. Summary of how I identified Bacillus cereus.
a. First, I performed the gram stain test, I then went on to do the spore stain.
b. The results I obtained from the gram stain were gram positive rods, I could tell they were positive by the purple color to them and the rod shape by the comparison provided in the lab manual (Wilkosz, Peterson). After I confirmed the results I performed the spore stain, which indicated that my sample was positive so it contained endospores. The sample should have shown that there was a red vegetative cell and a green stained endospore (Wilkosz, Peterson), but I must have over rinsed with water because the cells appeared clear with an outline, and the spores that were seen appeared as black dots.
c. The first test performed was the gram stain, the purple color indicated that it was gram positive, this removes all gram negative possibilities including Pseudomonas aeruginosa, Klebsiella pneumonaie, and Proteus vulgaris. Since I also observed that the bacteria were rod shaped, it excluded the cocci specimens Staphylococcus aureus and Streptococcus pyogenes. After performing the spore stain and noticing that there were spores, which concluded that it was Bacillus cereus.
d. I had Unknown plate #12 which I determined
…show more content…
Bacillus anthracis can enter the body in four different ways: cutaneous, ingestion, injection, and inhalation. The endospores found in this bacteria live in the soil, a break in the skin can be exposed to contaminated water or soil. Farm animals could ingest the bacteria where they will begin to grow. Once that animal is made into meat for human consumption, especially when undercooked, the person consuming that meat could become infected. Those who inject heroin into their system, only cases known have been in Europe, run a risk of the infection. Inhalation of the spores can be from those who work with animal products, if some of those animals were infected the spores could be released into the air. (Mayo Clinic Staff

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