Bacillus Cereus Bacteria

a. What were your results? Name the bacteria and appearance after staining.

The morphology was viewed under microscope 1000x magnification using oil immersion. The microorganism has rod shape and purple colouring at the end of the Gram stain procedure. This implies that the bacteria had only one cell layer, which absorbed the crystal violet stain. Therefore, the microorganism is gram positive, and based on the morphology, the microorganism is Bacillus cereus (Brooks et al. 2013).b. Describe two ways the food(s) could have become contaminated. Food gets contaminated in several ways. Notably, all hands look clean but may still harbour bacteria. Uncovered coughs as well as sneezes may cause the spread of pathogens. In most cases, food borne pathogens

Name two ways contamination could have been avoided.Most of food pathogen endospores are heat resistant; therefore, they are likely to survive the temperatures that normally destroy food borne pathogens. It has been hypothesised that heat resistant increases with salinity and tends to decrease with acidity. According to recommendation by Food Code, hot food should be maintained at 57 degrees Celsius (135º F) and cold foods should be kept at 5 degrees Celsius (41ºF). Other methods recommended include steaming under pressure to destroy spores. It is important to ensure that the refrigerated foods are not stacked together, thereby allowing adequate flow of air (Brooks et al. 2013).d. Did you find any microorganism known not to cause food poisoning? What?Yes, Clostridium tetani- a gram positive spore forming bacteria. It was differentiated from Bacillus cereus in that C. tetani appearance resembles tennis rackets (Brooks et al. 2013).e. In what ways does Gram staining aide in the identification of unknown bacteria? Gram stain procedure is the single most common identification procedure used by bacteriologist. It helps describe bacteria into Gram negative or Gram positive bacillus. This is important when identifying unknown bacteria, because it helps one note the colony morphology, individual bacteria shape, as well as their reaction to the Gram stain. This information aids in reaching diagnosis and treatment procedures (Leboffe and Pierce, 2010). f. If you forgot to add

This is because the cells are normally stained with Gram's iodine solution which forms a complex with crystal violet stain that is insoluble in water. Addition of decolourizer dehydrates the peptidoglycan layer; tightening it and shrinking peptidoglycan layer of the gram positives, making the large complex not penetrate the layer. When a counter stain is added, it does not disrupt the complex i.e. purple colouration of the Gram positive cells. Therefore, in absence of Gram's iodine solution, the Gram positive cells would stain brownish red as gram negative cells, making it difficult for the identification of the unknown bacteria (Leboffe and Pierce, 2010). 13. (2 points) Control slides are missing in The Gram Stain Investigation. What are they and what is their importance in the straining