Bacteria can be found almost anywhere. For human life, some help us, some hurt us, and others are neutral. It is now known that good bacteria, or normal microflora, can reach 1014 microbial cells. This is far more than the 1013 cells that make up the human body (Tannock, 1995). The total number of bacteria on Earth is estimated to be around 4-6 x 1030 (Horner-Devine, 2004). It is important to know the extent of bacteria, how they live, and how they are transmitted because some of them can cause disease. Before 1673, microbes were unknown and people seemed to be dying from unknown causes. It was in this year that Anton van Leeuwenhoek was the first person to see and identify living bacteria (Tortora, 2010). Since this amazing discovery, very extensive research has been done on these tiny organisms and currently a great deal of information is known about them. The lab I am reporting on examines different sources of bacteria. How can these bacteria get on the human body and be problematic?
Methods and Materials
The design of this lab experiment is to isolate bacteria from any location or item without getting bacterial contamination from unwanted places. Microorganisms are found in dust particles suspended in the air or and on nasal secretions that are a result of sneezing (Department, 2009). Materials needed are: 100 ml of melted nutrient agar, five sterile petri plates, and sterile cotton swabs.
The first step is to pour nutrient agar into each of the five plates making sure to use aseptic techniques. Allow this to solidify. While waiting, give each plate one of the following labels: sterile, 1, 2, 3, 4. The sterile plate will be the control. Nothing will be done with this plate to make sure that agar can be poured into a plate without contamination. For plate 1, remove the cover to expose it to the lab atmosphere for allow for any airborne contamination. For plates 2, 3, and 4, choose a source of...
Cited: Department of Veterinary and Microbiological Sciences. 2009. Experiment 3: The widespread distribution of microorganisms in A Laboratory Manual for Introductory Microbiology. North Dakota State University, Fargo, North Dakota.
Horner-Devine, M.C., K.M. Carney, B.J.M. Bohannan. 2004. An ecological perspective on bacterial biodiversity. Proceedings of the Royal Society Biological Sciences 271:113-122.
Tancrede, C. 1992. Role of human microflora in health and disease. European Journal of Clinical Microbiology & Infectious Diseases 11:1012-1015.
Tortora, G.J., B.R. Funke, and C.L. Case. 2010. The Microbial World and You and Principles of Disease and Epidemiology in Microbiology: an introduction, L. Berriman ed. Pearson Education, Inc., San Francisco, California.
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