Identifying Bacteria Essay Example for Free

Identifying Bacteria EssayBacteria appellation is accomplished in a number of ways. Two common tools microbiologists use to identify little-known bacteria include dichotomous key and biochemical tests. The dichotomous key is useful when a microbiologist only needs to know which group an unknown hemipteran belongs to on a general level. When a microbiologist needs to identify a specific bacterium, biochemical tests atomic number 18 used.PART ONE GENERAL BACTERIA namingReview the dichotomous key in issue A, the bacterial frames in Figure B, and the Gram stain randomness below. You will use all 3 to determine to which major group unknown bacteria belong.Gram Stain ResultsPurple = Gram positiveRed = Gram negativeNeither purplish nor red = No cell wall (neither Gram positive nor Gram negative)Review Figure C on the following page. Use Figure C to identify the type of arrangement displayed by the unknown bacteria. Read through the Sample Identification on the following page f or an example of how to identify bacterial groups and arrangements using Figures A, B, C, and the Gram stain results.Sample IdentificationAfter performing a Gram stain, you observe the following under a microscope(Cells are varnished red.)Begin with item 1 on the dichotomous key (Figure A). Because the organismsare red, they are not Gram-positive. According to the key, continue to item 3. Because the organism is red (not light or another color), it is indeed Gram-negative according to item 3. The key directs you to item 5. Consider the shape of individual cells for item 5. According to Figure B, the shape type is closest to spherical. (Note spherical is circular.) The bacteria belong to the Gram-negative cocci group.Now use Figure C to describe arrangement of bacteria. (The bacteria are not rod- or club-shaped, so focus on the cocci arrangements.) Identify the arrangement that is most prominent. The bacteria are arranged in a diplo- fashion. register the group and arrangement in th e table.ApplicationUse Figures A, B, C, and Gram stain results to identify group and arrangement of bacteria. Continue to Part Two after terminate the table.View from MicroscopeGroup of BacteriaArrangement(stained red)Gram-negative cocciDiplo-(stained purple)(stained purple)(stained red)(stained red)(stained purple)(stained purple)PART TWOCAse study scenario identify specific bacteria through biochemical testing To gain an understanding of the processes involved with identifying bacteria through biochemical tests, access Chapter 6 of the text in WileyPlus located on the Week unmatched course page. Once in WileyPlus (Chapter 6), select the Bacterial Identification by API link located under the heading, Take Another Look. Once selected, review the information and watch the Flash-animated movie (animation) located within this link. Then, review the following scenario and answer the questions that follow.Case StudyA recent outbreak of food poisoning has occurred in a community. One po ssible source of contamination may be the produce that is grown and distributed locally at a farmers market. A test sample of some of the produce revealed evidence of bacterial contamination. The bacteria sample was tested in a microbiology lab and showed the results that follow. The laboratory also performed a Gram stain of the isolated bacteria and ran a number of biochemical tests to aid identification. The biochemical tests were assayed using the Analytical Profile Index (API) 20E system for identification of Enterobacteriaceae and other gram-negative bacteria.Figure 1. Microbiology laboratory results Unknown bacteria present on produce (API Results)Figure 2. API Results of Unknown Bacteria in textual matter FormatGram stainGram-negativeBased on Gram stain results and the knowledge that this bacterium caused foodpoisoning, the laboratory is able to narrow galvanic pile the possibilities to three bacterial strains.Figure 3 shows the API results Figure3. API Results of Known Ba cterial Strains in Text Format Gram stainApplicationCompare the API biochemical test results in Figure 2 (unknown bacteria fromproduce) with API test results in Figure 3 (known bacterial strains identified in the gray boxes on the left). The bacterial strain in Figure 3 that matches Figure 2 will identify the bacterial strain causing illness. Based upon your observations, which of the bacteria in Figure 3 is the most likely cause of the food poisoning outbreak?