In order to correctly identify each organism, a chart was created from Bergey’s Manual of Determinative Bacteriology that incorporated all known biochemical test results for each of the thirteen possible organisms. The thirteen organisms were separated into three separate categories, Gram-negative bacilli, Gram-positive bacilli, and Gram-positive cocci. This table can be found in the appendix (Bergey and Holt, 1994). Based on the information in the chart, the order of biochemical tests performed was decided.
Table 1 provides the results of the tests and observations made on unknown 18Y. These results lead to the identification of unknown 18Y as Staphylococcus epiedermidis. The Gram test was first performed on the provided culture of unknown …show more content…
These results lead to the identification of unknown 18X as Escherichia Coli. The Gram test was first performed on the provided culture of unknown 18X. To double-check the results, a second Gram test was performed from the incubated nutrient broth that was grown from a colony of the streak plate. It provided the same results as the first test, Gram-negative bacilli. Since, unknown 18X was determined to be a Gram-negative bacillus that grows best at 30°C, seven of the potential thirteen possibilities matched these characteristics. In order to identify the organism correctly, information assembled from Bergey’s Manual in Appendix 1 was used to decide the order of tests administered. This order can be seen in Figure 2. The first test performed on unknown 18X was the Voges-Proskauer test. Initially, the Methyl-Red test was chosen to be the initial test, however, inconsistent results meant the class was advised to avoid using the Methyl-Red test. Organisms that are normally negative for the methyl-red test will most likely be positive for the VP test, so therefore this relationship can be exploited and the VP test was used instead as the first test (Ljutov, 1961). The negative results of the VP test narrowed to potential identity down to five possibilities (Bergey and Holt, 1994). Using the known characteristics of these five organisms, a citrate test was performed next to future narrow …show more content…
Biochemical tests were selected in an order that would allow the quickest and most efficient process of identifying the correct organism and eliminating the possibilities of the others. Doing so helped conserve supplies and eliminate unnecessary tests. This has real world implications. For example, patients that come to a doctor with an infection expect a quick identification of the organism causing it at the cheapest possible price (Galar A et al., 2012). The more tests performed the higher the cost. However, as a result of running fewer tests, there arises the potential of a false test result that could potentially lead to a false
Table 1 provides the results of the tests and observations made on unknown 18Y. These results lead to the identification of unknown 18Y as Staphylococcus epiedermidis. The Gram test was first performed on the provided culture of unknown …show more content…
These results lead to the identification of unknown 18X as Escherichia Coli. The Gram test was first performed on the provided culture of unknown 18X. To double-check the results, a second Gram test was performed from the incubated nutrient broth that was grown from a colony of the streak plate. It provided the same results as the first test, Gram-negative bacilli. Since, unknown 18X was determined to be a Gram-negative bacillus that grows best at 30°C, seven of the potential thirteen possibilities matched these characteristics. In order to identify the organism correctly, information assembled from Bergey’s Manual in Appendix 1 was used to decide the order of tests administered. This order can be seen in Figure 2. The first test performed on unknown 18X was the Voges-Proskauer test. Initially, the Methyl-Red test was chosen to be the initial test, however, inconsistent results meant the class was advised to avoid using the Methyl-Red test. Organisms that are normally negative for the methyl-red test will most likely be positive for the VP test, so therefore this relationship can be exploited and the VP test was used instead as the first test (Ljutov, 1961). The negative results of the VP test narrowed to potential identity down to five possibilities (Bergey and Holt, 1994). Using the known characteristics of these five organisms, a citrate test was performed next to future narrow …show more content…
Biochemical tests were selected in an order that would allow the quickest and most efficient process of identifying the correct organism and eliminating the possibilities of the others. Doing so helped conserve supplies and eliminate unnecessary tests. This has real world implications. For example, patients that come to a doctor with an infection expect a quick identification of the organism causing it at the cheapest possible price (Galar A et al., 2012). The more tests performed the higher the cost. However, as a result of running fewer tests, there arises the potential of a false test result that could potentially lead to a false