Being aware of your expertise in microbiology a colleague hassent you four different strains of unknown bacteria and asks you tohelp in identifying each isolate.
Table 1 lists some characteristics you have determined for eachisolate (Strain A, Strain B, Strain C and Strain D).
Table 1. Characteristics of four unknown bacteriaisolates.
Test | Strain A | Strain B | Strain C | Strain D |
Gram stain | Gram positive | Gram negative | Gram positive | Gram positive |
Cell morphology | Rod | Rod | Rod | Coccus, in clusters |
motility | motile | motile | motile | Non-motile |
Aerobic growth | yes | yes | no | yes |
Anaerobic growth | yes fermentative | no | yes fermentative | yes fermentative |
Pigment of colonies | white | cream fluorescent | white | white |
Growth on MSA | No growth | No growth | No growth | Yes, growth |
Endospores | yes | no | yes | no |
Catalase test | positive | positive | negative | positive |
Oxidase test | negative | positive | negative | negative |
- Based on the information in Table 1 suggest a possiblegenus for each strain. Clearly explain the keycharacteristics and your reasoning for your proposedidentifications. It is NOT necessary to provideidentification tospecies.                      Â
b. What techniques could you use toconfirm your suggested identification for each isolate and enableyou to determine identification to species?
