Exam 10: Identifying and Classifying Microorganisms

You tell the patient that his sample contains white blood cells in which Gram-negative diplococci can be detected. Your patient asks how you obtained this result and you tell him you

You isolate a prokaryote. After performing analysis on the organism, you cannot find a description matching that of your organism in the reference text Bergey's Manual of Systematic Bacteriology. This suggests that you have likely isolated a new organism.

Streptococcus pyogenes can be easily distinguished microscopically from other Streptococcus species.

Which statement regarding the Gram stain is FALSE?

You are working in a clinical lab. Two E. coli samples are sent to you for analysis and you are asked to determined whether they are the same strain. You perform an antibiogram and find that the two samples exhibit the same sensitivity to the antibiotics you use in the procedure. This indicates

The three domain systems consist of Archaea, Bacteria, and Eukarya.

To study the phylogeny of eukaryotes,

Serological methods

Explain the difference between a biotype and a serotype.

All known species of bacteria are described in Bergey's Manual of Systematic Bacteriology.

Gram-positive encapsulated diplococci found in sputum are likely

Very often clinically relevant information may be obtained by examining

You have identified the causative organism of the outbreak as E. coli. In an effort to characterize the strain of the organism involved, you do different tests. The results are as follows: Gram stain-Gram-negative rods; Oxidase test-negative; Lactose fermentation-positive; Serological testing-O157:H7; Colony morphology-smooth, creamy colonies; RFLPs-E. coli O157:H7; Antibiogram-resistant to ampicillin. Which test(s) confirm the identity of the organism at the strain level?

Please select the FALSE statement regarding taxonomic hierarchy.

Modern approaches to evolutionary taxonomy often involve

E. coli is a Gram-negative bacillus that is found as intestinal normal microbiota. Which of the following would not be useful for an initial step in identifying E. coli O157:H7 strains in a stool sample?

In a MALDI-TOF assay,

The three domain classification scheme uses

Media that change color as a result of the biochemical activity of growing bacteria

Which of the following is NOT a method used to differentiate E. coli O157:H7 from other strains based directly on genotype?