Question

Questions 1. What does the term IMVIC mean? 2. Why is the IMVIC useful in identifying Enterobacteriaceae? Are further biochemical tests necessary for complete identification? 3. What diagnostic test differentiates Proteus and Providencia species from other Enterobacteriaceae? om other Enterobacteriaceae 4. How is E. coli distinguished from P. vulgaris on MacConkey agar? On a TSI slant? 5. Instead of TSI, why would a slant medium containing only dextrose and lactose (not sucrose) be preferable for detecting Y enterocolitica? Name such a medium. What procedures, other than biochemical, are used to identify microorganisms! purpose of the control test run in parallel with bacterial agglutination?

Answer 1

1.

IMVic is reffered to as a cipher which is based on four unique tests. These tests include :

a. Indole test : This test is conducted in sulfide-indole-motility culture with Kovac’s reagent added.

b. Methyl red test and c. Voges-Proskauer test : Both these tests are conducted in methyl red–Voges-Proskauer brew with methyl red reagent added to methyl red test and Barritt’s A - Barritt’s B reagents.added to voges proskauer test.

d. Citrate utilization test.: This test is conducted on agar medium of Simmons citrate.

2.

IMVic test is extremely useful in identifying enterobacteriaceae particularly when completed with the use of urease as they assimilate four unique tests, that is, Indole, Methyl red, Voges-Proskauer and citrate utilization test which are responsible for identifying the gram negative bacteria in enterobacteriaceae. Apart from these tests serological and phage tests are also performed for enterobacteriaceae identification.