Download Name: 1 LAB: IMViC TESTS Worksheet 1. The term

Name:______________________________
LAB: IMViC TESTS Worksheet
1.
The term ‘IMViC’ is an acronym for four tests and the order in which they are normally run.
These tests are normally run in order to distinguish between varying __________ bacteria.
2.
The definition of coliform bacteria is ___________________________, facultatively
____________________ or aerobic, non-endospore forming, bacilli (_______ shaped).
3.
These usually produce __________ and acid from _________ fermentation.
4.
Most of the coliforms are placed with their relatives in the family Enterobacteriacae. This
group is more commonly known as the ________________.
5.
Most of these bacteria exist in the _________________ of humans and other animals.
6.
The IMViC tests are good for differentiating between the ______________ bacteria and
Enterobacter cloacae.
7.
IMViC stands for I - _________________________, M -______________________, Vi _____________________________ and C - _________________________
8.
_____________________ is one of the products produced when the amino acid
tryptophan is hydrolyzed. (Not all bacteria break down tryptophan)
9.
Two other products of tryptophan are __________________ and ____________ acid.
10. Some coliforms are able to break tryptophan down because they contain
____________________________ (the enzyme responsible for hydrolyzing tryptophan).
11. 1% _______________________- in water is used to determine whether a coliform has
tryptophanase or not.
12. Following incubation, Kovac’s reagent is added to the tryptone broth. If the reagent forms
a red ring, ______________________ has been produced and thus the organism contains
tryptophan.
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Name:______________________________
13. If the ring is ___________________ and stays green even after sitting 15 minutes, it can
be assumed that there was no indole produced
14. Therefore the organism does not contain _______________________.
15. SIM media may also be used to detect _____________________ production.
16. SIM stands for ________________________, __________________________ and
__________________________.
17.
____________________ reagent is added after the SIM is incubated for 24-48 hours.
18. To properly perform MR-VP tests, the organisms must be grown in MR-VP medium. MRVP has the key ingredient of _______________________.
19. Most of the coliform bacteria convert some dextrose to _____________________ when
initially placed in the medium.
20. After the initial conversion, however, some genera are able to go on and produce more acid
in what is known as mixed ______________ fermentation
21. Other coliform bacteria yield much more neutral end products in what is known as
_____________________________ fermentation.
22. These are good reactions for determining the _____________________ of an enteric
genus.
23. Methyl red is a ______________ indicator that turns ____________ if the pH is 4.4 or
below, indicating ___________________ formation.
24. Voges-Proskauer used two reagents (Barritt’s Reagents A and B) which react with acetyl
methyl carbinol which is a precursor to ___________________________.
25. The VP test will turn _________________ if the precursor is present.
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Name:______________________________
26. It sometimes takes up to _______________ minutes before theVP reagents will react.
27. Citrate is a source of ________________ and is the only source in the synthetic medium
known as ____________________________.
28. The medium also contains the pH indicator bromthymol _____________________ which
indicates _____________________ conditions of pH above 7.6 by turning a
__________________________.
29. The only coliform bacteria that grows well in Simmons Citrate medium are those that can
_________________________ the citrate and use ammonium ions as their source of
nitrogen.
30. If these two things are accomplished, __________________ conditions are produced and
the Simmons Citrate will become bright, __________________.
*= previous lab
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= Lab on ~ P 77 Enzymes with amino acid substrates
31. *Levine EMB Agar inhibits the growth of _________________________ bacteria and
selects for the growth of ____________________________________.
32. *Levine EMB can also be considered ___________________, because______________
______________________________________________________________________
______________________________________________________________________
33. *Levine EMB Agar is differential in that it distinguishes between Enterobacter aerogenes
(colonies _________________ to buff with _________________ centers), Escherichia coli
(colonies have a ____________________ __________________ _______________), and
those that remain _________________________ (Pseudomonas, Salmonella, Shigella).
34.
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35.
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_______________________ remove the amine group (NH).
Cysteine desulfhydrase removes both the sulfhydryl group and the amine group from the
amino acid cysteine. This removal results in the formation of pyruvic acid, hydrogen
sulfide (H2S), and ammonia (NH2). While hydrogen sulfide will have the distinctive odor of
___________________ ________________, it also reacts with heavy metals.
36.
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In the presence of a heavy metal, hydrogen sulfide will leave a ________________
__________________________.
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Name:______________________________
37.
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Triple Sugar Iron agar is used when testing for cysteine desulfhydrase. Once inoculated, if
the triple sugar iron agar develops a _______________________ ___________________,
H2S is definitely present.
38.
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Triple Sugar Iron (TSI) also tests for the presence of _____________________ &/or
lactose in the slant and glucose in the butt.
39.
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The default color is pink but the test is positive for sugar utilization if the pink changes to
________________________ due to a change in the pH.
40.
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Lysine decarboxylase is able to remove the _____________________ group from
lysine. When the carboxyl group is removed, carbon dioxide (CO2) gas and an amine
known as cadaverine is produced.
41.
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The durham tube in the broth will indicate the presence of ____________________ and
the pH indicator dye present in the broth will indicate the formation of cadaverine.
42.
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If bacteria are able to remove an amine group, they contain a ________________
enzyme.
43. Red Violet agar contains bile. Bile is produced by the __________________ stored in the
______________ ________________ and released into the small intestine.
44. Bacteria that thrive in this bile rich environment are known as _____________________
bacteria.
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