IMViC
The IMViC test is a microbiological method to distinguish Escherichia coli from other Enterobacteriaceae . Here stands
- I for -indole test on indole
- M for the methyl red sample for the detection of acid formation
- V for the Voges-Proskauer test for acetoin formation
- i is a filler for better pronunciation
- C for the test for citrate utilization .
The method is mainly used for drinking water analyzes , since Escherichia coli is a faecal indicator , but must be distinguished from other Enterobacteriaceae. Microbiological companies have developed test sticks that contain all four IMViC tests so that they can also be performed by untrained personnel. After inoculation and subsequent incubation , only the discoloration of the individual test fields has to be read off.
| Microorganism | Indole formation | Methyl red sample | Acetoin formation | Citrate utilization |
|---|---|---|---|---|
| Escherichia coli | + | + | - | - |
| Klebsiella aerogenes | - | - | + | + |
| Pseudomonas aeruginosa | - | - | - | + |
| Citrobacter freundii | - | + | - | + |
The test for utilization of citrate as the only energy source is carried out by growing on a culture medium that contains only citrate as an energy source. The medium also contains bromothymol blue as a suitable acid-base indicator , which is green at a medium pH value and turns blue if the test result is positive as a result of the acid consumption and the alkalization of the medium.
The classic IMViC test is currently mostly supplemented by further examinations as part of a so-called colorful series . Tests for hydrogen sulfide formation, starch utilization, urea utilization, hydrolases, decarboxylases and the coagulation of blood serum are common.
The test can be combined with the Eijkman test in order, among other things, to obtain faster intermediate results.
literature
- EM Powers, TG Latt: Simplified 48-hour IMVic test: an agar plate method . In: Applied and Environmental Microbiology , Vol. 34, 1977, pp. 274-279, PMID 334074 , PMC 242642 (free full text, PDF)
Web links
- IMViC Test ( Memento from May 28, 2007 in the Internet Archive )
Individual evidence
- ^ Hans G. Schlegel, Christiane Zaborosch: General microbiology. 7th edition. Thieme Verlag, Stuttgart / New York 1992, ISBN 3-13-444607-3 , p. 310
- ↑ Publication by Gutenberg University Mainz (PDF; 23 kB)
- ↑ Steve K. Alexander, Dennis Strete: Microbiology - A photographic atlas for the laboratory . ISBN 0-8053-2732-0 .
- ↑ Michael T. Madigan, John M. Martinko: Brock Mikrobiologie 11th Edition, 2009, p. 896.
- ^ Direct MPN for faecal coliform . PMID 7006259
- ↑ sciencedirect.com
- ↑ Sonnia Levine: The Effects of Temperature on the Imvic Reactions of Coliform Organisms: With a Comparative Study of the Eijkman Test. Massachusetts State College, 1940.