Indol Test ( Kovac's Reagent): E.a. = negative = yellow/gold ring at meniscus; as for E.c. = positive = red ring at meniscus (immediate change).
Methyl Red Test (Methyl Red Reagent): E.a. = negative = yellow = pH > 7.0; as for E.c. = red color = pH < 5 (immediate change).
Vogues-Proskauer Test (Napthol + KOH Reagent): E.a. = positive = reddish color (not immediate change); as for E.c. = negative = brown/yellow (straw color).
Citrate (Bromothymol Blue Reagent - alkaline pH): E.a. = positive = blue color + growth; as for E.c. = negative = green color.
The IMViC series of tests provides an identification of the principal groups of Enterobacteriaceae that cause intestinal infections, by using the biochemical properties and their enzymatic reactions to specific substrates
IMViC tests (indole, methyl red, Voges-Proskauer, citrate utilization) are typically used for the identification of enteric bacteria, not for streptococci. Streptococci are usually identified using other methods such as hemolysis patterns, catalase, and Lancefield grouping based on cell wall antigens.
I recently completed colony morphology on the E.colispecimen.The results displayed small colonies that were circular in shape, a diameter of approximately 0.5mm, the elevation of the colonies was seen to be slightly raised with the surface incredibly smooth.The colonies were also seen to have a pink colour pigmentation in Mac conkey agar due to its lactose fermenter after growth.The gram stain for these bacteria should be negative rod shaped.
The Kirby-Bauer antibiotic test is a general test that determines if an organism is resistant or susceptible to different antibiotics. Many different types of antibiotics can be used but some of the common ones are penicillin, tetracycline, chloramphenicol, and streptomycin.
IMVIC farmula for e.coli is ++--
The IMViC series of tests provides an identification of the principal groups of Enterobacteriaceae that cause intestinal infections, by using the biochemical properties and their enzymatic reactions to specific substrates
Indol Test ( Kovac's Reagent): E.a. = negative = yellow/gold ring at meniscus; as for E.c. = positive = red ring at meniscus (immediate change). Methyl Red Test (Methyl Red Reagent): E.a. = negative = yellow = pH > 7.0; as for E.c. = red color = pH < 5 (immediate change). Vogues-Proskauer Test (Napthol + KOH Reagent): E.a. = positive = reddish color (not immediate change); as for E.c. = negative = brown/yellow (straw color). Citrate (Bromothymol Blue Reagent - alkaline pH): E.a. = positive = blue color + growth; as for E.c. = negative = green color.
The IMViC test (Indole, Methyl Red, Voges-Proskauer, Citrate) is useful in identifying Enterobacteriaceae because it helps differentiate between different members within this bacterial family based on their biochemical characteristics. Each test targets a specific metabolic pathway that can be used to distinguish between different genera or species of Enterobacteriaceae. This information can aid in the accurate identification of a particular strain and help determine its pathogenic potential.
IMViC tests (indole, methyl red, Voges-Proskauer, citrate utilization) are typically used for the identification of enteric bacteria, not for streptococci. Streptococci are usually identified using other methods such as hemolysis patterns, catalase, and Lancefield grouping based on cell wall antigens.
The IMViC test results that would indicate the presence of fecal coliforms are negative for indole production, positive for methyl red test, negative for Voges-Proskauer test, and positive for citrate utilization.
Quality control in IMViC (Indole, Methyl Red, Voges-Proskauer, and Citrate tests) is performed by using control strains that provide known results for each test. These control organisms ensure the reliability of the test results and help identify any inconsistencies in the testing procedure. Regular calibration of equipment and adherence to standardized protocols further support the accuracy and validity of the IMViC tests. Additionally, periodic reviews and documentation of results contribute to maintaining quality assurance in the microbiological analysis.
IMViC results for Proteus vulgaris are typically indole negative, methyl red positive, Voges-Proskauer negative, and citrate positive. TSI results for Proteus vulgaris show alkaline/alkaline (red/red) slant/butt with no gas production and no hydrogen sulfide production.
Staphylococcus epidermidis indole test - negative methyl red - negative voges proskauer test - positive citrate test - no idea
Indole - NegativeMethyl Red - PositiveVouges Proskauer - NegativeCitrate-NegativeTSI - Alkaline slant/Acid butt with H2SSIM - Motile, H2S positiveUrease - Negative
Given that the two species of swarming gram negative bacilli are Proteus vulgaris and Proteus mirabilis, one must find the tests that differentiate these two organisms. Referencing the Textbook of Diagnostic Microbiology by Mahon, Lehman, and Manuselis, I've found the two major differences are their reactions to citrate and sucrose.One can use automation or strip testing to discover the organisms reactions to these substances.
For the Indole test, you add Kovac's reagent. For the Methyl Red test, you add Methyl Red indicator. For the Voges-Proskauer test, you add alpha-naphthol and potassium hydroxide. And for the Citrate test, you add Simmons citrate agar.