What kind of medium is macconkey agar

Media that support the growth of many different microorganisms without distinguishing genera or species are nutritive. In contrast, differential media allow several different types of bacteria to grow, but also contain compounds that allow microbial genera or even species to be visually differentiated. The organisms interact with the added compounds e. This allows for the rapid identification of organisms of interest, which is especially important for heavily mixed cultures, such as stool.

Result Interpretation on MacConkey Agar Lactose fermenting strains grow as red or pink and may be surrounded by a zone of acid precipitated bile. It is necessary to subculture and carry out confirmation tests for final identification. Some strains may be encountered that grow poorly or fail to grow on this medium.

Incubation of MacConkey Agar plates under increased CO2 has been reported to reduce growth and recovery of a number of strains of Gram-negative bacilli. Some strains of Proteus may swarm on this medium. Collin County Community College District. Microbe Online Wikipedia. Please help me Reply. Why does lactose not caramelise in MacConkey despite being autoclaved at 15psi?

Is it possible to get a colorless bacterial lawn of E. Aerobacter aerogenes? Pls what is the colour of salmonella spp on MacConkey agar Reply. Colourless or cream Reply. Pathological specimens. Due to its ability to support the growth of pathogenic Gram-positive cocci e.

Whilst it is selective it does not suppress a mixed bacterial flora to the same extent as other inhibitory media including other MacConkey agars. It provides a number of other diagnostic indications in addition to bile tolerance, such as colony morphology and chromogenesis.

Colonies composed of Gram-negative non-sporing rods are subcultured for further identification. The presence of enterococci in azide or tellurite media may be confirmed by subculture on MacConkey Agar. See below for colonial morphology. Yersinia and Pasteurella differentiation. MacConkey Agar can be used to differentiate Yersinia species from Pasteurella species 4. Pasteurella species including Pasteurella multocida will not grow on MacConkey Agar.

Pectinolytic Organisms Stewart 6 Stewart used Oxoid MacConkey Agar as the basis of a selective-diagnostic medium for pectinolytic organisms, in order to isolate soft-rot Erwinia species from specimens containing other Enterobacteriaceae. United States Pharmacopeial Convention, Inc. The United States pharmacopeia, 23rd ed. Murray, P.

Baron, M. Pfaller, F. It provides a number of other diagnostic indications in addition to bile tolerance, such as colony morphology and chromogenesis. Colonies composed of Gram-negative non-sporing rods are subcultured for further identification. The presence of enterococci in azide or tellurite media may be confirmed by subculture on MacConkey Agar. See below for colonial morphology. Yersinia and Pasteurella differentiation MacConkey Agar can be used to differentiate Yersinia species from Pasteurella species 4.

Pasteurella species including Pasteurella multocida will not grow on MacConkey Agar. Pectinolytic Organisms Stewart 6 Stewart used Oxoid MacConkey Agar as the basis of a selective-diagnostic medium for pectinolytic organisms, in order to isolate soft-rot Erwinia species from specimens containing other Enterobacteriaceae.