| Chromogenic media are used for applications which | | | | media are becoming an increasingly common item in |
| require the detection or enumeration of bacteria and | | | | clinics, hospitals and medical laboratories, with testing |
| other microbiological growth. These media are available | | | | for nosocomial MRSA and Clostridium being especially |
| as a granular material or as a powder which contain | | | | important in clinical settings. |
| enzymes which react chromogenically with different | | | | An especially important use for this type of media is |
| types of microorganisms. The exact type of media | | | | for preliminary screening for common diseases; urinary |
| chosen is dependent on the sort organisms whose | | | | tract infections, for one. These types of infections can |
| presence is being tested for; the enzymes produced | | | | be quickly tested for at clinics using plated |
| by the target population react with the substrate, | | | | chromogenic media, with Klebsiella, Enterobacter and E. |
| causing a change of color. With customized incubation | | | | coli among the organisms readily detectible in urine |
| procedures, the selectivity of the application can be | | | | samples. |
| increased, often allowing for a confirmation of the | | | | Testing for bacterial contamination in foodstuffs is |
| target organism without any need for further testing. | | | | another common application where chromogenic |
| Chromogenic media is a somewhat recent | | | | testing is useful; their ability to determine the presence |
| development in the life sciences, having first been used | | | | of Staphylococcus aureus, Campylobacter, Salmonella, |
| in the late 1980s when the possibilities of selective | | | | E. coli and other coliform bacteria and Listeria can all |
| detection of microorganisms through chromogenic | | | | be tested for. Specific organisms can also be tested |
| reactions came to be recognized. This procedure is | | | | for using chromogenic analysis, making this an ideal |
| often used as a simple test for the presence or | | | | method of ensuring the safety of the food supply. |
| absence of a particular microorganism, but along with | | | | Quite often, the media must be pre-enriched for at |
| other materials or by plating the media, they can also | | | | least 24 hours in order to allow the target organism to |
| be used for the quantitative analysis of microbes. | | | | reach a high enough population to guarantee that |
| It is color differentiation of this type of media which | | | | these microbes will also be present in the chromogenic |
| gives it an advantage over traditional types of culture | | | | media when a subsample is taken for analysis. |
| media. Various types of bacterial colonies can be | | | | However, this is not always necessary, depending on |
| quickly identified through the distinctive hue or intensity | | | | the target organism, the type of media used and any |
| of color that these organisms produce when in contact | | | | other particular demands imposed by the application or |
| with chromogenic media. These media are used for | | | | environment, whether in water and food testing, |
| easy identification of pathogenic microorganisms | | | | screening for common infections or prenatal care. |
| including Candida albicans, Staphylococcus aureus, | | | | Chromogenic testing has become a valuable tool for |
| Streptococcus B (used for screening for perinatal | | | | quickly detecting potentially disease causing organisms |
| Group B Strep in infants) and all serotypes of | | | | and given the increase in dangerous antibiotic resistant |
| Salmonella. | | | | microorganisms, is certain to take on an even larger |
| Due to the increase infections acquired in medical | | | | role in medicine and the environmental sciences. |
| facilities and the rise of multiply resistant bacteria, these | | | | |