Microbiology

HiMedia offers broth media (bouillon), agar media and semi-solid media in dehydrated form for the cultivation and enrichment of microorganisms. In addition to standard media (for standard organisms used in microbiological and clinical research), the product range also includes special media for the cultivation and propagation of specific microorganisms. One focus here is on media for the cultivation of anaerobic bacteria.

Growth media are rich in nutrients and are used for rapid and optimal growth of the test organism. Due to the rich, mostly complex ingredients, however, they are not specific for a certain species, but provide whole groups of microorganisms with optimal growth conditions.

The rapid identification of (pathogenic) bacteria or fungi is of great importance when, for example, the source causing an infection has to be found. For analytical or diagnostic purposes (quality control, clinical microbiology, hospital diagnostics, infectiology), selective media (selective culture media) or differential media (differential culture media) are used to identify microorganisms.

Selective media are characterized by the fact that they promote the selective growth of a specific species (nutrient composition, pH value) and at the same time inhibit the growth of other microorganisms (e.g. by certain chemicals). As a result, only the target organism is able to grow and to form colonies on the culture medium.

By using differential media, on the other hand, it is possible to differentiate between several micro-organisms by means of certain parameters. Differential media are used to differentiate between contaminations or pathogens by the growth pattern, morphology or color of their colonies. This is achieved by the different metabolic activities and enzyme configurations of the various microorganisms. The test organisms carry out a specific chemical reaction with components of the medium and can thus be distinguished from one another. In case it is possible to differentiate the colonies on the basis of color reactions, a medium is referred to as chromogenic medium.
HiMedia has the largest number of chromogenic media (HiCrome™) worldwide. Visual differentiation is a simple, fast and – due to the large amount of data – reliable method that eliminates the need to grow subcultures, thus saving time and money.

In addition to diagnostic media, HiMedia offers a wide range of ready-to-use biochemical differentiation discs, stains, indicators and reagents for rapid identification and differentiation of microorganisms. These products enable rapid screening of bacteria based on staining properties and biochemical characteristics.

The determination of antibiotic susceptibility (sensitivity) – the measurement of the susceptibility of bacterial or fungal isolates to defined antibiotics/antifungals – is an important technique in most clinical laboratories. The test provides a reliable result for the selection of the most appropriate antimicrobial agent for the treatment of an infectious pathogen.

To be in a position to test a maximum number of antibiotics at once, HiMedia offers organism and application specific antibiotic discs for susceptibility testing. In addition to the common Octo-Discs, Hexa-, Dodeka- and Icosa-Discs are also available. The discs are made of an inert material that improves their absorption and thus enables faster adhesion to the medium. By optimizing the location of the individual antibiotics on the disc surface, the merging of the zones of action (zone of inhibition) is kept as small as possible.

There is also a solution from HiMedia for determining the Minimum Inhibitor Concentration (MIC). The EZY MIC™ Strips allow quantification of antimicrobial sensitivity of a wide range of aerobic and anaerobic organisms. The user-friendly system consists of a paper strip with predefined antibiotic gradients. The appropriate EZY MIC™ strip is simply placed on the agar medium inoculated with the test organism and the medium is then incubated under conditions suitable for the test organism.
EZY MIC™ Strip are therefore also recommended for determining the MICs of demanding, slow-growing microorganisms. It offers a high medical value, e.g. for

• Confirmation/detection of a specific resistant phenotype (e.g. ESBL, MBL, VISA/hVISA)
• Selection and dosage of antimicrobial agents
• Detection of low levels of resistance
• Promotion of Antibiotic Stewardship (ABS)

For more information, see our Antimicrobial Susceptibility Systems and EZY MIC™ Strips brochures.