Clinical / Veterinary

Kirchner medium is a liquid medium for the selective enrichment and isolation of Mycobacteria spp from clinical specimens, particularly when the organisms may be present only in small numbers (e.g. CSF and tissue biopsies).  This medium has been enriched by the addition of calf serum as it is a widely used supplement because it is rich in growth factors. The medium is made selective by the inclusion of Polymyxin B, Ticarcillin and Trimethoprim to inhibit other bacteria and Amphotericin B to inhibit yeasts and fungi. It is generally used in conjunction with a solid medium such as Lowenstein Jensen Medium. Specimens from normally sterile body sites may be inoculated without digestion and decontamination. Other specimens should be pre-treated according to standard procedures. The inoculated medium should be incubated at 35-37°C for up to 8 weeks. Kirchner medium should be used in conjunction with a solid medium (e.g. Lowenstein-Jensen medium) in order to accelerate differentiation and identification testing.

Selenite Mannitol Broth is an alternative to Selenite F Broth for the selective enrichment of Salmonellae spp from Clinical, Food and Environmental specimens. Based on Buffered Mannitol Broth, it is made selective by the addition of Sodium Biselenite. The fermentation of Mannitol by Salmonellae is said to correct the alkaline pH swing which can occur during incubation. Following overnight incubation subculture(s) are usually made on to one or more of the many selective enteric solid media.

This is an agar-based medium for the isolation of Mycobacterium spp. from veterinary samples; particularly the species primarily responsible for bovine TB, M.bovis. The medium is complex but includes L-Glutamic acid, Ammonium sulphate, Sodium citrate, Pyridoxine and Biotin as growth factors and Magnesium sulphate, Ferric ammonium citrate as sources of trace ions. Di-sodium phosphate and Mono-potassium phosphate are also present to maintain the pH of the medium. Further enrichment is provided by the addition of Oleic acid, Albumin and Dextrose. The medium is made selective by the inclusion of Ticarcillin, Polymyxin B, Trimethoprim and Amphotericin B. Malachite green is also incorporated to provide a colour contrast between the colonies and the medium as well as contributing some inhibitory effect on organisms other than mycobacteria. It should be noted that Glycerol is NOT added to this medium as Glycerol can be inhibitory for M.bovis when examining veterinary samples. However, this product contains Lysed sheep blood, Adult bovine serum and Sodium pyruvate to enhance the growth of M.bovis.

Approved by the Clinical & Laboratory Standards Institute (CLSI formerly known as the NCCLS) in USA this medium can be considered as an alternative to Iso-Sensitest Broth for antimicrobial sensitivity testing and MIC determinations by tube dilution methods. It is low in Thymine and Thymidine and is therefore suitable for use in testing Sulphonamides & Trimethoprim. It is sometimes used in conjunction with Mueller-Hinton Agar.

This is an egg-based medium for the isolation and presumptive identification of Mycobacterium spp., particularly Mycobacterium tuberculosis. Designed for use with NaOH treated samples which are neutralised using known buffering solutions to achieve a pH of 6.8 to 7.0 and which are inoculated directly onto LJ media after concentration by centrifugation. NB: this media will NOT isolate M.bovis which requires the addition of pyruvate as a growth supplement.This is normally overcome by the inclusion of a pyruvate slope. Based on the original formulation of Lowenstein that was subsequently modified by Jensen, the medium contains glycerol and egg which provide the required protein and fatty acids. The coagulation of the egg albumin during preparation also provides a solid surface for inoculation purposes. Malachite green is incorporated into the medium to inhibit contaminating organisms other than the mycobacteria that may still be present in the specimen after decontamination. Lowenstein-Jensen slopes should be inoculated with pre-treated specimens and incubated at 35-37°C for 8 weeks in 5-10% CO2. Container caps should be left loose for the first week of incubation to allow for circulation of the carbon dioxide as this will help to stimulate growth. Caps should then be tightened to prevent any dehydration of the medium.

This is an egg-based medium for the isolation and presumptive identification of Mycobacterium spp. Designed for use with NaOH treated samples which are neutralised using known buffering solutions to achieve a pH of 6.8 to 7.0 and which are inoculated directly onto LJ media after concentration by centrifugation. This medium will isolate most common mycobacteria including M.bovis. Based on the original formulation of Lowenstein that was subsequently modified by Jensen, the medium contains pyruvate and egg which provide the required protein and fatty acids. It differs from Lowenstein-Jensen Medium in that Sodium Pyruvate has replaced the Glycerol, which has been demonstrated to be inhibitory to some species, particularly M.bovis. The coagulation of the egg albumin during preparation also provides a solid surface for inoculation purposes. Malachite green is incorporated into the medium to inhibit contaminating organisms other than the mycobacteria that may still be present in the specimen after decontamination. Lowenstein-Jensen slopes should be inoculated with pre-treated specimens and incubated at 35-37°C for 8 weeks in 5-10% CO2. Container caps should be left loose for the first week of incubation to allow for circulation of the carbon dioxide as this will help to stimulate growth. Caps should then be tightened to prevent any dehydration of the medium.