Microbiology

Oxoid Corn Meal Agar Mycological medium is used for identification of Candida albicans and maintenance of fungal stock cultures.

Corn Meal Agar, Oxoid Composition

Corn Meal Agar, Oxoid Preparation:
Suspend 17g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Precautions
Glucose supplemented Corn Meal Agar should not be used for chlamydospore production.
Corn Meal Agar with `Tween 80’ (or other wetting agents) will allow Candida stellatoides and Candida tropicalis to produce chlamydospores.
Some Candida strains lose their ability to produce chlamydospores after repeated subculturing.

For the isolation of yeast and molds associated with spoilage, add Oxoid Chloramphenicol Selective Supplement to DRBC Agar Base, Part No. CM0727B; for the enumeration of yeast and molds in foods, add to Rose Bengal Chloramphenicol Agar Base, Part No. CM0549B.

Chloramphenicol Selective Supplement, Oxoid Composition

Chloramphenicol Selective Medium, Oxoid Preparation:
Reconstitute one vial SR0078H per 2 litres medium as directed. Add the vial contents to base medium and mix gently. Sterilise by autoclaving (see media for full details), cool to 50°C, mix gently and pour into Petri dishes.

• Oxoid Raka-Ray Agar Base is a medium for the isolation of lactic acid bacteria in beer and brewing processes.
• Requires supplementation with phenylethanol, sorbitan mono-oleate, and cycloheximide Part No. SR0222C.

Raka-Ray Agar Base, Oxoid Composition

Raka-Ray Agar, Oxoid Preparation:
Suspend 77.1g in 1 litre of distilled water. Add 10ml of sorbitan mono-oleate and 7ml of 0.1% Cycloheximide Solution (SR0222). Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50-55°C and aseptically add 3g of phenylethanol. Pour into sterile Petri dishes or distribute into 4ml volumes held at 55°C if the overlay technique is to be used.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Precautions
Although the concentration of cycloheximide in the medium is below toxic levels, precautions should be observed as detailed under HAZARDS section.

Oxoid Stuart Transport Medium is a semi-solid non-nutritional transport medium for fastidious, pathogenic organisms.

Stuart Transport Medium, Oxoid Composition

Stuart Transport Medium, Oxoid Preparation:
Suspend 16g in 1 litre of distilled water. Bring to the boil to dissolve completely and dispense into screw-capped 7ml bottles. Fill each bottle to the brim, tighten the cap and sterilise by autoclaving at 121°C for 15 minutes. When sufficiently cool to handle, mix by inversion.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 15-25°C.

Precautions
A small amount of blue colour at the top of the bottle indicates oxidation. If this colour extends down into the medium it should be discarded.
Avoid prolonged heating in open flasks, during the preparation of the medium, because thioglycollate is volatile.
Sodium glycerophosphate may be metabolised by some organisms and thus promote their growth.

Oxoid Brilliant Green Bile Broth 2% is used for detection or confirmation of presence of members of coli-aerogenes group.

• Recommended for 44°C confirmatory test for Escherichia coli

Brilliant Green Bile Broth 2%, Oxoid Composition

Brilliant Green Bile Broth 2%, Oxoid Preparation:
Dissolve 40g in 1 litre of distilled water. Mix well, distribute into containers fitted with Durham’s tubes and sterilise by autoclaving at 121°C for 15 minutes.

Do not autoclave double stregnth medium. The alternative procedure is to heat the dissolved broth at 100°C for 30 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared tubes of broth at 2-8°C.

Precautions
Do not autoclave double-strength broth.
Gram-positive sporing organisms may produce gas if the bile/brilliant green inhibition is attenuated by food material.

• Oxoid C-T Supplement is a chromogenic medium for the identification of Escherichia coli O157:H7.
• Add to Sorbitol MacConkey Agar, Part No. CM0813B or to Sorbitol MacConkey Agar with BCIG, Part No. CM0981B.

Cefixime Tellurite Selective Supplement, Oxoid Composition

Sorbitol MacConkey Agar, Oxoid Preparation:
Reconstitute one vial as directed, aseptically add the contents to 500 ml of Sorbitol MacConkey Agar Base CM0813 cooled to approximately 50°C. Mix well and pour the medium into Petri dishes.

Storage conditions and Shelf life
Cefixime-Tellurite Supplement (SR0172) should be stored in the dark at temperatures below 0°C.

Oxoid Sorbitol MacConkey and Cefixime Tellurite Sorbitol MacConkey plates should be stored in the original packaging, at the temperature stated on the pack or product specification, and protected from direct light. When stored as directed, the unopened product will remain stable until the expiry date on the label.

Locally prepared media can be stored for up to 2 weeks when made from CM0813 and SR0172 according to the manufacturer’s instructions and stored at 2-8ºC, out of direct sunlight and protected from dessication. A longer shelf life may be attainable, but should be validated under the relevant, local manufacturing and storage conditions.

Oxoid CCDA Selective Supplement is used for the isolation of Campylobacter spp., especially C. upsaliensis or Arcobacter.

• For the isolation of Arcobacter spp., add to Arcobacter Broth Base, Part No. CM0965B
• For the isolation of Campylobacter spp., especially C. upsaliensis, add to Campylobacter Blood-Free Selective Agar Base (CCDA Preston), Part No. CM0739B

CCDA Selective Supplement, Oxoid Composition

Campylobacter Blood-Free Selective Agar, Oxoid Preparation:
Suspend 22.75g of Campylobacter Blood-Free Selective Agar Base in 500ml of distilled water and bring to the boil to dissolve. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C. Aseptically add 1 vial of CCDA Selective Supplement SR0155 reconstituted as directed. Mix well and pour into sterile Petri dishes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the selective supplement in the dark at 2-8°C and use before the expiry date on the label.
The prepared medium may be stored for up to 2 weeks at 2-8°C .

• Oxoid Kanamycin Aesculin Azide Agar Base is a selective medium for the isolation of Enterococci in foodstuffs.
• Also available Kanamycin Sulphate Selective Supplement, Part No. SR0092E.

Kanamycin Aesculin Azide Agar Base, Oxoid Composition

Kanamycin Aesculin Azide Agar, Oxoid Preparation:
Suspend 21.3g in 500ml of distilled water. Add one vial of Kanamycin Supplement (SR0092) reconstituted as directed. Bring to the boil. Sterilise by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared media at 2-8°C.

Precautions
Observe the hazard precautions regarding sodium azide when disposing of the medium.
There is no universal medium which will isolate all strains of enterococci.
Unless a presumptive count is acceptable all isolates should have their identity confirmed with further tests.

Oxoid Bile Salts No. 3 is a specifically refined fraction of bile acid salts.

• Normal working concentration 0.15% w/v.
• Each vial supplements 500mL of medium.

Oxoid Bile Salts is a standardized ox-bile extract used as a selective inhibitory agent in culture media.

Isolate and enumerate spoilage organisms of citrus products with Thermo Scientific™ Oxoid™ Orange Serum Agar (Dehydrated). Orange Serum Agar is developed specifically for the isolation and enumeration of microorganisms that are capable of surviving citrus products. The low pH of these products limits the growth of microorganisms to those capable of tolerating the acidic environment.

Orange Serum Agar, Oxoid Composition

Orange Serum Agar, Oxoid Preparation:
Suspend 37g in 1 litre of distilled water and bring gently to the boil to dissolve completely. Dispense into final containers and sterilise by autoclaving at 121°C for 15 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

• Oxoid Charcoal Agar Base (Bordetella Selective Medium) is used for selective isolation of B. pertussis and B. parapertussis.
• Requires addition of Bordetella Selective Supplement, Part No. SR0082E.

Charcoal Agar Base, Oxoid Composition

Charcoal Agar, Oxoid Preparation:
Suspend 51g in 1 litre of distilled water. Bring to the boil to dissolve completely. Sterilise by autoclaving at 121°C for 15 minutes. Cool to 50°C, add 10% of defibrinated blood and mix gently. The medium is made selective for the isolation of Bordetella pertussis and Bordetella parapertussis by the addition of Bordetella Selective Supplement SR0082.

To one vial add 2ml of sterile distilled water and dissolve the contents completely. Add this solution to 500ml of sterile, molten Charcoal Agar, cooled to 50°C, together with 10% v/v defibrinated horse blood SR0050. Mix well before pouring into sterile Petri dishes.
For Haemophilus influenzae, omit the selective agents and convert to `chocolate’ agar.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared plates of medium at 2-8°C.

Precautions
Stuart’s transport medium or similar formulation media should not be used for Bordetella-containing specimens.
Two pernasal swabs should be taken from each patient, one through each nostril.
Make sure the charcoal remains in suspension when dispensing the medium by gently swirling the flask.
Lysed horse blood is used in the transport medium but whole blood is used in the isolation medium.
Most naso-pharyngeal flora are inhibited by cephalexin but Pseudomonas aeruginosa and some fungi may grow through. Amphotericin B can be added (12mg/ml) as an antifungal agent to prevent the growth of filamentous fungi. However, this level of amphotericin B can be inhibitory to Bordetella pertussis and should not be used routinely.

Grow and isolate aerobic and anaerobic organisms of the intestinal tract, which may require selective conditions to inhibit the growth of background organisms like Escherichia coli, with Thermo Scientific™ Oxoid™ Schaedler Anaerobe Agar. The presence of cysteine in the medium provides selectivity against Escherichia coli as cysteine has shown to have inhibitory effects on several enzymatic reactions of Escherichia coli in vitro.¹

Schaedler Anaerobe Agar, Oxoid Composition

Schaedler Anaerobe Agar, Oxoid Preparation:
Suspend 40g in 1 litre of distilled water and boil to dissolve the medium completely. Sterilise by autoclaving at 121°C for 15 minutes. Mix well before pouring.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Prepared plates may be stored at 2-8°C if suitably protected.

Oxoid Brucella Selective Supplement is used for the isolation of Brucella spp.

• Add to Blood Agar Base No. 2, Part No. CM0271B; Columbia Blood Agar Base, Part No. CM0331B; or Brucella Medium Base, Part No. CM0169B
• Each vial supplements 500mL of medium

 Brucella Selective Supplement, Oxoid Composition

 Brucella Medium, Oxoid Preparation:
Reconstitute supplement as directed. Incubate for 10-15 minutes at 35°C. Mix thoroughly and immediately add the vial contents to 500 ml of sterile Oxoid Brucella Medium Base, cooled to 50°C together with 5-10% v/v sterile inactivated horse serum SR0035 and 1-5% w/v of a filter-sterilised 10% solution of dextrose. Mix well and pour into sterile petri dishes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared agar plates at 2-8°C.

Selectively enrich Listeria monocytogenes and other Listeria spp. from food and environmental samples with Thermo Scientific™ Oxoid™ 24 Listeria Enrichment Broth (24 LEB) (Dehydrated). The medium provides optimal growing conditions for all Listeria species for PCR applications. It is specifically designed for use with PCR systems, such as Thermo Scientific™ SureTect™ molecular assays for Listeria.

24 LISTERIA ENRICHMENT BROTH (24 LEB), Oxoid Composition

24 LISTERIA ENRICHMENT BROTH (24 LEB), Oxoid Preparation:

Completely dissolve 21.75g of 24 LEB Base per 500ml of distilled water. Sterilize by autoclaving at 121°C for 15 minutes. Cool to 50°C. Aseptically add the contents of 1 vial of 24 LEB Selective Supplement per 500ml medium, reconstituted as directed. Cool to room temperature before use, and, once made, store the medium at 2-8°C in the dark.

Oxoid EC Broth with MUG is used for the isolation and presumptive identification of E. coli.

EC Broth with MUG, Oxoid Composition

EC Broth with MUG, Oxoid Preparation:
Suspend 37g of EC Broth with MUG in 1 litre of distilled water. Mix well to dissolve and distribute into final containers containing inverted Durham tubes. Sterilise by autoclaving at 121° C for 15 minutes.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Precautions
Ensure that the glass tubes used for the preparation of the medium do not auto fluoresce and take the relevant safety precautions when using a UV lamp.
Some pathogenic strains, typically Escherichia coli O157:H7 are usually glucuronidase negative and therefore will not give a positive result in this test.
Other enteric organisms e.g. some Shigella species are also glucuronidase positive.

Isolate and enumerate wild yeasts encountered in brewing while suppressing pitching yeasts with Thermo Scientific™ Oxoid™ Lysine Medium (Dehydrated). This complex, synthetic medium is based on the original formula of Morris & Eddy which utilizes the susceptibility of pitching yeasts to lysine to differentiate it from the wild yeast.

Lysine Medium, Oxoid Composition

Lysine Medium, Oxoid Preparation:
Suspend 6.6g in 100ml distilled water containing 1.0ml Potassium lactate SR0037. Bring to the boil to dissolve completely. Agitate frequently to prevent superheating. Cool to 50°C and add 0.1ml of lactic acid 10% SR0021 to adjust to pH 4.8 ± 0.2. Dispense into Petri dishes and remove surface moisture by drying at 37°C.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Oxoid Mycoplasma Supplement G is for the isolation of mycoplasmas.

• Add to Mycoplasma Pneumoniae Agar, Part No. CM0401B or CM0403B
• Each vial supplements 80mL of medium

Mycoplasma Supplement G, Oxoid Composition
POISON – CONTAINS THALLIUM SALT

Mycoplasma Medium Preparation:
Prepare the sterile supplement by aseptically adding 20ml sterile distilled water to the vial and mix gently. Add 1ml of Oxoid Mycoplasma Base without supplements to each of ten small bottles. Sterilise by autoclaving at 121°C for 15 minutes. Allow to set. Aseptically add 2ml of the reconstituted Supplement-P to each bottle containing agar.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

The Oxoid Liver Digest Neutralized is a biologically standardized papaic digest of ox liver for use as a source of nutrients in microbiological culture media.