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Bile Aesculin Medium is generally used for the differentiation and presumptive identification of Group D streptococci (enterococci). Enterococci hydrolyse aesculin forming, amongst other products, aesculetin which in turn combines with Ferric ammonium citrate producing a dark brown or black complex. The presence of Bile salts in the medium inhibits gram positive organisms other than enterococci. The medium can also be used for the presumptive identification of certain organisms within the Enterobacteriaceae group such as Klebsiella spp., Enterobacter spp., etc. -
A very nutritious general-purpose medium based on Columbia Agar Base enriched with 7% Horse Blood, suitable for the cultivation and maintenance of most organisms including many fastidious anaerobes of clinical significance. -
A sterile concentrated emulsion of premium egg yolks, suitable for incorporation in culture media which detect lecithinase production by bacteria. It can be used in media for Bacillus cereus and Staphylococci. Used with serum and Filde’s extract it may be used to produce Nagler plates for Clostridia. -
Rappaport Vassiliadis (R.V.) Single Component Enrichment Broth This is an alternative to Selenite and Tetrathionate broths, as a selective enrichment broth for the isolation of Salmonellae spp from food, dairy and environmental samples and is claimed by some workers to be superior to both these formulations. It can also be used in clinical bacteriology but care must be taken to ensure that only a light inoculum is used. Malachite Green and Magnesium Chloride are included in the formulation as selective agents due to their ability to inhibit most enteric organisms but allow salmonellae to multiply freely. NB: This media is not recommended for use when salmonella typhi is suspected. -
This is a selective enrichment broth for the isolation of Salmonella spp. from pharmaceutical, food, dairy and environmental samples. Malachite Green and Magnesium Chloride are included in the formulation as selective agents due to their ability to inhibit most enteric organisms whilst allowing Salmonella spp. to multiply freely. Gram +ve bacteria and most other enteric bacteria, are typically susceptible to or inhibited by Malachite Green, the high osmotic pressure and/or the low pH of the medium. It should be noted that S.typhi and S.choleraesuis are sensitive to Malachite Green and may therefore be inhibited. This medium conforms to the requirements of the Harmonised USP/EP/JP. -
This medium is based on the formula described by Kupferburg, Johnson and Sprince for the selective isolation of Trichomonas spp. The medium is selective due to the inclusion of the broad spectrum antibiotic, chloramphenicol, to inhibit a wide range of Gram-positive and Gram-negative bacterial species. This medium does not contain an antifungal agent and Candida spp. will not be suppressed. However, the growth of Candida spp. does not interfere with that of Trichomonas spp. The inclusion of methylene blue as a redox indicator allows for the visualisation of any significant oxygen diffusion in the medium. Cultures may be examined microscopically after 48 hours incubation at 37°C for the presence of flagellate protozoans. If a negative result is obtained then the culture may be re-incubated for a further 72 hours. -
This medium is based on the formula described by Kupferburg, Johnson and Sprince for the selective isolation of Trichomonas spp. The medium is selective due to the inclusion of two selective agents namely, Chloramphenicol and Nystatin, to inhibit a wide range of both Gram-positive and Gram-negative bacterial species as well as yeasts and fungi. The inclusion of methylene blue as a redox indicator allows for the visualisation of any significant oxygen diffusion in the medium. Cultures may be examined microscopically after 48 hours incubation at 37°C for the presence of flagellate protozoans. If a negative result is obtained then the culture may be re-incubated for a further 72 hours.
This is a medium that can be used to differentiate between some of the Enterobacteriacae on the basis of four reactions, fermentation of Lactose, Glucose and Sucrose and the production of H2S. For use the medium is inoculated using a pure culture of the test organism which should be smeared onto the surface of the slope and stabbed into the butt of the medium. For details of the many reactions that may arise during the use of this medium reference should be made to one of the many standard textbooks.
Based on Christensen’s Medium this medium is generally used to detect rapid urease activity of Proteus spp although it can be used to detect urease activity of other Enterobacteriaceae. When used for the later purpose it is necessary to increase the incubation time to as long as 48 hours.
A medium for the selective isolation of group B streptococci. This information has been obtained directly from the HPA files at the customers request.
A modification of Christensen’s Medium by Maslen this medium is generally used to detect rapid Urease activity of Proteus spp although it can be used to detect Urease activity of other Enterobacteriaceae including Urease producing Salmonella and Shigella. Unlike Christensen’s Medium when used for the later purpose it is not necessary to increase the incubation time.
Suplex is a semi-defined nutritional supplement developed to enhance the growth of many different microorganisms. Suplex is composed of a blended amino acid mix, anhydrous glucose and yeast extract, which provides a source of essential amino acids, peptides, vitamins and carbohydrates for the growth of the microorganisms. Due to the heat sensitive nature of some components in Suplex, the supplement should be added post sterilisation normally at 20ml per Litre, with any other additives (42-48°C) and allowed to mix just before pouring.
This is a sterile emulsion of Egg Yolk in Saline containing Potassium Tellurite and is generally used as a selective differential agent in Baird Parker Medium. The complete medium is selective for Staphylococcus aureus as the Potassium Tellurite inhibits most coliform organisms and is also reduced by Staphylococcus aureus to tellurite giving typical black colonies on the Baird Parker Medium.
Recent developments in culture media have given rise to the use of chromogenic substrates as a means of differentiating bacteria particularly among the coliform group of organisms. This is one such medium and has been developed primarily as a selective medium for the isolation and enumeration of Escherichia coli in food samples. Based on Tryptone Bile Agar it incorporates the chromogenic agent X-glucuronide, which detects glucuronidase activity, the same enzyme as is detected by MUG reagent. Escherichia coli can be differentiated from other coliform organisms by the presence of glucuronidase resulting in the colonies being blue/green while the other coliforms are colourless. For information on the full technical detail as to the functionality of this medium reference should be made to the many publications available.
A highly nutritious medium enriched with Horse Blood, where the blood has been ‘chocolated’ by heating the medium to 60°C. Suitable for the cultivation of most pathogens including many fastidious organisms and is particularly suitable for Haemophilus and Neisseria spp.
A modification of UVM Medium, Fraser Broth is a secondary selective enrichment broth for the isolation of Listeria spp primarily from food and environmental specimens. The medium is made selective by the inclusion of Nalidixic Acid and Acriflavine. Darkening of the broth following incubation, due to the presence of Aesculin and Ferric Ammonium Citrate, is indicative of the presence of Listeria spp. Lithium Chloride is also included to inhibit the growth of enterococci that would otherwise hydrolyse the Aesculin. This medium is generally used in conjunction with Fraser Broth Half-Strength (BM0647). NB: It should be noted that the lack of darkening of the broth should not be taken as a final negative result and all Fraser Broth enrichment cultures should be sub-cultured onto an appropriate selective agar medium irrespective of colour.
A modification of UVM11 Medium, Fraser Broth Half-Strength is a primary selective enrichment broth for the isolation of Listeria spp. from food and environmental samples and is generally used in conjunction with Fraser Broth (BM0640). Although the base is identical to Fraser Broth it differs in that it contains only half the quantity of selective agents (Nalidixic acid and Acriflavine).
Dermatophyte Test Medium with Chloramphenicol (Slope) (100mg/L) Dermatophyte Test Medium is a selective medium for the isolation of dermatophytes from hair, skin etc. and is based on a modification of the original formulation of Taplin, Zaias, Rebell and Blank. Although the low pH (5.5) of the medium inhibits most bacteria, Chloramphenicol is added to further reduce the risk when processing material that may be more heavily contaminated particularly with organisms of the coliform group. The inclusion of Phenol Red indicator assists in differentiation between saprophytic and environmental fungi. Dermatophytes appear as fluffy colonies with reddening of the medium while other fungi cause the medium to become yellow due to acid production. Yeasts will also grow on this medium but are readily distinguished by their distinct white/creamy colonies and distinctive smell. N.B: Prolonged incubation should be avoided as this may cause fungi other than dermatophytes to turn the medium red.
For the enumeration of Escherichia coli and coliform organisms in water using a Membrane Filtration Technique. Previously known as Membrane Enriched Teepol Broth, Lauryl Sulphate has replaced Teepol 610, which is no longer available. Phenol Red is included in the medium making it possible for coliforms to be more readily detected following incubation.
This is a modification of the traditional liquid media used to differentiate and identify micro-organisms. It consists of a Buffered Tryptose base containing Lactose and solidified with Gelatin which permits detection of Gelatin Liquefaction where appropriate. Phenol Red Indicator is also included as an indicator of pH change.
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.
This is a liquid medium for growing pure cultures of Mycobacterium spp., including M. tuberculosis, for use in antimicrobial assays and biochemical tests. The medium is complex but includes L-Glutamic acid, ammonium sulphate, sodium citrate, pyridoxine and biotin as growth factors as well as magnesium sulphate and 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. The medium is further enriched by the addition of the Middlebrook OADC Enrichment supplement. OADC contains oleic acid to provide fatty acids for growth promotion, bovine albumin and catalase as protective compounds as well as sodium chloride and dextrose.
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.
Tetrathonate broth is a selective enrichment broth for the isolation of Salmonella spp. primarily from food and food samples. It can however be used in other applications including for clinical and environmental specimen testing. Salmonella spp. can reduce Tetrathionate and will proliferate in the medium whilst most other enteric organisms are inhibited. Immediately prior to use it is necessary to add 2% Iodine Solution (BM0946 - Supplied with the medium). Once the Iodine Solution has been added the medium should be used immediately and cannot be stored for future use. NB: As this is an opaque medium, turbidity cannot be used as an indication of growth.
This is a selective enrichment broth for the isolation of Salmonella spp. primarily from food and food product samples and conforms to the requirements ISO 6579:2002. It can however be used in other areas including clinical and environmental specimens. Salmonella reduce Tetrathionate and will proliferate in the medium whilst most other enteric organisms are inhibited. Unlike the older traditional Tetrathionate Broth the addition of Novobiocin (40mg/L) improves the inhibition of Proteus spp. Immediately prior to use it is necessary to add 200µl of 2% Iodine/Iodide Solution (BM0946 - Supplied with the medium). Once the Iodine/Iodide Solution has been added the medium should be used immediately and cannot be stored for future use. NB: As this is an opaque medium, the turbidity of the broth alone cannot be used as an indication of growth.
This is a selective enrichment broth for the isolation of Salmonellae spp. primarily from food and food product samples and conforms to the requirements as described in ISO 6579:2002. It can however be used in other areas including for clinical and environmental specimens. Salmonella reduce Tetrathionate and will proliferate in the medium whilst most other enteric organisms are inhibited. Unlike the older traditional Tetrathionate Broth the addition of Novobiocin (40mg/L) improves the inhibition of Proteus spp. This complete medium already includes the 2% Iodine solution that is traditionally added immediately before use. NB: As this is an opaque medium turbidity cannot be used as an indication of growth.
This is a modified Cameron Sulphite Agar with a reduced concentration of sodium sulphite from 0.1% to 0.05% to allow the growth of the more sulphite sensitive strains of clostridia. A positive result is indicated by distinct black growth throughout the media, however, this blackening is only presumptive evidence of clostridial growth. Confirmation tests must be carried out to identify the organism growing on the medium.
Based on the formulation of Dulbecco Solution ‘A’ this balanced salt solution with added Tween is intended for use primarily in Tissue Culture techniques. It can be used either on its own or with the addition of Calcium and Magnesium salts (Dulbecco Solution B).
This is a selective medium for the isolation of yeasts and moulds. The medium is enriched with Yeast Nitrogen Base and L-asparagine and made selective by the addition of Chloramphenicol to inhibit bacterial growth. It is buffered to maintain pH during incubation.
LIM Broth with 10% Serum A nutritious, selective broth medium utilising the base formulation developed by Todd and Hewitt for the enrichment of Group B Streptococci. The LIM broth is made selective by the inclusion of Colistin and Nalidixic Acid to suppress the growth of the majority of other bacteria. Serum is also included to enhance the nutritional qualities of the base medium.
This is one of a number of selective enrichment broths that can be used in the isolation of Campylobacter spp from clinical, food and environmental specimens and contains nutrients to aid in the resuscitation of damaged organisms. The medium is enriched with Lysed Horse Blood and made selective by the inclusion of Vancomycin, Cefoperazone, Trimethoprim and Amphotericin B. Following incubation at 37ºC the broth is usually sub-cultured onto an appropriate solid Campylobacter medium.
This is a liquid medium suitable for the selective isolation and presumptive identification of Methicillin Resistant Staphylococcus aureus (MRSA). The medium is made selective for MRSA through the addition of a number of antibiotics to suppress both Gram –ve and Gram +ve organisms other than staphylococci. As most strains of Staphylococcus aureus ferment D-Mannitol to produce acid this is detected by the change of colour of the medium from red to yellow/amber due to the presence of the Phenol Red Indicator. NB: It is recommended that cultures giving a presumptive positive result should be sub-cultured to a selective agar medium (PP3059 Colorex MRSA). Any resulting colonies should be subjected to further biochemical testing to confirm the full identity of the isolate.
One of two media usually used as a pair, the other being Kohn’s No 1 (BM2110), to differentiate members of the enterobacteriacae. Kohn’s No 2 contains Salicin and Sucrose as substrates and Bromothymol Blue as the indicator. The medium is inoculated by stabbing the inoculum into one third of the depth of the medium. After incubation, sugar fermentation of either or both sugar is indicated by the medium changing colour from blue/green to yellow. It is also possible to determine motility in this medium as a diffuse growth spreading from the line of inoculum. The production of Indole and/or Hydrogen Sulphide can also be tested for using this medium. To do so suspend appropriate Lead Acetate and Indole test papers in the neck of the tube at time of inoculation. After incubation examine the papers for colour changes, blackening of the lower end of the Lead Acetate Paper for H2S and the Indole strip changing from yellow to red.
Tryptone Soya Broth (Modified) with Novobiocin (20mg/L) This is a selective enrichment broth for the isolation of Escherichia coli 0157, primarily from food and food products, and is capable of detecting the organisms even when they are present in small numbers. It is also increasingly being used in clinical laboratories when screening faecal samples. Based on Tryptone Soya Broth it is made selective for Escherichia coli 0157 by the addition of bile salts and Novobiocin and is also buffered to maintain the pH during incubation. This medium is generally used in conjunction with selective agar subculture (e.g. Sorbitol MacConkey Agar with Cefixime Tellurite – (CT-SMAC)).
A broth suitable for the cultivation of bacteria especially members of the Enterobacteriacae genus. Which allows the detection of acid & gas when a Durhum tube is incorporated in the medium.
A broth suitable for the cultivation of bacteria especially members of the Enterobacteriacae genus. This medium allows for the detection of gas when a Durhum tube is incorporated in the medium.
Urea is recommended for use in bacteriological culture media. The ability of an organism to hydrolyse urea is often a salient characteristic in its differentiation from other bacteria which have identical biochemical reactivity’s except in their urease producing characteristic.
This is a modification of the original Nitrate Reduction Broth which is generally used as one of a series of identification tests for the enterobacteriaceae group of organisms. In addition to allowing the testing of Nitrate Reduction this formulation also contains Agar making it possible to concurrently determine motility. The medium is recommended for use in the confirmatory testing of Clostridium perfringens in water samples. The medium is inoculated by “stabbing” the test organism into the medium, using an inoculating needle or straight wire, and after appropriate incubation motility is demonstrated by diffusion of the organism from the line of inoculation into the medium. The Nitrate Reduction Test is a test for the presence of the enzyme nitrate reductase which, in the presence of an appropriate electron donor, reduces nitrate to nitrite. Following incubation “Nitrate Reagent” is added to the medium and a positive reaction is indicated by the formation of a red colour. For full details of the test method reference should be made to appropriate publications.
An enriched general purpose broth enriched with 10% defibrinated horse blood for the isolation of fastidious organisms.
Kirchner medium is a liquid medium for the 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). 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.
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). 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.
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.
It is not possible to sterilise whole blood products and therefore they must be collected aseptically. Horse and sheep blood are the most widely used animal blood products in culture media. The choice of which type of blood to use with culture media is largely traditional, with much of continental Europe preferring sheep blood, whilst the UK and certain parts of the Commonwealth prefer horse blood. Defibrinated horse blood is aseptically collected whole horse blood that has been processed to remove fibrin. There are no additives or preservatives in this product. Defibrination is now accepted as the best method of preventing blood clotting. It must be carried out immediately after drawing the blood and the agitation must be sufficient to denature the fibrinogen but not to cause rupture of the erythrocytes and haemolysis. The haemolytic reactions of horse blood are not identical to sheep blood and blood agar media designed for horse blood may not be satisfactory with sheep blood and vice versa.
It is not possible to sterilise whole blood products and therefore they must be collected aseptically. Horse and sheep blood are the most widely used animal blood products in culture media. The choice of which type of blood to use with culture media is largely traditional, with much of continental Europe preferring sheep blood, whilst the UK and certain parts of the Commonwealth prefer horse blood. Defibrinated sheep cells are aseptically collected whole sheep blood that has been processed to remove fibrin. There are no additives or preservatives in this product. Defibrination is now accepted as the best method of preventing blood clotting. It must be carried out immediately after drawing the blood and the agitation must be sufficient to denature the fibrinogen but not to cause rupture of the erythrocytes and haemolysis. The haemolytic reactions of sheep blood are not identical to the reactions of horse blood and blood agar media designed for sheep blood may not be satisfactory with horse blood and vice versa.
Fastidious Anaerobe Agar is intended as a primary isolation medium capable of supporting most clinically significant anaerobes including fastidious organisms. The formulation is complex and includes detoxification agents (starch and sodium bicarbonate), growth enhancing agents (cysteine, arginine, vitamin K, sodium succinate, glucose and pyrophosphate), as well as haemin to encourage pigment production in Porphyromonas melaninogenicus. Sodium pyruvate is also included to help neutralise hydrogen peroxide. In this instance the medium is further enriched by the addition of 5% horse blood. This product is suitable for use with the EUCAST disc diffusion method for selected rapidly growing anaerobic bacteria.
Lysed horse blood is used for special purposes in culture media. It has been used for many years in Corynebacterium diphtheriae media, where better growth was observed after lysis of the horse blood by the tellurite in the medium. It is also documented that lysed blood stimulates the growth of Haemophilus influenzae due to the release of Nicotinamide Adenine Dinucleotide in the horse blood from the ruptured erythrocytes. In antibiotic susceptibility testing, lysed horse blood is added to the medium to improve the reactions with trimethoprim and sulphonamides. Most culture media, unless specially processed for susceptibility testing, contain amounts of thymidine which can antagonise the inhibitory effects of these antimicrobials. When horse blood is lysed the erythrocytes release an enzyme thymidine phosphorylase which converts thymidine into the much less antagonistic compound thymine.
GC LCAT Selective Supplement E&O Laboratories Ltd LCAT Selective Supplement (LS0001) is an antibiotic supplement used to enhance the selective isolation of Neisseria gonorrhoeae and Neisseria meningitidis.
Vancomycin. Colistin, Amphotericin, Trimehtoprim (V.C.A.T) E&O Laboratories Ltd VCAT Selective Supplement (LS0002) is an antibiotic supplement used to enhance the selective isolation of Neisseria gonorrhoeae and Neisseria meningitidis.
b-Nicotinamide-Adenine Dinucleotide (N.A.D.) Supplement E&O Laboratories Ltd N.A.D. Supplement (LS0005) is an enrichment supplement for Haemophilus spp. and Neisseria gonorrhoeae. This supplement can be used in conjunction with sensitivity test agars such as: E&O products PP2148 Iso Sensitivity test agar with 5% Horse Blood and 20mgs/L N.A.D. and PP0972 Mueller Hinton agar with 5 % Horse Blood with 20mgs/L N.A.D.
