Dermatophyte is a medical term used to designate a particular group of fungi that infect the skin, hair and nails of humans and animals, causing various skin infections commonly known as “tineas.” Any filamentous fungus isolated from culture samples of skin, hair and nails must be evaluated to determine the presence of dermatophytes. The dermatophytes are divided into three genera: Microsporum, Trichophyton and Epidermophyton, on the basis of their microscopic morphological differences and modes of sporulation. Species of these genera can be divided into three types by their normal habitat: Anthropophilic, are found only in human hosts and are transmitted from person to person; zoophilic are found in animals but can be transmitted to humans and geophilic, which can be found in the ground and may infect humans and animals. Dermatophyte Selective Agar was proposed in 1969 by Taplin and colleagues for the isolation and presumptive identification of pathogenic dermatophytes. The medium contains a plant peptone providing carbon and nitrogen required for growth, while dextrose provides the energy source needed for metabolism. Cycloheximide inhibits saprophytic fungi that may be present in the sample, without affecting the growth of dermatophytes. Gentamicin is an antibiotic that acts on gram-negative bacteria, (including Pseudomonas) and Chlortetracycline is a broadspectrum antibiotic acting on both gram-positive and gram-negative bacteria. This mixture of antimicrobials partially inhibits the growth of bacteria, yeasts and moulds that can contaminate samples and does not affect or has little effect on the growth of dermatophytes. In addition, the medium includes a pH indicator, phenol red, which is yellow-orange in acid medium and red in alkaline medium. The growth of most dermatophytes results in the production of alkaline metabolites that cause the indicator to change from yellow to red, but there are non-pathogenic fungi (nondermatophytes) that cause a colour change. Also there are some strains of microsporum that grow without altering the appearance of the medium. These other organisms that manage to grow in this medium can be recognized as non-dermatophytes both by their colour and colony morphology. The bacteria and few yeasts that may develop produce typically creamy white colonies. Saprophytic contaminants that sometimes cause colour change in the medium can be disregarded if they produce blackish-green coloured hyphae, since dermatophytes always produce white aerial hyphae. However, as the final identification of dermatophyte is the microscopic observation of sporangia and verification of colour on the reverse of the colony, it is recommended that along with the Dermatophyte Selective Agar another medium for fungi e.g. Sabouraud Agar (with or without inhibitors) is inoculated simultaneously in order to verify these characteristics. Thus, DTM is used as an isolation and presumptive identification medium and Sabouraud as an isolation and confirmation medium.

DESCRIPTION Glucose Salt Teepol Broth is a selective enrichment medium used for the enumeration of V. parahemolyticus from seafoods by the most-probable-number (MPN) technique.

PRINCIPLE Peptone and meat extract provide amino acids, nitrogen, carbon, minerals, vitamins and minerals which support the growth of microorganism. Glucose is the fermentable carbohydrate. The high concentration of sodium chloride helps for the better enrichment of halophilic V. parahemolyticus. Methyl violet is the pH indicator. Supplementation with Teepol serves to inhibit the growth of gram-positive organisms.

PREPARATION Suspend 48.0 g of powder in 1 liter of deionized or distilled water. Add Teepol to obtain a concentration of 4 g/l in the complete medium. Mix well. Sterilize by autoclaving at 121°C for 15 minutes. Distribute into final containers.

Principles and uses Trypticasein Soy Broth Modified with Novobiocin (mTSB) is recommended by ISO 16654 for the enrichment of E.coli O157:H7. Casein peptone and soy peptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Dipotassium phosphate acts as a buffer system. Glucose is the fermentable carbohydrate providing carbon and energy. Bile salts and Novobiocin are inhibitors of gram-positive organisms. ISO 16654 recommends preparing the initial suspension and adding a test portion to the 41,5 ºC pre-warmed broth to obtain a ratio of test portion to mTSB + sample of 1/10 (mass to volume, or volume to volume). Incubate for 6 hours then a further 12 hours to 18 hours at 41,5 ºC.

Thành phần phù hợp với yêu cầu của phương pháp phân tích E.coli O157 hoặc theo ISO 16654, cụ thể thành phần trong mỗi lít môi trường pha chế như sau:

• Sodium chloride: 8g
• Potassium chloride: 0,2g
• Disodium hydrogen phosphate (anhydrous) (hoặc Disodium phosphate): 1,44g
• Potassium dihydrogen phosphate (anhydrous) (hoặc Potassium phosphate): 0,24g
• Polyoxyethylene sorbitan monolaurate (tween 20 syrup) (hoặc Polysorbate): 0,2ml

– Giá trị pH:  7.2 + 0.2 ở 25⁰C.

• Casein peptone: 7,5g
• Meat peptone: 2,5g
• Sodium chloride: 5g
• MUG (4-methylumbelliferyl –β-D-glucuronide): 0,02g
• Lactose: 1g
• Phenol red: 0,025g
• L-Tryptophan: 0,5g
• Agar: 13-14g

• Thông số hiệu suất: Vi khuẩn coli O157:H7 phát triển tốt, âm tính MUG (không phát huỳnh quang dưới đèn UV)

Composition

Per vial sufficient for 500 ml medium
Potassium tellurite 1.250mg
Cefixime 0.025mg

Directions
Rehydrate the contents of 1 vial aseptically with 5 ml of sterile distilled water. Mix gently to dissolve the contents completely. Aseptically add the contents to 495 ml of sterile, molten, cooled (45-50ºC) MacConkey Sorbitol Agar Base . Mix well and pour into sterile petri plates

Principles and uses Casein Peptone is a pancreatic digest of casein. Pancreatic digestion produces a balanced mixture of amino acids, including essential amino acids, in optimal ration and low molecular peptides. In many cases, this makes for a more nutritious hydrolysate, especially for those organisms that prefer peptides to amino acids. It can be used in the production of toxins, vaccines, enzymes, in fermentation applications and microbiological culture media, especially in blood-containing media.

Principles and uses Bacteriological agar is a gelling agent used in the preparation of culture media and in other bacteriological applications. Its main advantage is the absence of inhibitors which could hinder optimal development of microorganisms. In addition, bacterio-logical agar also possesses other attributes such as transparency, high hysteresis and very reliable reproducibility. Bacteriological agar European Type has higher gel strength and is used in concentrations from 1,0% to 2,0%. Each batch produced by us is thoroughly tested for biological performance against a battery of known bacterial cultures in order to ensure proper growth characteristics and absence of inhibitors. Also, other tests are carried out to be certain that each batch meets established physical and chemical specifications.

This culture medium contains lactose, whose degradation to acid is indicated by the pH indicator phenol red, which changes its colour to yellow. The indicator exhibits a deep red colour in the alkaline range. The growth of the accompanying Gram-positive microbial flora, Salmonella typhi and Shigella is largely inhibited by brilliant green. The growth of Salmonella is, however, improved by the richer nutrient base. Increased growth of accompanying microorganisms is considerably prevented by raising the concentration of brilliant green. Salmonellae are not able to ferment either lactose or sucrose. Thus in contrast to BPL agar, the sucrose contained in this medium allows identification of accompanying, weakly lactose-positive or lactose-negative, but sucrose-positive microorganisms.

Principles and uses Irgasan Ticarcillin and Potassium Chlorate Broth (ITC) is recommended by ISO 10273 as a selective enrichment broth for the detection of the human pathogenic strain of Yersinia enterocolitica in food and water samples. Enzymatic casein digest provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Magnesium chloride and malachite green, make the broth highly selective. Irgasan inhibits Gram-positive bacteria, Ticarcillin has bactericide on Gram-negative and Gram-positive bacteria and potassium chlorate has a disinfecting property.

Principles and uses
Sorbitol Peptone Broth And Bile Salts (PSB) is a medium recommended by ISO 10273 for the selective enrichment of Yersinia enterocolitica in food samples. Outbreaks of gastroenteritis associated with Yersinia enterocolitica are increasing. Contaminated food products such as pork, beef, and raw and processed milk have been identified as sources of infection.
Enzymatic digest of casein provides nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Potassium phosphates act as a buffer system. Sorbitol is the fermentable carbohydrate providing carbon and energy.

Preparation
Suspend 31 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 121°C for 15 minutes.

Yersinia Selective supplement is based on the formulation of Schiemann and is added to Yersinia medium base (CIN) in order to obtain a final selective medium for the isolation and enumeration of Yersinia enterocolitica from clinical specimens and food. Yersinia enterocolitica is becoming increasingly recognised as a cause of diarrhoeal disease of man and also polyarthritis, mesenteric adenitis and septicaemia.

Principles and uses
Yersinia Select Agar Base (ISO 10273) is a selective and differential medium when used with supplements. The formula is based on the CIN Agar described by Schiemann, and is recommended by ISO 10273 for the isolation and detection of presumptive pathogenic Yersinia enterocolitica from a variety of clinical and food samples.
Antibiotics are added as a supplement in order to inhibit the accompanying flora. The growth of Yersinia is promoted by pyruvate as well as by the nutrients content in the base. Yersinia degrades the mannitol of the medium to an acid form; the colonies are turning to red color due to the neutral red indicator. Mannitol fermentation in the presence of neutral red produces a characteristic “bull’s-eye” colony, colorless with a red center.
Mannitol is the fermentable carbohydrate, source of carbon and energy. Enzymatic digest of gelatin and the enzymatic digest of casein and animal tissues provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group.
Sodium pyruvate is added as a source of energy and as a protective substance in order to overcome oxygen toxicity biologically produced by the organisms. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Magnesium sulphate is an ion required in a large variation of enzymatic reactions, including DNA replication. Neutral red is the pH indicator. Selective inhibition of Gram-negative and Gram-positive organisms is obtained through crystal violet, sodium desoxycholate and Irgasan (triclosan). Cefsulodin and novobiocin improve the inhibition of normal enteric organisms.

Preparation
Suspend 28,5 grams of the medium in 500 ml of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 121 ºC for 15 minutes. Cool to 45 ºC and aseptically add one vial of Yersinia Selective Supplement Homogenize gently and dispense into Petri dishes.

Principles and uses A1 Medium, also known as A1 Broth, is used for the detection of fecal coliforms in water samples. The enumeration of coliforms, specifically Escherichia coli, has been used to determine water purity by the most-probable-number method. This medium was created to hasten the recovery time of E. coli and to reduce the number of false positive cultures. A-1 Medium can be used in a single-step procedure, also in foods, not requiring a previous enrichment step. Tryptone provides nitrogen, vitamins, minerals and aminoacids. Lactose is the carbon source and in combinationwith salicin, provides energy for organism growth. Ecosurf is a surfactant and sodium chloride supplies essential electrolytes for transport and osmotic balance. Gas production is a positive reaction indicating the presence of Coliforms. Gas may be produced inside the Durham tubes or may appear as dissolved gas that forms gas bubbles when slightly agitated.

The use of animal tissue for culturing anaerobic organisms was first employed by Theobald Smith in 1890. Von Hibler later used brain tissue for cultivating and classifying anaerobic bacilli. Robertson replaced brain tissue with beef heart and used this medium to differentiate putrefactive and saccharolytic species. The formulation presently used is a modified version of Robertson’s formulation. This medium is also referred to as Chopped Meat Medium.  Nutritional requirements needed by most bacteria are provided by beef heart, peptone and dextrose. Dextrose, yeast extract, hemin and vitamin K are added to enhance the growth of anaerobic microorganisms. Amino acids and other nutrients are supplied by the muscle protein in the heart tissue granules. Reducing substances, which permit the growth of strict anaerobes, are supplied by the muscle tissue and the iron filings. It is thought that the meat particles act as a reducing and detoxifying substance, thereby disabling harmful by products that may be produced by the replicating organism. Because reducing substances are more available in denatured protein, the meat particles are cooked before use in the medium. Growth of spore-forming and non-spore-forming obligate anaerobes is supported by this medium. Cooked Meat Medium is also useful as an enrichment broth for cultivating organisms from a very small inoculum. Additionally, researchers have found that Cooked Meat Medium preserves viability of organisms over a long period of time and is useful in maintaining anaerobic stock organisms. The Food and Drug Administration recommends its use in the enumeration and identification of Clostridium perfringens from food.

Principles and uses TGEA Medium (Tryptone Glucose Yeast Extract Agar) is a medium used for the total count of aerobic mesophilic bacteria in water and dairy products. Casein Peptone and Beed Extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is source of vitamins, particularly the B-group. Dextrose is the fermentable carbohydrate providing carbon and energy. Bacteriological agar is the solidifying agent

A sterile selective supplement used for isolation and presumptive identification of Clostridium perfringens, according to ISO 7937 and ISO 14189, and other regulations.

Compositon (g/vial) D-Cycloserine………………………………………………. 0.200 Reconstitute the original freeze-dried vial by adding Sterile Distilled Water…………………………………….6 ml

Note: each vial is sufficient to supplement 500 ml of medium. TSC Agar Base.

D-cycloserine selective supplement is added to TSC Agar in order to obtain a final selective medium which has the advantage to simplify the counting of plates with high numbers of colonies because smaller colonies of C.perfringrens are formed. Sodium metabisulphite and ferric ammonium citrate are used as an indicator of sulphite reduction made by Clostridium perfringens spp. that produce black colonies in TSC agar.

Principles and uses
Hektoen Enteric Agar is a differential and selective medium used for isolating and differentiating enteric pathogens such as Salmonella and Shigella, both of which cause a variety of serious human gastrointestinal diseases; and other Gram-negative Enterobacteriaceae.
It is used particularly in foods where multi-steps are followed to isolate the pathogens of gastroenteritis. The nutrients for growth are provided by the Meat Peptone and Yeast extract. The increased content of the Peptone and the three fermentable carbohydrates (Lactose, Sucrose, Salicin) as sources of carbon and energy reduce the inhibitory action of the Bile salts on Salmonella and Shigella spp. The lactose concentration in this medium is higher than in many other media used for enterics since this helps the visualization of enteric pathogens and minimizes the problem of delayed lactose fermentation. Bromothymol blue and Acid fuchsin are pH indicators. Sodium thiosulfate provides Sulphur, and Ferric ammonium citrate is the indicator for
H2S production. H2S positive colonies are black-centered. Sodium chloride maintains the osmotic balance.
The norma ISO 21567 recommends the Hektoen Agar as a selective solid media for the enumeration of Shigella spp. Although suppressed, partially inhibited E. coli and other organisms which use lactose, sucrose, and/or salicin with the production of acid, give colonies whose tones vary from yellow to orange to salmon. The Salmonella and Shigella are green or green-blue. Proteus is not inhibited but produces a green-yellow colony when it grows. The colonies of Proteus and Salmonella may present a black center and clear edges if they form iron sulfide as a result of H2S production.

Preparation
Suspend 75,6 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. AVOID OVERHEATING. DO NOT AUTOCLAVE. Cool to 47 ºC and pour into Petri dishes.

Description:
Completed with all its supplements the Agar Listeria Ottaviani & Agosti is a selective and differential medium for the detection of Listeria species and the presumptive identification of Listeria monocytogenes.
The selectivity is achieved by the high concentration of lithium chloride and the mixture of antimicrobics. The differential activity is due to the chromogenic substrate to detect the βglucosidase enzyme that is present in all Listeria species.
The specific identification is obtained by the L-α-phosphatidylinositol, that acts as substratre for a phospholipase C present only in Listeria monocytogenes and some strains of Listeria ivanovii.
The combination of both substrates allows the differentiation L. monocytogenes, which grow in produces colonies blue-green in colour and surrounded by an opaque zone, from the other Listeria species, which blue-green colonies but without any halo. This differentiation is evident after incubating the plates for 24 ± 2 hours at 37 ºC.
Sometimes, especially with highly contaminated samples, it is possible that some colonies, white in colour, are not Listeria growth. In this case an enrichment step is recommended prior to plate inoculation.

Observations:

Most Listeria ivanovii also produce an opaque halo around the colonies after 48 h of incubation. This presumptive evidence must be confirmed by performing the biochemical or serological identification tests (Rhamnose / Xylose sugar fermentation, hemolysis tests, CAMP test, etc.) or any test confirming the species without hesitation.

Technique:
Add 1 botlle supplement Ottaviani & Agosti (L-alpha-phosphatidylinositol) and 1 vial supplemet Ottaviani & Agosti for complete 500 ml medium.
Homogenize by mixing and distribute in Petri dishes. The solidified cool medium appears homogeneously turbid.
There are many standardised methodologies (ISO, FDA-BAM, AOAC, AFNOR, etc.). The technician must follow the protocol validated in his laboratory.

It is used for confirmation after using Listeria Enrichment Broth Base Fraser . This medium is also recommended by ISO 11290-1 for the detection and enumeration for Listeria monocytogenes. Enzymatic digest of animal tissues and enzymatic digest of casein provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Sodium pyruvate is a source of energy for bacterial metabolism and aids in the resuscitation of stressed organisms. Glucose is the fermentable carbohydrate providing carbon and energy. Magnesium glycerophosphate is a buffering compound. Magnesium sulphate is a magnesium ion required for a large variety of enzymatic reactions, including DNA replication. The differential activity of the medium is due to two factors. Lithium chloride in the base medium and supplementary antimicrobial compounds Ceftazidime, Polymyxin, Nalidixic acid and Cycloheximide provide the medium’s selectivity. Bacteriological agar is the solidifying agent. The presence of the chromogenic component X-glucoside, a substrate for the detection of the enzyme ß-glucosidase, is common to all Listeria species giving the colonies their blue colour. Other organisms that possess this enzyme, for example, Enterococci, are inhibited by the selective agents within the medium and by the selective supplement. The differential activity is also obtained by lipase C substrate, upon which the specific enzyme for L. monocytogenes acts. The lipase is responsible for the opaque white halo which surrounds L. monocytogenes. The combination of both substrates allows us to differentiate the colonies of Listeria monocytogenes from the rest of Listeria spp. since, although all are blue in colour, L. monocytogenes present an opaque white halo surrounding them. It has been observed that some strains of Listeria ivanovii, mostly pathogenic to animals although some have caused infections in humans, also possess lipase activity.

Principles and uses Listeria Half-Fraser Broth Base is a modification of Listeria Fraser Broth Base in which the nalidixic acid and acriflavine concentrations have been reduced to 10 mg/L and 12.5 mg/L respectively. The antibiotics are already included in the formula so it is only necessary to add the Ferric Ammonium Citrate Supplement.

Listeria spp. may be present in small numbers and are often accompanied by considerably larger numbers of other microorganisms, therefore selective enrichment is necessary.

Listeria Half-Fraser broth is used in this selective enrichment and enumeration of Listeria monocytogenes and other Listeria species in all food types, including milk and dairy products, and environmental samples. This formula adheres to ISO 11290. Enzymatic digest of casein, enzymatic digest of animal tissues and meat extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Potassium phosphates act as a buffer system. All Listeria species hydrolyze esculin, which reacts with ferric ions producing a blackening of the medium. The addition of ferric ammonium citrate improves the growth of Listeria monocytogenes. Lithium chloride inhibits the growth of enterococci that can hydrolyze the esculin.

Description: Listeria PALCAM selective supplement is added to PALCAM Medium base in order to obtain a complete selective medium used for the detection and the isolation of Listeria monocytogenes from foods. Palcam Agar is based on the formulation described initially by van Netten et al. which has a high selectivity and produces good colonial differentiation. Selectivity is achieved by the inclusion of lithium chloride, acriflavine, polymyxin B and ceftazidime, since they inhibit the growth of almost all the Gram negative and most of the Gram positive companion bacteria. Listeria hydrolyze esculin to esculetin, which reacts with ferric ammonium citrate producing a dark precipitate and green-grey colonies with beige halos. If colonies of enterococci or staphylococci do grow on this medium they can be easily recognized, since they utilise mannitol and produce yellow colonies and haloes, contrasting with the cherry-red colour of medium. However, when there are many Listeria colonies, the entire medium darkens, which can cause interference in differentiation. In these cases it is advisable to perform the inoculation with a more diluted sample.

Technique: Collect, dilute and prepare samples and volumes as required according to specifications, directives, official standard regulations and/or expected results. Reconstitute the vial with the 6 ml sterile distilled water in aseptic conditions and add it to 500 ml of sterilized PALCAM agar base cooled to 50ºC. Do not overheat once suplemented. Pour the complete medium into Petri dishes and, once solidified on a flat surface, spread the plates by streaking methodology or by spiral method. Incubate the plates in aerobic atmosphere at 37 ± 1ºC for 44 ± 4h. (Incubation times longer than those mentioned above or different incubation temperatures may be requied depending on the sample, on the specifications,…) After incubation, enumerate all the colonies that have appeared onto the surface of the agar, observing any blackening of the medium due to esculin hydrolysis, typical for Listeria strains. Presumptive isolation of Listeria sp. must be confirmed by further microbiological and biochemical tests.

Principles and uses Listeria Agar Base Palcam, used with supplements, is a selective and differential medium for Listeria spp. It is recommended by ISO 11290 for the detection and enumeration of Listeria monocytogenes in food products and clinical samples, and can also be used for environmental samples.

It is used after a primary and secondary enrichment stage, using Listeria Enrichment Broth Base (Cat.1120). It allows the easy differential diagnosis of Listeria monocytogenes using a double-system indicator: Esculin/Iron and Mannitol/Phenol red. All Listeria species hydrolyze the esculin to esculetin, which reacts with iron ions producing a blackening of the medium. Lithium chloride included in the medium, along with ceftazidime, polymyxin B sulfate and Acryflavine from the supplement, inhibit the growth of the non-Listeria accompanying bacteria present in foods, which can hydrolyze the esculin. Peptones and maize starch provide a rich nutrient base for growth. Yeast extract is the source of vitamins, particularly of the B-group. Glucose is the fermentable carbohydrate. Ferric ammonium citrate improves the growth of L. monocytogenes. The Mannitol/Phenol red differentiation system is used to differentiate Listeria spp that do not ferment mannitol from other species that occasionally grow in the medium such as enterococci or staphylococci. Differentiation is achieved by the acid increase in the media, causing the phenol red indicator to change the color of the medium from red to yellow. Confirmation of Listeria is done by biochemical and serological identifications tests.

This supplement is used in selective media in order to detect the hydrolization of esculin, typical, for example, of Listeria spp.
For this reason this supplement is added to Listeria enrichment broth base in order to obtain Fraser broth or Half Fraser broth.
This medium is also supplemented with specific antibiotics.
In the complete medium any darkness of the medium can be taken as presumptive presence of Listeria , because in the same time the growth of enterococci, which are also able to hydrolyze esculin, is suppressed by the inclusion of lithium chloride and the companion flora is inhibited by Nalidixic acid and Acriflavine hydrochloride .

Principles and uses
Listeria Fraser Broth Base is used for the rapid detection of Listeria from food and environmental samples. The antibiotics are already included in the formula so it is only necessary to add the Ferric Ammonium Citrate Supplement.
Listeria spp. may be present in small numbers and are often accompanied by considerably larger numbers of other microorganisms, therefore selective enrichment is necessary. Listeria Fraser broth is used in this selective enrichment of Listeria monocytogenes and other Listeria species in all food types, including milk and dairy products, and environmental samples. This formula is described according to the ISO 11290.
Enzymatic digest of casein, enzymatic digest of animal tissues and meat extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Potassium phosphates act as a buffer system. All Listeria species hydrolyze esculin, which reacts with ferric ions producing a blackening of the medium. The addition of ferric ammonium citrate improves the growth of Listeria monocytogenes. Lithium chloride inhibits the growth of enterococci that can hydrolyze the esculin.

Preparation
Suspend 28,7 grams of the medium in 500 ml. of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 121 ºC for 15 minutes. Cool to 45-50 ºC and aseptically add one vial of Ferric Ammonium Citrate Supplement . Homogenize gently and dispense into sterile containers.

Principles and uses
Alkaline Peptone Water is used for the enrichment of Vibrio cholera and Vibrio species from food, water, feces and clinical studies.
This medium has been recommended by various authors to increase the recovery of Vibrio species in fecal materials and other samples. Peptones provide nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance and encourages the growth of Vibrio cholerae.
It is claimed that raising the medium’s pH leads the medium’s alkalinity to inhibit most of the unwanted flora background, leaving the viability of the Vibrio species intact.
Growth in tubes is indicated by turbidity compared to an uninoculated control. Additional steps are recommended, like plating onto a selective and non-selective media for isolation and morphology, and biochemical and serological studies for identification.

Rappaport Soy Broth (Vassiliadis) is recommended by ISO 6579 and ISO 19250, after the pre-enrichment step, for the selective isolation of Salmonella spp. Rappaport medium was modified by Vassiliadis by reducing Malachite green concentration and increasing incubation temperature, thus offering a better stability of the pH of the prepared medium and optimizing the concentration of Magnesium chloride, resulting in an improved recovery of Salmonellae. Soy peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Potassium phosphates balance the low pH of the medium, combined with the presence of Magnesium chloride to raise the osmotic pressure, and Malachite green to inhibit other organisms. Sodium chloride supplies essential electrolytes for transport and osmotic balance.

Preparation Suspend 26,6 grams of the medium in 1 liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 115 °C for 15 minutes. DO NOT OVERHEAT.

Instructions for use * For detection of Salmonella spp. in food, animal feed, animal faeces, and environmental samples according to ISO 6579: – Preenrichment in non-selective liquid medium: Inoculate the Buffered Peptone Water  with the sample or dilutions, and incubate at 34-38 ºC for 18±2 h. – Enrichment in/on selective media: Inoculate, with the culture obtained in the pre-enrichment stage, the Rappaport Soy Broth (Vassiliadis) or the Modified Semisolid Rappaport Vassiliadis medium (MSRV), and the MKKTN Broth. The Rappaport Soy Broth and the Modified Semisolid Rappaport medium are incubated at 41,5 ºC for 24±3 h, and the MKKTN Broth at 34-38 ºC for 24±3 h. – Plating out on selective solid media: From the selective enriched cultures, inoculate two selective isolation agar; XLD agar and any other selective medium complementary to XLD agar, Salmonella Chromogenic Agar , Brilliant Green Agar, Bismuth Sulfite Agar, DCLS Agar, Desoxycholate Citrate Agar , Hektoen Enteric Agar, Salmonella Shigella Agar and XLT4 Agar. Incubate the XLD plates inverted at 34-38 ºC for 24±3 h. Incubate the second selective medium in accordance with the manufacturer’s instructions. – Confirmation: Subculture colonies of presumptive Salmonella and confirm their identity by biochemicals and serological tests.

Principles and uses Bair Parker Agar Base is used for the isolation and enumeration of coagulase-positive staphylococci in food and other materials. Its formula is described in ISO 6888-1 normative.

Casein pancreatic digest, beef extract and yeast extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Lithium chloride, trypsin inhibitor and potassium tellurite inhibit the accompanying flora, and glycine and sodium pyruvate facilitate the staphylococci growth. Bacteriological agar is the solidifying agent. The ISO 6888-1 Standard recommends adding Egg Yolk Tellurite Emulsion Supplement  to Baird Parker Agar Base to make the complete medium Baird Parker Agar, used for the general count of coagulase-positive staphylococci in products intended for human or animal feed, through the counting of colonies obtained in a solid medium. The identity of Staphylococcus aureus isolated on Baird Parker Agar must be confirmed with a coagulase reaction. The ISO 6888-2 Standard recommends the addition of Rabbit Plasma Fibrinogen (RPF) Supplement  to Baird-Parker Agar Base, to make Rabbit Plasma Fibrinogen (RPF) Agar used for food (such as cheese made from raw milk and certain raw meat products) that may be contaminated with: Staphylococcus forming non-characteristic colonies in Baird-Parker Agar or with base flora that can mask the colonies sought. This medium should be used immediately after preparation. In Baird-Parker Agar the characteristic colonies are black or grey, shiny and convex and surrounded by a clear area. After 24 h of incubation an opalescent ring may appear in the clear area. Non characteristic colonies may be bright black or gray, with or without a narrow white border, without a clear area or opalescent ring. In Rabbit Plasma Fibrinogen Agar, staphylococcus colonies are small, black or gray, even white, surrounded by a halo of precipitation indicating the coagulase activity. At the start of incubation, Proteus colonies can present similar physical characteristics to coagulase-positive Staphylococcus aureus colonies. However, after 24 or 48 hours of incubation, they can acquire a brown color that expands and invades the plate, and which allows them to be distinguished from staphylococcus.

Principles and uses Campylobacter Agar Base Blood Free (CCDA) is a modified formula described by Bolton et al., replacing blood by charcoal, sodium pyruvate and ferrous sulfate. This medium supports the growth of most enteric Campylobacter and it is recommended for the selective isolation of Campylobacter jejuni, Campylobacter coli and thermophilic Campylobacter in foods. It is recommended by ISO 10272. Campylobacter is considered the main cause of enteric illnesses. Campylobacter spp. can cause mild to severe diarrhea, with loose, watery stools frequently followed by bloody diarrhea. These pathogens are very infective and are transmitted by contaminated food or water. The medium contains ferrous sulfate, sodium pyruvate and charcoal to promote the growth of Campylobacter species, as they quench the toxic forms of oxygen (hydrogen peroxide) increasing the aerotolerance and enabling the oxygen sensitive strains to be readily isolated. Sodium desoxycholate partially or completely inhibits Gram positive organisms, coliforms and Proteus. Enzymatic digest of animal tissue and casein, and beef extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Bacteriological agar is the solidifying agent. Cefoperazone increases selectivity and inhibits the growth of Gram negative enteric bacilli and some Gram-positive species, whilst Amphotericin B suppresses yeasts and fungi growth. The increment of temperature has shown an increase in selectivity.

Saline Peptone Water (Maximum Recovery Diluent) is an isotonic diluent used for maximum recovery of microorganisms, and for the growth of bacterial cultures, principally marine bacteria. ISO 6887 recommends this medium as a diluent for the preparation of initial suspension for microbiological samples. The low concentration of peptone does not cause a multiplication of the organisms within 1-2 hours of dilution of the sample. It is also used for carbohydrate fermentation tests in many food and environment studies, amongst others. To determine carbohydrate fermentation patterns, add 1,8 ml of 1% Phenol red to reconstitute the dry medium. After dispensing into test tubes with Durham gas collecting vials for gas detection, sterilize at 121 ºC for 15 minutes. Aseptically add sterile carbohydrate solution (Dextrose) to yield 1% final concentration. Peptone is the nutrient source of nitrogen, vitamins, amino acids and minerals. Sodium chloride maintains the osmotic balance.

Principles and uses
Yeast Extract Agar is a medium rich in nutrients that permits the recovery of a wide spectrum of bacteria, yeasts and molds. This medium is recommended by ISO 6222 for the plate count of microorganisms in all types of water, including for human consumption.
Tryptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the water-soluble portion of hydrolyzed yeast and is a source of vitamins, particularly of the B-group. Bacteriological agar is the solidifying agent.
The norm ISO 6222 recommend this medium for the enumeration of culturable microorganisms in potable water at 36 ºC and 22 ºC.

Preparation
Suspend 24 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 121ºC for 15 minutes. Cool to 45±1 ºC, mix well and dispense into plates.

Dichloran Glycerol Agar (DG 18) is a selective medium based on the formulation of Hocking and Pitt. It is recommended for the enumeration and isolation of xerophilic molds from dried and semi-dried foods, such as fruits, spices, cereals, nuts, meat and fish products. Glycerol reduces the water activity from 0.999 to 0.95, thereby reducing bacterial growth, and is also the carbon source. Chloramphenicol is an antibiotic which aids in isolating pathogenic fungi from heavily contaminated material, as it inhibits most contaminating bacteria. It is a recommended antibiotic for use with media due to its heat stability and wide bacterial spectrum. Bacteria growth inhibition and spreading of more-rapidly growing molds restriction aids in the isolation of slow-growing fungi by preventing their overgrowth by more-rapidly growing species. Dichloran prevents the fast spreading of mucoraceous fungi, improving the colony count. Peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Dextrose is the fermentable carbohydrate providing carbon and energy. Potassium phosphate acts as a buffer system. Magnesium sulfate provides sulfur and other trace elements. Bacteriological agar isthe solidifying agent.

Principles and uses Giolitti-Cantoni Broth ISO is a modified formula of a medium formulated by Giolitti and Canton in 1996. It is recommended by ISO 6888-3 for the enumeration and detection of coagulase-positive staphylococci from food and animal feeding stuffs, using the MPN method.. Casein peptone and beef extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Mannitol is the fermentable carbohydrate providing carbon and energy. Lithium chloride inhibits the growth of Gram-negative bacteria. Polysorbate 80 is incorporated to neutralize phenols, hexachlorophene and formalin. The growth of staphylococci is encouraged by sodium pyruvate and glycine. Gram-negative contaminants are inhibited by potassium tellurite. This method is recommended for products where staphylococci are expected to be stressed and in low numbers such as dried products. Coagulase-positive staphylococci will mostly be Staphylococcus aureus, but Staphylococcus intermedius and some strains of Staphylococcus hyicus are also coagulase-positive. The confirmation of staphylococci which produce coagulase is based on a strongly positive coagulase reaction, but it is also known that some strains of coagulase-positive staphylococci give weak positive coagulase reactions. These latter strains can be confused with other bacteria but can be differentiated by the use of additional tests such as one for the production of thermonuclease.

Principles and uses Violet Red Bile Agar with Glucose (VRBG) is a selective medium, containing Bile and Violet Red dye, for the isolation and enumeration of enterobacteria. It is based on MacConkey Medium  for the detection and enumeration of bile-tolerant Gram-negative Enterobacteriaceae in dairy products and foods. In this medium, the lactose is replaced by glucose as the carbohydrate. VRBG agar is becoming the preferred medium for use in investigations into raw materials, processed foods and plant hygiene. The Enterobacteriaceae group includes lactose-fermenting coliforms bacteria and non-lactose fermenting species like Salmonella and Shigella. Pancreatic digest of gelatin provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Glucose is the fermentable carbohydrate providing carbon and energy. Glucose fermenters form red colonies in the presence of the pH indicator neutral red. Bile salts and crystal violet inhibit Gram-positive bacteria. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent. The European Pharmacopoeia, USP in paragraph 2.6.13: “Microbiological examination of non-sterile products: test for specified microorganisms” recommends this medium for the testing of bile-tolerant Gram-negative bacteria in products. ISO 21528 proposes VRBG Agar for the detection and enumeration of Enterobacteriaceae. The pour plate method suppresses the growth of Gram-negative non-fermenting bacteria due to its semi-anaerobic conditions. The fermentation of glucose is likewise stimulated and results in the formation of purple-red colonies, clearly visible, surrounded by a zone of the same color. Note that coliforms will ferment the glucose and produce acid with or without gas. Klebsiella and Citrobacter, which are more heat-resident than coliforms, also grow in this medium and can indicate a production process defect (insufficient heating).

Principles and uses Violet Red Bile Agar with Lacose (VRBL), containing Bile and Violet Red dye, is based on MacConkey Agar  for the detection and enumeration of lactose-fermenting bacteria and the differentiation of coliforms or Coliaerogenes group from non-lactose fermenting organisms in dairy products, water and foods. Peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group. Lactose is the fermentable carbohydrate providing carbon and energy. Bile salts and crystal violet inhibit Gram-positive bacteria. Neutral red is a pH indicator. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent. It is convenient to use the pour plate method. Lactose fermenters form red colonies with red-purple halos. Occasionally the cocci of the intestinal tract can develop as small, punctiform red colonies. The purplish red colonies with a diameter of at least (sometimes surrounded by a reddish zone of precipitated bile) are considered as typical colonies of coliforms and do not require further confirmation. Atypical colonies (e.g. of smaller size), and all colonies derived from milk products that contain sugars other than lactose, may result in colonies with an appearance that looks similar to the typical coliforms. These colonies should be confirmed in tubes of Brilliant Green Bile Broth

Bacillus Cereus Selective Agar Base (MYP) is a medium recommended by the ISO normative 7932 for the presumptive enumeration of Bacillus cereus with the count plate technique at 30 ºC.
Beef extract and enzymatic digest of casein provide nitrogen, vitamins, minerals and amino acids essential for growth. Mannitol is the fermentable carbohydrate providing carbon and energy, Bacillus cereus is mannitol-negative. The mannitol content allows the identification of the accompanying mannitol positive flora, which are characterized by a yellow color. Phenol red is the pH indicator. Bacteriological agar is the solidifying agent. Bacillus cereus is resistant to certain concentrations of polymyxin, which inhibits the accompanying flora, and it is effective mainly against gram-negative organisms. Bacillus cereus produces lecithinases. The insoluble degradation products of the lecithin from egg yolk, are accumulated around the Bacillus cereus colonies, forming a white precipitate. The presumptive colonies are large, pink (indicating that mannitol fermentation has not occurred) and generally surrounded by a zone of precipitation (indicating the production of lecithinase).

For the enumeration and isolation of Bacillus cereus in food

Principles and uses
Bacillus Cereus Selective Agar Base (PEMBA) has been adapted to meet the nutritional needs of Bacillus cereus, and was proposed for the enumeration, detection and isolation of Bacillus cereus in food. This bacterium is resistant to certain concentrations of polymyxin, which inhibits the
accompanying flora, and is effective mainly against Gram-negative organisms. This medium is recommended by ISO 21871 for the determination of low number of Bacillus cereus.
Casein peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Sodium pyruvate reduces the colony size of the organisms.
Bromothymol blue acts as pH indicator to detect mannitol fermentation. Mannitol is the fermentable carbohydrate providing carbon and energy, Bacillus cereus is mannitol-negative. The Mannitol content allows the identification of the accompanying mannitol positive flora. Sodium chloride maintains the osmotic balance of the medium. Bacteriological agar is the solidifying agent.
Bacillus cereus produces lecithinases. The insoluble degradation products from the lecithin of egg yolk accumulate around the Bacillus cereus colonies, forming a white precipitate. The colonies of Bacillus cereus will appear blue colonies surrounded by a zone of opacity in the medium

• Môi trường Lactobacilli MRS dựa trên công thức của deMan, Rogosa và Sharpe với một chút sửa đổi.
• Nó hỗ trợ sự phát triển mạnh mẽ của tất cả các Lactobacilli từ khoang miệng, các sản phẩm từ sữa, thực phẩm, phân và các nguồn khác.
• Proteose peptone và HM peptone B cung cấp các hợp chất nitơ và cacbon. Chiết xuất men cung cấp phức hợp vitamin B và dextrose là nguồn năng lượng và carbohydrate có thể lên men. Polysorbate 80 cung cấp axit béo cần thiết cho sự chuyển hóa của Lactobacilli. Natri axetat và amoni xitrat ức chế Streptococci, nấm mốc và nhiều loại vi sinh vật khác.

Môi trường LB Agar – Luria Bertani Agar, Miller

• Môi trường LB Agar dùng để nuôi cấy các chủng vi sinh vật. LB agar thường dùng để nuôi E. Coli tái tổ hợp trong các nghiên cứu di truyền và phân tử.
• LB agar thường dùng để nuôi các chủng không khó tính.
• Luria Bertani Agar được điều chế theo mô tả của Lennox để nuôi cấy và duy trì các chủng Escherichia coli tái tổ hợp. Luria Bertani Agar, Miller hơi khác biệt với lượng NaCl gấp đôi.
• Casein thủy phân enzyme cung cấp peptide và pepton trong khi phức hợp Vitamin B được cung cấp bởi chiết xuất men. Natri clorua cung cấp các ion natri để vận chuyển màng và cũng duy trì trạng thái cân bằng thẩm thấu của môi trường.

Enterobacter sakazakii Agar (ESA) là môi trường chọn lọc chuyên biệt dùng để phát hiện và phân lập vi khuẩn Cronobacter spp. (trước đây gọi là Enterobacter sakazakii) trong thực phẩm, đặc biệt là sữa bột dành cho trẻ sơ sinh và nguyên liệu, môi trường sản xuất liên quan.

🧫 1. Mục đích sử dụng

Enterobacter sakazakii Agar được thiết kế để phân lập và nhận diện sơ bộ Cronobacter spp. sau khi tăng sinh chọn lọc (thường sau bước nuôi trong môi trường như Cronobacter Selective Broth hoặc Modified Lauryl Sulfate Broth).
Môi trường này giúp phân biệt Cronobacter spp. với các vi sinh vật đường ruột khác nhờ vào khả năng:

• Thủy phân α-glucosidase (một đặc tính sinh hoá đặc trưng),
• Và lên màu đặc hiệu trên môi trường có cơ chất chỉ thị.

⚗️ 2. Nguyên lý hoạt động

Môi trường Enterobacter sakazakii Agar chứa:

• Chất dinh dưỡng cơ bản cho sự phát triển của Enterobacteriaceae,
• Chất ức chế chọn lọc (ức chế Gram dương và nhiều vi khuẩn không mong muốn),
• Cơ chất chỉ thị (thường là một hợp chất chứa chromogenic α-glucoside) — khi bị thủy phân bởi enzyme α-glucosidase của Cronobacter spp., sẽ sinh ra khuẩn lạc có màu đặc trưng (thường vàng hoặc xanh lục).
  Các vi khuẩn không có enzym này sẽ cho khuẩn lạc không màu hoặc màu khác → dễ dàng phân biệt.

🎨 3. Đặc điểm nhận diện điển hình

🔬 4. Ứng dụng trong quy trình ISO 22964:2017

Trong phương pháp ISO 22964:2017, ESA thường được dùng ở bước phân lập (isolation stage) sau tăng sinh chọn lọc.
Các khuẩn lạc nghi ngờ được chuyển sang bước xác nhận định danh bằng:

• Kiểm tra sinh hoá (oxidase, indole, sorbitol, v.v.), hoặc
• Phương pháp phân tử (PCR định danh Cronobacter).

📦 5. Bảo quản và lưu ý

• Bảo quản ở 2–8°C, tránh ánh sáng.
• Không sử dụng môi trường đã đổi màu, khô hoặc có tạp nhiễm.
• Trước khi sử dụng, phải đảm bảo môi trường đạt kiểm tra chất lượng nội bộ (QC test với chủng chuẩn:
  • Cronobacter sakazakii ATCC 29544 — dương tính
  • Escherichia coli ATCC 25922 — âm tính).

Medium used for the isolation and cultivation of Staphylococcus aureus from food and clinical specimens.

PROCEDURE

Suspend 60.03 G of powder in 1 L of distilled or deionized water. Heat to boiling until completely dissolved. Sterilize by autoclave at 121°C for 15 minutes. Cool to 45 – 50°C in water bath. Aseptically add 2 vials of Potassium Tellurite 1% supplement (MB-P1842). Mix well. Pour into petri dishes.

STORE

The powder is very hygroscopic. Store the powder at room temperature, in a dry environment, in its original container tightly closed and use it before the expiry date on the label or until signs of deterioration or contamination are evident. Store prepared medium at 2 – 8 ° C.

Wilkins Chalgren Anaerobic Broth Base is used for cultivation and susceptibility testing of anaerobic bacteria. This medium formulated by Wilkins and Chalgren, is the preferred medium for susceptibility testing of anaerobes. This medium is also recommended for testing anaerobic bacteria. This media needs to be appropriately supplemented to support the growth of certain anaerobic bacteria. Hemin and Menadione (Vitamin K3) enhances the growth of Bacteroides species and Prevotella melaninogenica, respectively and many other species of gram-negative anaerobic rods. The medium can also be supplemented with defibrinated or lysed blood for the growth of fastidious anaerobic bacteria.

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 as a selective medium for the isolation and enumeration of Escherichia coli without the need for membranes or pre-incubation. Based on the formulation of Tryptone Bile Agar it incorporates a chromogenic substrate, X-Glucuronide, to detect the ß-glucuronidase enzyme which is specific for the majority of E. coli strains. Approximately, 3-4% of E. coli are glucuronidase negative including E. coli O157.(1) The advantage of the chromogenic substrate is that the reaction is concentrated within the colony resulting in distinctive blue/green colonies of E. coli while the other coliforms produce cream colonies.

The tryptone provides the required carbon, nitrogen and vitamins. Bile salts No.3 is a selective agent against Gram-positive bacteria. X-glucuronide is a chromogenic substrate. Agar is solidifying agent.

This medium is used to detect and/or confirm the presence of coli-aerogenes group of organisms in water, food and dairy laboratories. Bile and Brilliant Green are included in the medium to inhibit gram positive organisms while the coli-aerogenes organisms are identified by the formation of gas during the fermentation of Lactose. The medium can also be used for the confirmation of Escherichia coli by incubating at 44°C.

Brain heart infusion agar is very nutritious general-purpose medium and is suitable for the isolation of most micro-organisms including many fastidious organisms.
The formulation is a modification of that from Rosenow and Hayden.
The medium is not recommended for the determination of haemolytic reactions because of the glucose content.
The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone.
Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance.
A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms.
NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may ‘auto-sterilize’ the culture.

Recommended for enrichment of Vibrio species from food and water samples in accordance with ISO.

Alkaline Saline Peptone Water (ASPW) is recommended for enrichment of Vibrio species from food and water samples in accordance with ISO. This medium specifies a horizontal method for the detection of the two main pathogenic Vibrio species causing intestinal illness in humans: V. parahaemolyticus and V. cholera . It is applicable to products intended for human consumption and the feeding of animals, and environmental samples in the area of food production and food handling.

Mueller Hinton Agar is used as a base to make various media for antimicrobial susceptibility testing by the disk diffusion method as described by Bauer-Kirby. First described by Mueller and Hinton, Mueller Hinton Agar has been approved as the definitive medium for antimicrobial susceptibility testing by European Committee on Antimicrobial Susceptibility Testing (EUCAST), Clinical and Laboratory Standards Institute (CLSI) and is compliant with ISO16782:2016.

KM0183, when prepared as unsupplemented Mueller Hinton Agar, is suggested by EUCAST and CLSI for non-fastidious organisms such as Enterobacterales, Pseudomonas spp., Stenotrophomonas maltophilia, Acinetobacter spp., Staphylococcus spp., Enterococcus spp., Aeromonas spp., Achromobacter xylosoxidans, Vibrio spp., Bacillus spp. and Burkholderia pseudomallei.

KM0183, when prepared supplemented with 5% horse blood and nicotinamide adenine dinucleotide (NAD), is suggested by EUCAST and CLSI for fastidious organisms such as Streptococcus pneumoniae, Streptococcus groups A, B, C and G, Viridans group streptococci, Haemophilus influenzae, Moraxella catarrhalis, Listeria monocytogenes, Pasteurella multocida, Campylobacter jejuni and coli, Corynebacterium spp., Aerococcus sanguinicola and urinae and Kingella kingae.

Additionally, according to the UK Standards for Microbiology Investigations, when supplemented appropriately, Mueller Hinton Agar can be used in the process of identifying Haemophilus species and the HACEK group of organisms and Helicobacter species from clinical specimens.

Palcam agar is a selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens.
The Columbia peptone mix and starch provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Differentiation of Listeria spp. from enterococci and staphylococci occurs through aesculin hydrolysis and mannitol fermentation. Listeria monocytogenes will hydrolyse aesculin and the associated reaction with the ferric ammonium citrate gives rise to a brown/black precipitate around the colonies. Listeria spp. do not however ferment mannitol. Mannitol fermentation is seen through a colour change of the colony or the area around the colony from red to yellow due to the production of acidic end products. Phenol red is the pH indicator in the medium.
Lithium chloride is included to inhibit enterococci. The associated Palcam selective supplement, LS0038, contains polymyxin B, acriflavine and ceftazidime to inhibit other Gram-positive and Gram-negative organisms that may be present in specimens.

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 spp. 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 (40 mg/l) improves the inhibition of Proteus spp.
Immediately prior to use it is necessary to add 20 ml/l of 2% iodine/iodide solution 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.

Principles and uses
Muller-Kauffmann Broth Base with Brilliant Green and Novobiocin (MKTTN) is recommended by the ISO 6579 and ISO 19250 norms to be used as a selective enrichment broth for the detection of Salmonella spp in all food types, including milk and dairy products, molluscan shellfish and other fish products, and in water samples and environmental swabs.
Beef extract and casein peptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Calcium carbonate is a neutralizer which absorbs toxic metabolites. Bile salts, brilliant green and novobiocin inhibit organisms other than Salmonella. Selectivity is also obtained by both sodium thiosulfate and tetrathionate, suppressing coliforms. Tetrathionate is formed in the medium with the addition of the iodine and potassium iodide solution.
Organisms containing the enzyme tetrathionate reductase will thrive in this medium. Sodium chloride supplies essential electrolytes for transport and osmotic balance.

Preparation
Suspend 89,53 grams of the medium in one litre of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. AVOID OVERHEATING. DO NOT AUTOCLAVE. Cool to 45-50ºC. Aseptically Add 20 ml of an iodine and potassium iodide
solution (20 g of iodine and 25 g of potassium iodide in 100 ml of sterile distilled water). Homogenize gently and dispense into sterile containers.

Formulated to ISO 6579, Buffered Peptone Water (BPW) is a pre-enrichment medium designed to help sub-lethally damaged Salmonella spp. recover before introducing them into a selective enrichment medium.
Enzymatic digest of casein is the source of the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance in the medium. Di-sodium hydrogen phosphate and potassium di-hydrogen phosphate act as buffers in the medium. This nutritious medium is free from inhibitors and is well buffered to maintain pH 7.0 for the incubation period. Sub-lethal injury to Salmonella spp. occurs in many food processes and this pre-enrichment step greatly increases the chance of their recovery, especially if a low number of cells are present in a sample.

For in vitro diagnostic use.

KM0159 SIM Medium is a multi-purpose medium for the differentiation of Enterobacteriaceae.

This is best described as a multi-purpose medium for the differentiation of Enterobacteriaceae that combines three individual tests into a single medium (hydrogen sulphide production, indole formation and motility).

The presence of motility is apparent by the organism tracking out from the line of inoculation and often turning the medium turbid. Non-motile organisms generally grow within the stab line leaving the surrounding medium clear.

H₂S positive organisms turn the medium black due to the formation of hydrogen sulphide in the presence of the sodium thiosulfate and ferric ammonium citrate often making it difficult to determine the other parameters.

Indole production is tested for by layering a small amount of Indole Reagent (Kovac’s) onto the surface of the medium. A positive result is indicated by the formation of a pink colour at the interface of the reagent and the medium. The enzymatic digest of casein and enzymatic digest of animal tissue provide the required carbon, nitrogen, and vitamins in this medium. Ferric ammonium citrate and sodium thiosulfate are used to detect hydrogen sulphide production. The low concentration of agar allows for a semisolid media which is used for motility detection

A general purpose and nutritious medium for the non-selective enrichment of non-fastidious and some fastidious organisms. Tryptone and soy peptone are the nitrogen and vitamin source in the medium. Glucose is the carbon energy source that facilitates organism growth and sodium chloride maintains osmotic balance. Di-potassium hydrogen phosphate is a buffering agent to prevent auto-sterilisation due to acid production during the growth of some organisms.
Tryptone Soya Broth is also commonly referred to as Soybean-Casein Digest Medium or Tryptic Soya Broth and is abbreviated as TSB. TSB conforms to the Harmonized United States Pharmacopoeia (USP), European Pharmacopoeia (EU), and Japanese Pharmacopoeia (JP).

Tryptone Soya Agar is used for a wide range of applications, including culture storage, enumeration of cells, isolation of pure cultures, or simply general culture. It has been found to be useful in cosmetic testing, water, and wastewater applications. Tryptone Soya Agar may be used to determine X and V factor requirements of Haemophilus species; sterility testing; and environmental monitoring within pharmaceutical cleanrooms and sterile facilities. This medium meets the requirements of the Harmonized USP/EP/JP and is based on the original formulation described by Leavitt et al. in 1955. Tryptone Soya Agar is recommended as a reference medium when testing selective media, to measure the degree of inhibition. In environmental monitoring applications, it is common for plates to be incubated at 30-35°C for bacterial colonies and 20-25°C for mould and fungi. Tryptone Soya Agar will support the growth of both aerobic and anaerobic organisms depending on incubation conditions.

KM0024 unsupplemented is recommended by the World Health Organization, UK Standards for Microbiology Investigations, International Organization for Standardization and is tested in accordance with ISO 11133:2014. This medium is also included in the Bacteriological Analytical Manual for cosmetics testing. UK Standards for Microbiology Investigations also call for Tryptone Soya Agar supplemented with 5% sheep blood (E&O DSC) for aid in the identification of Bordetella species from clinical specimens.

The addition of defibrinated animal blood to the base medium, promotes the growth of most fastidious organisms and presumptive identification can be made based on haemolytic reactions. It should be noted that the haemolytic patterns of isolates may vary with the source of animal blood. Addition of selective agents allows isolation and presumptive identification of specific species or groups of organisms

Thayer Martin Agar là một môi trường nuôi cấy giàu dinh dưỡng và chọn lọc, được phát triển đặc biệt để phân lập chính xác Neisseria gonorrhoeae và Neisseria meningitidis. Công thức đặc biệt của môi trường này chứa các kháng sinh có tác dụng ức chế sự phát triển của vi khuẩn hoại sinh và các tác nhân gây nhiễm khác, đảm bảo độ đặc hiệu cao hơn khi xử lý các mẫu từ những vị trí dễ bị nhiễm tạp.

Mặc dù Thayer Martin Agar cho hiệu suất tuyệt vời đối với hầu hết các chủng Neisseria spp, một số biến thể chỉ có thể phát triển trên Chocolate Agar. Do đó, chúng tôi khuyến nghị sử dụng kết hợp cả hai loại môi trường này để đảm bảo phạm vi chẩn đoán rộng và khả năng thu hồi vi khuẩn tối đa

Formula
Tryptone: 20.0
Lactose :5.0
Bile Salts No. 3 :1.5
Di-potassium phosphate :4.0
Mono-potassium phosphate :1.5
Sodium chloride :5.0

Directions
Dissolve 37 g in 1 litre of distilled water. Dispense into final containers and sterilize by autoclaving at 121oC for 15 minutes.

For the confirmation of coliforms in water and food samples.

Blood Agar Base is used for the isolation, cultivation and detection of hemolytic reaction of fastidious microorganisms.
It is suitable for isolating and cultivating a wide range of microorganisms with difficult growth characteristics. Upon adding blood, it can be utilized for determining hemolytic reactions.
The heart infusion and meat peptone are rich sources of nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent.
The addition of blood provides extra growth factors for fastidious microorganisms and is the basis for determining hemolytic reactions. Hemolytic patterns may vary with the type of blood or base medium used. For example, defibrinated sheep blood gives best results for Group A streptococci.

Principles and uses
Sabouraud Dextrose Agar can be used for cultivating yeasts, molds (as cultivating pathogenic fungi, particularly those associated with skin infections) and aciduric microorganisms. This medium is also used for determining the microbial and fungal content of cosmetics and for the mycological evaluation of food.
The formula is based on the European Pharmacopoeia. Dextrose is the fermentable carbohydrate providing carbon and energy. Peptone mixture provides nitrogen, vitamins, minerals and amino acids essential for growth. Bacteriological agar is the solidifying agent. The high dextrose concentration and acidic pH make this medium selective for fungi.
Georg et al. demonstrated that the basic agar fortified by three antibiotics considerably improves the isolation of pathogenic fungi from heavily contaminated sources. To prepare a selective culture medium aseptically add the following for every liter of the medium before use: 0,4 g Cycloheximide; 20 units Penicillin; 40 mg Streptomycin. One can obtain a very rich Sabouraud medium by dissolving the medium in one liter of Heart Infusion.
The European Pharmacopoeia recommends this medium in the paragraph 2.6.12: “Microbiological examination of non – sterile products: Microbial enumeration test” for the examination of TYMC in products. In the paragraph 2.6.13: “Microbiological examination of non-sterile products: Test for specified microorganisms” for the test of Candida albicans in products.

Preparation
Suspend 65 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Distribute in proper containers and sterilize in autoclave at 118-121 ºC for 15 minutes. AVOID OVEARHEATING as it facilitates the hydrolysis of the components and the medium remains soft.

For the isolation, cultivation and detection of hemolytic activity.

Blood Agar Base is used for the isolation, cultivation and detection of hemolytic reaction of fastidious microorganisms.
It is suitable for isolating and cultivating a wide range of microorganisms with difficult growth characteristics. Upon adding blood, it can be utilized for determining hemolytic reactions.
The heart infusion and meat peptone are rich sources of nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Bacteriological agar is the solidifying agent.
The addition of blood provides extra growth factors for fastidious microorganisms and is the basis for determining hemolytic reactions. Hemolytic patterns may vary with the type of blood or base medium used. For example, defibrinated sheep blood gives best results for Group A streptococci.

Listeria Half Fraser Broth Base with antibiotic is a re-enrichment medium for the isolation of Listeria spp. from food and environmental specimens acc. ISO 11290

Preparation
# Dissolve 27.5g in 500ml of distilled water (purified water)
# Heat and frequent stirring to completely dissolve the medium
# Autoclave at 121°C for 15 minutes
# Cool to 45-50°C, add 1 vial of AgarCult Listeria FAC supplements
# Mix well and dispense into appropriate sterile containers

For the identification and enumeration of Pseudomonas aeruginosa by membrane filtration

Pseudomonas CN Agar Base is used for the identification of Pseudomonas aeruginosa by membrane filtration technique, based on the detection of pyocyanin production. It is a modification of Pseudomonas P Agar (King A Medium ). This medium is recommended by ISO 16266. Pseudomonas aeruginosa is an opportunist pathogen for humans, capable of growing in water with a low concentration of nutrients. This is why natural mineral water and spring water should be checked to be free of Pseudomonas aeruginosa at the time of commercialization. This microorganism can also be found in swimming pool water.
Peptone and casein provide nitrogen, vitamins, minerals and amino acids essential for growth. Cetrimide is added as a selective agent, and nalidixic acid to suppress contaminants of cetrimide media such as Klebsiella, Proteus and Providencia spp. Potassium sulfate and magnesium chloride provide cations to activate pyocyanin production and enhance pigment production. Bacteriological agar is the solidifying agent.

Principles and uses
XLD Agar (Xylose Lysine Desoxycholate Agar) is prepared according to the formulation of the ISO 6579 norm. It is recommended for the identification of Salmonella in food products, after pre-enrichment in a non-selective fluid such as Buffered Peptone Water and enrichment in a selective fluid medium such as Muller Kauffmann Broth Base with Brilliant Green & Novobiocin (MKTTN), Rappaport Soy Broth (Vassiliadis)  or Modified Semisolid Rappaport Vassiliadis Medium (MSRV).
The reactions are the degradation of the three fermentable carbohydrates: xylose, lactose, and sucrose, with the production of acid, manifested in the color change from red to yellow. Sodium thiosulfate serves as a reactive substance with Ferric ammonium citrate as an indicator of the formation of hydrogen sulfide under alkaline conditions. Lysine is included to enable the Salmonella group to be differentiated from the non-pathogens since, in its absence, salmonellae would quickly ferment the xylose, making it indistinguishable from non-pathogenic species. After the salmonellae terminate the xylose present, the lysine is attacked through the enzyme lysine decarboxylase with a change to an alkaline pH, similar to the Shigella reaction. The bacteria that decarboxylate the L-Lysine to cadaverine are identified by the presence of a purple-red color around the colonies due to the elevation of the pH. Phenol red is the pH indicator. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Sodium desoxycholate is the selective agent and is thus inhibitory to Gram-positive microorganisms. Bacteriological Agar is the solidifying agent.
Typical colonies of Salmonella on XLD agar have a black center and lightly transparent zone of reddish color due to the color change of the indicator.
Salmonella H2S-negative variants grown on XLD agar are pink with a darker pink center. Lactose-positive Salmonella grown on XLD agar are yellow with or without blackening.

Preparation
Suspend 54 grams of the medium in one liter of distilled water Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. AVOID OVERHEATING. DO NOT AUTOCLAVE.Cool the medium according to the applicable normative and pour into Petri dishes as soon as it has cooled.
Preparation of large volumes, overheating and prolonged storage in water bath is to be avoided. Precipitates may be formed but do not affect the performance of the culture media.

Principles and uses
Lysine Decarboxylase Broth is used to detect and differentiate Enterobacteria from other microorganisms, based on lysine decarboxylation.
Gelatin peptone provides nitrogen, vitamins, minerals and amino acids essential for growth.Yeast extract is a source of vitamins, particularly of the B-group. Dextrose is the fermentable carbohydrate. Bromocresol purple is the pH indicator. Lysine is added to detect the production of the specific enzyme.
When the medium is inoculated with a bacterium that is able to ferment dextrose, the acid produced lowers the pH of the medium and changes the color of the indicator from purple to yellow. The acidic condition also stimulates decarboxylase activity. The bacteria that decarboxylate the L-Lysine to cadaverine are identified by the presence of a purple-red color. The production of these amines elevates the pH of the medium. A yellow color after 24 hours indicates a negative result. By substituting L-Lysine with Arginine or Ornithine, the new resulting medium (Falkow Broth Base) can be used to study the decarboxylation of these amino acids.

Preparation
Suspend 14 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense quantities of 5 ml into screw-capped tubes. Sterilize in autoclave at 121 ºC for 15 minutes. Leave caps loose to allow gas exchange. Close well after sterilization.

Instructions for use

• Gently insert the inoculation loop with the sample into the tube and move the loop back and forth several times to inoculate the media.
• Incubate at 35±2 °C for 24 hours
• Color change to purple: positive decarboxylation reaction (Escherichia, Klebsiella, Salmonella, except S.parathyphi, Arizona, Alkalescens Dispar, Serratia).
• Yellow color: negative decarboxylation reaction (Proteus, Providencia, S.parathypi A,Shigella, Aeromonas, Citrobacter).