CHROMOGENIC MEDIA

CHROMOGENIC MEDIA
DEHYDRATED CULTURE
DEHYDRATED CULTURE
FOR MICROBIOLOGY
CHROMOGENIC
MEDIA FOR
FOODS & WATERS
life science products because
life is a great discovery
TBX CHROMOGENIC AGAR
(TRYPTONE BILE X-GLUCURONIDE) (ISO 16649-2:2001)
Selective medium for the detection and
Enumeration of E.Coli in foods.
Cat: 1151
FORMULA IN GRAMS PER LITRE
Casein Peptone………………………………
20.0
Bile Salts………………………………….……………1.50
x-ß-D-Glucuronide…………………………
0.075
Bacteriological Agar………………………………….15.00
Final pH 7.2 ± 0.2 at 25°C
Preparation
Suspend 36.6grams of the medium in one liter of distilled water. Mix well. Heat with frequent agitation and boil for one minute. Dispense into
appropriate containers and sterilize at 121ºC for 15 minutes.
Uses
TBX Agart is based on the tryptone Bile Salts Agar medium to detect and enumerate E.coli in
foods, with the addition of a chromogenic agent, x-ß-D-Glucuronide, to detect the presence of the
enzyme glucuronidase, which is highly specific for E.Coli.
The released chromophore in TBX Agar is insoluble and colored target colonies are easily
identified. E. coli absorbs the chromogenic agent x-ß-D-glucuronide, and the intracellular
glucuronidase enzyme activity breaks the bond between the chromophore and the glucuronide.
The released chromophore is colored and builds up within the cells, causing the E. coli colonies to
be blue-green colored. Casein peptone provides essential nutrients for growth: nitrogen, vitamins,
minerals and amino acids. Bile Salts are inhibitors to other Gram-positive organisms and
suppress coliform bacteria. Bacteriological agar is the solidifying agent.
The standard ISO 16649 specifies a horizontal method for the enumeration of ß-glucuronidase
positive E. coli in products intended for human consumption or for the feeding of animals. It uses
a colony-count technique at 37 and 44°C on a solid medium containing a chromogenic ingredient
for the enzyme ß-glucuronidase. Inoculate and incubate at a temperature of 37 and 44°C for 18 –
24 hours.
Note: The negative E. coli b-ß-glucuronidase colonies are colorless, e.g. E. coli O157:H7. The
high temperatures (44°C) inhibit the growth of E. coli O157:H7.
Escherichia coli
ATCC 25922
Bibliography
International Standard ISO 16649-2:2001 Microbiology of food animal feeding stuffs. Horizontal method for the enumeration of presumptive
Escherichia coli.
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 37ºC and 44ºC
and observed after 18-24 hours
Micro-organisms
Growth
Colony Color
44ºC
37º
Good
Good
Blue-green
Salmonella typhimurium ATCC 14028
Inhibited
Inhibited
Colorless
Streptococcus faecilis ATCC 19433
Inhibited
Inhibited
---
Klebsiella pneumoniae ATCC 13883
Inhibited
Inhibited
Colorless
Escherichia coli ATCC 25922
www.condalab.com
Dehydrated Culture Media
E.COLI-COLIFORMS
CHROMOGENIC MEDIUM
Cat: 1340
Selective medium for the simultaneous detection of E. coli
and other Coliforms in water and food samples.
FORMULA IN GRAMS PER LITER
Sodium Chloride………………………………………..
5.00
Phosphate Buffer………………………………………….4.90
Bacteriological Peptone………………………………
3.00
Sodium Pyruvate…………………………………………..1.00
Tryptophan……………………………………………….
1.00
Sorbitol……………………………………………………..1.00
Chromogenic Mixture…………………………………
0.36
Tergitol -7…………………………………………………..0.10
Bacteriological Agar……………………………………
10.00
Final pH 6.8 ± 0.2 at 25°C
Preparation
Suspend 26.4 grams of the medium in one liter of distilled water. Heat with frequent agitation and boil for one minute. AVOID
OVERHEATING. DO NOT AUTOCLAVE. Dispense into Petri Dishes. Store the plates in the refrigerator, protected from the light.
Uses
E.COLI-COLIFORMS CHROMOGENIC MEDIUM is a selective medium for the detection of E.coli
and other Coliforms in waters and foods. The interaction of ingredients in the medium, such as
peptone, sorbitol, etc, grants a quick colony growth, including infectious Coliforms. Tergitol-7
inhibits Gram-positive bacteria. Sodium chloride maintains the osmotic balance and the
Phosphate is the buffer. Bacteriological agar is the solidifying agent.
The chromogenic mixture contains chromogenic substrates as Salmon-GAL and X-glucuronide.
Coliform enzymes produced, such as galactosidase and glucuronidase, cleave these substrates,
resulting in the different coloration of certain bacteria colonies. The ß-D-galactosidase cleaves
Salmon-GAL substrate, and gives a salmon to red color to the coliform colonies. The ß-Dglucuronidase cleaves both substrates Salmon-Gal and X-glucuronide, giving a dark blue to violet
color to the colonies, easily distinguishable from other coliform colonies that have a salmon to red
color.
The addition of tryptophan to the medium allows the performance of the Indole test for further E.
coli confirmation. Inoculate and incubate at 35 ± 2°C for 18 – 24. hours.
Escherichia coli
Coliforms
Bibliography
Alonso, J.L. Soriano, K., Amoros I., Ferrus, M.A. 1998 Cevartitatine determination of E. coli and fecal coliforms in water using a
chromogenic medium.J. Environ. Sci Health 33.
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 35ºC ± 2ºC and
observed after 18-24 hours
Micro-organisms
Growth
Colony Color
Escherichia coli ATCC 25922
Good
Blue-dark violet
Escherichia coli ATCC 11775
Good
Blue-dark violet
Citrobacter freundii ATCC 8090
Good
Salmon
Salmonella enteritidis ATCC 13076
Good
Colorless
Streptococcus faecalis ATCC 19433
Null
------
www.condalab.com
Dehydrated Culture Media
SALMONELLA CHROMOGENIC AGAR
For the isolation of Salmonella
in clinical samples, foods and waters.
Cat: 1122
FORMULA IN GRAMS PER LITER
Sodium Citrate…………………………………….
8.50
Chromogenic Mixture……………………………………5.81
Casein Peptone……………………………………..
5.00
Beef Extract……………………………………………….5.00
Bacteriological Agar………………………………
12.80
Final pH 7.2 ± 0.2 at 25°C
Preparation
Suspend 37. 1 grams of the medium in one liter of distilled water. Dissolve by heating agitating frequently. Boil for one minute. DO NOT
OVERHEAT. DO NOT AUTOCLAVE. Pour into Petri dishes. Keep plates refrigerated at 8-14ºC protecting them from light ( it may present a
slight precipitate). It is recommended to prepare the plates on the same day of use.
Uses
SALMONELLA CHROMOGENIC AGAR is a new selective chromogenic medium, used for the
detection and presumptive identification of Salmonella species from stool samples, foods and
waters. The media used, traditionally, to differentiate species of Salmonella from the rest of
Enterobacteriaceae family, based on their capacity to produce hydrogen sulfide associated with its
inability to ferment lactose, are not really adequate as there are more than 2000 species of
Salmonella, which do not have these characteristics.
Casein peptone and Beef extract are the nutrient sources of nitrogen, vitamins, amino acids and
minerals; the Chromogenic mixture aids in inhibiting Gram-positive organisms and Proteus and
Coliforms in conjunction with the Sodium citrate. Bacteriological agar is the solidifying agent. To
identify Salmonella species, this chromogenic agent is based on the combination of two
chromogenic substrates that ease quick identification. These two chromogenes are X-gal and
Magenta-caprylate. X-gal is a substrate incorporated to visualize the enzyme ß-D-galactosidaseproducing organisms as blue colonies. Magenta colonies are a result of the hydrolysis of
Magenta-caprylate by the Lactose negative Salmonella species. Thus, non-Salmonella organisms
appear blue or are not stained by any of the chromogenes of the medium.
Inoculate with sample and incubate at 35 ± 2°C for 18 – 24 hours.
Salmonella enteritidis
ATCC 13076
Bibliography
Journal Clinical Microbiology, Vol. 41 nº 7 p. 3229-3232. July 2003 Robert Cassar and Paul Cuschieri.
J.D. Perry, Michael Furs, Jeffrey Taylor, Et. Al. Journal Clinical Microbiology, March 1999, pag. 766-768 Vol. 37. nº 3
Gallioto di camillo, p. Et. Al. (J. Clinil Microbiol. March 1999.
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 35ºC ± 2ºC and
observed after 18-24 hours
Micro-organisms
Growth
Colony Color
Partially Inhibited
Blue-green
Salmonella enteritidis ATCC 13076
Good
Magenta
Salmonella typhi ATCC 19430
Good
Magenta
Escherichia coli ATCC 25922
Salmonella typhimurium ATCC 14028
Proteus vulgaris ATCC 13315
www.condalab.com
Good
Magenta
Inhibited
Colorless
Dehydrated Culture Media
LISTERIA CHROMOGENIC AGAR BASE
(ISO 11290:2004)
Cat: 1345
Selective medium for the detection and enumeration of
Listeria monocytogenes.
FORMULA IN GRAMS PER LITER
Meat Peptone…………………………………………………
Yeast Extract……………………………………………………
Sodium Chloride………………………………………………
Glucose…………………………………………………………
Magnesium glycerophosphate………………………………..
X-glucoside……………………………………………………
18.00
10.00
5.00
2.00
1.00
0.05
Lithium Chloride……………….……………….10.00
Tryptone………………………………………….6.00
Disodium Phosphate…………..………………..2.50
Sodium Pyruvate……………..……………….…2.00
Magnesium Sulphate………………………..…..0.50
Bacteriological Agar……………………………13.50
Final pH 7.2 ± 0.2 at 25°C
Preparation
Suspend 35,3 grams of the medium in 500 ml of distilled water agitating frequently and boil for one minute. Sterilize at 121°C for 15
minutes. Cool to 45 - 50°C and aseptically 1 vial of each supplement. Mix well and distribute into Petri dishes.
Listeria Lipase C Supplement (Cat. 6031)
(1 vial for 500 ml of the medium)
Lipase C Substrate ……………..….1 gram
LISTERIA CHROMOGENIC SELECTIVE SUPPLEMENT (6040)
Reconstitute with 5 ml of sterile v/v ethanol - distilled water. (1 vial for
500 ml of the medium)
Cycloheximide …………….……… 25 mg
Ceftazidime …………………………. 10 mg
Nalidixic acid ………..…..…………. 10 mg
Polymyxin B ……………..……. 38350 IU
Caution: Listeria Chromogenic Selective Supplement contains Cycloheximide and it is very toxic if swallowed, inhaled or comes into contact with the
skin. Wear gloves and eye face protection.
Uses
LISTERIA CHROMOGENIC AGAR BASE is a selective medium for the presumptive isolation and
identification of Listeria monocytogenes and Listeria spp. in food and clinical samples.It is used for
confirmation after using Listeria Enrichment Broth Base Fraser (Cat. 1120).
Lithium chloride and the selective supplement provide the selectivity of the medium.
The differential activity of the medium is due to two factors. On one hand, the presence of the
chromogenic component X-glucoside, a substrate for the detection of the enzyme ß-glucosidase,
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.
On the other hand, the differential activity is also obtained by the lipase 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
of which have caused infections in humans, also possess lipase activity.
Listeria monocytogenes
ATCC 13932
Bibliography
Ottaviani, F., Ottaviani, M. and Agosti, M (1987) Quimper Froid Symposium Proceedings, P6 A.D.R.I.A Quimper (F) 16-18 June
ISO 11290-1:2004 Horizontal method for the detection and enumeration of Listeria monocytogenes Part 1: Detection Method
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 37ºC ± 1ºC and observed
after 24 hours
Micro-organisms
L. monocytogenes ATCC 1911
L. monocytogenes ATCC 13932
L. innocua ATCC 33090
Streptococcus faecalis ATCC 19433
Escherichia coli ATCC 25922
www.condalab.com
Growth
Good
Good
Good
Inhibited
Inhibited
Colony Color
Blue
Blue
Blue
-
Halo
+
+
-
Dehydrated Culture Media
m-EI Chromogenic Agar Base
Cat:1412
Medium to detect and enumerate the enterococcus in water
through the single-step membrane filtration technique
FORMULA IN GRAMS PER LITRE
Peptone……………..……………………………………
Esculine……………………………………………………
Sodium Azide…………………………………………….
X-Glucoside………………………………………………..
10.0
1.0
0.15
0.75
Yeast Extract………………………………....……...30.0
Cycloheximide……………………................……….0.05
Sodium Chloride…………………………....……….15.0
Bacteriological Agar…………………………….…..15.0
Final pH 7.1 ± 0.2 at 25°C
Preparation
Suspend 71.95 grams of the medium in one liter of distilled water. Mix well and heat with frequent agitation for approximately a minute until
the medium is completely dissolved. Sterilize in autoclave at 121ºC for 15 minutes. Cool at 50ºC and pour in Petri Dishes. For a more
selective medium prepare a solution of 0.24 grams of nalidixic acid in 5ml of sterile distilled water with a few drops of sodium hydroxide 0,1N
(for a better dissolution) and aseptically add to one liter of the medium.
Uses
The medium was developed as a single step procedure that does not require the transfer of the
membrane filter to another substrate. Observation of blue color colonies confirm the presence of
enterococci. A wide range of sample volumes or dilutions can be tested by this single step
membrane-filtration procedure for the detection and enumeration of enterococci in potable, fresh,
estuarine, marine and shellfish-growing waters
The peptone supplies nitrogen and carbon compounds. Yeast extract provides trace elements,
vitamins and amino acids. Esculin is hydrolyzed by enterococci to form esculetin and dextrose.
Cycloheximide inhibits most fungi, and the sodium azide inhibits gram-negative bacteria. The XGlucoside is the substrate of the glucosidase-postive enterococci and the agar is added into the
medium as a solidifying agent
Enterococcus sp
Bibliography
1. U.S. Environmental Protection Agency. 1997. Method 1600: Membrane filter test method for enterococci in water. Publication EPA-821-R97-004a. Office of Water, USEPA, Washington, D.C.
2. U.S. Environmental Protection Agency. 1986. Bacteriological ambient water quality criteria:
availability. Fed. Reg. 51(45):8012.
3. U.S. Environmental Protection Agency. 2000. Improved enumeration methods for the recreational water quality indicators: enterococci and
Escherichia coli. Publication EPA/821/R-97/004. Office of Science and Technology, USEPA, Washington, D.
4. Levin, Fischer and Cabelli. 1975. Appl. Microbiol. 30:66.
5. U.S. Environmental Protection Agency. 2002. Method 1600: Enterococci in water by membrane filtration using membrane-enterococcus
indoxyl-β-D-glucoside agar (mEI). Publication EPA-821- R-02-022. USEPA Office of Water, Office of Science and Technology, USEPA,
Washington, DC.
MICROBIOLOGICAL TEST
The following results were obtained of the medium from type cultures added to the supplement, after incubation at a temperature of 41ºC ±
0.5ºC and observed after 18-24 hours
Micro-organisms
Growth
Colony Color
Enterococcus faecium ATCC 9790
Good
Blue
Enterococcus faecalis ATCC 19433
Good
Blue
www.condalab.com
Dehydrated Culture Media
ENTEROBACTER SAKAZAKII ISOLATION
CHROMOGENIC AGAR
(ESIA)
ISO 22964
For the isolation of presumptive Enterobacter Sakazakii
Cat: 1446
FORMULA IN GRAMS PER LITRE
Pancreatic Digest of Casein………………………………………
Yeast Extract…………………………………………………………………
α-X Glucose……………………………………………………………………
Bacteriological Agar…………………………………………………….
7.00
3.00
0.15
15.00
Sodium Chloride………………………………………………………………………….5.00
Sodium Desoxycholate………………………………………………………………0.60
Crystal Violet…………………………………………………………………………….0.002
Final pH 7.0 ± 0.2 at 25°C
Preparation
Suspend 30,7 grams of the dehydrated medium in one liter of distilled water. Mix well, agitate frequently and boil for one minute. Distribute in adequate
containers and sterilize and autoclave at 121ºC for 15 minutes. Cool to 44-47ºC. Pour in Petri Dishes of 15 ml.
Uses
Enterobacter sakazakii is currently considered and emerging pathogen responsible for, unweaned babies, risking severe meningitis and necrotic enterocolitis that can be the cause of
mortality rate between 40-80%.
The pathogenicity of Enterobacter sakazakii for un-weaned babies’ makes it necessary to review
the manufacturing process of the products specialized for babies, guaranteeing the absence of
the bacteria in the final product
Additional prevention measures at a hospital include the sanitary hygiene of the prepared
media; reducing the time between the preparation and its administration, to impede the
multiplication of micro-organisms.
The ISO normative 22964 recommends this medium for the isolation go Enterobacter
sakazakii the typical colony colors of green – blue greenish should be confirmed in TSA Agar
Cat. 1068 in which they present yellow coloring. A Biochemical confirmation is needed from
the yellow pigmentation colonies.
Incubate at 41ºC ± 1ºC and observe after 24 hours ± 2 hours
Enterobacter Sakazakii
ATCC 29544
Bibliography
ISO normative 22964
GUILLAUME-Gentil, O., Sonnard, V. Kandahai, M.C., Mauragg, J.D. and Jootsen, H. A simple and Rapad Cultural Method for Detection of Enterobacter
Sakazakii in environmental samples. Journal of Food.
Protection, 68 (1), 2005, pp. 64-69
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 41ºC ± 1ºC and
observed after 24 ± 2 hours
Micro-organisms
www.condalab.com
Growth
Colony Color
Transparent –
red/violet
Transparent –
red/violet
Transparent –
red/violet
Green-blue greenish
Escherichia coli ATCC 25922
Good
Escherichia coli ATCC 8739
Good
Enterobacter aerogenes ATCC 13048
Good
Enterobacter sakazakii ATCC 29544
Good
Staphylococcus aureus ATCC 25923
Inhibited
-----------------------------
Streptococcus faecalis ATCC 29212
Inhibited
------------------------------
Dehydrated Culture Media
DEHYDRATED CULTURE
CHROMOGENIC
MEDIA FOR
CLINICAL SAMPLES
life science products because
life is a great discovery
CANDIDA CHROMOGENIC AGAR
Cat: 1382
Differential and selective medium for the isolation and quick
Identification of Candida species of clinical importance.
FORMULA IN GRAMS PER LITER
Glucose………………………………………………
20.00
Peptone………………………………………………10.00
Chloranphenicol……………………………………….
Bacteriological Agar………………………………….
0.50
15.00
Chromogenic Mixture…………………………….....0.40
Final pH 6.1 ± 0.2 at 25°C
Preparation
Suspend 45. 9 grams of the medium in one liter of distilled water. Mix well and heat with frequent agitation until complete dissolution.
Distribute into adequate containers.
Uses
CANDIDA CHROMOGENIC AGAR is an alternative chromogenic formulation to the traditional
media for the detection and isolation of Candida spp.
Candida krusei
ATCC 34135
Candida tropicalis
ATCC 1369
The different species of Candida produce different kinds of infections. Candida albicans is the
most common and is usually susceptible to the antigfungal agents’ azole group. However,
Candida glabrata, Candida tropicalis and Candida krusei are azole-tolerant, thus the rapid
identification of the different species of Candida is essential for its correct diagnosis and
treatment.
In this chromogenic medium , the three different species of Candida albicans, Candida tropicalis
and Candida krusei can be differentiated due to the chromogenic substrates present within the
medium. Candida Chromogenic Agar allows the easy and rapid identification and differentiation of
all 3 species by producing easy-to-read results in one plate, since they present different colored
colonies.
Candida albicans
ATCC 10321
Colonies of Candida albicans are green, those of Candida krusei are purple-pink and those of
Candida tropicalis are blue.
Bibliography
Sheehan, D.J. et. al.(1999) Current and Emerging Azole Antifungal Agents Clinical Microbiology Reviews, 12 (1): 40-79
Odds, F.C. (1988) Candida and candidiosis, 2nd ed, Baillière Tindall, London, England.
Ibrahim E.H. et al. (2001) The influence of inadequate antimicrobial treatment of bloodstream infections on patient outcomes in the
ICU setting. Chest, 118 (1): 146-55
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 30-37 and
observed after 24, 48 and 72 hours
Micro-organisms
Growth
Colony Color
Candida tropicalis ATCC 1369
Good
Blue
Candida albicans ATCC 10321
Good
Green
Inhibited
Purple-Pink
Candida Krusei ATCC 34135
www.condalab.com
Dehydrated Culture Media
URINARY TRACT INFECTIONS
CHROMOGENIC AGAR (UTIC)
For the presumptive detection and differentiation of
organism which cause urinary tract infections.
Cat: 1424
FORMULA IN GRAMS PER LITRE
Mix peptone…………………………..….…………….
Tryptophane……………………….…….……………..
Bacteriological Agar……………………………………
16.0
2.0
16.0
Growth factors……………………………….13.0
Chromogenic Substrate……………………… 0.5
Final pH 7.2 ± 0.2 at 25°C
Preparation
Suspend 47,5 grams of the medium in one litre of distilled water. Mix well and heat agitating frequently until completely dissolved. Sterlize in autoclave
at 121ºC for 15 minutes. Cool to 45-50ºC and pour into Petri Dishes.
Uses
The urinary tract infection chromogenic agar (UTIC) medium includes 2 chromogenic substrates which
are cleaved by enzymes produced by Enterococcus spp, Escherichia coli and coliforms. It also includes
phenylalanine and tryptophane which provide a presumptive indication of the tryptophane deaminase
activity; which illustrate the presence of Proteus spp., Morganella spp. and Providencia spp. This is
based on the Agar CLED.
One of the chromogens is metabolised by β-glucosidase enzyme activity, allowing the specific detection
of enterococci which form blue or turquoise colonies.
The other chromogen is cleaved β-galactosidase, an enzyme produced by Escherichia coli, which grow
as pink colonies. (In case of unreliable colony results, do test of Indol)
Cleavage of both the chromogens shows as a result dark blue – purple colonies. Tryptophane in the
medium acts as an indicator of the tryptophane deaminase resulting in colonies of Proteus, Morganella,
and Providencia spp of brown colour.
It should be noted that, as with all chromogenic media, micro-organisms with atypical enzyme patterns
may give anomalous reactions. For example 45% of Enterobacter cloacae doesn’t contain β-glucosidase,
therefore resulting in pink colonies not distinguishable from Escherichia coli. In this case, do Indol test
Bibliography
Samra Z, Heifetz M, Talmor J, Bain E and Bahar J. Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens. J Clin
Microbiol. 1998;36(4): 990-4.
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a temperature of 35 ± 2ºC and observed
18-24 hours
Microorganisms
Growth
Colour Colony
Escherichia coli ATCC 25922
Good
Rose
Enterobacter aerogenes ATCC 13048
Good
Dark Blue
Klebsiella pneumonieae ATCC 13883
Good
Dark Blue
Proteus miriabilis ATCC 13315
Staphylococcus aureus ATCC 25923
Enterococcu faecalis ATCC 19433
www.condalab.com
Good
Good
Good
Light Brown
White Cream
(natural pigmentation)
Light Blue
Dehydrated Culture Media
MRSA AGAR
Cat: 1423
For the detection of Methicilin resistant Staphylococcus
aureus
FORMULA IN GRAMS PER LITRE
Peptone mixture……………………………………………….
11.00
Growth Factors………………………………….78,00
Chromogenic Substrate……………………………………….
1.90
Bacteriological Agar…………………………….12.50
Final pH 7.2 ± 0.2 at 25°C
Preparation
Suspend 103.5 grams of the medium in one liter of distilled water. Mix well and heat agitating continuously until dissolved. Sterilize in
autoclave at 121ºC for 15 minutes. Cool to 45-50ºC and aseptically add 4 mg per liter of Cefoxitin supplement.
Uses
Methicilin resistant Staphylococcus aureus, MRSA, are of particular interest at an international
level due to its virulence and resistance to multiple antibiotics. The antimicrobial resistance is a
serious threat to public health as it is now regarded as a major hospital acquired disease
worldwide.
The important changes observed in the epidemiological and microbiological
characteristics of the infections caused by Staphylococcus aureus are the reason for the
increment and prevalence of methicilin-resitant Staphylococcus aureus nosocomial (associated to
hopitalized patients) and the proliferation of methicilin-resistent Staphylococcus aureus acquired
by the community
The MRSA continues being a serious problem in many healthcare centres; more than 50% of the
Staphylococcus aureus obtained are from Intensive Care Units (ICU) and close to 40% are from
hospital patients.
Effective, rapid laboratory diagnosis and susceptibility testing is critical in treating, managing and
preventing MRSA infections.
This chromogenic media has been designed and is adequate for the screening of Staphylococcus
aureus resistant to methicilin. The α-glucosidase produced by Stahphlococcus aureus cleaves
the chromogenic substrate and gives a blue color to the Staphylococcus aureus colony. The
Cefoxitin inhibits the growth of Staphylococcus aureus sensitive to methicilin.
Staphylococcus aureus
ATCC 25923
Bibliography
Hutchison, M.J., Edwards, G.F.S., Morrison, D., ,, Evaluation of chromogenic MRSA Reference Laboratory presented at the 2005 Institute of
BioMedical
MICROBIOLOGICAL TEST
The following results were obtained of the medium from type cultures, with the supplement added, after incubation at a temperature of 37ºC
± 2ºC and observed after 18-24 hours
Micro-organisms
Growth
Colony Color
Staphylococcus aureus ATCC 25923
Inhibited
----
Staphylococcus aureus ATCC 43300
Good
Blue
Inhibited
----
Escherichia Coli ATCC 25922
www.condalab.com
Dehydrated Culture Media