Contact Slides C MacConkey Agar, Coliform bacteria, HYCON® [Pack of 20]

Description

HYCON® Contact Slides C are designed for the determination of the coliform and E. coli count on dry, sanitized surfaces as well as personnel in controlled environments of production lines, i.e. food and beverages as well as non-sterile and terminally sterilized pharmaceuticals.

Each contact slide is individually sealed in the transparent, primary package and provides a rectangular surface of 25 cm2. The agar is filled in a flexible backing film. The formulation of the basic medium (MacConkey Agar) complies with the recommendations of the current European, Japanese and United States Pharmacopoeia

Mode of Action
MayConkey Agar is a weak selective medium for the isolation of Enterobacteriaceae or specifically E. coli in pharmaceutical products, food, water, and other materials. Enterobacteriaceae can be clearly identified even in the presence of Salmonella and Shigella. Bile salts and crystal violet largely inhibit the growth of the gram-positive microbial flora, whereas the growth of most Gram-negative bacteria is supported.

Lactose and the pH indicator neutral red are used to detect lactose degradation. Bacteria degrading lactose to acids grow in pink to red colored colonies. Additionally, Escherichia coli and other acid forming bacteria will show a zone of precipitated bile salt around the colonies. Bacteria not degrading Lactose will grow colorless.

The family of Enterobacteriaceae is defined by the growth on MacConkey Agar. It is not possible to detect low numbers of Salmonella while the accompanying microbial flora is abundant.

Typical Composition
Pancreatic digest of gelatin: 15 g/L
Peptones (meat and casein): 3 g/L
Lactose: 10 g/L
NaCl: 5 g/L
Bile salts No. 3: 1.5 g/L
Neutral red: 0.03 g/L
Crystal violet: 1 mg/L
Agar: 13.5 g/L
Supplements: –

The appearance of the medium is clear and pink to brown. The pH value is in the range of 6.9-7.3. The medium can be adjusted and/or supplemented according to the performance criteria required.

Application and Interpretation
Prior to use the contact slides should be equilibrated to room temperature. Please check each contact slide before use to verify sterility and take care on aseptic handling in order to avoid false positive results. Contaminated or dehydrated contact slides should not be used for sampling.

It is recommended to put the cover slide in place before opening the contact slide. For sampling, the sealing of the
primary packaging is opened by approximately one third. The backing film filled with agar facing downwards is
removed while taking care of aseptic handling and the agar surface is pressed on the dry surface to be tested for
some seconds with a steady pressure (see also ISO 14698).

Afterwards the backing film is returned into the primary packaging with the agar facing downwards and closed by moving the cover slide to the opening end of the contact slide. Please take care on cleaning the surface which came into contact with the agar medium. The closed contact slides are transferred to an incubator.

According to the recommendations of the current EP, JP and USP MacConkey Agar is incubated for 18-72h at
30-35°C. Individual incubation conditions can chosen and should be validated at the application site.

Finally, the number of CFU per slide is examined. Growth of colonies indicates the possible presence of E.coli . This may be confirmed by identification tests.
For microbiological identification chromogenic media such as CHROM Tryptone Bile X-Glucoronide (TBX) Agar (article number 146326) or Chromocult® Coliform Agar (CCA) (article number 146689) detecting ß-glucuronidase may be used. More than 94% of E. c . strains are ß-glucuronidase-positive and will grow as blue colored colonies on TBX Agar or dark blue to violet violet colonies on CCA. Typical reactions for detection of E. coli. are a positive indole-reaction as well as a negative oxidase- and catalase-reaction.

Storage
The product can be used until the expiry date if stored in the original box, protected from light and properly sealed
at the temperature range indicated on the box label. The total shelf life from date of production is 6 months.
Condensation can be prevented by avoiding quick temperature shifts and mechanical stress. Upon storage
contact slides should not be placed near heat sources such as refrigerators with heat-emitting condensers.
Boxes should be stored with the coated side of the contact slide facing downwards.

Disposal
Please mind the respective regulations for the disposal of used culture medium (e.g. autoclave for 20 min at
121°C, disinfect, incinerate etc.).